SERVIZIO GEOLOGICO NAZIONALE
MEMORIE DESCRITTIVE DELLA CARTA GEOLOGICA D'ITALIA
VOLUME LI
3rd WORKSHOP ON EARLY CRETACEOUS CEPHALOPODS
3° WORKSHOP SUI CEFALOPODI DEL CRETACEO INFERIORE
by
A VRAM E. - CECCA F - COMPANY M. - DELANOY G. - ERBA E - ETTACHFINI M. FARAONI P. - HOEDEMAEKER Ph. J. - KAKABADZE M. V. - KOTETISHVILIE - LANDRA G. MARINI A - MEMMI L. - PALLINI G. - RAKUS M. - RAWSON P F. - ROPOLO P. - SANDOVAL J - TA VERA J. M - VASICEK Z.
ISTITUTO POLIGRAFICO E ZECCA DELLO STATO Comitato di Redazione:
A. TODISCO (Presidente), C. CAMPOBASSO, F. CECCA, C. CESI, E. CIRESE, M. COSCI, M. D'OREFICE, G. GIARDINI, N.I. MELLINO, M.L. PAMPALONI, F. PILATO, L. SACCHI, M. SANTANTONIO, D. TERRIBILI, F. VISICCHIO G. PESCI (Segretaria di Redazione)
Allestimento: FABRIZIO CECCA Revisione iconografica: MARINA COSCI, MARIA LUISA VATOVEC
Istituto Poligrafico e Zecca dello Stato - Roma (1995) SERVIZIO GEOLOGICO NAZIONALE ROMA
PROCEEDINGS
3rd WORKSHOP ON EARLY CRETACEOUS CEPHALOPODS
ATTI DEL
3° WORKSHOP SUI CEFALOPODI DEL CRETACEO INFERIORE
IGCP PROJECTS 343: STRATIGRAPHIC CORRELATIONS BASINS OF PERTTETHYAN BASINS 362: TETHYAN AND BOREAL CRETACEOUS
5-8 July 1994 Piobbico
Edited by
FABRIZIO CECCA
ORGANIZED BY SERVIZIO GEOLOGICO NAZIONALE AND COMUNE DI PIOBBICO
ISTITUTO POLIGRAFICO E ZECCA DELLO STATO ROMA 1995 Workshop organization: Fabrizio CECCA - Servizio Geologico Nazionale - Roma Giovanni PALLINI - Dipartimento di Scienze della Terra - Roma
Chairman: Philip J. HOEDEMAEKER - Nationaal Natuurhistorisch Museum - Leiden
Contribution to the organization: Lino PAJARDINI - Comune di Piobbico Romeo FAGGIANI - Comune di Cagli
Referees' Committee: Fabrizio CECCA - Servizio Geologico Nazionale - Roma Miguel COMPANY - Departamento de Estratigrafìa y Paleontologia - Granada Philip J. HOEDEMAEKER - Nationaal Natuurhistorisch Museum - Leiden Peter F. RAWSON - Department of Geological Sciences - London
Software consulting: Giovanni M. BORGIA PREFACE
The 3rd Workshop of the Working Group on Lower Cretaceous Cephalopods gave us the opportunity to meet again some old friends and particularly to compare with them the Lower Cretaceous ammonite biostratigraphy of Umbria- Marche Apennines with the successions described in other countries. The meeting was organized in the Apennines, close to the outcrops, in a small, peaceful town of the Marche region where we forgot the typical "stress" of the big cities (noise, traffic jams, pollution). This pleasant atmosphere aroused a stimulating and productive workshop. We are grateful to the Piobbico Town: the meeting would not have been possible without the efficient cooperation in all aspects of organization, both during the oral sessions than in the excursions. Everything has been done to satisfy our needs in the most efficacious and simplest way. The warm and friendly hospitality will be remembered by all the participants. We thank the Mayor of Piobbico for his inaugural speech and for his support to keep on our activities in this area. Piobbico is actually one of the most active local promoter for the research on Stratigraphy and Palaeontology. The residents are very proud and conscious of the natural treasure preserved in the mountains enclosing their town. A special thank to Mr. Lino PAIARDINI who, from time immemorial resolves any logistic problems of all the geologists who work in the Monte Nerone area. Lino is able to find surprising solutions on all occasions: the lunch improvised on top of Monte Nerone during the first excursion was very nice and it is one of the unforgettable things of this meeting. The Town of Cagli organized for us a pretty lunch on top of Monte Petrano: Mr Romeo FAGGIANI was particularly appreciated for his cuisine and juggler capabilities to build a "field restaurant" in some hours. Our friend Elisabetta ERBA (Milan University) gave us an important support both during the first excursion, guiding us on the Marne a Fucoidi outcrops she studied for many years, and in the scientific discussions. Thanks to everybody else who we risk to forget. See you soon.
Fabrizio CECCA (Servizio Geologico Nazionale) Giovanni PALLINI (Università "La Sapienza"-Rome) Organisers of the Workshop
PREMESSA
II 3° Workshop del Gruppo di Lavoro sui Cefalopodi del Cretaceo inferiore ci ha dato l'occasione di rincontrare alcuni vecchi amici e, in particolare, di confrontare con loro la biostratigrafia ad ammoniti del Cretaceo inferiore dell'Appennino umbro-marchigiano con le successioni descritte in altri paesi. La riunione è stata organizzata in pieno Appennino, vicino agli affioramenti, in un piccolo e tranquillo comune delle Marche dove abbiamo dimenticato il tipico "stress" cittadino (rumore, ingorghi, inquinamento). Da questa piacevole atmosfera è scaturito un workshop produttivo e stimolante. Siamo grati alla città di Piobbico: non avremmo potuto organizzare questa riunione senza l'efficiente cooperazione in tutti i dettagli organizzativi, sia durante le discussioni che durante le escursioni geologiche. Tutto è stato fatto per soddisfare ogni esigenza nel modo più semplice ed efficace. L'ospitalità calorosa e amichevole rimarrà nei ricordi di tutti i partecipanti. Ringraziamo il Sindaco di Piobbico per il suo discorso di apertura e per il suo incitamento a continuare le nostre attività in quest'area. Piobbico è realmente uno dei promotori locali più attivi della ricerca nei campi della Stratigrafia e della Paleontologia. Gli abitanti sono molto orgogliosi e consci di possedere un tesoro naturale nei monti che circondano la loro cittadina. Un ringraziamento speciale va espresso al Sig. Lino PAIARDINI che, da sempre, risolve tutti i problemi logistici di tutti i geologi che vengono a lavorare a Monte Nerone. Lino sa sempre trovare soluzioni sorprendenti: il simpatico pranzo improvvisato in cima al Monte Nerone nel giorno della prima escursione rimarrà una delle cose indimenticabili di questa riunione. Il comune di Cagli ci ha organizzato un piacevole pranzo in cima al Monte Petrano: il Sig. Romeo FAGGIANI si è particolarmente distinto per la sua cucina e per le sue doti da prestigiatore nel montare in poche ore un vero e proprio "ristorante da campo". La nostra amica Elisabetta ERBA .dell'Università di Milano, ci ha dato un importante contributo nelle sessioni scientifiche e guidandoci il primo giorno di escursione sugli affioramenti di Marne a Fucoidi da lei studiati per molti anni. Grazie a tutti quelli che, purtroppo, rischiamo di dimenticare. Arrivederci a presto. INTRODUCTION
The meetings of the Working Group on Lower Cretaceous Cephalopods in the IGCP Projects 262 and 362 clearly meet a need, which is evident from the participation of scientists from so many countries. The purpose of the workshops is the reconstruction of a workable standard Lower Cretaceous ammonite zonation for the Mediterranean region,its refinement and its correlation with other (e. g. boreal) ammonite zonation. In the Proceedings of the third workshop on Early Cretaceous Cephalopods held in Piobbico (5-8 july 1994) the papers cover all Lower Cretaceous stages and their subjects mainly pivot around correcting and completing the standard zonation of the Mediterranean region. Two papers deal with Tethyan-Boreal correlation. As the dead-line for the reception of the refereed papers was only a few weeks later, the submitted manuscripts have been refereed during the meeting by a small chosen group of participants. E. A VRAM gives a detailed overview of the holcodiscid genera Jeanthieuloyites, Astieridiscus, Spitidiscus and Holcodiscus deposited in scientific collections in Rumania. Some new species are described and the subages of the various assemblages are given. F. CECCA is able to precisely date parts of the Maiolica formation of Umbria-Marche Apennines, in which ammonites are extremely rare. Late Valanginian ammonites were collected in three outcrops around Monte Catria. Upper Barremian pulchellids are described in a second paper. G. DELANOY tries to approximate the position of the lower boundary of the Aptian by studying the earliest Deshayesites, Prodeshayesites and Cheloniceras from the Angles section and other neighbouring sections in SE France. The representatives of these genera are very rare in these sections. The rather arbitrary position of the base of the Aptian selected in 1965 by Busnardo in the Angles section does not appear to be as bad as it seemed, because the first deshayesitid appears only three beds above it. M. KAKABADZE and E. KOTETISHVILI try to locate the lower boundary of the Aptian in the Republic of Georgia. The authors propose to draw this boundary at the base of a 10 m limestone packet with Acrioceras furcatum (D'ORBIGNY) and Pseudocrioceras sp. between the Securiformis and Weissi Zones. L. MEMMI gives a review of the Aptian and Albian ammonite zones in Tunisia. The ammonite assemblages in the paleobasin are compared with those on the paleoshelf. P. RAWSON is the only author who gives a tentative correlation of Boreal and Tethyan ammonite zones. He gives a review of the occasional migration of the boreal ammonites into the Tethys and of Tethyan ammonites into the Boreal Realm during the Pre-Aptian Lower Cretaceous. He also proposes a palaeobiogeographic explanation for the occurrence of the Tehyan genus Heteroceras in the Upper Barremian of Speeton. P. ROPOLO was able to unambiguously show that criocone Crioceratites are macroconchs and that the corresponding microconchs are hook-shaped. The last whorl of a macroconch may also acquire the shape of a hook, but the criocone part in the macroconchs is larger than in the microconchs. This has great taxonomic implications, already surmised earlier, but never unambiguously proven until now. Z. VASICEK describes the Aptian and Albian ammonites collected in the Western Carpathians. Remarkable is the short presence of boreal Hoplites dentatus and Anahoplites splendens amongst the otherwise entirely Tethyan association. Together with M. RAKUS, in a separate paper, special attention is paid to the Lower Aptian ammonites from the Mala Fatra mountains. The participants were impressed by the accurate and detailed way in which all the sections of the Maiolica limestone and Marne a Fucoidi, shown with great enthousiasm and dedication during the excursions, were measured and studied. In the appendix F. CECCA, P. FARAONI, A. MARINI and G. PALLINI describe the most representative Hauterivian-Barremian sections visited during the field trip of the meeting. I am grateful to be among this group of enthousiastic and mainly young ammonitologists who join forces in order to try to erect a detailed and well-founded ammonite zonation, with which they try to correlate over long distances.
Ph. J. HOEDEMAEKER Chairman of the Working Group on Lower Cretaceous Cephalopods INTRODUZIONE
I meeting del Working Group sui Cefalopodi del Cretaceo inferiore, nell'ambito dei Progetti 1GCP 262 e 362 rappresentano un momento di incontro fondamentale, come dimostra la massiccia partecipazione di scienziati di così tanti Paesi. Lo scopo dei workshop è la ricostruzione di un 'attuabile zonazione standard ad ammoniti per il Cretaceo inferiore della regione mediterranea, il suo affinamento e la sua correlazione con altre zonazioni ad ammoniti (ad es. quella valida per le regioni boreali). Gli articoli contenuti negli Atti del 3° workshop sui Cefalopodi del Cretaceo inferiore tenutosi a Piobbico (5-8 luglio 1994), riguardano tutti i piani del Cretaceo inferiore e gli argomenti trattati ruotano principalmente attorno alla correzione e al completamento della zonazione standard della regione mediterranea. Due articoli trattano della correlazione tra ì Domimi Tetideo e Boreale. Poiché il termine ultimo per la ricezione degli articoli referenziati era stato fissato a poche settimane dopo il workshop, i manoscritti presentati sono stati esaminati durante il meeting da un ristretto gruppo di partecipanti. E. A VRAM offre un 'immagine dettagliata dei generi Jeanthieuloyites, Astieridiscus, Spitidiscus e Holcodiscus, della Famiglia Holcodiscidae, conservati nelle collezioni scientifiche rumene. Vengono descritte alcune specie nuove e vengono datate le età di diverse associazioni. F. CECCA è in grado di datare con precisione porzioni della formazione della Maiolica dell'Appennino umbro- marchigiano, in cui le ammoniti risultano estremamente rare. Alcune ammoniti del Valanginiano superiore sono state raccolte in tre affioramenti nei pressi del Monte Catrìa. In un secondo articolo vengono descritti pulchellidi del Barremiano superiore. G. DELANOY dà con approssimazione la posizione del limite inferiore dell 'Aptiano studiando i primi Deshayesites, Prodeshayesites e Cheloniceras della sezione di Angles e di altre sezioni limitrofe nel Sud Est della Francia. In queste sezioni i rappresentanti di tali generi sono molto rari. La posizione piuttosto arbitraria della base dell'Aptiano, selezionato nel 1965 da BUSNARDO nella sezione di Angles, non è poi così male come sembrava perché i primi deshayesitidi compaiono solo tre strati al dì sopra. M. KAKABÀDZE & E. KOTETISHVILI tracciano il limite inferiore dell'Aptiano nella Repubblica di Georgia alla base di un pacco di calcari dello spessore di 10 metri con Acrioceras furcatum (D'ORBIGNY) e Pseudocrioceras sp. tra le Zone a Securiformis e Weissi. L. MEMMI propone una sintesi delle zone ad ammoniti dell 'Aptiano e Albiano in Tunisia. 1 gruppi di ammoniti nel paleobacino vengono messi a confronto con quelli della paleopiattaforma. P. RAWSON è l'unico Autore che tenta una correlazione delle zone ad ammoniti boreali e tetidee, attraverso la revisione della migrazione occasionale delle ammoniti boreali nella Tetide e delle ammoniti tetidee nel Dominio Boreale durante il Cretaceo inferiore, ante Aptiano. Inoltre propone una spiegazione paleobiogeografica per la presenza del genere Tetideo Heteroceras nel Barremiano superiore di Speeton. P. ROPOLO è stato in grado di mostrare senza ambiguità che i Crioceratites a conchìglia criocona sono macroconchi e che i corrispettivi microconchi hanno conchiglie a forma di uncino. Anche l'ultima spirale di un macroconco può assumere la forma ad uncino, ma la parte crioconica nei macroconchi è più grande di quella dei microconchi. Ciò comporta vaste implicazioni tassonomiche, già precedentemente ipotizzate ma mai finora provate senza ombra di dubbio. Z. VASICEK descrive le ammoniti dell'Aptiano ed Albiano raccolte nei Carpazi occidentali. Notevole risulta la breve presenza di Hoplites dentatus e Anahoplites splendens, boreali, tra associazioni invece interamente tetidee. In un altro articolo in collaborazione con M. RAKUS, l'attenzione si sposta sulle ammoniti dell'Aptiano inferiore delle montagne di Mala Fatra. I partecipanti sono rimasti colpiti dal modo accurato e dettagliato con cui tutte le sezioni di Maiolica e di Marne a Fucoidi, illustrate con grande entusiasmo e dedizione durante le escursioni, sono state misurate e studiate. Nell'appendice F. CECCA, P. FARAONI, A. MARINI e G. PALLINI descrivono le sezioni più rappresentative dell 'Hauteriviano-Barremiano visitate durante le escursioni del meeting. Sono grato di far parte di questo gruppo dì ammonitologi entusiasti e soprattutto giovani che uniscono le proprie forze per cercare di costruire una zonazione ad ammoniti solida e dettagliata, con cui tentano di praticare correlazioni a largo raggio. Mem. Descr. Carta Geo!, d'lt. LI (1995), pp. 11-45
Representatives of the Family Holcodiscidae SPATH, 1924 (Ammonitina) in Rumania
Rappresentanti della Famiglia Holcodiscidae SPATH, 1924 (Ammonitina) in Romania
EMILAVRAM (*)
IGCP Projects I u[g s 343: Stratigraphie Correlations Basins of Peritethyan ' UNESHO 362: Tethyan and Boreal Cretaceous
ABSTRACT - The family Holcodiscidae is represented in Rumania in Barremian age are crowded in an about 4-5 m thick rock-sequence, toget (he Upper Valanginian-Lower Barremian interval by species of the genera her with Leptoceratoides spp., Subpulchellia spp., Patruliusiceras spp., Jeanthieuloyites, Astieridiscus, Spitidiscus and Holcodiscus, as follows: Silesites ex gr. vulpes (COQUAND) and Melchiorites spp., in the Svinita 1 ) in the Upper Valanginian deposits of the Brasov Formation, round the area, or are recorded in a few larger successions, rich in almost the same Brasov town, Central Rumania; in the Valanginian deposits of the Carhaga ammonite species (Spitidiscus seunesi (KUAN), Holcodiscus diverseco- Formation, in the Persani Mts.,East Carpathians; 2) in the Hauterivian status (COQUAND), H. gastaldii KUJAN (non D'ORHGNY), H. ziczac fossiliferous successions of the Dâmbovicioara Formation/Dealul Sasului KARAKASCH, H. geronimaeformis TZANKOV) together with Leptocera Member of the Dâmbovicioara Couloir, and the Murguceva Formation of toides spp., Subpulchellia sauvageaui (HERMITE), etc.; then, Astieridi the Svinita region (Central Rumania and south-western Rumania, respec scus elegans KARAKASCH, Holcodiscus ctcaillaudianus (D'ORHGNY) tively); 3) in the Barremian rock-sequences of the Dâmbovicioara Couloir, H. tzankovi n.sp., H. diversecostatus (COQUAND), assembled with Toreà- in the East Carpathians Flysch (in the Baraott Mts., and in the Zizin and pella suessi (SIMIONESCU), i.e. at the top of the Lower Barremian, in the Târlung valleys basins), and in the Svinita region. The condensed sedimen Dâmbovicioara Couloir. Four new species of the genus Holcodiscus have tation ( of the lowermost member of the Brasov Formation) and, in places, been defined: H. tzankovi n.sp, H. simionescui n. sp., H. decorus n. sp the relatively narrow successions (of the Lower Barremian deposits in the and H. ouachensis n. sp. Baraolt Mts. and in the Svinita region ) prevent the accurate establishment of the holcodiscid species stratigraphie range, except when it is checked by KEY WORDS: Lower Cretaceous, Ammonitina, Holcodiscidae, Taxo the complementary ammonite assemblage of the same strata. Thus, except nomy, Biostratigraphy, Rumania. Jeanthieuloyites nodosus (MANDOV) which passes into the Lower Haute rivian, (he other species of Jeanthieuloyites are restricted to the Verruco- RIASSUNTO - La famiglia Holcodiscidae è rappresentala in Romania sum and Trinodosum Zones of the Upper Valanginian; Jeantieuloyites nell'intervallo Valanginiano superiore-Barremiano inferiore, dalle specie cf.nodosus and Spitidiscus"! meneghina (DE ZIGNO in RODIGHERO) were dei generi Jeanthieuloyites, Astieridiscus, Spitidiscus e Holcodiscus co recorded in association with Leopoldia leopoldina (D'ORHGNY) in the me segue: 1) nei depositi del Valanginiano superiore della Formazione di Lower Hauterivian; Spitidiscus intermedius (D'ORHGNY), S. cf. darderi Brasov (vicino alla citta' di Brasov, Romania centrale), e nella Formazione FALLOT & TERMIER, and S. cf. rotula (SOWERBY) (assembled with Lyti- di Carhaga nei Monti Persani (Carpazi Orientali); 2) nella successione coceras cf. vicarius (VACEK), Crioceratites matsumotoi SARKAR, etc.) hauteriviana della Formazione di Dâmbovicioara (Membro Dealul Sasului are also of Early Hauterivian age; Spitidiscus vandeckii {D'ORHGNY), S. nel "Colouoir" Dâmbovicioara, Romania centrale) e nella Formazione oosteri (SARASN & SCHDNDELMAYER) and Holcodiscus cf. caillaudia- Murguceva della regione di Svinita (Romania sud-occidentale); 3) gli hol- nus (D'ORHGNY) were found in association with Pulchellia changarnieri codiscidi barremiani sono abbondantemente rappresentati nel "Colouoir" (SAYN) in the Dâmbovicioara "Couloir", immediately above the beds with Dâmbovicioara, nei depositi flyschoidi dei Carpazi Orientali (nei Monti Pseudothurmannia; but almost all the holcodiscid species of the Early Baraolt e nei bacini idrografici di Zizin e Târlung) e nella regione di Svini-
(*) Rumaniana Institute of Geology, Caransebes str. 1, Bucuresti-32, 78344 Rumania. 12 AVRAME. ta. I.a sedimentazione condensata (membro inferiore della Formazione di scidi del Barremiano inferiore sono concentrati in una successione di 4-5 Brasov) c, a luoghi, la successione a spessore relativamente ridotto dei de m di spessore, insieme con Leptoceratoides spp., Subpulchellia spp., Pa- positi del Barremiano inferiore dei Monti Baraolt e della regione di Svinita truliusiceras spp., Silesites ex gr. vulpes (COQUAND) e Melchiorites spp. impediscono l'accurata definizione della sicura distribuzione stratigrafica nell'area di Svinita; altri sono stati ritrovati in una successione più spessa delle specie, salvo quando essa è evidenziata, per quanto possibile, da as caratterizzata dalle stesse associazioni ad ammoniti (Spitidiscus seunesi sociazioni complementari raccolte negli stessi strati. Ad eccezione di (KILIAN), Holcodiscus diversecostatus (COQUAND), H. gastaldii KlLIAN Jeanthieuloyites nodosus (MANDOV), che passa nell' Hauteriviano infe (non D'ORHGNY), H. ziczac KARAKASCH, H. geronimaeformis riore, le specie del genere Jeanthieuloyites sono limitate alle Zone a Ver- TZANKOV) insieme a Leptoceratoides spp., Subpulchellia sauvageaui rucosum ed a Trinodosum del Valanginiano superiore; Jeanthieuloyites (HERMTTE) ecc.; infine, Astieridiscus elegans KARAKASCH, Holcodiscus cf. nodosus e Spitidiscus ? meneghina (DE ZIGNO in RODIGHERO) sono cf. caillaudianus (D'ORHGNY), H. tzankovi n. sp., H. diversecostatus associati con Leopoldia leopoldina (D'ORHGNY) nell' Hauteriviano infe (COQUAND), associati con Torcapella suessi (SIMONESCU), nella parte riore; SpUidiscus intermedins (D'ORHGNY), S cf darderi FAIXOT & superiore del Barremiano inferiore nel "Couloir" Dâmbovicioara. Nel ge TERMIER e S. cf. rotula (SOWERBY) (associati con Lyticoceras cf. vica- nere Holcodiscus sono state istituite quattro nuove specie: H. tzankovi rius (VACEK), Crioceratites matsumotoi SARKAR, etc.) sono anch'essi n.sp, H. simionescui n. sp.. H. decorus n. sp. eH. ouachensis n. sp. dell' Hauteriviano inferiore; Spitidiscus vandeckii (D'ORHGNY), S. oosteri (SARASN & SCHÒNDELMAYER) e Holcodiscus cf. caillaudianus (D'ORHGNY) sono slati rinvenuti in associazione con Pulchellia chan- garmeri (SAYN) nel "Couloir" Dâmbovicioara, nei livelli immediatamente PAROLE CHIAVE: Cretaceo inferiore, Ammonitina, Holcodiscidae, soprastanti quelli con Pseudothurmannia; quasi tutte le specie di holcodi Tassonomia, Biostratigrafia, Romania
1. - INTRODUCTION 4) the upper part, Barremian in age, of the Sinaia Formation, exposed on the Zizin valley (East of Brasov) The present paper attempts to present together all the presented some crushed holcodiscids, such as Holcodi data existing now on the holcodiscid representatives in scus caillaudianus (D'ORBIGNY) and H. aff. perezianus Rumania as they could be controlled with the paleonto razgradi Tzankov (recognised by Graf, 1970, 1975), logie material still existing in repositories. These data but these fossils are not available anymore; refer to species of the genera Jeanthieuloyites, Spitidi 5) in the same lithostratigraphic unit of the East Car scus, Holcodiscus and Astieridiscus yielded by the Va- langinian-Lower Barremian fossiliferous successions of pathians flysch, but southwards, Avram (1976 a) recor the Persani, Ciuc and Baraolt Mts. and on the Zizin, ded in the Târlung valley: Spitidiscus sp., Holcodiscus Târlung and Doftana valleys (all situated in the East perezianus (d'Orbigny), H. cf. geronimae (Hermite), Carpathians), of the Brasov-Codlea area, Dâmbovicioara Holcodiscus sp. aff. H. nicklesi Karakasch, and in the Couloir (which corresponds to the structural unit and Doftana valley - crushed specimens of Holcodiscus, all morphologic depression developed SSW-NNE between lodged in the repository of the Geological Institute of the crystalline massifs of Leaota and Iezer Mts.) and Rumania; Svinita village area (from the South Carpathians), and of 6) in the Upper Valanginian-?Aptian Brasov For the western part of the Carpathians foreland southern mation, developed both in the Brasov and Codlea towns unit - the Moesian Platform (Fig. 1), as follows: areas, Jekelius (1915) signaled a Holcodiscus (Spitidiscus) lorioli Kilian (lost collection), in the 1) in the Persani Mts., the upper, marly member of Dracului valley; then, Valceanu (1960) and Semaka the Tithonian-Hauterivian Carhaga Formation provided (1967) (revised by Patrulius, 1969, listed in the Valea an unidentifiable species of Jeanthieuloyites, preserved Lata, near Codlea: Spitidiscus intermedius (d'Orbigny). in the repository of the Geological Institute of Rumania, S. vandecki (d'Orbigny), S. aff. heeri Ooster (an as listed as Spitidiscus sp. ex gr. S. incertus (d'Orbigny) by semblage also lost), and Avram & Gradinaru (1993) Patrulius & Avram (1976 a); recorded in the basal, condensed bed of the formation, 2) in the Ciuc Mts., Nicolaescu el alii (1970) poin exposed in the "Piatra Mare" quarry: Jeanthieuloyites ted out a Spitidiscus aff. S. fallacior Coquand within the keyserlingiformis n.sp., J. trapezoidalis n.sp., J. nodosus Barremian flysch, namely in the Bistra Formation, but (Mandov) and an unnamed new species of the same ge this badly figured specimen is lost; nus, an assemblage now preserved in the Bucharest Uni versity repository; 3) the same Bistra Formation yielded in the Baraolt Mts. (Kiss, 1911; Vadasz, 1911; Kusko & Savu, 1970; 7) south of Brasov, in the Dâmbovicioara Couloir, Avram & Kusko, 1984) a rich assemblage of Barremian HERBICH (1888), POPOVICI-HATZEG (1898), SlMIONESCU ammonites, including Holcodiscus, Spitidiscus and (1898), Patrulius (1969), Patrulius & Avram (1976 Astieridiscus species; among them only the fossils col b) and Avram (1988), and also Neagu, Bulmez, lected by the last authors (listed here below, in the chap Grigorescu and Andrasanu (in coll.) listed the rich ter on the biostratigraphic value of the holcodiscispecies) ammonite content of the Upper Valanginian - Lower arc still available; they are preserved in the repository of Aptian Dâmbovicioara Formation; except Herbich's the Geological Institute of Rumania; material, which is housed in the Cluj University reposito- THE FAMILY HOLCODISCIDAE IN RUMANIA 13
ry, and partly SIMIONESCU'S collections, preserved in the (d'ORBiGNY) group of species, by the ontogenetic study Iassy University and in the Bucharest University reposi of both the Rumanian holcodiscid representatives and tories, the paleontological collections of these authors are the species figured in the paleontological literature. lodged in the repository of the Geological Institute of On the other hand, the pyritised ammonites from Rumania (an up-to-date list of the holcodiscid species Svinita illustrate the large diversity of the holcodiscid coming from Dâmbovicioara results from the present morphology, especially within the genus Holcodi- revision) ; scus,W\\h a consequence in the new interpretation pre 8) the Svinita village area is highly important by the sented below, of some already published taxa and in the pyritised, well preserved Lower Barremian ammonites, proposition of some new species.
among which numerous species of holcodiscids were as 2. - BIOSTRATIGRAPH1C VALUE OF THE HOLCODI signed (AVRAM, 1976 b, 1988, revised here below), yiel SCID SPECIES ded by the Murguceva and Svinita Formations; these are also preserved in the repository of the Geological Institu Of all the region mentioned above, only the Baraolt te of Rumania ; Mts., Brasov-Codlea region, Dâmbovicioara Couloir and 9) finally, from the Hauterivian limestone sequence Svinita village area are indicative for the biostratigraphic of the western part of the Moesian Platform, developed position of the holcodiscid species. Even in these regions in subsurface, MUTIU (1967) cited Spitidiscus sp. and the unfavourable structural setting and, in places, the un Holcodiscus sp., none of them stored in any official re complete exposure of fossiliferous successions made pository. possible the estimation of the biostratigraphic value of The main result of the present paleontological study the species only when they are directly assembled to non- is the revision of the Holcodiscus caillaudianus holcodiscid index taxa. 14 AVRAM E.
As a matter of fact, the Upper Valanginian species of In the Dâmbovicioara Couloir, the Lower Barremian the genus Jeanthieuloyites come from an Upper assemblage containing Holcodiscids were counted Valanginian, almost 20 cm thick, condensed bed at the (PATRULIUS & AVRAM, 1976 b) as the biozone with Pul base of the Brasov Formation in the Codlea town area; chellia changarnieri (SAYN) and Spitidiscus spp., and there they were assembled to numerous ammonite spe the biozone with Pulchellia compressissima cies of the Verrucosum and Trinodosum Zones; moreo (D'ORBIGNY), Leptoceratoides spp., Holcodiscus spp. ver, in the bed next to the condensed base Eleniceras and Torcapella suessi (SIMIONESCU). The former was transsylvanicum (JEKELIUS) was recognised, a species recognised along the Brasov - Rucar route on the western which supports the latest Valanginian age (Callidiscus slope of the Sasului Hill, where Pulchellia changarnieri, Zone). Subpulchellia sauvageaui (HERMITE), Spitidiscus The Lower Hauterivian age of some holcodiscid spe vandeckii (D'ORBIGNY), S. oosteri (SARASIN & cies could be checked up only in the Dâmbovicioara SCHÒNDELMAYER), Holcodiscus cf. caillaudianus Couloir. Here, a biozone with Leopoldia leopoldina and (D'ORBIGNY), Crioceratites sp. were recorded within an Distoloceras sp. was proposed by PATRULIUS & AVRAM almost 3-4 m sequence above the beds with Pseudothur- (1976 b), this biozone containing in the same outcrop: mannia. The latter was identified as an about 5-10 m Spitidiscus ? meneghina (de ZIGNO in RODIGHIERO), thick sequences on the Muierii, Zamvelei, Oratii and Jeanthieuloyites cf. nodosus (MANDOV) and Leopoldia Cheii valleys as follows: in the Muierii valley: Lepto leopoldina (D'ORBIGNY). ceras pumilum (UHLIG), L. subtilis (UHLIG), Pulchellia The next biozone proposed by the same authors, na cf. compressissima (D'ORBIGNY), Subpulchellia sau mely that with Lyticoceras and Spitidiscus intermedius, vageaui (HERMITE), Spitidiscus seunesi (KILIAN), Hol contains: Spitidiscus intermedius (D'ORBIGNY), S. cf. codiscus diversecostatus (COQUAND), H. gastaldii darderi FALLOT & TERMIER, and also S. cf. rotula KILIAN (non D'ORBIGNY), H. ziczac KARAKASCH, H. (SOWERBY) (here revised), in assemblege with Lyticoce geronimaeformis TZANKOV, Barremites spp., etc.; in the ras cf. vicarius (VACEK), Crioceratites matsumotoi Oratii valley: Leptoceras sp., Pulchellia compressissima SARKAR, C. sornayi SARKAR, etc. (D'ORBIGNY), Silesites vulpes (COQUAND), Barremites It should be also emphasized the presence of Spitidi spp., Torcapella suessi (SIMIONESCU), Crioceratites ex scus ? meneghina (example here figured in pi. 2, fig. 1), gr. thiollierei ASTIER, etc., and Astieridiscus elegans in the uppermost Hauterivian, in assemblage with Pseu- KARAKASCH, Holcodiscus cf. caillaudianus dothurmannia spp. The Lower Barremian holcodiscid (D'ORBIGNY), H. diversecostatus (COQUAND); in the species were almost equally represented in the Baraolt Zamvelei valley: Spitidiscus cf. vandeckii (D'ORBIGNY), Mts., Dâmbovicioara Couloir and in Svinita region, all Holcodiscus tzankovi n.sp., H. cf. caillaudianus characterised by the narrow interval (of some meters) of (D'ORBIGNY), Barremites spp. and Torcapella suessi their occurrence. In these conditions the largest part of (SIMIONESCU). the inventories are collective as follows: In the Svinita area all the Lower Barremian hol In the Baraolt Mts. (KUSKO & SAVU, 1970; AVRAM & codiscid species come from a single sequence, almost KUSKO, 1984), the fossiliferous sequence crops out as a 5 m thick, near the water reservoir of the village. marly-sandstone flysch, longitudinally recognised on all Here, Astieridiscus morteti (KILIAN), Spitidiscus the tributaries on the right side of the Olt river, display gastaldianus (D'ORBIGNY), S. cf. seunesi (KILIAN), S. ing fossils in the Arcus Valley (explored by Kiss, 1911), cf. hugii (OOSTER), S. cf. andrussowi (KARAKASCH), Valea Mare (= Large valley), and especially in the SAN Holcodiscus cf. caillaudianus (D'ORBIGNY), H. tzank erai valley. The assemblage on Valea Mare, containing ovi n. sp., H. alpha TZANKOV, H. decorus n. sp., H. Spitidiscus oosteri (SARASIN & SCHÒNDELMAYER) (= S. ouachensis n. sp., H. aff. nodosus KARAKASCH, H. di fallacior COQUAND, in KUSKO & SAVU, 1970) and Psi- versecostatus (COQUAND/ H. ziczac KARAKASCH, H. lotissotia sp. (unregistered in any repositories) seems to aff. cadoceroides (KARAKASCH), are assembled with be situated lower than the assemblage on the Sanerai Leptoceras spp., Eoleptoceras (E.) wrighti valley, where a very rich ammonite assemblage was (MANOLO v), E. (E.) cf. pumilum (UHLIG), E. gathered in a sequence almost 1 m thick; among these (Tzankoviceras) n. sp., Veleziceras aff. saharievae species Crioceratites aff. emerici LÉVEILLÉ, Leptoceras (MANOLOV), Subpulchellia nicklesi HYATT, S. sau subtile UHLIG, L. pumilum UHLIG, Eoleptoceras (E.) aff. vageaui (HERMITE) and Melchiorites spp. occur. fragile (UHLIG), Holcodiscus cf. caillaudianus (D'ORBIGNY), H. gastaldii KILIAN (non D'ORBIGNY), //. irregularis TZANKOV, H. aff. nodosus KARAKASCH, 3. - PALAEONTOLOGICAL DESCRIPTIONS Spitidiscus hugii (OOSTER), S. oosteri (SARASIN & SCHÒNDELMAYER), S. andrussowi (KARAKASCH), Ast ieridiscus uhligi KARAKASCH, beside Pulchellia aff. The repositories which allowed the present revision compressissima (D'ORBIGNY), Subpulchellia sauvageaui are the follows: the repository of the Geological Institute (HERMITE), Silesites ex gr. vulpes (COQUAND), Patruli- of Rumania (indicated "IG" in the next quotations), the usiceras spp., Barremites cf. difficilis (D'ORBIGNY), Bucharest University repository (BU), the Cluj Universi Melchiorites spp. were recorded. ty (CU) and Iassy University (IU) repositories. THE FAMILY HOLCODISCIDAE IN RUMANIA 15
The following symbols were used for the shell measu Jeanthieuloyites nodosus (MANDOV) rements: D = diameter of the shell; U = width of the Pl. 1, fig. 3 a-b; pi. 7, fig.2a , b umbilical area, as it is limited by the umbilical seam, at a measured diameter; H = whorl heght, along the same 1919 Polyptychites Meneghina de ZIGNO; RODIGHERO, pl. X, fig. 4 (only). diameter; W = whorl width at the measured diameter, all 1976 Spitidiscus nodosus MANDOV, p. 99, pl. XX, fig. 1; pl. XXI, expressed in mm; u, h, w, mean the LVD, H/D and W/D fig. I (holotype). ratio, respectively; the index of involution represents the ? 1976 Spitidiscus Meneghina ((DE ZIGNO) RODIGHERO); MANDOV, ratio between the part covered by the next whorl and the p. 85, pl. XXII, fig.2 . complete height of the whorl. 1986 Spitidiscus nodosus MANDOV; VASICEK & MICHALK, p. 472, pl. V, fig.3 . 1993 Jeanthieuloyites nodosus (MANDOV); AVRAM & GRA GENUS Jeanthieuloyites COOPER, 1981 DINARU, p. 673, pl. 1, fig.14 ; pi. 2, fig.12 , 13; pi. 4, fig.1 , 2, text-fig. 1/2. TYPE SPECIES: Rogersites quinquestriatus BESAIRIE, 1936 SPECIFIC CHARACTERS - Medium sized species, with As shown by AVRAM & GRADINARLI (1993) the genus relatively wide umbilicus, and an involution of almost Jeanthieuloyites is surprisingly frequent in Rumania, 1/3; its ornamentation is composed of six constrictions, with some Upper Valanginian species such as J. keyser- wide, gently prorsiradiate on the last whorl, each of them lingiformis AVRAM & GRADINARLI, J. trapezoidalis bounded by 2 ribs, sharpened near the umbilicus and on AVRAM & GRADINARLI, Jeanthieuloyites sp. ind., beside the ventral area; between constrictions there are 6 to 2 J. nodosus (MANDOV) which crosses the Valanginian- (progressively fewer towards the aperture) umbilical ribs, Hauterivian boundary. generally bifurcated on the mid-sides, some of them ri sing in bunches of 2-3 from the periumbilical swellings, these disposed behind the constrictions; the ribs are pa Jeanthieuloyites keyserlingiformis AVRAM & rallel to the adapically situated constriction and fall obli GRADIN ARU quely on the adorally disposed constriction. Pl. 1, fig. 1 a-c; pi. 7, fig. 1 MATERIAL - 3 septate specimens recorded in the Co v 1993 Jeanthieuloyites keyserlingiformis A VRAM & GRADINARU, dlea town area (E. GRADINARU'S coll., BU - 00274). p. 674, pl. 1, fig. 13; pi. 2, fig. 11; pi. 4, fig. 3; lext-fig. 2/1 (all showing the holotype). MEASUREMENTS - No measurements were presented for the holotype, which is deformed. In the better preser SPECIFIC CHARACTERS - Very depressed, oval whorl ved material from the Codlea town area, they are: section; the inner whorls display a Spitidiscus-like orna mentation, but with bunches of 2-4 ribs starting from periumbilical swellings; outer whorl (still septate in the D U H W W/H holotype) resembles Polyptychites keyserlingi NEUMAYR 62.5 15.6(0.25) 28.6(0.45) 30.8(0.49) 1.07 & UHLIG but bears also 6 deep, almost straight, prorsi- radiate constrictions. OCCURRENCE - Upper Valanginian, Codlea town But in the large specimen from Dâmbovicioara (here area, Central Rumania (E. GRADINARU'S coll., BU - figured in pi. 2, fig.3 and in pi. 7, fig. 5 as Jeanthieuloyi 00613). tes cf. nodosus (MANDOV)) the umbilicus is wider, the ribbing is denser and the constrictions are 7 in number instead of 6, in the holotype. This specimen displays Jeanthieuloyites trapezoidalis A VRAM & GRADINARU umbilical swellings only at the beginning of the last Pl. 1, fig. 2 a-c; pi. 7, fig. 3 whorl.
v 1993 Jeanthieuloyites trapezoidalis AVRAM & GRADINARU, p. OCCURRENCE - Lower Hauterivian in Bulgaria and in 675, pl. 1, fig. 15; pi. 2, fig. 14; pi. 4, fig. 4; text-fig. 2/3 (all showing the holotype). Slovakia. In Rumania it was recorded in the Upper Va langinian (in the Codlea town area) and in the Lower SPECIFIC CHARACTERS - Trapeze-shaped, gently de Hauterivian (with Leopoldia leopoldina (D'ORBIGNY)), pressed whorl section; narrow and deep umbilicus in Dâmbovicioara. (u=0.25); 7 almost straight, prorsiradiate deep constric tions on the (still septate) last whorl, bordered by 2 ribs; 4 to 5 umbilical costae in bunches of 2 or 3 from 2 pe Jeanthieuloyites sp.ind. riumbilical swellings on each interval between the con Pl. 1, fig.4 ; pi. 7, fig. 4 strictions, bifurcating/polifurcating on the sides.
OCCURRENCE - As in Jeanthieuloyites keyserlingi v 1993 Jeanthieuloyites n.sp.ind., AVRAM & GRADINARU, p. 675, pi. formis (E. GRADINARU'S coll., BU - 00615). 1, fig. 16; pi. 4, fig.5 , 6; text-fig. 1/4. 16 AVRAM E.
Description - Two septate specimens (E. Specific characters - The species is here accepted Gradinaru's coll., BU-00616), characterised by a semi after the figuration and (partly) the description of the ty circular, depressed whorl section, by the deep and mid pe made by Kilian (1888), although its first interpreta dle-sized umbilicus, and a ribbing density very different tion was published by Uhlig (1883). Namely, the holo from young to mature stage; they also bear straight, wide type is medium in size, its whorls displaying almost flat constrictions, prorsiradiate on the sides and describing side and flat venter, almost isometric, subquadrate on the venter an angle towards the aperture. They are whorl-section (W/H= 1.1), a relatively small umbilicus (u partly similar by the general shape and the thin ribbing = 0.33 at a diameter of 46.5 mm) and an ornamentation on inner whorls, to Jeanthieuloyites quinquestriatus composed of main, bituberculate ribs, and thinner, non- (Besairie), but are different from this species by their tuberculate intercalatories; the former are 8 in number on narrower umbilicus and fewer depressed whorl section. a half-whorl, and the latter - from 4 to 6 on every inter space. The ventro-lateral tubercles are stronger than the Occurrence - As for Jeanthieuloyites keyserlingi lateral ones, which are bullate; the intercalatory ribs are formis Avram & Gradinaru. somewhere bifurcated and, as in almost all the Holcodi scid species, the last of them on each interspace falls obliquely on the main tuberculate adorally disposed rib. GENUS Holcodiscus Uhlig, 1882 The ventro-lateral tubercles seem to smoothen at a larger TYPE SPECIES: Ammonites Caillaudianus d'Orbigny, diameter than 45 mm. On the inner whorls, the main 1850 ribs bounding adapically the constrictions and bearing marginal tubercles are differentiated beginning from a Well represented in Rumania, the genus Holcodiscus diameter of 12-15 mm, but the bifurcate intercalatories was recognised in the Lower Barremian deposits in all are more frequent than in mature stages. the fossiliferous sites displaying holcodiscid ammonites. After the revision presented below, 17 species, a lot of Material - 28 specimens, 16 of them recorded in the them belonging to the Holcodiscus caillaudianus group, Dâmbovicioara Couloir (D. Patrulius & E. Avram's were counted in Rumania. coll., IG P-18689, 18690, 18692; D. Popescu- Raileanu's coll., IG P- 18691; G. Bulmez's coll., BU- 0263), 9 in the Svinita region (E. Avram's coll., IG P- 18669) and 2 in the Baraolt Mts. (M. Kusko & M. Holcodiscus caillaudianus (d'Orbigny) Savu's coll., IG P-6463). PI. 3, fig. 1, 2 a-b, 3 a-b, 4-7; pi. 6, fig. 1; pi. 7, fig. 11 Measurements - Specimen figured in pi. 3, fig. 2. 1850 Ammonites Caillaudianus D'ORBIGNY, p. 99, n. 600. non 1883 Holcodiscus Caillaudianus D'ORBIGNY; UHLIG, p. 243, pi. D U H W XIX fig- 2-4, 6-7, 13-14 (= H.tzankovi n.sp.), 8-9 (= H. ga staldii KILIAN non d'ORBIGNY). 22.7 7.1 (0.31) 9.2 (0.40) 10.1 (0.44) v 1888 Holcodiscus Caillaudi D'ORBIGNY; KILIAN, p. 669, pl. XIX, fig. 2 (first figuration of the holotype). Remarks non 1907 Holcodiscus Caillaudi D'ORBIGNY; KARAKASCH, p. 103, pi. - The Holcodiscus caillaudianus group is IX fig- 1 -5 (= H. aff gastaldii KILIAN non D'ORHGNY). remarquable by its large diversity of the ontogenetic ? 1907 Holcodiscus Perezi D'ORBIGNY; KARAKASCH, pl. IX fig- 10 evolution of the species: from almost typical H. caillau (only). dianus, bearing minute lateral and strong marginal tu 1923 Holcodiscus Perezi D'ORBIGNY; FALLOT & TERMLER, pl. IV, bercles in almost all the growing stages, to the specimen fig. 10 (only). figured here in pi. 3, fig. 16, which presents bituberculate 1935 Holcodiscus caillaudianus D'ORHGNY; TZANKOV, p. 76, pi. (with lateral and marginal bullae) main ribs on the last- 3, fig. 6-8. but-one whorl, and only nontuberculate main ribs borde 1937 Ammonites Caillaudianus D'ORHGNY; COTTREAU, p. 57, pi. ring the constrictions, on the end of the shell, or Uhlig's LXXVII, fig. 24, 25 (type refigured). specimens figured in his pl. XIX, fig. 8-9, which display ? 1955 Holcodiscus caillaudi D'ORHGNY; ERISTAVL p. 73, pl. Ill, fig. 1 (crushed specimen). denser ornamentation, bullate on the ventral margin. In these conditions a revision of the entire group was neces non 1960 Holcodiscus caillaudianus ORBIGNY; DRUSHTCHITS, p. 304, pl. XLVI, figs. 1-2 (= H. tzankovi n. sp.). sary, the species here discussed being restricted to the ? 1966 Holcodiscus caillaudianus (D'ORHGNY); BRESKOVSKI, p. specimens well related to the holotype. 101, pl. I, fig. 5-6. Among the Rumanian specimens, all identified as 1967 Holcodiscus caillaudianus (D'ORHGNY); DLMTTROVA, p. cf. because of their rounded 156, pl. LXXI, fig. 5. Holcodiscus caillaudianus and not subquadrate whorl-section, the best preserved are 1975 Holcodiscus caillaudianus (D'ORHGNY); GRAF, p. 111, pl. I, fig- 3. the pyritised nuclei recorded in the Svinita village area. v 1984 Holcodiscus cf. caillaudianus (D'ORHGNY) KILIAN; AVRAM They are small, completely septate, displaying a slightly & KUSKO, p. 17, pl. Ill, fig. 8. depressed (W/H=l.l), but subcircular whorl-section; al 1985 Holcodiscus perezianus caillaudianus (D'ORHGNY); most 10-11 straight main ribs bearing minute lateral TZANKOV & BRESKOVSKI, p. 21, pl. VI, fig. 4-8. bullae and ventro-lateral tubercles, and 2-4 single or bi- THE FAMILY HOLCODISCIDAE IN RUMANIA 17 furcated intercalatories on each interval between the 1888 Holcodiscus Caillaudianus D'ORBIGNY; UHLIG, pl. XIX, main ribs are observed, two of them joined to the main figs. 2-4,6-7, 13-14. adorally situated rib; all the ribs are strengthened on the ? 1923 Holcodiscus Perezi D'ORBIGNY; FALLOT & TERMKR, p. 47, rounded ventral side. pl. IV, fig. 7-9 (only). 1935 Holcodiscus perezianus D'ORBIGNY; TZANKOV, p. 77, pi. The crushed specimens of the Dâmbovicioara Couloir IV, fig. 7-9, ? pl. V, fig.I . (PI. 3, fig. 1, 5-7) present the lateral ornamentation very 1960 Holcodiscus caillaudianus ORBIGNY; DRUSHTCTDTS, p. 304, similar to that of the holotype, although they have more pl. XLVI, fig. 1, 2. numerous intercalatories and fewer main ribs in youth. 1976 Holcodiscus perezianus (D'ORBIGNY); AVRAM, 1976 a, p. Finally, the two specimens of the Baraolt Mts. are al 48, pl. IV, fig. 13. so crushed and much resemble the holotype by the nume 1985 Holcodiscus perezianus perezianus (D'ORBIGNY); rous main ribs, the small lateral bullae, the strong ven TZANKOV & BRESKOVSKL pl. VI, fig. 1-3 (only). tro-lateral tubercles and the bifurcate intercalatories. HOLOTYPUS - The pyritised phragmocone figured in pi.3, OCCURRENCE - Lower Barremian in France, Silezia, fig. 10 (E. AVRAM'S coll., IG P-18671). Bulgaria, Crimea, Caucasus; Upper Barremian (!) in DERIVATIO NOMINIS - In the memory of the Bulgarian Bulgaria. In Rumania all the specimens are recorded in eminent paleontologist, professor V.TZANKOV the Lower Barremian. Locus TYPICUS - The Svinita village area, Banat, SW Holcodiscus fallax (COQUAND inMATHERON) Rumania. PI. 4, fig. 12 STRATUM TYPICUM - Svinita Formation, lower part of the 1878 Ammonites fallax COQUAND in Coll., MATHERON, pl. C-19, Temeneacia Member, Lower Barremian in age. fig. 5 a-b (leclolype), 5 c-d. DIAGNOSIS - Middle sized Holcodiscid, with rounded, 1888 Holcodiscus fallax COQUAND in MATHERON; KILIAN, p. 667, pl. XX, fig.I . slightly depressed whorl section, 7-8 main ribs bearing 1955 Holcodiscus fallax COQUAND; ERISTAVI, p. 75. bullate lateral and marginal tubercles and 3-5 single or non 1966 Holcodiscus fallax (COQUAND); BRESKOVSKI, p. 102, pi. bifurcated intercalatories on each interval between the VII, fig. 3 (= Holcodiscus n. sp. ind.). main ribs. 1967 Holcodiscus fallax (COQUAND in MATHERON); DDvflTROVA, p. 160, pl. LXXVIII, fig. 9. DESCRIPTION - The holotype preserves in good con ditions only the last whorls of the phragmocone. It di 1985 Holcodiscus fallax (COQUAND in MATHERON); TZANKOV & BRESKOVSKI, p. 24,. pl. VII, fig. 4-8. splays an oval, almost isometric (gently depressed) whorl section, seven almost straight constrictions, adapically SPECIFIC CHARACTERS - KILIAN (1888) first described bordered by sharp, tuberculate ribs, progressively stron the species, considering it very variable, similar to Hol ger towards the ventral margin, and bearing lateral and codiscus caillaudianus (d'ORBIGNY) but devoid of the perisiphonal bullate tubercles. On every interval between lateral bullae and displaying denser (10 to 14) main ribs the tuberculate ribs, rise 4-5 single or bifurcate intercala (which bear only ventro-lateral tubercles). After the figu tories, 1 or, rarely, 2 of them falling obliquely on the ration of the type, its ge-rontic ornamantation is cha main adorally disposed rib. racterised by a kind of ridges, separated by constrictions The other specimens, generally smaller, present the (but no note concerning the constrictions was given by inner whorls, displaying the same features as the holoty the cited author). pe from the smallest diameter observed (almost 10 mm), except the rarer (six) constrictions and almost all the bi MATERIAL - A single, fragmentary specimen, recor furcate intercalatories. ded in the Dâmbovicioara Couloir (D. PATRULIUS & E. AVRAM'S coll., IG P-18701). MATERIAL - 12 pyritised nuclei, recorded in the Svinita village area (E. AVRAM'S coll., IG P-18670, REMARKS - The fragmentary specimen, here presen 18671); three other specimens coming from the Dâmbo ted as Holcodiscus aff. fallax, displays the straight, ra vicioara Couloir (D. PATRULIUS & E. AVRAM'S coll., IG dial, almost parallel lateral ornamentation of the species, P-18694; P. DUMITRICA'S coll., IG P-18693, 18695) and the main ribs bearing only marginal tubercles, and single one from the East Carpathian flysch (E. AVRAM'S coll., or, rarely, bifurcated intercalatories. But unlike the type, IG P-11167). on the aged end of the shell appear true constrictions, bounded adapically by a main, tuberculate rib, and ado- MEASUREMENTS - Holotype rally - by a sharp and strong simple (nontuberculate) rib. OCCURRENCE - Barremian in France and Georgia; D U H W W/H Lower Barremian in Bulgaria and in Rumania. 29.6 9.8 (0.33) 12.4 (0.42) 14.2(0.48) 1.14 22.6 7(0.31) 9.8 (0.43) 11.2(0.49) 1.14
Holcodiscus tzankovi n. sp. PI. 3, fig. 8, 9, 10 a-c, 11 a-b, 12 a-b; pi. 6, fig. 2; REMARKS - Holcodiscus tzankovi includes a homoge pi. 7, fig. 13 neous group of specimens, very frequent in the Lower 18 AVRAME.
Barremian deposits of Rumania, resembling both Hol the species "alpha" having the priority according to the codiscus caillaudianus (d'ORBIGNY) and H.perezianus Code (ICZN). (d'ORBIGNY): in fact, the largest part of the specimens On the other hand Holcodiscus alpha reminds the assigned in literature to the d'ORBiGNY's above men more frequent species H. tzankovi n. sp. by its lateral or tioned species are related to the species here described. It namentation and especially by the large development of differs from both mentioned species by its subcircular the lateral tubercles, although the whorl sections are very whorl-section, rapid growth of the whorls, and by its or different. namentation with strong lateral tubercles (even in The Rumanian specimens, with their strong main youth). ribs, strong lateral (beginning from a diameter of 5 mm) and ventro-lateral tubercles (these starting at a OCCURRENCE - Lower Barremian in Rumania, Sile- diameter of almost 8 mm), and numerous intercalato zia, Bulgaria; Upper Barremian (!) in Bulgaria (under ries, are nearer to the "mutation" toulai TZANKOV Holcodiscus perezianus perezianus). than to the "mutation" alpha.They also remind Hol codiscus sophonisba (COQUAND in SAYN) at a compa Holcodiscus alpha TZANKOV rable diameter, by the presence of the lateral and PI. 3, fig. 13 a-b, 14 a-b, 15 a-b; pi. 7, fig. 12, 14. marginal tubercles and by the frequency of the bifur cate intercalatory ribs, but they are different because of the earlier appearance of the constrictions (from a 1890 Holcodiscus cf. Perezianus d'ORBIGNY; TOULA , pl. I, fig. 3. diameter of 8 mm) and by a larger umbilicus even in ? 1907 Holcodiscus Perezi D'ORHGNY; KARAKASCH, pl. IX, fig. 6- 13 (6 = a different species, without tubercles on its ventral youth. side; 7-8, 10-13 = Holcodiscus ex gr. tzankovi; 9 = inde terminable, poorly preserved specimen). MEASUREMENTS - (on a small pyritised specimen): 1923 Holcodiscus Perezi D'ORHGNY; FALLOT & TERMER (partim), p. 47, pl. IV, fig. 7-9, non fig. 10 (= H. caillau D U H W W/H dianus (d'ORHGNY)). 1935 Holcodiscus perezianus mut. alpha TZANKOV, p. 78, pl. IV, 11.2 3.3 (0.30) 4.4 (0.39) 5.9 (0.52) 1.34 fig. 4-6 (holotype). 1935 Holcodiscus perezianus mut. toulai TZANKOV, p. 78, pl. V, fig. 2. OCCURRENCE - Barremian in Bulgaria and in the ? 1935 Holcodiscus angulatus TZANKOV, p. 80, pl. VI, fig. 3, 4. Balearic Islands; Lower Barremian in Rumania. ? 1955 Holcodiscus gastaldi D'ORHGNY; E RISTA VI, p. 74, pl. Ill, fig. 3. Holcodiscus gastaldii KILIAN (non D'ORBIGNY) 1966 Holcodiscus perezianus (D'ORHGNY); BRESKOVSKI, p. 102, pl. VI, fig.6 . PI. 3. fig. 18 a-b. 19 a-b; pi. 4, fig. 10 1967 Holcodiscus perezianus (D'ORBIGNY); DMTROVA, p. 156, pl. LXXIX, fig. 1 (only). 1883 Holcodiscus Caillaudianus D'ORBIGNY; UHLIG, pl. XIX. fig. 8,9. 1967 Holcodiscus perezianus alpha TZANKOV; DIMTTROVA, p. non 1883 Holcodiscus Gastaldinus D'ORBIGNY; UHLIG, p, 245, pi. 157, pi. LXXIX, fig. 7 (type refigured). XIX, fig. 10 (= Holcodiscus sp. ex gr. H. caillaudianus 1985 Holcodiscus perezianus perezianus (D'ORHGNY); (d'ORHGNY)). TZANKOV & BRESKOVSKI, p. 20, pl. V. fig. 10, 11. 1888 Holcodiscus Gastaldi! D'ORHGNY; KILIAN, p. 671, pl. XIX, fig. 3 (holotype). SPECIFIC CHARACTERS - The species Holcodiscus al non 1891 Holcodiscus gastaldii D'ORHGNY; SAYN, p. 53, pl. Ill, fig. 3 pha is characterised by its very depressed whorl-section (= Holcodiscus sp. ex gr. H. diversecostatus (COQUAND)). non 1898 Holcodiscus Gastaldii D'ORBIGNY; SIMONESCU, p. 134, pi. (W7H = 1.5), by a relatively narrow umbilicus (u = 0.31) VI, fig. 6 (= Holcodiscus simionescui n. sp.). and high, very convex sides (h = 0.45), and the ornamen 1907 Holcodiscus Gastaldii D'ORHGNY; KARAKASCH, p. 106. pi. tation displaying nine constrictions bounded by stronger IX, fig. 17. than usual ribs, slightly projected on the venter, one of 1935 Holcodiscus gastaldianus D'ORBIGNY; TZANKOV, p. 76, pi. IV, fig. 1-3. them (which is situated adapically) bearing lateral and non 1937 Ammonites Gastaldianus D'ORHGNY; COTTREAU, p. 58, pi. ventro-lateral tubercles, and also 6 to 2 intercalatory ribs VI, fig. 6 (= ? Holcodiscus n. sp.), fig. 27-29 (= Spitidiscus between two consecutive constrictions, bifurcating rarely. gastaldianus (D'ORHGNY)). non 1955 Holcodiscus gastaldi D'ORBIGNY; ERISTAVI, p. 74, pl. Ill, MATERIAL - 12 specimens, very different in size fig. 3 (= Holcodiscus sp. ex gr. H. tzankovi n. sp.). (from the smallest size up to the diameter of almost 30 non 1960 Holcodiscus gastaldinus ORHGNY; DRUSHTCHITS, p. 304, pl. XLVI, fig. 3, 4 (= Holcodiscus n. sp. ex gr. //. tzankovi). mm), preserved as pyritised nuclei; all recorded in the 1984 Holcodiscus aff. gastaldinus UHLIG (non D'ORHGNY); Svinita village area (E. AVRAM'S coll.JG P-18672). AVRAM & KUSKO, p. 18, pl. Ill, fig. 6. ? 1985 Holcodiscus dimitrovae TZANKOV & BRESKOVSKI, p. 40, pi. REMARKS - Holcodiscus alpha displays the same IX, fig. 10-11 and 12, 13 (only). whorl-section as H. perezianus mut. toulai TZANKOV (see ? 1985 Holcodiscus monotuberculatus TZANKOV & BRESKOVSKI, the complete figuration of this "mutation" in TZANKOV & p. 44, pl. X, fig.3-4 . BRESKOVSKI, 1985) and H. angulatus TZANKOV, small differences in ornamentation of which are due to the very SPECIFIC CHARACTERS - According to KILIAN (1888) different size of the type specimens; consequently, all who described in great detail the holotype, the species is these "mutations" are to be included in a single taxon, characterised by the compressed, subquadrate whorl- THE FAMILY HOLCODISCIDAE IN RUMANIA 19
section, with flat venter and sides, covered by thin, STRATUM TYPICUM - Lower Barremian, Dâmbovicioara flexuous, mostly bifurcated ribs, part of them (almost 10 Formation, Muierii valley Member. on the last half-whorl), a little stronger than the other, bearing marginal tubercles; these tubercles join also the DIAGNOSIS - Holcodiscus with dense, bifurcate ribs, last secondary rib on the flanks, and the pair of ribs thus sharpened at the point of bifurcation in youth; mature obteined crosses the venter marking a fair sinus for stage with main, bituberculate ribs and bifurcate interca wards. latories, too.
MATERIA!, - Three specimens, two of them recorded DESCRIPTION - Even incomplete, the holotype pre in the Dâmbovicioara Couloir (D. PATRULIUS & E. sents some very peculiar features which define a new AVRAM'S coll., IG P-18696; V. POPOVICI-HATZEG'S coll., species: the end of the last-but-one whorl is almost iden IG P-760), and one in the Baraolt Mts. (M. KUSKO & M. tical with the specimen figured by SIMIONESCU'S (1898) SAVU'S coll., IG P-6465). by lacking true constrictions and by the dense and bifur
REMARKS - As BRESKOVSKI (1966) discussed, the late cate ribbing, somewhere rising in small crests at the figuration (by COTTREAU, 1937) of the Ammonites Ga point of bifurcation; its whorl section is subtrapezoidal, staldianus D'ORBIGNY type, which is a Spitidiscus, and the venter is crossed by thin, equal ribs, part of them Holcodiscus ga brought in question the name of Holcodiscus Gastaldii bearing small, bullate tubercles, as in staldii KILIAN (non D'ORBIGNY). D'ORBIGNY in KILIAN (1888) and of H. Gastaldinus In the mature stage, D'ORBIGNY in UHLIG (1883). According to the Code (XII, dense constrictions bordered adapically by strong, Homonimy, Article 57 c) the name Holcodiscus gastaldii flexuous ribs bearing lateral bullae (and also ventro is valid for the taxon thus defined by KILIAN (1888). I lateral ones ?), and 2 or 3 flexuous, generally bifurcate prefer now to use KILIAN'S definition of this taxon, be intercalatories are observed on the side, all these features Holcodiscus Ga cause //. gastaldinus figured by UHLIG (1883) is in fact a resembling the specimen figured as transitional example to the Holcodiscus caillaudianus staldinus d'ORBIGNY by UHLIG (1883) in his pl. XIX. fig. group, by its well developed lateral bullae. 10 a.
Holcodiscus dimitrovae TZANKOV & BRESKOVSKI The other specimens are smaller, displaying the thin, (1985) is very near to the here discussed species, only the regularly bifurcate ribbing, and lacking the constrictions fewer constrictions (8 instead of 10) justifying its separa of the young stage of the species SIMIONESCU'S (1898) tion. Holcodiscus monotuberculatus TZANKOV & specimen also presents dense ventro-lateral pairs of tu BRESKOVSKI seems also to be an accidental individual bercles, poorely preserved and unfigured by the author. variation (lacking a row of perisiphonal tubercles) of H. gastaldii KILIAN. MATERIAL - Beside the holotype, SIMIONESCU'S spe cimen (IU, no.Crb D 99) and another, recorded also in The Rumanian individuals of the species, recorded in Dâmboviciara by PATRULIUS & AVRAM (IG P-18698). the Dâmbovicioara Couloir arc almost identical to the holotype. But the one found in the Baraolt Mts. (here fi OCCURRENCE - All the specimens studied come from gured in the plate 4, fig. 10) displays stronger and almost the Lower Barremian rock-sequence. straight main ribs, being also related to Holcodiscus caillaudianus (D'ORBIGNY); its appartenance to the spe cies under discussion is based on the complete lack of the Holcodiscus geronimae (HERMITE) lateral tubercles. PI. 4, fig.1 4
OCCURRENCE - Lower Barremian in France, Ruma nia, Bulgaria, Crimea. 1891 Holcodiscus Geronimae HERMITE; SAYN, p. 56, pl. Ill, fig. 4.
1923 Holcodiscus Geronimae HERMTIE; FALLOT & TERMER, p. Holcodiscus simionescui n. sp. 51, pl. V, fig. 3,7-14.
PI. 3, fig. 17 a-c; pi. 7, fig. 8 1976 Holcodiscus cf. geronimae (HERMITE); AVRAM, (1976 a), p. 48, pl. IV, fig. 14. v 1898 Holcodiscus Gastaldii D'ORBIGNY; SIMIONESCU, p. 134, pi. VI, fig. 6. MATERIAL - Only a specimen (E. AVRAM'S coll., IG P-11168), recorded in the East Carpathian flysch depo HOLOTYPUS - the (incomplete) specimen here figured in sits, on the Târlung valley (= Holcodiscus cf. geronimae pi. 3, fig. 17 (D. PATRULIUS & E.AVRAM'S coll., IG P- (HERMITE)). 18697).
REMARKS - No indication about the original figure DERIVATIO NOMINIS - in the memory of the Rumanian and description I had. Consequently, I reported the spe eminent paleontologist Professor I.SIMIONESCU. cimen under discussion to HERMITE'S species on the LOCUS TYPICUS - Dâmbovicioara Formation, Muierii ground of SAYN'S and FALLOT & TERMIER'S figurations valley. and descriptions: small species, characterised by wide, 20 AVRAM E. depressed, subhexagonal in section and rapidly growing HOLOTYPUS - The pyritised nucleus figured in pi. 4, fig. whorls, small and deep umbilicus and ornamentation 2, pi. 6. fig. 3, pi. 7, fig. 6, 15 (IG P-18673). composed of 15-17 tuberculate ribs on a whorl, stronger DERIVATIO NOMINIS - Its nice, decorative ornamentation. between the umbilical margin and the lateral, strong, tu- bercles,and fasciculate by 3 or 4 of these tubercles to Locus TYPICUS - Svinita, Banat (SW Rumania). wards the ventral part; well developed marginal tubercles also appear, irregularly disposed on two secondary ribs, STRATUM TYPICUM - Lower part of the Svinita Forma without any relation with the lateral ones; intercalatory tion, Temeneacia Member; Lower Barremian. ribs are very rare or lack. DIAGNOSIS - Very ornamented Holcodiscus, with subcir- The Rumanian specimen is larger than SAYN'S and cular whorl section, 10 constrictions on a whorl, strougly FALLOT & TERMIF.R'S ones and crushed, differing from these by its flexuous ribs, part of them (almost 12 on the bituberculate main ribs, 1 to 3 secondary ribs starting last whorl) bearing lateral tubercles and bifurcating on from the lateral tubercles and also 1-2 bifurcate intercala the outer half of the side; marginal tubercles are irregu tories, one of their secondaries bearing a supplementary larly disposed on both a secondary and an intercalatory marginal tubercle on every interval between the con ribs. With these features it stands between the typical strictions. Holcodiscus geronimae and the wider umbilicate H. ge- DESCRIPTION - The holotype is a nucleus preserving a ronimaeformis TZANKOV. whorl and a quarter, at a diameter of 20 mm. It displays OCCURRENCE - Barremian in Algeria and Neocomi an an almost circular (slightly depressed) whorl-section, (!) in the Balearic Islands; Lower Barremian in Rumania. with gentle convex sides and flat venter, growing quite rapidly and covering one another on almost 1/2. Its or Holcodiscus geronimaeformis TZANKOV namentation consists of 10 constrictions bordered by PI. 4, fig.1 3 sharp ribs, from which that situated adorally is stronger near the umbilicus and that disposed adapically rises just 1935 Holcodiscus geronimaeformis TZANKOV, p. 79, pl. V, fig.8 - 10 (lectolype established by BRESKOVSKI, 1966), pl. VI, fig. below the middle of the sides, is progressively stronger 1-2. towards the venter and bears strong and high lateral 1937 Ammonites Perezianus D'ORHGNY; COTTREAU, pl. LXXVII, marginal bullate tubercles. 1 to 3 thinner secondary ribs fig. 22, 23 (only). start from the lateral tubercle or above it, and crosses the 1966 Holcodiscus geronimaeformis TZANKOV; BRESKOVSKI, p. venter without any diminution. Usually 1 (rarely 2) in 106, pl. X, fig.6 . 1967 Holcodiscus geronimaeformis TZANKOV; DIMI- tercalatory rib appears between constrictions and ge TROVA, p. 157, pi. LXXIX, fig. 9, 10. nerally bifurcates in the middle of the flanks, one of the 1985 Holcodiscus geronimaeformis TZANKOV; TZANKOV & secondaries bearing also a strong marginal tubercle, at BRESKOVSKI, p. 26, pl. VII, fig. 10, 11 (type refigured), pi. mid-distance between the main ribs; in places, these in VIII, fig. 1,2. tercalatories rise in a tubercle at the point of bifurcation too. SPECIFIC CHARACTERS - According to the revised de Because of the supplementary tuberculation, the pairs scription by TZANKOV & BRESKOVSKI (1985) the species is small, with medium-sized umbilicus, and involution of outer tubercles are almost 18 on a whorl. about 1/3 ; its ornamentation consists of 12 prorsiradiate The body chamber of the largest specimen (pi. 4, fig. constrictions on a whorl, each of them bounded by 2 4) is preserved on almost half a whorl, beginning at a strong ribs: the adapically disposed rib bears a lateral diameter of 25 mm. The number of the main ribs varies and a larger marginal tubercle, between which it bifurca between 6 and 11 (denser in youth) and the number of tes or, in places, trifurcates. The marginal tubercles are the marginal tubercles could be up to 19 on a whorl. As also irregularly joined over the siphuncle by 1-3 seconda an exception, two other tubercles could be observed on ry ribs. Almost 3 intercalatory ribs between the tubercu the ribs between the main ones. late ones are also present. MATERIAL - A fragmentary specimen, recorded in the Dâmbovicioara Couloir (D. MATERIAL - 18 pyritised nuclei, partly crushed or frag PATRULIUS & E. AVRAM'S coll., unregistered). mentary; 1 specimen preserved as an impresion in marls. All of them recorded in the same bed, at the water reservoir of REMARKS - Even fragmentary, the individual from the Svinita village (E. AVRAM'S coll., IG P-18673,18674). Dâmbovicioara displays the wide umbilicus and the cha racteristic ornamentation of TZANKOV'S species, favou MEASUREMENTS ring a sure identification.
OCCURRENCE - Lower Barremian in Bulgaria; the Specimen D U H W W/H same age in Rumania. PI. 4, fig. 4 37.2 11 (0.30) 6 (0.43) - -
Holotype 18.4 5.7 (0.31) 7.5 (0.41) 8.1 (0.44) 1.08 Holcodiscus decor us n. sp. PI. 4, fig. 3 16 4.6 (0.29) 6.2 (0.39) 7.2(0.45) 1.16 PI. 4, fig. 2 a-d, 3, 4; pi. 6, fig. 3; pi. 7, fig.6 , 15. THE FAMILY HOLCODISCIDAE IN RUMANIA 21
REMARKS - The peculiar development of the ribs REMARKS - The Rumanian specimen is identical by bounding the constrictions (including also their large tu the lateral ornamentation with the holotype, at an equal bercles) makes the species here described comparable to diameter. Holcodiscus geronimaeformis TZANKOV; but it is diffe OCCURRENCE - Lower Barremian in Bulgaria; the rent by the supplementary marginal tubercles and lack of same age in Rumania. the secondary ribs between the marginal tubercles in the ventral area. The stronger and irregularly disposed rib bing, and also the supplementary marginal tubercles se Holcodiscus ouachensis n. sp. parate Holcodiscus decorus from H. razgradi TZANKOV, PI. 4, fig. 8, 9 a-c; pi. 6, fig. 5; pi. 7. fig.7 , 17. too. The presence of the intercalatory ribs makes it diffe rent from H. acutituberculatus BRESKOVSKI. Finally, the 1891 Holcodiscus Gastaldii D'ORBIGNY ; SAYN, p. 53, pl. Ill, fig. presence of the supplementary marginal tubercles makes 3. it comparable to H. irregularis TZANKOV. On the other hand, 14 other pyritised specimens, re HOLOTYPUS - The specimen figured in pi. 4, fig. 9, pi. 6, corded in the same site and interval as H. decorus (presented in the present paper as H. aff. decorus in pi. fig. 5, pi. 7, fig.7 .
4, fig. 1, 5-7, pi. 6, fig. 4, pi. 7, fig. 16) are different DERIVATIO NOMINIS - From Djebel Ouach, the site where from the type by having regularly 2 (rarely 1) bifurcate the first individual of the species was gathered. or single intercalatories on each interspace between the main, tuberculate ribs, one of them bearing also a margi Locus TYPICUS - Svinita, Banat (SW Rumania). nal tubercle, up to the diameter of almost 18 mm. So, STRATUM TYPICUS - Svinita Formation, lower part of the some 14-15 marginal pairs of tubercles (only 1 or 2 sup Temeneacia Member; Lower Barremian. ported by intercalatories) can be counted. The body DIAGNOSIS - Holcodiscus with almost isometric whorl sec chamber begins at a diameter of 30-31 mm and is longer tion, dense main ribs bearing marginal and, in places, minu than half a whorl. te lateral tubercles, and also very few intercalatories. This second group is nearer to Holcodiscus razgradi TZANKOV than the typical specimens, but it differs be DESCRIPTION - The holotype is a nucleus almost cause of the supplementary tuberculation inthe young identical with the specimen figured by SAYN (1891) stage. as Holcodiscus gastaldii. It displays almost isometric whorl-section, a deep, medium-sized umbilicus, and OCCURRENCE - Lower Barremian. thin straight, single or bifurcate ribs bearing perisi- phonal tubercles, and, in places, minute lateral ones, Holcodiscus irregularis TZANKOV situated above the middle of the sides and supported PI. 4, fig.11 . by some of the ribs bearing marginal tubercles, too. The immature ornamentation, at the beginning of the 1935 Holcodiscus irregularis TZANKOV; p. 92, pl. Ill, fig. 3-5 last whorl, resembles Holcodiscus diversecostatus (holotype). (COQUAND in NICKLÈS 1890) (= H. nicklesi KA 1966 Holcodiscus irregularis TZANKOV; DIMHROVA, p. 155, pi. RAKASCH) by its fine, dense ribs, single or bifurcate LXXIX, fig. 3,4. on the sides and joined by two at the marginal tuber 1984 Holcodiscus irregularis TZANKOV; AVRAM & KUSKO, p. 18, cles. pl. Ill, fig. 5. The paratype (IG P-18677), larger in size but poorer 1985 Holcodiscus irregularis TZANKOV; TZANKOV & preserved, shows numerous shallow constrictions, borde BRESKOVSKI, p. 23, pl. VII, fig. 1-3. red adorally by a single rib, which rises above the umbi lical margin, becomes stronger on the upper part of the SPECIFIC CHARACTERS - Medium-sized, with relati sides and normal on the ventral area. In places, one in vely small umbilicus and subtrapezoidal-oval, slightly tercalatory rib, bearing a marginal tubercle, is observed compressed whorl-section; flexuous constrictions on the beside some shorter ones (1 or 2), which regularly start last whorl, adapically bordered by a main rib, progressi behind the tuberculate ribs, but are not clearly branched vely stronger towards the venter, bearing lateral bullae from. and sharp marginal tubercles; the bullae and the tuber cles are also related each other by a secondary rib, ma MATERIAL - 2 pyritised nuclei, collected in the same king "clasps" on the outer half of the sides and on the bed, in the Svinita village area (E. AVRAM'S coll., IG P- venter; the intercalatory ribs are thinner, single or bifur 18676, 18677). cate, in mature stage one of them bearing a marginal tu bercle, too, at mid-distance between the main ribs. REMARKS - Holcodiscus ouachensis is partly compa rable to H. decorus n. sp., but this species is more stron MATERIAL - A single specimen, compressed, recorded gly tuberculate and displays rarer perisiphonal tubercles in the Baraolt Mts. (M. KUSKO & M. SAVU'S coll., IG P- because of more numerous nontuberculate intercalatori 6475). es. 22 AVRAM E.
OCCURRENCE - Lower Barremian in Rumania and in 1923 HOLCODISCUS DIVERSE-COSTATUS COQUAND NON NICKLES; Algeria. FALLOT & TERMIER, p. 52. NON 1935 HOLCODISCUS DIVERSECOSTATUS COQUAND; TZANKOV, p. 82, pi. VI, fig.8 , 9 (- H. NICKLESI KARAKASCH). Holcodiscus nodosus KARAKASCH ? 1960 HOLCODISCUS DIVERSE-COSTATUS COQUAND; DRUSHTCHITS, p. PI. 4, 17, 18. fig. 305, pl. XLVI, fig. 8. ? 1967HOLCODISCUS DIVERSECOSTATUS COQUAND; DIMTIROVA, p. 158, 1907 HOLCODISCUS NODOSUS KARAKASCH, p. 120, pl. X, fig. 1, 2 pl. LXXVIII, fig. 6. (leclolype here established), 4. 1985 HOLCODISCUS DIVERSECOSTATUS DIVERSECOSTATUS (COQUAND); 1984 HOLCODISCUS aff. NODOSUS KARAKASCH; AVRAM & KUSKO, TZANKOV & BRESKOVSKI, p. 34, pl. VIII, fig. 23, 24. p. 19, pl. Ill, fig. 7. SPECIFIC CHARACTERS - Small species, with flat whorl-sides and narrow, flat ventrum, and with narrow SPECIFIC CHARACTERS - Small Holcodiscus, cha umbilical area; shell covered by dense, thin, flexuous racterised (after KARAKASCH, 1907) by its isometric ribs, bifurcate or with shorter inter-calatories on the ou whorls, deep umbilicus, large development of the perisi- ter half of the sides; two or three ribs are sometimes phonal tubercles of the main ribs, these tubercles gathe buckled in small and sharp marginal tubercles, the other ring 1 or 2 or, in places, 3 thin ribs, which then cross the (1 or 2 on each interval ) crossing the venter without any venter; the main ribs rise from the umbilical margin and, interruption; the marginal tubercles are united over the between them occur 1-2 shorter intercalatories, part of venter by 1 or 2 ribs, not always symetrically. them crossing the siphonal area, the other ending in the perisiphonal tubercles. No mention about the lateral tu MATERIAL - 10 specimens, 8 of them recorded in the bercles in KARAKASCH'S diagnosis is given, although Dâmbovicioara Couloir, and 2 - in the Svinita village they are clearly seen on the paralectotypes in KA area (D. PATRULIUS & E. AVRAM'S coll., IG P-18700, and RAKASCH'S figures 1 and 4. E. AVRAM'S coll., IG P-18681, respectively). They are very different in size, the former preserved in marls, and MATERIAL - 9 specimens coming from the Svinita the latter - as pyritised nuclei. village area (7 of them - E. AVRAM'S coll., IG P-18679) and from the Baraolt Mts.(2 specimens, KUSKO'S coll., REMARKS - The above described ornamentation is IG P-17124). obvious on all specimens studied, from a diameter of al most 6 mm up to (the largest diameter of) 30 mm; al a MEASUREMENTS - Specimen figured in pi. 4, fig. 18. diameter smaller than 6 mm, which is seen only on some of the pyritised nuclei, the ribs start as bunches of 2 from
D U II W minute periumbilical tubercles. 7.5 2.2 (0. 29) 3.2 (0.40) 3.7(0.48) As for the specimens figured in the literature as Hol codiscus diversecostatus, such as those figured by TZANKOV and by DIMITROVA, they seem to be transitio REMARKS - The Rumanian specimens identified as nal to H. nicklesi by their ribs which are stronger, rarer Holcodiscus aff. nodosus axe all very small, with largely and buckled in a different kind to the marginal tubercles developed perisiphonal tubercles, but in places with than in typical examples. small lateral ones up to the diameter of almost 7-8 mm. The phragmocone ends in gerontic specimens at a dia meter of 9.2-9.5 mm. Besides, the specimens recorded in OCCURRENCE - Holcodiscus diversecostatus was re the Baraolt Mts. display thinner and more flexuous rib corded in the Barremian, in France and Balearic Islands, bing on the sides than in the lectotype. and also in the Lower Barremian in Rumania, Bulgaria and Crimea.
OCCURRENCE - Lower Barremian in Crimea; the sa me age in Rumania. Holcodiscus ziczac KARAKASCH PI. 4, fig. 19 a-b, 20 a-b, 21.
Holcodiscus diversecostatus (COQUAND) PI. 4, fig. 22. 1890 HOLCODISCUS ZICZAC KARAKASCH; p. 436, pl. 1, fig. 8 (holotype), 10. \%%0 AMMONITES DIVERSE-COSLALUS COQUAND; p. 19. 1907 HOLCODISCUS ZICZAC KARAKASCH; KARAKASCH, p. 118, pl. I, 1886 AMMONITES DIVERSE-COSTATUS COQUAND; HEINZ, pl. I fig. 3, 5, 14. (holotype). v ? 1960 HOLCODISCUS ZICZAC KARAKASCH; DRUSHTCfflTS, p. 305, pi. XLVI, fig. 5, 6. 1890 HOLCODISCUS DIVERSE-COSTATUS COQUAND; NICKLÈS, (PARTIM) p. 26, pl. I (VIII), fig. 20; NON pl. I, fig. 21-24, pl. II, fig. 14- 1966 HOLCODISCUS ZICZAC (KARAKASCH); BRESKOVSKI, p. 105, pi. 19, pl. IV, fig. 1 (=H. NICKLESI KARAKASCH). X, fig. 5. 1891 HOLCODISCUS DIVERSE-COSTATUS COQUAND; SAYN, p. 53, pi. 1967 HOLCODISCUS ZICZAC (KARAKASCH); DIMITROVA, p. 160, pi. Ill, fig.1,2 . LXXVIII, fig. 10. 1907 HOLCODISCUS DIVERSE-COSTATUS COQUAND; KARAKASCH, p. 1985 HOLCODISCUS ZICZAC (KARAKASCH); TZANKOV & 118, pl. IX, fig. 15, 16. BRESKOVSKI, p. 32, pl. VIII, fig. 15,16 THE FAMILY HOLCODISCIDAE IN RUMANIA 23
SPECIFIC CHARACTERS - According to KARAKASCH OCCURRENCE - Barremian in Crimea and Bulgaria; (1890, 1907) the species is small (maximum 18 mm in Lower Barremian in Rumania. diameter), with flat whorl sides and venter, and relatively narrow umbilicus; sides covered by fine, flexuous ribs, in Holcodiscus sp.ind. places progressively stronger towards the ventral margin, PI. 4, fig. 15, 16 a-b; pi. 7. fig. 9, 10. where 2 or 3 of them are buckled in sharp marginal tu bercles. Besides, rare intercalatory ribs cross indepen dently the ventral area. The perisiphonal tubercles, DESCRIPTION - Small specimens, with medium wide usually disposed asymetrically from one side to another, umbilicus and almost isometrical whorl section. The in arc joined over the siphonal area by ribs drawing a nermost whorls rather smooth, then with rare lateral, "zigzagged" ornamentation. round tubercles; from a diameter of 5 mm, appear 2-3 thin, bifurcate ribs between the tuberculate ones, wich MATERIAL - 7 small, pyritised, flattened specimens, co are also bifurcate or trifurcate, their secondaries situated ming from the same beds as almost all the Lower Barremian adapically bearing progressively stronger marginal tu holcodiscid species in the Svinila area (E. AVRAM'S coll., IG bercles, too. At a diameter of almost 8 mm, the marginal P-18680) and one (D. PATRULIUS & E. AVRAM'S coll., unre tubercles are denser and join together the secondary ribs gistered) from the Dâmbovicioara Couloir. pertaining to the bifurcate intercalatories disposed in REMARKS - Only two of the Rumanian specimens front of and behind them, thus resulting a zigzagged or show the alternate ventrolateral tubercles. But all of them namentation on the sides; the marginal tubercles are joi arc almost identical with the holotype by the lateral or ned over the venter by a double rib, in places interrupted namentation, although the ribs are denser in some spe along the siphuncle. At a larger diameter (seen on the cimens, as in Holcodiscus nicklesi KARAKASCH. crushed, larger specimen figured), the lateral and margi nal tubercles (both bullate) rise on different ribs develo OCCURRENCE - Barremian in Crimea; Lower Barre ped independently one another; some of these ribs are mian in Bulgaria and Rumania. well developed and stronger on the sides and the other, stronger on the venter, are short and fall on the sides Holcodiscus cadoceroides (KARAKASCH) behind the former. On the body chamber (the fourth un- PI. 4, fig. 23 a, 23 b. figured specimen) appear rare constrictions, bordered by equal ribs, from which that disposed adorally is bifurca
\907Astieria cadoceroides KARAKASCH; p. 127, pl. X, fig. 20 ted, one of its secondaries bearing a sharp, bullate, mar (holotype). ginal tubercle; between the constrictions, the ribs bearing 1935 Holcodiscus (Astieridiscus) cadoceroides KARAKASCH; both latero-external and marginal tubercles rise higher TZANKOV, p. 82. on the sides and join near the ventral margin the interca latory rib situated foreward; there are also single or bi SPECIFIC CHARACTERS - According to KARAKASCH furcate intercalatory ribs, in places united in a marginal (1907) Holcodiscus cadoceroides is small, coronate, tubercle, too. with medium-sized umbilicus. The lower part of the whorl-sides is covered by thin, short, prorsiradiate ribs, MATERIAL - 4 pyritised nuclei; 2 of them are very thickening on the lateral edge in small tubercles. Almost small, while the others are crushed and present the adult all these ribs are bifurcate on the outer half of the sides stages, including a part of the body chamber (E. (in places, even trifurcate). From the beginning of the AVRAM'S coll., IG P-18683). body chamber, the shell is covered by parabolic ribs sup porting on the ventral side 2 tubercles, very near one another. REMARKS - The nuclei here described are considered to belong to a new species, apart from all the strongly tu MATERIAL - A single, very crushed specimen, recor berculate and strongly ribbed holcodiscids by the irregu ded in the Svinita area (E. AVRAM'S coll., IG P-18682). lar ornamentation on the sides - with ribs long and short, zigzagged or only joined together in the latero-external REMARKS - Even very deformed, the Rumanian tubercles. This new species is here only signaled, because specimen (here identified as Holcodiscus aff. cadoceroi of the unsatisfactory preservation of the specimens stu des) displays an "Astieria" type of ornamentation up to the diameter of some 15 mm, with bunches of 2 or 3 sec died which prevents an accurate definition. ondary ribs on the outer part of the whorl-sides and on OCCURRENCE - Lower Barremian. the venter. But 3 strong ribs, tuberculate at the lateral edge and perisiphonal, are observed on the mature quar ter of the last whorl, instead of only one marginal tuber GENUS Spitidiscus KILIAN, 1910 cle, at the larger diameter, of the holotype. These strong TYPE SPECIES: Ammonites rotula SOWERBY, 1827. ribs border adapically shallow constrictions and are sepa rated one another by some 3-4 intercalatories. The body The genus Spitidiscus is mainly represented in Ru chamber is observed on 2/3 of the last whorl. mania in the Brasov-Dâmbovicioara areas, in the East 24 AVRAM E.
Carpathian flysch deposits (Baraolt Mts), and in the OCCURRENCE - Lower Hauterivian in England, Fran Svinita region, where 11 species have been identified. ce, Germany, Bulgaria, Crimea, N Africa. In Rumania, this species was recorded in the Lower Hauterivian too, assembled with Lyticoceras spp. Spitidiscus rotula (SOWERBY)
PI. 5, fig. 1, 2, 3 a-b Spitidiscus ? meneghina (DE ZlGNO in RODIGHIERO) Pl. 1, fig. 5 a-b, 6; pi. 2, fig.1 . 1892 Holcostephanus (Holcodiscus) rotula SOWERBY; PAVLOW & LAMPLUGH (panini) p. 131, pl. V (XVII), fig. 13, non fig. 11-12 (= Spitidiscus pavlowi (KARAKASCH)). \9\9 PolyptychitesMeneghina DE ZIGNO; RODIGHERO (partim), p. 94, pl. X (III), fig. 7 (lectotype established by DIMTTROVA, 1907 Holcodiscus rotula SOWERBY; KARAKASCH, p. 116, pl. IX, 1967), non fig.4 (^Jeanthieuloyites nodosus (MANDOV)). fig. 27. 1912 Spitidiscus (Holcodiscus) rotula var. infiala KILIAN, p. 2, pi. non 1967 Spitidiscus meneghini! (ZIGNO in RODIGHERO); DIMTTROVA, p. 150, pl.LXXVII, fig.5 (= Spitidiscus cancovi VASICEK). I, fig.2 . ? 1976 Spitidiscus meneghina (ZIGNO(RODIGHERO)); MANDOV, p. 1957 Holcodiscus aff. rotula SOWERBY; BUSNARDO & DAVID, p. 85, pl. XXII, fig. 2 (?= Jeanthieuloyites nodosus 98, pi. 2, fig.2 . (MANDOV)). 1972 Spitidiscus rotula inflatus KILIAN; THEULOY, p. 32, pi. 2, fig. 4-5, pi. 3, fig. 2-3, pi. 4, fig.2 . non 1985 Spitidiscus meneghini! (ZIGNO in RODIGHERO); TZANKOV & BRESKOVSKI, p. 9, pl. II, fig. 2 (= Spitidiscus cancovi ? 1976 Spitidiscus cf. rotula (SOWERBY); MANDOV, p. 86, pl. XX, VASICEK). fig. 3. 1981 Spitidiscus cf. rotula (SOWERBY); KEMPER, RAWSON& THEULOY, pi. 34, fig. 7, 8. SPECIFIC CHARACTERS - Large species with small 1981 Spitidiscus rotula (SOWERBY); KEMPER, RAWSON& umbilicus (u= 0.22-023), high and flat whorl-sides THEULOY., p. 304, pi. 34, fig. 11-15 (11-13 = type refigu- red). (h=0.45-0.46) and rounded venter, the whorls covering 1984 Spitidiscus rotula (SOWERBY); TZANKOV & BRESKOVSKI, p. one another 2/3 of their height, ornamentation composed 7, pl. I, fig.4-6 . of almost 6 prorsiradiate, deep constrictions on every 1988 Spitidiscus rotula SOWERBY); WUXE, pl. II, fig. 19. whorl, straight on the sides and slightly projected on the venter, bounded by two ribs from which that disposed SPECIFIC CHARACTERS - Because of the incomplete adorally is simple, stronger on the lower part of the si and partly deformed specimens studied, the species is he des, and the opposite one is stronger only on the ventral re accepted in a larger sense, to include also the subspe area. Some 5, gentle flexuous, intercalatory ribs on each cies Spitidiscus rotula inflatus KILIAN. It is characterised interval between constrictions start single or in bunches by a discoidal shell, with almost isometric, trapezoidal of 2 from the umbilical margin, and almost all bifurcate whorls (W/H= 1.11-1.23), narrow and deep umbilicus, in the middle of the sides. When bifurcate at the umbili displaying 5-7 constrictions; these are typically prorsi cal margin they rise in a node at the point of bifurcation radiate and straight on the sides and strongly projected (also observed by RODIGHIERO). There are also at least on the venter, where the ribs bounding them adapically three single or bifurcate ribs which fall oblique on the rib strengthen in a calosity. Thin and dense intermediary bounding adapically the constrictions. ribs, in places bifurcate on the sides and/or near the ven tral margin, part of them falling oblique on the constric MATERIAL - Seven specimens, all coming from the tion disposed adorally, are also observed. Dâmbovicioara Couloir (4 of them - D. PATRULIUS & E. AVRAM'S coll., IG P-17004, 18707; 3 others - T. NEAGU'S MATERIAL - Four specimens, more or less fragmenta coll., BU - 0079 A). ry: three of them have been collected in the Dâmbovi REMARKS - The presence of umbilical nodes in the cioara Couloir (D. PATRULIUS & E. AVRAM'S coll., IG P- holotype of Spitidiscus ? meneghina could be accidental, 18704, 18705) and one in the Svinita area (E. AVRAM'S coll., unregistered). and not usual as in Jeanthieuloyites nodosus (MANDOV); besides, coarser ribbed and larger umbilicatc MANDOV'S REMARKS - Except the representatives of Spitidiscus species could not be confused with the species here in di rotula inflatus, there are two types to which the paleonto scussion. On the other hand, both species arc very close logical material in the literature was reported: the holo (TZANKOV & BRESKOVSKI, 1985, even considered them a type and PAVLOW'S (1892) type, the latter with rather ar single species) because of their periumbilical tubercles, a ched on the sides and more calibrate constrictions. The character rather of Jeanthieuloyites than of Spitidiscus. Rumanian specimens, much larger than the holotype S. ? meneghina is generally represented in Rumania by (thus identified with caution), are more comparable to typical specimens, very comparable to the lectotype by the former by the shape and the number of their con ornamentation, including also the presence of the pe strictions, narrow umbilicus, etc. riumbilical tubercles, and by the dimensional characters.
MEASUREMENTS - Specimen figured in pi. 5, fig. 2 MEASUREMENTS - Specimen figured in pl. 1, fig. 5
D U H W D U H W
57.5 10(0.17) 26.5 (0.43) 25.5 (0.47) 101 24.5 (0.24) 45 (0.45) - THE FAMILY HOLCODISCIDAE IN RUMANIA 25
OCURRENCE - Hauterivian in Italy; Lower Hauterivian in non 1890 Holcostephanus intermedins D'ORBIGNY; NICKLÈS. p. 24, pi. Bulgaria, Slovakia. In Rumania almost all the specimens he II, fig. 12-13, pl. IV, fig. 2 (=Spitidiscus querolensis BUSNARDO & DAVID). re discussed come from the Lower Hauterivian, in assembla 1901 Holcodiscus intermedius D'ORBIGNY; SARASIN & ge with Leopoldia leopoldina. Only one deformed specimen SCHÒNDELMAYER, p. 43, pl. IV, fig. 4-5 (figured in pi. 2, fig. 1) was collected from the beds with 1919 Holcodiscus (Spitidiscus) intermedius D'ORBIGNY; RODIGHIERO, Pseudothurmannia, in the late Hauterivian. p. 99, pl. X, fig. 5. 1923 Spitidiscus intermedius D'ORBIGNY ; FALLOT & TERMER, p. 59. Spitidiscus cankovi VASICEK non 1935 Holcodiscus (Spitidiscus) intermedius D'ORBIGNY; TZANKOV, p. 68, pl. I, fig. 1-4 (^Spitidiscus rotula inflatus PI 2, fig. 4 a-b. KUAN?). 1966 Spitidiscus douvillei (NICKLËS); BRESKOVSKI, p. 100, pl. X, fig. 1. 1935 Holcodiscus (Spitidiscus) van-de-heckei D'ORBIGNY; ? 1967 Spitidiscus douvillei (NICKLÈS); DIMTTROVA, p. 152, pi. TZANKOV, p. 71, pi. 2, fig. 1. LXXVIII, fig. 16.
1967 Spitidiscus meneghina (ZIGNO in RODIGHIERO); DIMTTROVA, ? 1985 Spitidiscus intermedius (D'ORBIGNY); TZANKOV & p. 150, pl. LXXVII, fig. 5 BRESKOVSKI, p. 10, pl. Ill, fig. 2-7. 1986 Spitidiscus cankovi VASICEK, p. 474, pl. VI. fig. 1 (holotype). SPECIFIC CHARACTERS - Small, compressed, with 1985 Spitidiscus meneghina (ZIGNO in RODIGHIERO); TZANKOV & medium-sized umbilicus, involution of almost 1/2, and BRESKOVSKI, p. 9. pl. II, fig. 1, 2. high-oval whorl section. Six deep, arcuate and prorsi radiate constrictions are seen on the last whorl, with so me 13, partly bifurcate, thin ribs inbetween. SPECIFIC CHARACTERS - As described by VASICEK (1986), Spitidiscus cankovi is characterised by a semiin volute shell, with 7 deep, straight, projected constrictions MATERIAL - Two deformed specimens, all recorded in per whorl, bordered by ribs thicker than the others, ex the Dâmbovicioara Couloir (D. PATRULIUS & E. AVRAM'S cept the rib bounding adapically the constrictions, which coll., IG P-18713), here identified as Spitidiscus cf. in is always simple, all the other bifurcate or trifurcate on termedius. the sides, so that there are almost 5 ribs at the umbilical REMARKS - No specification about any stronger ribs margin and 10-12 on the periphery; the general shape of accompanying the constrictions is given by d'ORBIGNY, the ornamentation reminds Spitidiscus! meneghina (DE although they are seen even on the holotype. These ZiGNO in RODIGHIERO) except the presence of the pe stronger ribs are also present on the deformed (crushed) riumbilical nodes in the latter species. specimens studied, which display a relatively wide (and crenulated) umbilicus, beside 6 constrictions, arcuate MATERIAL - One specimen, found in the Dâmbovi forward in a symmetrically deformed specimen, but bor cioara Couloir (T. NEAGU'S coll., BU - 0079 B). dered adorally by a main stronger rib, on the outer half REMARKS - The Rumanian specimen is apart from the of the sides. There are also typically thin, in places bifur Spitidiscus cankovi type, by a narrower umbilicus and some cate ribs in the interspace between the constrictions. It is higher whorl-sides. Thus, it is better related to the Bulgarian also to be emphasized the relationship between the here individual figured by TZANKOV (1935), DIMITROVA (1967) described specimen and those identified as Spitidiscus cf. and TZANKOV & BRESKOVSKI (1985), and considered by darderi FALLOT & TERMIER, in spite of their different VASICEK as pertaining to his new species. shape of the main ribs and the wider umbilicus.
MEASUREMENTS OCCURRENCE - Neocomian in France, Hauterivian in Italy, Barremian in the Baléares; from the Lower Haute Specimen D U H W rivian (Radiatus Zone) up to the Lower Barremian in I lolotype 82 21 (0.25) 35 (0.43) - Bulgaria. The Rumanian examples are recorded in the PI. 2, fig.4 , Lower Hauterivian, in assemblage with Lyticoceras spp. right side 97 8.3 43.3 (0.44) 28 (0.28) lell side - (0.188) 47 (0.48) - 18.7 (0.19) Spitidiscus darderi FALLOT & TERMIER PI. 5, fig.9 . OCCURRENCE - Lower Hauterivian in Slovak Republic and in Bulgaria; in the Valanginian-Hauterivian bounda 1923 Spitidiscus Darderi FALLOT & TERMIER, p. 62, pl. IV, fig. 3 ry beds, in Rumania. (holotype). 1985 Spitidiscus darderi darderi (FALLOT & TERMIER); TZANKOV & BRESKOVSKL p. 5, pl. I, fig. 2. Spitidiscus intermedius (D'ORBIGNY) PI. 5, fig.7 , 8. SPECIFIC CHARACTERS - Small and compressed, with
1840-1841 Ammonites intermedius D'ORBIGNY, p. 128, pi. 38, fig. rather narrow, crenulated umbilicus, involution of almost 5-6 (holotype). 3/4 and high, subtrapezoidal whorl-section. Whorls di- 26 AVRAM E. splaying 6 lo 8 flexuous constrictions, cut longitudinally REMARKS - The larger Rumanian specimen is very by the main ribs, and with fasciculate intercalatories in near to the lectotype at a comparable diameter. The pyri between. tised specimens, which could be measured, present a subtrapezoidal,almost isometric whorl-section, and a MATERIAL - Two crushed specimens, both recorded in thin, partly bifurcate, flexuous ribbing, interrupted in the Dâmbovicioara Couloir (D. PATRULIUS & E. AVRAM'S places by shallow, flexuous constrictions, bounded by coll., IG P-18714) and identified here as Spitidiscus cf. ribs stronger than the others. darderi. MEASUREMENTS REMARKS - The Rumanian specimens bear narrow umbilicus (with crenulated umbilicus) and display 7 to 8 Specimens D U II W flexuous main ribs bordered (adorally and adapically) by PI. 5, fig. 14 16.5 3.9 (0.23) 8.2 (0.50) 8.2 (0.50) shallow, also flexuous constrictions. On each interval 15.6 3.4(0.22) 7.5 (0.48) 8(0.51) between the main ribs, there are almost 7-8 flexuous, 12.6 2.8 (0.22) 6.2 (0.49) 5.9 (0.47) thin intercalatories, whose largest part bifurcate or trifur cate on the sides. PI. 5, fig. 15 29 7 (0.24) 13 (0.45) - Although it is very close to Spitidiscus fasciger
THIEULOY, S. darderi differs by its smaller number of OCCURRENCE - Barremian in Switzerland; Lower main ribs and by their presence in the middle of larger Barremian in Crimea and in Rumania. constrictions.
OCCURRENCE - Hauterivian in the Balearic Islands Spitidiscus oosteri (SARASIN & SCHÒNDELMAYER) and in Bulgaria, Spitidiscus darderi was recognised in PI. 5, fig. 18, 19. Rumania in the Lower Hauterivian (with Lyticoceras spp). 1860 Ammonites Hugii OOSTER, p. 103, pi. 24, fig. 7-9, 10 (holotype), 12 ?, 14, 15 (only). Spitidiscus hugii (OOSTER) 1901 Holcodiscus Hugii OOSTER; SARASIN & SCHÒNDELMAYER, PI. 5, fig. 14 a-b, 15; pi. 6, fig. 11; pi. 7, fig.18 . p. 48, pl. IV, fig. 8, 10, 11 (only). 1901 Holcodiscus Oosteri SARASIN & SCHÒNDELMAYER, p. 48, pl. IV, fig. 6 (holotype), 7. I860 Ammonites Hugii OOSTER (partim): p. 103, pi. 24, fig. 11 (lectotype selected by TZANKOV, 1935), non fig. 7-10, 12 ?, 1934 Holcodiscus (Spitidiscus) oosteri SARASIN & 14, 15 (^Spitidiscus oosteri (SARASIN & SCHÒNDEL SCHÒNDELMAYER; TZANKOV, p. 71, pl. II, fig. 2-5. 1966 Spitidiscus oosteri (SARASIN & SCHÒNDELMAYER); MAYER)). BRESKOVSKI, p. 99, pl. VIII, fig. 8. 1901 Holcodiscus Hugii OOSTER; SARASIN & SCHÒNDELMAYER 1967 Spitidiscus oosteri oosteri (SARASIN & SCHÒNDELMAYER); (partim), p. 47, pl. IV, fig. 9 (type refigured), non fig. 8, 10, DIMTTROVA, p. 153, pi. LXXVII, fig. 1. 11 (=Spitidiscus oosteri (SARASIN & SCHÒNDELMAYER)). 1907 Holcodiscus Andrussowi KARAKASCH, pl. IX, fig. 22 (only), v 1970 Spitidiscus fallacior COQUAND; KUSKO & SAVU, p. 74. v 1960 Holcodiscus andrussowi KARAKASCH; DRUSHTCHITS, pi. 1985 Spitidiscus oosteri oosteri (SARASIN & SCTCNDELMAYER); XLVII. fig. 1, 2 (only). TZANKOV & BRESKOVSKI, p. 16, pl. IV, fig. 4-6. 1984 Spitidiscus hugii (SARASIN & SCHÒNDELMAYER); AVRAM & KUSKO, p. 16, pl. Ill, fig. 4. SPECIFIC CHARACTERS - Like Spitidiscus hugii (OOSTER), but with smaller umbilicus and high whorl si
SPECIFIC CHARACTERS - Only the coarser-ribbed type des, very thin ribs and more distinct constrictions (at figured by OOSTER (1860) in plate 24, fig.ll(= SARASIN least at a larger diameter than 40 mm); the constrictions & SCHÒNDELMAYER, 1901, pl.IV, fig.9) was kept in the are flexuous, shallow and projected on the venter, but species by TZANKOV (1935). In this interpretation Spiti bordered adapically by a main rib, progressively stronger discus hugii is rather medium in size, with a narrow forward and on the venter. In the young stage, these umbilicus (u=0.23) and involution of almost 2/3, with main ribs smoothen, so that the constrictions are less high, flat sides and rounded venter, it is covered by evident. flexuous ribs, about 57-60 on half a whorl at a diameter MATERIAL - Three specimens, found in the Dâmbo of 51 mm; there are primary and intercalatory ribs star vicioara Couloir (D. PATRULIUS & E. AVRAM'S coll., IG ting in bunches from the umbilical margin, the latter also P-18702, 18706; T. NEAGU'S coll., BU-0281); four were bifurcating below the mid-sides; almost 5 shallow, collected in the Baraolt Mts. (M. KUSKO & M. SAVU'S flexuous constrictions on the last half a whorl, are more coll., IG P-6484; E. AVRAM'S coll., IG P-17122). evident only on the lower part of the sides. REMARKS - The here adopted interpretation of the MATERIAL - Five specimens, four of them are small species is related to TZANKOV'S re-group of the OOSTER'S pyritised nuclei yielded from the Svinita region (E. and SARASIN & SCHÒNDELMAYER'S type specimens (see AVRAM'S coll., IG P-18687) and one larger individual synonimy). The Rumanian individuals arc smaller then comes from the Baraolt Mts (M. KUSKO & M. SAVU'S the types, but display the clear constrictions and the thin coll., IG P-6464). ribbing of the species. THE FAME.Y HOLCODISCIDAE IN RUMANIA 27
OCCURRENCE - Barremian in Switzerland; Lower remian in France, Switzerland, Bulgaria. It was found in Barremian in France, Rumania, Bulgaria; Upper Bar Lower Barremian, in Rumania. remian (!) in Bulgaria. Spitidiscus seunesi (KILIAN)
Spitidiscus vandeckii (D'ORBIGNY) PI. 4, fig. 4, 5, 6 PI. 5, fig. 20 1888 Holcodiscus Seunesi KILIAN, p. 675, pl. XVIII, fig. 3 (holotype). 1850 Ammonites Vandeckii D'ORBIGNY, p. 99, n. 602. 1901 Holcodiscus Seunesi KLUAN; SARASIN & SCHÒNDELMAYER, p. non 1861 Ammonites Vandecki D'ORBIGNY; LORIOL, p. 28, pl. II, fig. 46, pl. V, fig. 1,2. 4, 5, 6 (--Spitidiscus lorioli (KILIAN)) 1907 Holcodiscus Seunesi KILIAN; KARAKASCH, p. 107, pl. IX, 1888 Holcodiscus van-den-heckei D'ORBIGNY; KILIAN, p. 673, pi. fig. 23, 24, 26. XIX, fig. 4 (holotype). 1960 Spitidiscus seunesi KILIAN; DRUSHTCHTTS, p. 305, pi. 1901 Holcodiscus van-den-Heckei D'ORBIGNY; SARASIN & XLVII, fig. 4. SCIIÓNDELMAYER, p. 43, pl. V, fig. 4. 1966 Spitidiscus seunesi (KILIAN); BRESKOVSKI, p. 99, pl. I, fig. 4. non 1935 Holcodiscus (Spitidiscus ) van-den-heckei D'ORBIGNY ; TZANKOV, p. 71, pl. II, fig. 1 (=Spitidiscus ? meneghina 1967 Spitidiscus seunesi (KILIAN); DIMTTROVA, p. 152, pi. LXXVIII, fig. 17. (DE ZIGNO in RODIGHIERO)). 1937 Ammonites Vandeckii D'ORBIGNY; COTTREAU, p. 59, pi. 1985 Spitidiscus seunesi (KILIAN); TZANKOV & BRESKOVSKI, p. 13, pl. IV, fig. 1-3; ? pl. Ill, fig. 13 (= ? S. vandeckii LXXVIII, fig. 1, 2-3, 4 (type refigured). (D'ORBIGNY)). 1966 Spitidiscus vandenheckei (D'ORBIGNY); BRESKOVSKI, p. 98, pl. II. fig. 8; pl. Ill, fig. 5. 1967 Spitidiscus vandeckii (D'ORBIGNY); DIMTTROVA, p. 151, pi. SPECIFIC CHARACTERS - According to KILIAN (1888), LXXVII, fig. 13, 14. Spitidiscus seunesi is characterised by a discoidal shell, 1985 Spitidiscus vandeckii (D'ORBIGNY); TZANKOV & displaying thin ribbing in the young stage, then covered BRESKOVSKI, p. 12, pl. Ill, fig. 8-10. by dense, straight and blunt ribs, single, bifurcate or, in places, trifurcate on the inner third of the whorl-sides. SPECIFIC CHARACTERS - According to KILIAN (1888), The ribs cross transversally, without any diminution, the Spitidiscus vandeckii displays a discoidal shell, whorls ventral area, but progressively smoofhen in larger speci overlapping each other on almost 1/3 of their height, or mens. In addition, 8 to 10 straight and deep constrictions namentation composed of 6 to 9 deep, prorsiradiate con on every whorl are present from the smallest diameter; strictions which describe on the venter, together with the they are bounded adapically and adorally by swellings, ribs, a sinus towards the peristome; 4 to 8 intercalatory former stronger and callous on the ventral side, with a ribs, partly bifurcate near the middle of the sides, are less typical angular shape. oblique than the constrictions, so that the rib disposed KILIAN'S diagnosis needs to be supplied with data on immediately behind the constriction joins it above the the intercalatory ribs, the last 1-2 of them on every inter umbilical margin. space falling obliquely on the constrictions, on the large KILIAN'S diagnosis needs to be supplied, observing umbilicus (u=0.39), the involution of almost 1/4 and the type material published by COTTREAU, with such almost isometric whorl-section (W/H=1.03). features as the presence of two ribs bounding the con MATERIAL - Four specimens, 2 of them coming from strictions, of which that situated adorally is stronger and the Dâmbovicioara Couloir (D. PATRULIUS & E. AVRAM'S higher on the lower part of the sides, and that disposed adapically is progressively stronger towards the external coll., IG P-18708, 18709), the others from the Svinita part of the sides and on the venter. village area (E. AVRAM'S coll., IG P-18686).
REMARKS - The species is homogeneously interpreted in MATERIAL - Two specimens, both found in the Dâm the literature. The Rumanian specimens are also typical. bovicioara Couloir (D. PATRULIUS & E. AVRAM'S coll., IG P-18711; P. DUMITRICA'S coll., IGP-18712). OCCURRENCE - Barremian in France, Switzerland, Crimea, N Caucasus, Georgia. Lower Barremian in Ru REMARKS - Except little lower whorls, wider umbili mania and in Bulgaria. cus, and also rather thinner intercalatory ribs, the best preserved Rumanian specimen is very comparable with (KARAKASCH) the specimen figured by COTTREAU (1937, pi. LXXVIII, Spitidiscus andrussowi fig. 2-3) and wrongly selected as lectotype by PI. 5, fig. 16, 17 a-b; pi. 6, fig. 10; pi. 7, 20. BRESKOVSKI (1966). 1890 Holcodiscus Andrussowi KARAKASCH, p. 437, pl. I, fig. 6, 7 The second specimen is a fragment displaying the (holotype). specific characters such as the large umbilicus, the pror- 1907 Holcodiscus Andrussowi KARAKASCH; KARAKASCH siradiate-constrictions and bifurcate intercalatory ribs, (partim), p. 107, pl. IX, fig. 25, non fig. 22 (= Spitidiscus but these are straight and not flexuous as in the typical hugii (OOSTER)). v 1960 Spitidiscus andrussovi KARAKASCH; DRUS1HQ ITI'S specimens. (partim), p. 306, pi. XLVII, fig. 3, non fig. 1, 2 (=Spitidiscus hugii (OOSTER)). OCCURRENCE - Spitidiscus vandeckii is known from 1984 Spitidiscus andrussowi (KARAKASCH); AVRAM & KUSKO, p. the Late Hauterivian (Late Neocomian) and Early Bar 16, pl. Ill, fig. 2. 28 AVRAM E.
SPECIFIC CHARACTERS - According to KARAKASCH coming from the Dâmbovicioara Couloir (one in F. (1890, 1907) this species is situated near Spitidiscus HERBICH'S coll., CU-4943; two other in G. BULMEZ'S vandeckii (D'ORBIGNY) and S. seunesi (KILIAN), but it is coll., BU-0273). different from them because of the very compressed REMARKS - The misinterpretation of the species by whorls (W/H=0.77), the involution of almost 2/5, the re UHLIG (1883) and KILIAN (1888), and the late publication latively higher whorls (h=0.45) and also the strongly si of d'ORBiGNY's type specimen by COTTREAU (1937) led nuous ribbing. It is especially similar to Spitidiscus van to differentiate a Spitidiscus gastaldianus (d'ORBIGNY) deckii, differing from it only by the particular shape of and a Holcodiscus gastaldii KILIAN (see above). As in the constrictions, reminding S. seunesi. terpreted now, S.gastaldianus is rather frequent, the Ru manian specimens being very close to the type by pro MATERIAL - 1 flattened specimen, recorded in the Ba portions, by the callous rib bounding the constricitons, by raolt Mts (M. KUSKO & M. SAVU'S coll., IG P-6461); 2 the dense, bifurcate intercalatories and the general aspect pyritised nuclei, found in the Svinita village area (E. of the ornamentation. In addition, there are up to 6 con AVRAM'S coll., IG P-18688). strictions on a whorl, and the body chamber begins at a REMARKS - Among the specimens figured by diameter of almost 20 mm and is at least 1/2 whorl long. KARAKASCH (1907), that presented in plate IX, fig. 22 is MEASUREMENTS - A pyritised specimen from Svinila: almost identical to the lectotype of the species Spitidiscus hugii (OOSTER). Our specimens are comparable to D U H W W/H KARAKASCH'S (1907) individual from plate IX, fig. 25, 16.6 4.1 (0.24) 8 (0.48) 9.1 (0.55) 1.14 and re-figured by DRUSHTCHITS (1960) in his plate XLVII, fig. 3. OCCURRENCE - Barremian in France, Crimea; Lower
OCCURRENCE - Known in the Lower Barremian de Barremian in Bulgaria and Rumania. posits from Crimea and Georgia; it is found in the same interval in Rumania. GENUS Astieridiscus KILIAN, 1910 TYPE SPECIES Holcodiscus Morteti KILIAN, 1888 Spitidiscus gastaldianus (D'ORBIGNY)
PI. 5, fig. 10 a-c, 11, 12, 13 a, b; pi. 6, fig.7-9 ; As accepted by WRIGHT (in MOORE, 1957), the genus pi. 7, fig.1 9 is characterised by oval, compressed whorl section, with slightly flattened sides and rounded wenter, and with 1850 Ammonites Gastaldianus D'ORBIGNY, p. 99, n. 601. dense, sharp, slightly flexuous, simple or branching ribs. v 1888 Lytoceras Stefanescuanum HERBICH, p. 238, pl. IX, fig.1 . It has no constrictions and no tubercles. 1907 Holcodiscus fallacior COQUAND; KARAKASCH, p. 115, pi. IX, fig. 28-31. 1935 Holcodiscus (Spitidiscus) fallacior COQUAND; TZANKOV, p. Astieridiscus morteti (KILIAN) 70, pl. I, fig.8-10 . PI. 5, fig. 23 a-b, 24 a-b; pi. 7, fig.2 1 \931 Ammonites Gastaldianus D'ORBIGNY; COTTREAU (partim), p. 58, pi. LXXVII, fig. 27-29 (lectotype selected by BRESKOVSKI, 1966), non fig.2 6 (=? Holcodiscus n. sp.). 1888 Holcodiscus Morteti KILIAN, p. 676, pl. XII, fig. 4 (holotype). 1966 Spitidiscus gastaldianus (D'ORBIGNY); BRESKOVSKI, p. 97, pl. Ill, fig.3 , 4. non 1907 Holcodiscus Morteti KILIAN; KARAKASCH, p. 110, pl. IX, 1966 Spitidiscus fallacior (COQUAND); BRESKOVSKI, p. 100, pi. fig. 18 (=Spitidiscus sp.) VI, fig.5 . non 1960 Astieridiscus morteti KILIAN; DRUSHTCIIITS, p. 306, pi. 1967 Spitidiscus gastaldianus (D'ORBIGNY); DIMTTROVA, p. 151, XLVI, fig. 9 (=Spitidiscus sp.). pi. LXXVIII, fig. 17. 1966 Astieridiscus morteti (KILIAN); BRESKOVSKI, p. 106, pl. X, 1985 Spitidiscus gastaldianus (D'ORBIGNY); TZANKOV & fig. 8. BRESKOVSKI, p. 12, pl. Ill, fig. 11, 12. 1967 Astieridiscus morteti (KILIAN); DIMTTROVA, p. 161, pi. LXXVIII, fig. 18. 1985 Astieridiscus morteti (KILIAN); TZANKOV & BRESKOVSKI. p. SPECIFIC CHARACTERS - Globulous, with depressed 46, pl. XI, fig.6 , 7. oval whorl-section (W7H=1.3), deep medium-sized um bilicus (u=0.29), and large, rounded venter. Its ornamen SPECIFIC CHARACTERS - Discoidal shell, with almost tation consists of almost 4 radial constrictions on the last isometric whorl-section; whorls covering one another 1/2 whorl (but starting prorsiradiate from the umbilical of their height, displaying equal, bifurcate or even trifur wall), bounded adapically by a large, callous rib, and of 8 cate in the middle of the sides ribs; they start prorsiradia to 10 intercalatory ribs on each interval between con te from the umbilical wall and became radial on the ouler strictions; they are almost all bifurcated in the middle of half of the sides. No constriction is observed. the sides, and cross continuously the ventral area. MATERIAL - A flattened specimen, recorded in the MATERIAL - Five pyritised nuclei and a small speci Dâmbovicioara Couloir (G. BULMEZ'S coll., BU-0259); a men preserved in marls, in the Svinita village area (E. single pyritised nucleus, coming from the Svinita village AVRAM'S coll., IG P-18685); three larger specimenss area (E. AVRAM'S coll., IG P-18684). THE FAMILY HOLCODISCIDAE IN RUMANIA 29
REMARKS - The Rumanian specimens are very close most 1/2. Its last whorl, at a diameter of almost 30 mm, to the holotype by the lateral ornamentation; but the is covered by 48-50 thin umbilical ribs; they cross, gently measurable pyritised one is apart because of its whorl- flexuous, the sides, regularly bifurcated at the middle of section which is compressed and not isometric as in the the sides (becoming higher and stronger at the point of typical specimens. bifurcation) and pass, slightly projected, over the ventral area. 96-100 ribs are counted at the periphery. MEASUREMENTS - The specimen figured in pi. 5, fig. 23. MATERIAL - A very fragmentary specimen (half a whorl, at a diameter of 19 mm) recorded in the Baraolt D U H W W/H Mts. (M. KUSKO & M. SAVU'S coll., IG P-6472). 15.8 4(0.25) 7.5 (0.46) 6.7 (0.42) 0.89 REMARKS - Although it is very close to Astieridiscus morie ti KILIAN, A. uhligi differs by its denser and very OCCURRENCE - Lower Barremian in France, Bulga regular bifurcate ribs. The Rumanian specimen is identi ria; the same age in Rumania. cal to the younger half of the last whorl of the holotype.
Astieridiscus elegans (KARAKASCH) OCCURRENCE - Barremian in Crimea; Lower Barre PI. 5, fig.2 2 a, b mian in Rumania.
\907Astieria elegans KARAKASCH, P. 126, PL. X, FIG. 11 (LECTOTYPE SELECTED BY BRESKOVSKI, 1966), 18. 1943 Astieria elegans KARAKASCH; TZANKOV, P. 27, PL. V, FIG. 4. ACKNOWLEDGEMENTS V 1960 Astieridiscus elegans KARAKASCH; DRUSHTCHITS, P. 306, PL. XVI, FIG. 3. The author is grateful to the head of the Geological 1966 Astieridiscus elegans (KARAKASCH); BRESKOVSKI, P. 107, Institute of Rumania, of the Faculty of Geology and Geo PL. X, FIG. 9. physics of the University of Bucharest, the Faculty of 1967 Astieridiscus elegans (KARAKASCH); DIMTTROVA, P. 162, PI. Geography and Geology of the University of Iassy, and LXXVIII, FIG. 19,20. the Faculty of Biology, Geography and Geology of the 1985 Astieridiscus elegans (KARAKASCH); TZANKOV & BRESKOVSKI, P. 47, PL. XI, FIG. 4, 5 University of Cluj-Napoca, for their permission to revise the Holcodiscid representatives housed in their reposito SPECIFIC CHARACTERS - The type specimens display a ries. He is also indebted to dr. Fabrizio CECCA and dr. medium-sized umbilicus (u=0.28) and wide (w=0.62), Philip HOEDEMAEKER for their critical review of the ma oval-depressed whorls (h=0.33). Their ornamentation nuscript. consists of thin, almost radial, equal ribs, bifurcate in the middle of the sides; in places, single (not bifurcate) ribs REFERENCES are also observed. All the ribs cross continuously the ventral area. AVRAM E. ( 1976 A) - Les fossiles du Flysch eocrétacé et des calcaires tithoniques des hautes vallées de la Doftana et du Târlung MATERIAL - A single specimen, recorded in the Dâm (Carpates Orientales). MEM. INST. GEOL., GEOPHYS., XXIV: 5-73, 10 PL., 18 FIGS., BUCURESTI. bovicioara Couloir (D. PATRULIUS & E. AVRAM'S coll., IG P-18715). AVRAM E. ( 1976 B) - La succession des dépôts tithoniques supérieurs et crétacés inférieurs de la région de Svinita (Banal). D. S. INST. GEOL., REMARKS - The Rumanian specimen, entirely septate, GEOFIZ., LXII (4): 53-71, 1 FIG., 1 TAB., BUCURESTI. is slightly deformed but presents all the typical features of the species, except denser umbilical ribs (39 instead of AVRAM E. (1988) - Early Cretaceous (Berriasian-Barremian) ammonite 29), although the ribs on the outline are almost equal in assemblages in Romania. IN: J. WIEDMANN & J. KULLMAN (EDS.) number with those of the type (70). "CEPHALOPODS -PRESENT AND PAST": 608-618, 4 TAB., 2 FIGS., STUTTGART.
OCCURRENCE - Lower Barremian in Crimea and also AVRAM E. & GRADINARU E. (1993) - A peculiar Upper Valanginian Ce- in Rumania (the top of the Lower Barremian, assembled phalopod fauna from the Carpathian Bend (Codlea town area. Ru with Torcapella suessi (SLMLONESCU)). mania): biostratigraphic and paleobiogeographic implications. JB. GEOL. B.-A., 136 (4): 665-700, 7 PIS., 2 FIGS., WIEN.
Astieridiscus uhligi (KARAKASCH) AVRAM E. & KUSKO M. (1984) - Céphalopodes éocrétacés de la partie PI. 5, fig.21 . centrale et méridionale des monts Baraolt (Carpates Orientales). D. S. INST. GEOL., GEOFIZ., LXIX (3): 5-24, 3 PIS., BUCURESTI.
1907 Holcodiscus Uhligi KARAKASCH, P. 113, PL. IX, FIG. 19 BRESKOVSKI S. (1966) - Biostratigrafia na Barrema iujno ot s.Brestak, (HOLOTYPE). Varnensko. TRUDY VIRHU GEOL.BYLGARIA, SER.PALEONT, VIII: 71-121, 10 PIS., 1 TAB., SOFIA.
SPECIFIC CHARACTERS - The holotype is discoidal, BUSNARDO R. & DAVID L. (1957) - Contributions à l'étude des faunes compressed (W/H=0.81), with slightly convex sides, d'ammonoïdés de Medjez SFA (Est-Constantine). CARTES medium-sized umbilicus (w=0.27), and involuton of al GÉOL.D'ALGÉRIE (N.S.), 13, TRAV.COILAB.: 67-123, 3 PIS., ALGERS. 30 AVRAME.
COQUAND H. (1880) - Etudes supplémentaires sur la Paléontologie Al LORIOL P. de (1861) - Description des animaux invertébrés fossiles gérienne, faisant suite à la description géologique et paléontologi- contenus dans l'étage Néocomien moyen du Mont Salève: pp. 214, 8 que de la région sud de la Province de Constantine. Bull pis., Genève. Acad.Hippone, 15: pp. 449, Paris. MANDOV G. (1976) - L'étage Hauterivien dans les Balkanides Occiden COTTREAU J. (1937) - Types du Prodrome de paléontologie strati- tales (Bulgarie de l'ouest) et sa faune d'ammonites. An. Univ. Sofia, graphique universelle de d'ORBIGNY. Ann. Paleont. Boule, XXVI: Fac. Geol., Geogr., 67: 11-99, 22 pis., Sofia. 53-84, 7 pis., 3 figs., Paris.
MATHERON P. (1878) - Recherches paléonlologiques dans le Midi de la DIMITROVA N. (1967) - Fosilite na Bylgarija. IV. Dolna kreda. Glavo- France (Atlas): pis. B-20 and C-19, Marseille. nogi (Nautiloidea i Ammonoidea). Bulg. Ac: Sc. Press: 235 p., 93 pis., 93 figs., Sofia. MOORE R. (Ed.) (1957) - Treatise on Invertebrate Paleontology. Part L. Mollusco 4, Cephalopoda. Ammonoidea: pp. 490, 558 figs., Geol. DRUSHCHITS V. V. & KUDRJAVCEV M. P. (1960) - Ammonify. In: V. V. Soc.America & Univ. Kansas Press, Lawrence. MENNER (Ed.) "Atlas nizhnemelovoj fauny Severnogo Kavkaza i Kryma". Trudy VNIIGAZ: 232-369, pl.I-LXVII, figs.56-89, Moskva. MUTIU R. (1967) - Contributions a l'étude paléontologique du Crétacé inférieur dans la Plate-forme Moésique. Assoc. geol.Carpalho-Balk., ERISTAVI M. S. (1955) - Nizhnemelovaja fauna Gruzii. Ak. N. Gruz. Ville Congr., Belgrade, Rapports, Slratigr.: 315-321, 2 pis., 3 figs., SSR, Monografii, 6: 224 p., 8 pis., 4 tab., Tbilisi. Beograd.
FALLOT P. & TERMIER H. (1923) - Ammonites nouvelles des Iles Baléa NICKLÈS R. (1890-1894) - Contributions à la Paléontologie du Sud-Est res. Trab.Mus.Nac.Cienc. Nat., Ser. geol., 32: pp. 81, 6 pis., 32 figs., de l'Espagne. Mém. Pal. Soc. géol. France, 4: 1-59, 10 pis., 42 figs.. Madrid. Paris.
GRÀF I. (1970) - Prezenta unui orizont sincron eu straturile de Comar- NICOLAESCU V., lONESCU S. & CARAVETEANU C. (1970) - Observations nic in regiunea Zizin-Purcareni. Rev. Petrol si Gaze, 2 (11): 71-74, sur les couches de Sinaia et les couches de Bistra de la partie S des 5 figs., Bucuresti. monts de Ciuc. D. S. Inst. Geol., LV (4): 79-84, 1 pl., Bucuresti.
GRÀF I. O. (1975) - Studiul geologic al flisului cretacic din regiunea OOSTER W. A. (1857-1863) - Pétrifications remarquables des Alpes Zizin-VamaBuzaului. An. Inst. Geol., Geofiz., XLIV: 5-132, 19 pis., Suisses. Dentsch. Allgem. Schweiz. Gesellsch., XVIII (I-VI): pp. 11 figs., 1 tab., Bucuresti. 100, 64 pis., Zurich.
HEINZ M. (1886) - Fossiles décrits par COQUAND (Planches photo ORBIGNY A. d' (1840-1841) - Paléontologie française, terrains crétacés. graphiques). Bull. Acad. Hippone, 28: 5 pis., Paris. I. Céphalopodes: pp. 662, 148 pis., Paris.
HERB1CH F. (1888) - Données paléonlologiques sur les Carpathes rou ORBIGNY A. d' (1850) - Prodrome de paléontologie stratigraphique uni maines. An. Biur. geol. Rom., ILL (1): pp. 339, 29 tab., Bucuresti. verselle des animaux mollusque et rayonnes. II: pp. 428, Paris.
JEKELIUS E. (1915)- Die Mesozoischen Faunen der Berge von Brasso. PATRULIUS D. (1969) - Geologia Masivului Bucegi si a Culoarului Mitt. Jb. k. ung. Geol. R. A., 23 (2): 115-136, pl.VIII-X, figs.16-19, Dâmbovicioara. Rom. Ac. Sc. Press: pp. 321, 6 pis., 2 maps. 76 figs., Budapest. Bucuresti.
KARAKASCH N. (1890) - liber einige Neokomablagerungen in der Krim. PATRULIUS D. & AVRAM E. (1976 a) - Les Céphalopodes des couches de Sitzungsber.malh.-naturw. Cl. k. k. Ak.Wissensch., 98 (1): 428-438, Carhaga (Tithonique supérieur-Barrémien inférieur). Mem. Inst. 2 pis., Wien. Geol., Geophys., XXIV: 153-201, 10 pis., 9 figs., Bucuresti.
KARAKASCH N. (1907) - Nizhnemelovoj otlozhenija Krima i ix fauna. Trudy imp. St. Petersb. Obschchesl. Estest., 32 (5): pp. 482, 28 pis., PATRULIUS D. & AVRAM E. (1976 b) - Stratigraphie et corrélation des St.Petersbourg. terrains néocomiens et barrémo- bédouliens du Couloir de Dâm• bovicioara (Carpates Orientales). D. S. Inst. Geol., Geofiz., LXII (4): 135-160, 5 figs., 1 tab., Bucuresti. KEMPER E., RAWSON P. F. & THEULOY J. P. (1981) - Ammonites of Tethyan ancestry in the early Lower Cretaceous of north-west Eu rope. Palaeontology, 24 (2): 231-311, pls.34-47, 6 figs., London. PAVLOW A. P. & LAMPLUGH G. W. (1892) - Argiles de Speeton et leurs équivalents. Bull. Soc. Natur. Moscou, 5: 455-513, 6 pis., 2 figs., KHIAN W. (1888) - Sur quelques fossiles nouveaux ou peu connus du Moskva. Crétacé inférieur des Alpes et de la Provence. Bull. Soc. géol. Fran ce, sér.3, XVI: 663-691, pl.XVII-XXI, Paris. POPOVICI-HATZEG V. (1898) - Etude géologique des environs de Câm- pulung et de Sinaia. Thèse, Caree et Naud (Ed.): pp. 220, 27 figs., 1 KlUAN W. & REBOUL P. (1912) - Quelques Holcodiscus nouveaux de map, Paris. l'Hauterivien de la Bègue (Basses-Alpes). Assoc. franc. Av. Sc., XLI: 1-3, 1 pl., Nîmes. RODIGHERO A. (1919) - // sistema Cretaceo del Veneto Occidentale compreso fra l'Adige e il Piave con speciale riguardo al Neocomia- KISS E. (1911)-/! barotihegi seg kretakori kepzodmenyei (Die Kreide- no dei Setti Comuni. Paleont. Italica, 25: 37-125, pl.VIII-XIII, Pisa. bildungen des Baroter Gebirges). Zozl. a Koloszvari m. Kir. Tud. Egyelen Asvany es Fôldt. Inst. Bol., Cluj. SARASIN C. & SCHÒNDELMAYER C. (1901-1902) - Etude monographi que des ammonites du Crétacique inférieur de Châtel Saint-Denis. KUSKO M. & SAVU M. (1970) - Barremianul inferior din Muntii Baraol- Mém. Soc. Paléont. Suisse, XXVIII (1901)-XXIX (1902): pp. 195, tului. D. S. Inst. Geol., LV (4): 69-78, 3 pis., Bucuresti. 25 pis., Genève. THE FAMILY HOLCODISCIDAE IN RUMANIA 31
SAYN G. (1891) - Description des Ammonites du Barrémien du Djebel- TZANKOV V. (1943) - Contribution à l'étude du genre Holcostephanus. Ouach (près Constantme). Bull. Soc. Agric. Lyon, III (6) (1890): NEUMAÏR 1875. Rev. Bulg. géol. Soc, XIV: 167-206, 10 pis, 7 figs., pp. 78, 3 pis., Lyon. Sofia.
TZANKOV V. & BRESKOVSKI S. (1985) - Ammonites des familles Holco SEMAKA A (1967) - Geologia regiunii Vulcan-Codlea, cu privire spe discidae SPATH, 1924 et Astieridiscidae TZANKOV & BRESKOVSKI. dala asupra carbunilor si argilelor refractare. Stud. geol. econ., 1982). Geol. Balkanica, 15 (5): 3-52, 11 pis., Sofia. Ser. A, 7: 109-158, Bucuresti.
UHLIG V. (1883) - Die Cephalopodenfauna der Wernsdorferschichten. SIMIONESCU I. (1898) - Studii geologice si paleontologice din Carpata Denkschr.k.Akad.Wissensch., malh.-naturw. Kl., 66 (2): 127-290, 32 Sudici.!. Studii geologice asupra Basenului Dâmbovicioara. II. pis., Wien. Fauna neocomiana din Basenul Dâmbovicioara. Acad. Rom., Pubi, fondului "V.Adamachi", II: 5-167, 8 pis., Bucuresti. VADASZ E. (1911) - Petrefacten der Barreme Stufe aus Ordely (Siebenburgen). Centralbl.f.Mineral., Geol., Palàont., 189, Stuttgart.
THEULOY J.-P. (1972) - Biostratigraphie des lentilles à Pérégrinelles (Brachiopodes) de l'Hauterivien de Rottier (Drame, France). Geo- VASICEK Z. & MICHALK J. (1986) - The Lower Cretaceous of the Manin bios, 5 (1): 5-53, 5 pis., 6 figs., Lyon. Unit (Mt.Butkov, West Carpathians). Geol. Carpathica, 37 (4): 449- 481, 6 pis., I tab., Bratislava.
TOULA F. ( 1890) - Geologische Untersuchungen um ostlichen Balkan VALCEANU P. (1960) - Contribuai la cunoasterea geologica a regiunii und m den angrenzenden Gebieten. Denkschr. k. Ak. Wiss., 57: Codlea. Stud. Cere. Geol., 5(1): 119-134, Bucuresti. 232-400, 8 pis., Wien.
WILKE H.-G. (1988) - Stratigraphie und Sedimentologie der Kreide im TZANKOV V. (1935) - Notes sur le genre Holcodiscus. Ann. Univ. Sofia, Nordwesten der Provinz Alicante (SE Spanien). Berliner Geowiss. III (3, Se. Nat.): 57-100, 6 pis., Sofia. Abb., A. 95: pp. 72, 9 pis., 36 figs., 5 tab., Berlin. 32 AVRAME.
PLATE 1
Fig. 1 a-c. Jeanthieuloyites keyserlingiformis AVRAM & GRADINARU. Holotype, E. GRADINARU'S coll., BU-00613. Fig. 2 a-c - Jeanthieuloyites trapezoidalis AVRAM & GRADINARU. Holotype, E. GRADINARU'S coll., BU-00615. Fig. 3 a-b - Jeanthieuloyites nodosus (MANDOV). E. GRADINARU's coll., BU-00614. Fig. 4 - Jeanthieuloyites sp.ind. E. GRADINARU'S coll., BU-00616. Fig. 5 a-b, 6 - Spitidiscus? meneghina (DEZIGNO in RODIGHIERO). 5, T. NEAGU'S coll., BU-0079 A; 6, D. PATRULIUS & E. AVRAM'S coll., IG P-17004.
All figures natural size except figure 5, reduced 5/6.
TAVOLA 1
Fig. I a-c. Jeanthieuloyites keyserlingiformis A VRAM & GRADINARU. Olotipo, collezione E. GRADINARU, BU-00613. Fig. 2 a-c - Jeanthieuloyites trapezoidalis A VRAM & GRADINARU. Olotipo, collezione E. GRADINARU., BU-00615. Fig. 3 a-b - Jeanthieuloyites nodosus (MANDOV). Collezione E. GRADINARU, BU-00614. Fig. 4 - Jeanthieuloyites sp.ind. Collezione E. GRADINARU, BU-00616. Fig. 5 a-b, 6 - Spitidiscus ? meneghinii (DEZIGNO in RODIGHIERO). 5, collezione T. NEAGU, BU-0079 A; 6, collezione D. PATRULIUS & E. AVRAM, IG P-17004.
Tutte le figure sono a grandezza naturale, salvo la fig. 5 ridotta di 5/6.
34 AVRAM E.
PLATE 2
Fig. 1 - Spitidiscus ? meneghina (DE ZiGNO in RODIGHIERO). D. PATRULIUS & E. A VRAM's coll., IG P-18707. Fig. 2 - Jeanthieuloyites nodosus (MANDOV). E. GRADINARU'S coll., BU-00614. Fig. 3 -Jeanthieuloyites cf. nodosus (MANDOV). D. GRIGORESCU'S coll., BU-0274. Fig. 4 a-b - Spitidiscus cankovi VASICEK. T. NEAGU'S coll., BU-0079 B.
All the specimens are figured in natural size.
TAVOLA 2
Fig. 1 - Spitidiscus ? meneghinii (DE ZIGNO in RODIGHIERO). Collezione D. PATRULIUS & E. AVRAM , IG P-18707. Fig. 2 - Jeanthieuloyites nodosus (MANDOV). Collezione E. GRADINARU, BU-00614. Fig. 3 - Jeanthieuloyites cf. nodosus (MANDOV). Collezione D. GRIGORESCU, BU-0274. Fig. 4 a-b - Spitidiscus cankovi VASICEK. Collezione T. NEAGU, BU-0079 B.
Tutti gli esemplari sono figurati a grandezza naturale
36 AVRAME.
PLATE 3
Fig. 1, 2 a-b, 3 a-b, 4, 5, 6, 7 - Holcodiscus cf. caillaudianus (D'ORBIGNY). 1, D. POPESCU-RAILEANU'S coll., IG P-18691; 2, 3, E. AVRAM'S coll., IG P-18669; 4, M. KUSKO & M. SAVU'S coll., IG P-6463; 5, D. PATRULIUS & E. AVRAM'S coll., IG P-18689; 6, 7, G. BULMEZ'S coll., BU0263. Fig. 8, 9, 10 a-c, 11 a-b, 12 a-b - Holcodiscus tzankovi n. sp.: 8, D. PATRULIUS & E. AVRAM'S coll., IG P-18693; 9, P. DUMITRICA'S coll., IG P-18694; 10 (holotype), E. AVRAM'S coll., IG P 18671; 11, 12, E. AVRAM'S coll., IG P- 18670. Fig. 13 a-b, 14 a-b, 15 a-b - Holcodiscus alpha TZANKOV. E. AVRAM'S coll, IG P-18672. Fig. 16 - Holcodiscus sp. ex gr. H. caillaudianus (D'ORBIGNY). T. NEAGU'S coll., BU-0062 (note the mature ornamenta tion with untuberculate double ribs bounding the constrictions). Fig. 17 a-c - Holcodiscus simionescui n. sp., holotype: b, c = the fore-last whorl, with strengthened ribs at the mid-sides where they bifurcate. D. PATRULIUS & E. AVRAM'S coll., IG P-18697. Fig. 18 a-b, 19 a-b - Holcodiscus gastaldii KILIAN (non D'ORBIGNY): 18, V. POPOVICI-HATZEG'S coll., IG P-760; 19, D. PATRULIUS & E. AVRAM'S coll., IG P-18696.
All the specimens are figured in maturai size.
TAVOLA 3
Fig. 1, 2 a-b, 3 a-b, 4, 5, 6, 7 - Holcodiscus cf. caillaudianus (D'ORBIGNY). 1, collezione D. POPESCU- RAILEANU, IG P- 18691; 2, 3, collezione E. A VRAM, IG P-18669; 4, collezione M. KUSKO & M. SAW, IG P-6463; 5, collezione D. PATRULIUS & E. AVRAM, IG P-18689; 6, 7, collezione G. BULMEZ, BU0263. Fig. 8, 9, 10 a-c, 11 a-b, 12 a-b - Holcodiscus tzankovi n. sp.: 8, collezione D. PATRULIUS & E. AVRAM, IG P-18693; 9, collezione P. DUMITRICA, IG P-18694; 10 (olotipo), collezione E. AVRAM, IG P 18671; 11, 12, collezione E. AVRAM, IG P-18670. Fig. 13 a-b, 14 a-b, 15 a-b - Holcodiscus alpha TZANKOV. Collezione E. AVRAM, IG P-18672. Fig. 16 - Holcodiscus sp. ex gr. H. caillaudianus (D'ORBIGNY). Collezione T. NEAGU'S coll., BU-0062 (si noti l'ornamen tazione matura con coste non tubercolate bordanti le strozzature). Fig. 17 a-c - Holcodiscus simionescui n. sp., olotipo: b, c = penultimo giro con coste rafforzate a metà fianco nel punto di biforcazione. Collezione D. PATRULIUS & E. AVRAM, 1G P-18697. Fig. 18 a-b, 19 a-b - Holcodiscus gastaldii KILIAN (non D'ORBIGNY): 18, collezione V. POPOVICI-HATZEG, 1G P-760; 19, collezione D. PATRULIUS & E. AVRAM, IG P-18696.
Tutti gli esemplari sono figurati a grandezza naturale
38 AVRAME.
PLATE 4
Fig. 1 a-b, 5 a-b, 6 a-b, 7 - Holcodiscus aff. decorus n. sp. E. AVRAM'S coll., IG P-18674. Fig. 2 a-d, 3, 4. Holcodiscus decorus n. sp. E.AVRAM'S coll.: 2, holotype = IG P-18673; 3 and 4 = IG P-18674. Fig. 8, 9 a-c - Holcodiscus ouachensis n. sp. E. AVRAM'S coll.: 9, holotype = IG P-18676; 8 = IG P-18677. Fig. 10 - Holcodiscus aff. gastaldii KILIAN (non D'ORBIGNY). M. KUSKO & M. SAVU'S coll., IG P-6465. Fig. 11 - Holcodiscus irregularis TZANKOV. M. KUSKO & M. SAVU'S coll., IG P-6475. Fig. 12 - Holcodiscus aff. fallax ((COQUAND) MATHERON). D. PATRULIUS & E. AVRAM'S coll., IG P-18701. Fig. 13 - Holcodiscus geronimaeformis TZANKOV. D. PATRULIUS & E. AVRAM'S coll., unregistered. Fig. 14 - Holcodiscus cf. geronimae (HERMITE). E. AVRAM'S coll., IG P-l 1168. Fig. 15, 16 a-b - Holcodiscus sp. ind. E. AVRAM'S coll., IG P-l8685. Fig. 17, 18 - Holcodiscus aff. nodosus KARAKASCH. E. AVRAM'S coll., IG P-18679. Fig. 19 a-b, 20 a-b, 21 - Holcodiscus ziczac KARAKASCH: 19, 20, E. AVRAM'S coll., IG P-18680; 21, D. PATRULIUS & E. AVRAM'S coll., unregistered. Fig.22 - Holcodiscus diversecostatus (COQUAND). D. PATRULIUS & E. AVRAM'S coll., IG P-18700. Figs.23 a-b - Holcodiscus aff. cadoceroides (KARAKASCH). E. AVRAM'S coll., IG P-18682. Figs.24 a-c. Holcodiscus sp. ind. Nucleus of H. caillaudianus (D'ORBIGNY) ?. E. AVRAM'S coll., IG P-18678.
All the specimens are figured in natural size, except 2d, 9 b-c, 16 b, 19 b, 20 b and 20 c (x 2).
TA VOLA 4
Fig. 1 a-b, 5 a-b, 6 a-b, 7 - Holcodiscus aff. decorus n. sp. Collezione E. AVRAM, IG P-18674. Fig. 2 a-d, 3, 4. Holcodiscus decorus n. sp. CollezioneE.AVRAM: 2, olotipo = IG P-18673; 3 e 4 = IG P-18674. Fig. 8, 9 a-c - Holcodiscus ouachensis n. sp. Collezione E. AVRAM: 9, olotipo = IG P-18676; 8 = IG P-18677. Fig. 10 - Holcodiscus aff gastaldii KILIAN (non D'ORBIGNY). Collezione M. KUSKO & M. SAVU, IG P-6465. Fig. 11 - Holcodiscus irregularis TZANKOV. Collezione M. KUSKO & M. SAVU, IG P-6475. Fig. 12 - Holcodiscus aff. fallax ((COQUAND) MATHERON). Collezione D. PATRULIUS & E. AVRAM, IG P-18701. Fig. 13 - Holcodiscus geronimaeformis TZANKOV. Collezione D. PATRULIUS & E. AVRAM, non repertoriato. Fig. 14 - Holcodiscus cf. geronimae (HERMITE). Collezione E. AVRAM, IG P-l 1168. Fig. 15, 16 a-b - Holcodiscus sp. ind. Collezione E. AVRAM, IG P-18685. Fig. 17, 18 - Holcodiscus aff. nodosus KARAKASCH. Collezione E. AVRAM., IG P-18679. Fig. 19 a-b, 20 a-b, 21 - Holcodiscus ziczac KARAKASCH: 19, 20, collezione E. AVRAM, IG P-18680; 21, collezione D. PATRULIUS &E.A VRAM, non repertoriato. Fig.22 - Holcodiscus diversecostatus (COQUAND). Collezione D. PATRULIUS & E. AVRAM, IG P-18700. lugs. 23 a-b - Holcodiscus aff. cadoceroides (KARAKASCH). Collezione E. AVRAM, IG P-18682. Figs.24 a-c. Holcodiscus sp. ind. Nucleo di H. caillaudianus (D'ORBIGNY) ?. CollezioneEAVRAM, IG P-18678.
Tutti gli esemplari sono figurati a grandezza naturale, salvo 2d, 9 b-c, 16 b, 19 b, 20 b e 20 c (x 2). 'l'I II i FA.MII .VIK >l.< 'i 'I MS 'Il )AI; IN Iti 'MANIA 40 AVRAM E.
PLATE 5
Fig. 1, 2, 3 a-b - Spitidiscus cf. rotula (SOWERBY): 1, S. BORDEA'S coll., IG P-13799; 2, 3, D. PATRULIUS & E. AVRAM'S coll., IG P-l8704 and 18705, respectively. Fig. 4, 5, 6 - Spitidiscus seunesi (KILIAN): 4, 5, E. AVRAM'S coll., IG P-18686; 6, D. PATRULIUS & E. AVRAM'S coll., IG P-18708. Fig. 7, 8 - Spitidiscus cf. intermedius (D'ORBIGNY). D. PATRULIUS & E.AVRAM'S coll.,IG P-18713. Fig.9 - Spitidiscus cf. darderi FALLOT & TERMIER. D. PATRULIUS & E. AVRAM'S coll., IG P-18714. Fig. 10 a-c, 11, 12, 13 a-b - Spitidiscus gastaldianus (D'ORBIGNY): 10, 11, E. AVRAM'S coll., IG P-18685; 12, F. HERBICH'S coll., CU-4924 (= Lytoceras Stefanescuanum HERBICH, 1888, pl. IX, fig. 1); 13, G. BULMEZ'S coll., BU-0273. Fig. 14 a-b, 15 - Spitidiscus hugii (OOSTER): 14, E. AVRAM'S coll., IG P-18687; 15, M. KUSKO & M. SAVU'S coll., IG P- 6464. Fig. 16, 17 a-b - Spitidiscus andrussowi (KARAKASCH): 16, M. KUSKO & M. SAVU'S coll., IG P-6461; 17, E. AVRAM'S coll., IG P-18688. Fig. 18, 19 - Spitidiscus oosteri (SARASIN & SCHÒNDELMAYER): 18, M. KUSKO & M. SAVU'S coll., IG P-6484; 19. D. PATRULIUS & E. AVRAM'S coll., IG P-18706. Fig. 20 - Spitidiscus vandeckii (D'ORBIGNY). D. PATRULIUS & E. AVRAM'S coll., IG P-18711. Fig. 21 - Astieridiscus uhligi (KARAKASCH). M. KUSKO & M. SAVU'S coll., IG P-6472. Fig. 22 a-b - Astieridiscus elegans (KARAKASCH). D. PATRULIUS & E. AVRAM'S coll., IG P-18715. Fig. 23 a-b - Astieridiscus cf. morteti (KILIAN). E. AVRAM'S coll., IG P-18684. Fig. 24 a-b - Astieridiscus morteti (KILIAN). G. BULMEZ'S coll., BU-0259.
All the specimens are figured in natural size.
TAVOLA 5
Fig. 1, 2, 3 a-b - Spitidiscus cf. rotula (SOWERBY): 1, collezione S. BORDEA, IG P-13799; 2, 3, collezione D. PATRULIUS & E. AVRAM, IG P-18704 e 18705, rispettivamente. Fig. 4, 5, 6 - Spitidiscus seunesi (KILIAN): 4, 5, collezione E. AVRAM, IG P-18686; 6, collezione D. PATRULIUS & E. AVRAM, IG P-18708. Fig. 7, 8 - Spitidiscus cf. intermedius (D'ORBIGNY). CollezioneD. PATRULIUS & E.AVRAM, IG P-18713. Fig.9 - Spitidiscus cf. darderi FALLOT & TERMIER. Collezione D. PATRULIUS & E. AVRAM, IG P-18714. Fig. 10 a-c, 11, 12, 13 a-b - Spitidiscus gastaldianus (D'ORBIGNY): 10, 11, collezione E. AVRAM, IG P-18685; 12, colle zione F. HERBICH, CU-4924 (= Lytoceras Stefanescuanum HERBICH, 1888, pl. IX, fig. 1); 13, collezione G. BULMEZ, BU-0273. Fig. 14 a-b, 15 - Spitidiscus hugii (OOSTER): 14, collezione E. AVRAM, IG P-18687; 15, collezione M. KUSKO & M. SAVU, IG P-6464. Fig. 16, 17 a-b - Spitidiscus andrussowi (KARAKASCH): 16, collezione M. KUSKO & M. SAVU, IG P-6461; 17, collezione E. A VRAM, IG P-18688. Fig. 18, 19 - Spitidiscus oosteri (SARASIN & SCHÒNDELMAYER): 18, collezione M. KUSKO & M. SAVU, IG P-6484; 19, col lezione D. PATRULIUS &E.A VRAM, IG P-18706. Fig. 20 - Spitidiscus vandeckii (D'ORBIGNY). Collezione D. PATRULIUS & E. AVRAM, IG P-18711. Fig. 21 - Astieridiscus uhligi (KARAKASCH). Collezione M. KUSKO & M. SAVU, IG P-6472. Fig. 22 a-b - Astieridiscus elegans (KARAKASCH). Collezione D. PATRULIUS & E. A VRAM, IG P-18715. Fig. 23 a-b - Astieridiscus cf. morleti (KILIAN). Collezione E.AVRAM, IG P-18684. Fig. 24 a-b - Astieridiscus morleti (KILIAN). Collezione G. BULMEZ, BU-0259.
Tutti gli esemplari sono figurati a grandezza naturale.
42 AVRAM E.
PLATE 6
Suture lines of some holcodiscid species
Fig. 1 - Holcodiscus cf. caillaudianus (D'ORBIGNY), suture of the specimen figured in pi. 3, fig. 2, at a diameter of 21 mm. Fig. 2 - Holcodiscus tzankovi n. sp., holotype, at a diameter of 25 mm. Fig. 3 - Holcodiscus decorus n. sp., holotype, at a diameter of 18 mm. Fig. 4 - Holcodiscus aff. decorus n. sp., the specimen figured in pi. 4, fig. 1. Fig. 5 - Holcodiscus ouachensis n. sp., holotype, at a diameter of 11.6 mm. Fig. 6 - Holcodiscus aff. nodosus KARAKASCH, unfigured specimen, at a diameter of 7 mm. Fig. 7-9 - Spitidiscus gastaldianus (D'ORBIGNY): 7, the specimen figured in pi. 5, fig. 11; 8, unfigured specimen, at a diameter of 13 mm; 9, the specimen figured in pi. 5, fig. 10, at a diameter of 15 mm. Fig. 10 - Spitidiscus cf. andrussowi (KARAKASCH), the specimen figured in pi. 5, fig. 17, at a diameter of 18 mm. Fig. 11 - Spitidiscus cf. hugii (OOSTER), unfigured specimen, at a diameter of 15.6 mm.
TAVOLA 6 Linee di sutura di alcune specie di Holcodiscidae.
Fig. 1 - Holcodiscus cf. caillaudianus (D'ORBIGNY), sutura dell'esemplare figurato in tav. 3, fig. 2, al diametro di 21 mm. Fig. 2 - Holcodiscus tzankovi n. sp., olotipo, al diametro di 25 mm. Fig. 3 - Holcodiscus decorus n. sp., olotipo, al diametro di 18 mm. Fig. 4 - Holcodiscus aff. decorus n. sp., esemplare figurato in tav. 4, fig. 1. Fig. 5 - Holcodiscus ouachensis n. sp., olotipo, al diametro di 11.6 mm. Fig. 6 - Holcodiscus aff. nodosus KARAKASCH, esemplare non figurato, al diametro di 7 mm. Fig. 7-9 - Spitidiscus gastaldianus (D'ORBIGNY): 7, esemplare figurato in tav. 5, fig. 11; 8, esemplare non figurato, al diametro di 13 mm; 9, esemplare figurato in tav. 5, fig. 10, al diametro di 15 mm. Fig. 10 - Spitidiscus cf. andrussowi (KARAKASCH), esemplare figurato in tav. 5, fig. 17, al diametro di 18 mm. Fig. 11 - Spitidiscus cf. hugii (OOSTER), esemplare non figurato, al diametro di 15.6 mm.
44 AVRAM E.
PLATE 7
Lateral ornamentation and whorl section of some holcodiscid species.
Fig 1 - Jeanthieuloyites keyserlingiformis AVRAM & GRADINARLI, holotype. Fig 2 a-b - Jeanthieuloyites nodosus (MANDOV). Fig 3 - Jeanthieuloyites trapezoidalis AVRAM & GRADINARLI, holotype. Fig 4 - Jeanthieuloyites sp. ind. (= pl. 1, fig. 4). Fig 5 - Jeanthieuloyites cf. nodosus (MANDOV), a very large, gerontic individual (= pi. 2, fig. 3). Fig 6 - Holcodiscus decorus n. sp., holotype (enlarged x 2). Fig 7 a-b - Holcodiscus ouachensis n. sp., holotype (enlarged x 2). Fig 8 - Holcodiscus simionescui n. sp., plaster cast of the holotype (= pi. 3, fig. 17). Fig 9, 10 - Holcodiscus sp. ind. (= pl. 4, fig. 16 and 15, respectively; 9 enlarged x 2). Fig 11 - Holcodiscus cf. caillaudianus (D'ORBIGNY) (= pi. 3, fig. 2). Fig 12 - Holcodiscus alpha TZANKOV (= pi. 3, fig. 15, vanished specimen). Fig 13 - Holcodiscus tzankovi n. sp., holotype. Fig 14 - Holcodiscus alpha TZANKOV (= pi. 3, fig. 14). Fig 15 - Holcodiscus decorus n. sp., holotype. Fig 16 - Holcodiscus aff. decorus n. sp. (= pi. 4, fig. 1). Fig. 17 - Holcodiscus ouachensis n. sp., holotype. Fig. 18 - Spitidiscus cf. hugii (OOSTER), the unfigured specimen which offered the suture line, pi. 6, fig. 11. Fig 19 - Spitidiscus gastaldianus (D'ORBIGNY) (= pi. 5, fig. 10). Fig 20 - Spitidiscus cf. andrussowi (KARAKASCH) (= pi. 5, fig. 17). Fig 21 - Astieridiscus cf. morleti (KlLIAN) (= pi. 5, fig. 23). All figures natural size, except figures 6, 7 a-b and 9.
TAVOIA 7 Ornamentazione e sezione della spira di alcune specie di Holcodiscidae. Fig. 1 - Jeanthieuloyites keyserlingiformis A VRAM & GRADINARU, olotipo. Fig 2 a-b - Jeanthieuloyites nodosus (MANDOV). Fig.3 - Jeanthieuloyites trapezoidalis A VRAM & GRADINARU, olotipo. Fig.4 - Jeanthieuloyites sp. ind. (= tav, I, fig. 4). Fig-5 - Jeanthieuloyites cf. nodosus (MANDOV), individuo gerontico di grandissima taglia (= tav. 2, fig. 3). Fig.6, Holcodiscus decorus n. sp., olotipo (ingrandito x 2). Fig. 7 a-b - Holcodiscus ouachensis n. sp., olotipo (ingrandito x 2). Fig. 8 - Holcodiscus simionescui n. sp., calco dell'olotipo (= tav. 3, fig. 17). Fig. 9, 10 - Holcodiscus sp. ind. (= tav. 4, fig. 16 e 15, rispettivamente; 9 ingrandito x 2). Fig. 11 - Holcodiscus cf. caillaudianus (D'ORBIGNY) (= tav. 3,fig. 2). Fig. 12 - Holcodiscus alpha TZANKOV(= tav. 3,fig. 15, esemplare smarrito). Fig 13 - Holcodiscus tzankovi n. sp., olotipo. Fig 14 - Holcodiscus alpha TZANKOV(14 = tav. 3,fig. 14). Fig. 15 - Holcodiscus decorus n. sp., olotipo. Fig. 17) Holcodiscus ouachensis n. sp., olotipo (7 ingrandito x 2). Fig 18) Spitidiscus cf. hugii (OOSTER), l'esemplare non figurato da cui è rilevata la sutura di pi. 6, fig. 11;. Fig 19) Spitidiscus gastaldianus (D'ORBIGNY) (= tav. 5,fig. 10). Fig. 20) Spitidiscus cf. andrussowi (KARAKASCH) (= tav. 5, fig. 17). 7 l 'g 21) Astieridiscus cf. morleti (KILIAN) (= tav. 5,fig. 23). Tutte le figure sono a grandezza naturale, salvo le figure 6, 7 a-b e 9.
Mem. Descr. Carta Geol. d 'It. LI (1995), pp. 47-57
Late Valanginian ammonites from Monte Catria (Umbria-Marche Apennines, Italy)
Ammoniti del Valanginiano superiore del Monte Catria (Appennino Umbro-Marchigiano, Italia)
FABRIZIO CECCA (*)
IGCP Projects 343 : Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - Late Valanginian ammonite species from Umbria- RIASSUNTO - Nel presente lavoro sono descritte ammoniti del Marche Apennines have been discovered in the Maiolica formation at Valanginiano superiore dell'area umbro-marchigiana, raccolte nella three outcrops on the group of mountains called Monte Catria: the Monte Maiolica affiorante in tre località del gruppo montuoso del Catria: gli Alto outcrop and two outcrops already mentioned as "Como di Catria and affioramenti di Monte Alto più quelli già menzionati in un precedente Monte Catria" in a previous work. Due to poor exposure the Monte Alto lavoro come "affioramento di Como di Catria" e "affioramento di Monte outcrop cannot be logged. However, Valanginites bachelardi, Catria". A causa dell'intensa copertura non è stato possibile rilevare la Olcostephanus gr. nicklesi and a rich lytoceratid fauna were found. sezione stratigrafica di Monte Alto, dove sono stati rinvenuti Valanginites Neocomitinae are extremely rare. On the southern slope of Monte Acuto, bachelardi, Olcostephanus gr. nicklesi ed una ricca fauna a lytoceratidi. along the road from the top of Monte Catria s. str. to (he village of Le Neocomitinae sono estremamente rare. Nel versante meridionale di Chiasema a Late Valanginian fauna of the S. verrucosum and N. Monte Acuto è stata riconosciuta una fauna delle zone a S. verrucosum e pachydicranus zones was discovered: Oosterella sp. aff. stevenini, O. a N. pachydicranus: Oosterella sp. aff. stevenini, O. garciae, garciae, Olcostephanus aff. detonii and Neqcomites (N.) sp. gr. Olcostephanus aff. detonii and Neocomites (N.) sp. gr. neocomiensis neocomiensis sensu COMPANY, 1987 have been identified. NW of Como sensu COMPANY, 1987. A NW di Como di Catria è stata campionala una di Catria an Upper Valanginian section crops out and provides a rich sezione caratterizzata da una ricca fauna della zona a S. verrucosum ammonite fauna of the S. verrucosum zone characterized by Saynoceras composta da: Saynoceras contestanum, S. verrucosum, Paquiericeras contestanum, S. verrucosum, Paquiericeras (Julianites) undulatum, P. (Julianites) undulatum, P. (J.) mourrei, Olcostephanus ostieri sensu (J.) mourrei, Olcostephanus ostieri sensu COMPANY, 1987, O. COMPANY, 1987, O. guebhardi mor. querolensis e Haploceras guebhardi mor. querolensis and Haploceras (Neolissoceras) (Neolissoceras) extracornutum sp. n. Nella stessa sezione la zona a N. extracornulum sp. n. Some metres above, Oosterella gr. cultrata pachydicranus è indicata da Oosterella gr. cultrata. indicates the N.pachydicranus zone.
KEY WORDS: Ammonites, Lower Cretaceous, Valanginian, PAROLE CHIAVE: Ammoniti, Cretaceo inferiore, Valanginiano, Biostratigraphy, Palaeontology, Umbria - Marche Apennines. Biostratigrafia, Paleontologia, Appennino umbro-marchigiano.
(*) Servizio Geologico Nazionale Largo S. Susanna 13,1-00187 Roma, ITALY 48 CECCA F.
1. - INTRODUCTION The ammonites have been collected at three localities (Fig. 1): In the Umbria-Marche Apennines the Upper 1) M. Alto, near Monte Tenetra; Tithonian-Early Aptian interval is represented by the 2) the road from Monte Catria to Chiaserna on the Maiolica formation. This consists of white, micritic southern slope of Monte Acuto; limestones with cherts and represents a very widespread 3) the outcrop in the locality named "la Valle" close facies in the Tethyan Domain (FOURCADF, et alii, 1991). to Fosso del Fibbio at a height of 1050 metres. NW of Apart a Barremian pulchellid cited by ZITTEL (1869) Corno di Catria. and a Hauterivian Pseudothurmannia figured by Localities 2 and 3 were cited by CECCA (1985) and RAMACCIONI (1939), only the occurrence of aptychi was the results of new research are presented here. cited in the literature on the Umbria-Marche Apennines. The zonal scheme used in this work is that defined Valanginian ammonites from the Maiolica outcropping by the Lower Cretaceous Cephalopod Team (HOEDE in this region were figured for the first time by CECCA MAEKER & COMPANY, 1993). (1985). Recently, numerous Upper Hauterivian - Barremian ammonite levels have been discovered (CECCA et alii. 1994a, b; CECCA & PALLINI, in press) 2. - THE SECTIONS STUDIED and also the occurrence of bivalves and gastropods is now demonstrated (CECCA & PALLINI, in press). 2.1. -M. ALTO, NEAR MONTE TENETRA However, except the uppermost Hauterivian Faraoni Level (CECCA et alii, 1994a), ammonites remain very The Maiolica Formation crops out along the road rare in this facies and furthermore their preservation is from Acquaviva to Monte Catria. The outcrops are very bad. In fact they occur as crushed internal moulds mainly Barremian in age (CECCA et alii, this volume). and very often these are merely fragments unidentifiable Because of the dip of the beds from the top of Monte at the specific level. Tenetra, where a Barremian section has been studied by New localities and faunas of Valanginian age have CECCA & PALLINI (in press), to Monte Alto Hauterivian been discovered during recent research in Umbria- to Valanginian levels crop out. The succession is not Marche. The aim of this paper is to illustrate the most completely visible because of the vegetation; important elements of these new faunas. furthermore the erosion of the Maiolica limestone produces an abundant detritus of calcareous fragments which almost cover the outcrops. Hence, only some small portions of the succession can be logged. Along the road, below the top of Monte Alto, a rich Valanginian ammonite fauna has been found. Its interest is only palaeontological because the detritus cover and the presence of minor faults prevent the complete logging of the succession and thus a biostratigraphic study. The fauna has been collected in a 1 m thick level. Lytoceratids are the most abundant ammonites. Among the remainder, it is particular interesting to cite, for the first time from this region, Valanginites bachelardi (SAYN) (pl. 1, fig. 5). The vertical range of this species spans the uppermost B. campylotoxus zone (BULOT et alii, 1993) to the basal N. pachydicranus zone (COMPANY, 1987), although its acme is recorded at the base of the S. verrucosum zone - the verrucosum biohorizon (BULOT et alii, 1993). An interesting microconch of the genus Olcostephanus has been found in the same level. It is characterized by a wide umbilicus and shows affinities with the group of O. nicklesi WlEDMANN & DlENl/O. sanctifirminensis THIEULOY (pi. 1, fig. 7). This group characterizes a biohorizon at the base of the N. pachydicranus zone, i. e. the nicklesi biohorizon (BULOT et alii, 1993). A second Olcostephanus, possibly another microconch, is figured in pl. 1, fig. 25. This specimen can be identified as O. ostieri (D'ORBIGNY) sensu COMPANY, 1987, which is (COMPANY. Fig. 1 - Localities where Late Valanginian ammonite faunas have been limited to the S. verrucosum zone 1987). discovered. This author also stressed that the distinction between the - Ubicazione delle località fossilifere. microconchs of this species and the microconchs of O. LATE VALANGINIAN AMMONITES FROM THE APENNINES 49 balestrai (RODIGHIERO), which is limited to the N. France. BULOT et alii (1993) cite this species up to the pachydicranus zone, is particularly hard, especially on pronecostatum horizon of the S. verrucosum zone. single specimens. However, the identification of the specimen cited as The age of this ammonitiferous level spans the S. N. (N.) sp. gr. neocomiensis is doubtful because of its verrucosum zone to the nicklesi biohorizon at the base bad preservation. In any case its taxonomic position is of the N. pachydicranus zone. uncertain because it shows some morphologic affinities with the specimens figured by SAYN (1907, pi. 3, fig. 14) and COMPANY (1987, pi. 10, fig.2) , both from the S. verrucosum zone. BULOT et alii (1993) refer SAYN'S 2.2. - THE ROAD FROM MONTE CATRIA TO CHIASERNA ON specimen (1907, pi. 3, fig. 14) to N. subtenuis SAYN THE SOUTHERN SLOPE OF MONTE ACUTO (although SAYN'S species was originally based on a different ammonite (SAYN, 1907, pi. 3, fig. 5)) and the A complete Jurassic basin-type succession is exposed specimens figured by COMPANY (1987) pi. 10. fig. 1-5 to along the road from Monte Catria to Chiaserna (Southern a miniconch morphotype (MATYJA, 1986) of slope of Monte Acuto). It is overlain by Maiolica and the Varlheideites peregrinus RAWSON & KEMPER. If our Upper Tithonian-Upper Hauterivian interval is exposed, the specimen belong to N. subtenuis, then according to Barremian being covered by detritus. BULOT et alii (1993) it does not reach the peregrinus
Rare Valanginian ammonites were found by CECCA horizon of the S. verrucosum zone. In the second case it (1985, p. 140) but the most interesting levels have been should indicate the peregrinus horizon of the S. discovered recently in the Upper Valanginian - Upper verrucosum zone or the basal N. pachydicranus zone Hauterivian interval. This section is 87 metres thick and because BULOT et alii (1993) have found the last has been sampled for magnetostratigraphy by J. E. T. representatives of V. peregrinus associated with the first CIIANNELL. The magnetic signal is reliable and the Himantoceras trinodosum and Olcostephanus nicklesi. results will be published in a subsequent paper, together O. begastrensis is reported from the S. verrucosum with the correlation with ammonites and calcareous zone in Southern Spain (COMPANY, 1987) and in SE nannofossils (studied by E. ERBA). France, where it occurs in the K. pronecostatum horizon Ammonites are rare in this section (section A) but (BULOT et alii, 1993). the Upper Hauterivian ammonites Crioceratites gr. The level at metre 2. 20 contains Neolissoceras and duvali (LÉVEILLÉ) and Subsaynella sp. have been found Bochianites goubechensis MANDOV (pl. 1, fig. 23) and at metres 22 and 23, thus indicating the S. sayni zone. has been referred to the base of the N. pachydicranus From metre 23 down to metre 87 no ammonites were zone. This species is cited at the base of the N. found. Nevertheless beds corresponding to the interval pachydicranus zone from SE France by THIEULOY et alii from metres 78 to 87 are exposed in an outcrop (section (1990), who consider it as a morphotype of B. B) located only 10 metres away from the basal part of neocomiensis (D'ORBIGNY). I follow the palaeontologic section A through poor exposure and a minor fault. Here interpretation of the French authors. However, B. some Upper Valanginian ammonitiferous levels have goubechensis has been considered as a synonym of B. been recognized (Fig. 2). The bed-by-bed correlation neocomiensis by COMPANY (1987). At least two of the between these two sections has been established easily specimens figured by this author can be identified as B. on the basis of the lithologie characters of the chert goubechensis, in particular those on his pl. 1,fig. 1 2 levels and by means of the occurrence of a characteristic and 15 (COMPANY, 1987) which were collected in the TV. shaly interbed. Thus, the biostratigraphic information pachydicranus zone and in the S. verrucosum zone can be used for correlation with section A. Section B respectively. shows an additional 1.5 metres of section that correspond with a level immediately below the base of Higher ammonitiferous levels are characterized by section A. species of the genus Oosterella, especially levels at metres 5.20 and 8.20 of section B. The oldest level contains a relatively rich fauna. The most characteristic forms are: Neocomites (N.) sp. gr. In the level at 5. 20 m was found an Oosterella (pi. neocomiensis (D'ORBIGNY) sensu COMPANY (pl. 1, fig. 1, fig. 21) characterized by a keel without clear ventral 16), Oosterella cf. begastrensis COMPANY (pl. 1, fig. 22) furrows. The specimen is smooth, although it is slightly and an interesting oleostephanid, represented by six corroded by weathering; its diameter is 18 mm. It has specimens, identified as Olcostephanus aff. detonii been identified as O. sp. aff. stevenini (NICKLÈS) because (RODIGHIERO). The latter is discussed in the the smooth stage persists much later than in the other palaeontological part, below. species described by NICKLÈS (1892). According to COMPANY (1987), the range of N. In the level at 8.20 m I found a half whorl of a neocomiensis spans the B. campylotoxus zone to the Oosterella (pl. 1, fig.20 ) specimen which is characterized base of the N. pachydicranus zone, whilst BULOT (1993, by a keel bordered by clear furrows and by the suture and table 11.4) shows a longer range which begins at the top the sculpture of O. garciae (NICKLÈS), especially the of the T. pertransiens zone in the basin sequences of SE specimen figured by NICKLÈS (1892) pl. 7, fig. 9. 50 CECCA F.
SOUTHERN SLOPE OF MONTE ACUTO-SECTION B ROAD MONTE CATRIA - CHIASERNA, AT 1050 M
chert layer chert lenses CO — 3N O ILI • chert nodule shaly inlerbed AG I 11m I conrelation with H 79.051 Channell's samples CE LU ¥- CAE 10 -179.05 j 3 o Plychophylloceras sp., Lytoceras sp., -179.701 Neolissoceras sp , Teschenites sp I -H 80.001 V) -|80.40l 3 u CA -|80.75| Oosterella garciae "3 u I P" (/> Z 3 CE CO — -POI L_ Oosterella sp. alï. slevenini U Z Neolissoceras sp. T3 >, I £. ID O (S Z Q. CE Z _l CE I =1 CE Bochianiles neocomiensis MOR goubechensis, Neolissoceras grasi LU
Q.
Q.
3 U M I M O u I'hylloceras sp., Lytoceras sp., Neolissoceras sp., Bochianiles sp., 3 1. Olcostephanus ALL. detonii (M), Neocomiles sp. GR neocomiensis. L. 0m Oosterella cf. begastrensis. Neohoploceras sp. CU A
Fig. 2 Simplified stratigraphie log of the base of the section outcropping along the road from Monte Catria to Chiaserna. The occurrence of Late Valanginian ammonites and the correlation with some of J. CHANNEL'S magnetostratigraphic sample levels are shown. Colonnina stratigrafica semplificata della base della sezione affiorante lungo la strada che da Monte Catria conduce a Chiaserna. Sono rappresentati i punti di ritrovamento delle faune descritte e la correlazione con alcuni dei campioni prelevati da J. CHANNELL per la magnetostratigrafia. LATE VALANGINIAN AMMONITES FROM THE APENNINES 51
COMPANY (1987) considered NICKLÈS' species verrucosum zone, the verrucosum biohorizon (BULOT et gaudryi, stevenini and garciae as belonging to one alii, 1993). species, which should be identified with the name Olcostephanus ostieri (D'ORBIGNY) sensu COMPANY, gaudryi on the basis of the rules of priority. 1987 is a quite common form in this outcrop, although it Nevertheless, for the biostratigraphic purposes of this is rare to collect complete specimens. A microconch work I use NICKLÈS' nomenclature, while ackno characterized by long lappets (pl. 1, fig. 6) was collected wledging my agreement with COMPANY'S opinion. In at 28.20 m. fact, these records can be compared with those by BULOT At 25.80 m occur fragments of an Olcostephanus et alii (1993) who reported from SE France O. stevenini form (pl. 1, fig. 11) characterized by fine and dense ribs. in the nicklesi horizon and O. garciae across the H. These specimens show some similarities with some of trinodosum and T. callidiscus zones (which correspond the Spanish forms described by COMPANY (1987) as O. with the whole TV. pachydicranus zone). COMPANY densicostatus (WEGNER). According to BULOT (1992), (1987) observed that TV. (T.) callidiscus occurs above the these forms have to be referred to the species guebhardi LAD of O. gaudryi in SE Spain, whilst AUTRAN (1993) KILIAN, instead of densicostatus, and distinguished as figured an O. stevenini from a condensed horizon of the O. guebhardi morphotype querolensis. I refer to this T. callidiscus and A. radi a tus (base of the Hauterivian) morphotype the specimens collected at 25.80 m and also zones. the ammonite described as O. ostieri (D'ORBIGNY) In the last ammonitiferous level, at 9.10 m in section (CECCA, 1985, pl. 6, fig. 1), which was collected B, I found on the surface of the bed an impression of a together with S. verrucosum between metres 29 and 24. small neocomitid which surely belongs to the subgenus Neocomitids are very rare. Only two specimens of Teschenites (pl. 1, fig. 24). Due to its poor state of Neocomites (N.) neocomiensis (D'ORBIGNY) have been preservation it is difficult to reach a reliable collected in two distinct levels at metres 28 and 25.10 determination; some characters of the ribbing recall TV. (pl. 1, fig. 17, 18). (T.) flucticulus THIEULOY whose stratigraphie range Saynoceras contestanum COMPANY is represented in crosses the Valanginian-Hauterivian boundary two levels: a microconch, with the beginning of the lappet (THIEULOY, 1977; BULOT et alii, 1993). The other (pl. 1, fig. 3), found at metre 25 and a fragment (pl. 1, fig. ammonites found at the same level are unidentified or 4) found at 24.30 m. This species occurs mainly at the base not significant for biostratigraphic purposes. A fragment of the S. verrucosum zone although its first appearance is of a possible neocomitid macroconch is figured in pl. 1, recorded at the top of the B. campylotoxus zone (BULOT et fig. 26. alii, 1990). At metre 24 Paquiericeras (Julianites) undulatum THIEULOY (pl. 1, fig. 1) and P. (J.) mourrei VERMEULEN (pl. 1, fig. 2) are reported for the first time from Italy. Although the specimens are crushed, the 2.3. - "LA VALLE" OUTCROP NW OF CORNO DI CATRIA, distinctive specific characters are visible. On the basis of the NEAR FOSSO DEL FlBBIO AT A HEIGHT OF 1050 METRES biostratigraphic distribution of both species in SE France and SE Spain (THIEULOY, 1977; COMPANY, 1987; BULOT et The outcrop was cited in a previous work (CECCA, alii, 1993) it is possible to state that metre 24 belong to the 1985, p. 140) with the name "Affioramento di Corno di S. verrucosum zone, verrucosum biohorizon. Catria". The specimens identified as Saynoceras Above this interval ammonites become extremely verrucosum (D'ORBIGNY) and Olcostephanus ostieri rare. Oosterella gr. cultrata (D'ORBIGNY) has been (D'ORBIGNY) (figured in CECCA, 1985, pl. 5, fig. 2 and found at metre 10 (pl. 1, fig. 19) and it indicates a post pi. 6, fig. 1 respectively) were collected here. verrucosum Late Valanginian age. In particular, BULOT This outcrop has been re-studied during the last year. et alii (1993, tabi. VII) reported this species from the Unfortunately most of the levels which were visible furcillata horizon of the TV. pachydicranus zone. more than 10 years ago are now covered by Maiolica Oosterella sp. was found at metre 4.70 together with detritus and vegetation. Nevertheless, ammonites of the a Teschenites sp. S. verrucosum zone are quite abundant, though badly At metre 25.05 and 25.15 occurs a very peculiar preserved. Neolissoceras form. It belongs to the Haploceras The section studied is almost 30 metres thick, (Neolissoceras) salinarium UHLIG group but the although it is partly covered (Fig. 3). The most dramatic morphologic transformation of the keel into a fossiliferous levels are exposed from metre 30 to metre ventral horn leads to the definition of a new species 23. In this part of the section the limestone flakes off in called Haploceras (Neolissoceras) extracornutum sp. n. thin layers which often contain well preserved aptychi which is described below. and crushed ammonites. S. verrucosum (D'ORBIGNY) was found in these levels between metres 29 and 24 but it has not been rediscovered during the last study. 3- CONCLUSIONS The distribution of those ammonites collected bed- by-bed is shown in Fig. 3. At least the interval between The Valanginian ammonite fauna of the Apennines metres 29 and 24 can be ascribed to the base of the S. is still poorly known. In fact significant Early 52 CECCA F.
"La Valle" CO LU NW CORNO DI CATRIA, ATL 050 M LU Z ORTI. O M < 1
2
3
4 4.70 Oosterella 5
6 Z 7 W S 8 C 9 CD K_ Z 10 LO.(X) Oosterella GR. rulirala U
11 T3 —
12 -E U 13 re Z Q. 14 TX 15 Z
16
S 17 — CHER! leilSC'S ?- 18 • DIERL NODULE = 19
20 CE
21 LU E 22 3 U) 0_ 23 O 23.00 - • Neolissoceras SP. U Q_ 24 24.00 - Julianiles unilulalum../. mourrei. Raquiericeras SP 24.30 - Saynoceras conleslanum. Neocomiles SP. S 25 25. (X) - • Saynoceras conleslanum E R 25.05 10- Neolissoceras extracornutum. Neocomiles neocomiensis > 26 25.15 - Neolissoceras e.xlracornulum CO 25.80 - Olcostephanus guebhardi MOR. t/uerolensis 27
28 27.95 . Olcostephanus ostieri SENSU ( COMPANY 28.00 05- Neolissoceras SP., Neocomiles neocomiensis 28.15 20- 29 Bochianiles SP., Olcostephanus astieri SENSU ( COMPANY (m)
30
• FAULT
32 Neolissoceras. '/Neolwploceras
Fig. 3 - Simplified stratigraphie log of section "la Valle", NW Como di Catria and ammonite occurrences. - Colonnina stratigrafica semplificata della sezione "la Valle " a Nord-Ovest del Corno di Catria con la rappresentazione dei punti di ritrovamento delle ammoniti descritte. LATE VALANGINIAN AMMONITES FROM THE APENNINES 53
Valanginian faunas have not been discovered so far; base of this hom is triangular. This structure is slightly only the base of the S. verrucosum zone is well arched in the paratype Olof 504. On the ventro-lateral represented, whilst the ammonites of the TV. margin of the shell rursiradiate folds (10 on the pachydicranus zone occur sporadically. The holotype) appear approximately at the same diameter as palaeobiogeographic character of the fauna is clearly the keel begins to develop the horn. Two or three fine mediterranean. It is possible to compare the Apennine striae run from the folds towards the umbilicus. The fauna with that occurring in the Spanish ctions of the folds are connected to the horn development; their basin sectors (Subbetic area) described by COMPANY aspect gives the impression that this portion of the shell (1987). In Umbria-Marche area the Neocomitinae are is dragged backwards by the horn development. Between less abundant and Phylloceratina and Lytoceratina the adorai side of the horn and the aperture the keel are more represented than in the Subbetic area, the disappears. The paratype Olof 504 shows a lappet. percentage of Haploceratidae, Olcostephanidae and MATERIAL - Five specimens: CC 592, CC 604, CC Ancyloceratina being similar. 644, BT 486, Olof 504. MEASUREMENTS
4 - PALAEONTOLOGICAL DESCRIPTIONS Specimen D Uw Wh Ph CC592-holotype 28 16(0.11) 3 (0.57) -17 CC604-paratype 27 -2.5 (0.10) -15.5 (0.57) -15 This chapter is devoted to the description of two CC644-paratype -25 - - -15 forms which have never been reported in the literature. BT486-paralype 22 - - -14 The dimensions are expressed in millimetres and as Olof504-paratype 23 3.5 (0.15) 12.5 (0.54) -15 percentages of the diameter. The following abréviations have been used: D = maximum diameter; Uw = The whorl thickness cannot be measured in the umbilical width; Wh = whorl height; Ph = diameter studied specimens. corresponding to the end of the phragmocone. All the specimens studied are provisionally housed STRATIGRAPHIC DISTRIBUTION AND PROVENANCE - in the author's collections. Upper Valanginian, Saynoceras verrucosum zone, verrucosum biohorizon. The holotype and the paratype CC 604 have been respectively collected in the "la GENUS: Haploceras ZLTTEL, 1870 Valle" section at metre 25.05 and 25.15 of the section TYPE SPECIES: Ammonites carachtheis ZEUSCHNER, (Fig. 3); the paratype CC 644 was collected in 1980, 1846 (see ENAY & CECCA, 1986) together with the material described by CECCA (1985) at a level between metres 23 and 28. Olof 504 was collected in an isolated outcrop close to the "la Valle" SUBGENUS Neolissoceras SPATH, 1923 section. BT 486 came from an isolated outcrop near M. TYPE SPECIES: Ammonites Grasianus D'ORBIGNY, Alto. 1841 DISCUSSSION - It is important to stress that the Haploceras (Neolissoceras) extracornutum sp. n. complete development of this peculiar ventral structure is not preserved in all the specimens studied. Both in the Pl. 1, fig. 12 - 15 holotype and the paratype CC 604 only the triangular base of the horn is preserved because the rest of the DERIVATIO NOMINIS - The name refers to the ventral horn, i. e. its arched portion, is detached from the keel horn. and preserved above the shell (pi. 1, fig. 12) One might HOLOTYPE - The specimen CC 592. suggest that we are dealing with a shell fragment or a PARATYPES - The specimens CC 604, CC 644, BT 486, trace remaining around the ammonite. However, this Olof504. situation has been observed on both specimens and it is TYPE LOCALITY - "La Valle", near Fosso del Fibbio, at difficult to invoke a coincidence. Fortunately, on 1050 m (NW Corno di Catria). paratypes Olof 504 and CC 644 the horn is not detached TYPE LEVEL - Upper Valanginian, Saynoceras from its triangular base and develops for 17 mm in the verrucosum zone, verrucosum biohorizon. latter specimen. DIAGNOSIS - Neolissoceras with a keel which develops On the sediment surrounding the holotype, just on the adult body chamber a high ventral horn and above the folded ventral area, it is possible to observe folds. the impression of the ventral area and to distinguish the folds and the striae. This impression might represent the DESCRIPTION - Smooth, moderately involute shell, trace of the impact of the shell on the bottom. Probably with flat sides and rounded venter which bears a keel up the arched part of the rostrum was detached when the to d~19 mm. At this stage this species is identical to H. shell fell on the bottom. (N.) salinarium UHLIG. The keel's height dramatically H. (N.) salinarium UHLIG also develops a keel but the increases at D-21-23 mm and it develops a ventral horn high horn and the folds are absent. H. (N.) cristifer whose height reaches 17 mm on paratype CC 644. The ZITTEL develops keel and folds but the horn is absent. 54 CECCA F.
GENUS: Olcostephanus NEUMAYR, 1875 mm. Since the RODIGHIERO'S original description O. TYPE SPECIES: Ammonites astierianus D'ORBIGNY, detonii has never been cited again. Thus this species is 1840 poorly known. The specimens from the southern slope of Monte Acuto could correspond to the microconch of O. Olcostephanus aff. detonii (RODIGHIERO) M detonii but I prefer to designate them as O. aff. detonii Pl. 1, fig. 8 - 10 M because their macroconch is actually unknown.
DESCRIPTION - Evolute shell with rounded whorls. Strong sculpture characterized by a primary rib at the ACKNOWLEDGEMENTS base of the whorl-side which gives rise to a tubercle. 22 I would like to thank P. RAWSON (London), who tubercles have been counted on the last whorl. Two acted as referee, for his suggestions. I also thank my secondary ribs branch from the tubercle; an intercalatory friends A. MARINI (Cagli) for help in the field and A. rib, starting from the same height as the tubercle, is BUSSOLETTI (Roma) for his kindness in taking all the observed between two pairs of secondary ribs. In some ammonite photographs. Thanks to V. PANNUTI (Servizio cases the intercalatory rib joins the tubercle thus Geologico) for figure 1. producing bundles of three ribs. Up to the last half- whorl the ribbing is slightly prorsiradiate, then it becomes recti radiate. Three deep constrictions per whorl cut the ribbing abruptly. Two elevated ribs emphasise REFERENCES the constriction. A long lappet, which develops after a AUTRAN G. (1993) - L'évolution de la marge nord-est provençale (Arc constriction, is preserved on specimen MAb 614. The de Castellane) du Valanginian moyen à l'Hauterivien à travers sutures are not visible. l'analyse biostratigraphique des séries de la région de Peyronies: séries condensées, discontinuités et indices d'une tectogenèse MATERIAL - Six specimens: MAb 614, MAb 650 - distensive. Paléobiologie. Annales Mus. Hist. Nat. Nice. 10: 1-239, 654. 49 fig., 13 pl. MEASUREMENTS BULOT L. (1992) - Les Olcostephaninae valanginiens et hauteriviens (Ammonitina, Cephalopoda) du Jura franco-suisse: systématique Specimen D Uw Wh et intérêt biostratigraphique. Revue de Paléobiologie, 11 (1): 149- MAb 614 -33 166, 3 fig., 3 pl., Genève. 31 14(0.45) 9 (0.29) BULOT L. (1993) - Stratigraphical implications of the relationships between ammonites and facies: examples taken from the Lower The whorl thickness cannot be measured in the Cretaceous (Valanginian-Hauterivian) of the western Tethys. In: studied specimens. The preservation of the other M. R. HOUSE (Ed.): "The Ammonoidea: Environment, Ecology and specimens prevents the measurement of their characters. Evolutionary Change". Systematics Association, spec. vol. 47: 243- 266, 3 fig., 7 tab., Clarendon Press, Oxford. STRATIGRAPHIC DISTRIBUTION AND PROVENANCE - Upper Valanginian, probably the upper part of the BULOT L., COMPANY M. & THEULOY J. - P. (1990) - Origine, évolution Saynoceras verrucosum zone or the base of the et systématique du genre valanginien Saynoceras (Ammonitina, Neocomites pachydicranus zone. The six specimens Olcostephaninae). Geobios, 23 (4): 399-413, 3 fig., 2 pl., Lyon. have been collected in the same bed at the base of BULOT L., THIEULOY J.-P., BLANC E., & KLEIN J. (1993) - Le cadre section B, in the southern slope of Monte Acuto (Fig. 2). straligraphique du Valanginien supérieur et de l'Hauterivien du DISCUSSION - This form belongs to the group of Sud-Est de la France: définition des biochronozones et Olcostephanus characterized by a wide umbilicus such caractérisation de nouveaux biohorizons. Géologie Alpine, 68 (1992): 13-56, 6 fig., 16 lab., Grenoble. as O. nicklesi WIEDMANN & DIENI, O. mittreanus (D'ORBIGNY) and O. detonii (RODIGHIERO). O CECCA F. (1985) - Alcune Ammoniti provenienti dalla "Maiolica" dell'Appennino Centrale (Umbria, Marche e Sabina). Boll. Serv. sanctifirminensis THIEULOY is a synonym of O. nicklesi Geol. Italia, 103 (1982): 133-162, 6 pl.,Roma. (BULOT in THIEULOY et alii, 1990). THIEULOY (1977) created for this group the subgenus Lemurostephanus, CECCA F., FARAONI P., MARINI A. & PALLINI G. (this volume) - Field- with Holcostephanus madagascariensis LEMOINE as the trip across the representative sections for the Upper Hauterivian - Barremian ammonite biostratigraphy in the Maiolica exposed at type-species. COMPANY (1987) proposed to use this Monte Nerone, Monte Petrano and Monte Catria (Umbria-Marche name for the perigondwanian forms whilst BULOT Apennines). (1992) considers it as a synonym of Olcostephanus. The form described here differs from O. mittreanus CECCA F., MARINI A., PALLINI G., BAUDIN F. & BÉGOUEN V. (1994a) - and because of its almost A guide-level of the uppermost Hauterivian (Lower Cretaceous) in O. nicklesi / sanctifirminensis the pelagic succession of Umbria-Marche Apennines (Central rectiradiale ribbing, the wider umbilicus and the lower Italy): the Faraoni level. Rivista Italiana di Paleontologia e number of secondary ribs. It could be determined as O. Stratigrafia, 99 (4): 551-568, 7 fig., 2 lab., Milano. detonii (RODIGHIERO) because of the strong morphologic similarities. However only the internal whorls of O. CECCA F. & PALLINI G. (in press) - Latest Hauterivian-Barremian detonii can be compared with the form described. The ammonite biostratigraphy in the Umbria-Marche Apennines (Central Italy). In: L. BULOT & H. ARNAUD (Eds.): "Lower RODIGHIERO specimen depicted by (1919, pi. 9, fig. 12) Cretaceous Cephalopod Biostratigraphy of the Western Tethys". is probably a macroconch reaching a diameter of 70 Géologie Alpine, mém. spec. H. S., 20, Grenoble. LATE VALANGINIAN AMMONITES FROM THE APENNINES 55
CECCA F., PALLINI G., ERBA E., PREMOLI SILVA I. & COCCIONI R. NICKLES R. (1892) - Recherches géologiques sur les terrains (1994b) - Hauterìvian-Barremian chronostratigraphy based on secondaires et tertiaires de la province d'Alicante et du Sud de la ammonites, nannofossils, planktonic foraminifera and magnetic province de Valence. Ann. Hébert, 1: 1-219, Paris. chrons from the Mediterranean domain. Cretaceous Research, 15 (4): 457^*67, 3 fig., London. RAMACCIONL G. (1939) - Fauna giuraliassica e cretacea di Monte Cucco e dintorni (Appennino Centrale). Palaeont. Ita]., N.S., 39: COMPANY M. (1987) - Los Ammonites del Valanginiense del sector 143-214., 5 pl., Pisa. oriental de las Cordilleras Béticas (SE de Espana). Tesis Doct. Univ. Granada: 1-294, 46 fig., 19 pl. RODIGHERO A. (1919) - // sistema Cretaceo del Veneto Occidentale compreso fra l'Adige e il Piave con speciale riguardo al FOURCADE E., AZEMA J., CECCA F., BONNEAU M., PEYBERNES B. & Neocomiano dei Sette Comuni. Palaeont. Ita!., 25: 39-125, 6 pl., DERCOURT J. (1991) - Essai de reconstitution cartographique de la Pisa. paléogéographie et des paléoenvironnements de la Téthys au Tithonique supérieur (138 à 135 Ma). Bull. Soc.géol. France, 162, THEULOY J.-P. (1977) - Les ammonites boréales des formations (6): 1197-1208, 1 fig., 1 carte couleurs hors texte, Paris. néocomiennes du sud-est français (Province Subméditerranéenne). Geobios, 10 (3): 395-461, 3 fig., 9 pl., Lyon. HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. B., AVRAM E., BOGDANOVA T. N., BUTTOR L., BULOT L., CECCA F., DELANOY G., ETTACHFINI M., MEMMIL., OWEN H. G., RAWSON P. THEULOY J.-P., FUHR M. & BULOT L. (1990) - Biostratigraphie du F., SANDOVAL J., TAVERA J. M., THIEULOY J.-P., TOVBINA S. Z. & Crétacé inférieur de l'Arc de Castellane (S. E. de la France). 1: VASICEK Z. (1993) - Ammonite zonation for the Lower Cretaceous Faunes d'ammonites du Valanginien supérieur et âge de l'horizon of the Mediterranean region; basis for the stratigraphie dit de "La Grande Lumachelle". Géol. Médit, 17 (1): 55-99, 10 correlations within IGCP-Project 262. Rev. Espaiiola Paleont, 8 fig., 6 pl., Marseille. (1): 117-120, 1 tabi, Madrid. ZlTTEL K. A. (1869) - Geologische Beobachtungen aus den Central- MATYJA B.A (1986) - Developmental polymorphism in Oxfordian Apenninen. In: E. W. BENECKE Geognostisch-Palaeontologischen ammonites. Acta geol. poi., 36 (1-3): 37-68,13 fig., 4 pl., Warszawa. Beitr., 2 (2): 91-178, Mûnchen. 56 CECCA F.
PLATE 1 1 - Paquiehceras (Julianites) undulatum THIEULOY. "La Valle" section, level at 24 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 588. 2 - Paquiehceras (Julianites) mourrei VERMEULEN. "La Valle" section, level at 24 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 589. 3 - Saynoceras contestanum COMPANY. "La Valle" section, level at 25 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 595 4 - Idem, level at 24.30 m. Spec. CC 594. 5 - Valanginiles bachelardi (SAYN). M. Alto outcrop. Spec. BT 519. 6 - Olcostephanus ostieri (D'ORHGNY). "La Valle" section, level at 28.20 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 620. 7 - Olcostephanus gr. nicklesi WEDMANN & DENI. M. Alto outcrop. Spec. BT 510. 8 - Olcostephanus AFF. detonii (RODIGHERO) m. Southern slope of Monte Acuto, section B, bed MAb 0, S. verrucosum zone. Spec. MAb 650. 9 - Idem. SpecimenMAb 614. 10 - Idem. Specimen MAb 652. 11 - Olcostephanus guebhardi KILIAN, morphotype querolensis BULOT. "La Valle" section, level at 25.80 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 587. 12 - Haploceras (Neolissoceras) extracornutum sp. n. Holotype. "La Valle" section, level at 25.05 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 592. 13 - Idem. Paratype. Collected in an isolated outcrop near "La Valle". Spec. Olof 504. 14 - Idem. Paratype. "La Valle" section, level between metres 23 and 28, S. verrucosum zone, verrucosum biohorizon. Spec. CC 644. 15 - Idem. Paratype. M. Alto outcrop. Spec. BT 486. 16 - Neocomites (N.) gr. neocomiensis (D'ORBIGNY) sensu COMPANY. Southern slope of Monte Acuto, section B, bed M Ab 0, S. verrucosum zone. Spec. MAb 615. 17 - Neocomites (N.) neocomiensis (D'ORBIGNY). "La Valle" section, level at 28.05 m, S. verrucosum zone, verrucosum biohorizon. Spec. CC 621. 18 - Idem. Level at 25.10 m. Spec. CC 657. 19 - Oosterella gr. cultrata (D'ORBIGNY). "La Valle" section, level at 10.00 m, N. pachydicranus zone. Spec. CC 599. 20 - Oosterella garciae (NICKLÈS). Southern slope of Monte Acuto, section B, bed MAb 8.20, N. pachydicranus zone. Spec. M Ab 617. 21 - Oosterella AFF. stevenini (NICKLES). Southern slope of Monte Acuto, section B, bed MAb 5.40, AF. pachydicranus zone. Spec. MAb 616. 22 - Oosterella cf. begastrensis COMPANY. Note the aperture with a ventral rostrum. Southern slope of Monte Acuto, section B, bed M Ab 0, S. verrucosum zone. Spec. MAb 658. 23 - Bochianites neocomiensis (D'ORBIGNY) morph. goubechensis MANDOV. Southern slope of Monte Acuto, section B, bed MAb 2.20, N. pachydicranus zone. Spec. MAb 655. 24 - Neocomites (Teschenites) sp. Impression on the sediment. Southern slope of Monte Acuto, section B, bed MAb 9.10, Valanginian- Hauterivian transition. Spec. MAb 618. 25 - Olcostephanus ostieri (D'ORBIGNY). M. Alto outcrop. Specimen BT 514. 26 - Unidentified neocomitid (?M). Southern slope of M. Acuto, section B, bed MAb 9.10, Valanginian-Hauterivian transition. Spec. MAb 619.
All figures natural size. Photos by Andrea BUSSOLETTI.
TAVOLA 1 Fig. I - Paquiericeras (Julianites) undulatum THIEULOY. Sez. "La Valle", liv. a 24 m, zona a S. verrucosum, bio-orizzonte a verrucosum Es. CC 588. Fig. 2 - Paquiericeras (Julianites) mourrei VERMEULEN Sezione "La Valle", liv. a 24 m, zona a S. verrucosum, bio-orizzonte a verrucosum. Es. CC 589. Fig. 3 - Saynoceras contestanum COMPANY. Sezione "La Valle", liv.a 25 m, zona a S. verrucosum,bio-orizzonte a verrucosum. Es. CC 595 Fig. 4 - Idem, liv. a 24.30 m. Es. CC 594. Fig. 5 - Valanginites bachelardi (SAYN). Affioramento di M. Alto. Esemplare BT 519. Fig. 6 - Olcostephanus astieri (D'ORBIGNY). Sezione "La Valle", liv. a 28.20 m, zona a S. verrucosum, bio-orizzonte a verrucosum. Es. CC 620. Fig. 7 - Olcostephanus gr. nicklesi WlEDMANN& DENI. Affioramento diM. Alto. Es. BT 510. Fig. 8 - Olcostephanus aff. detonii (RODIGHIERO) m. Versante meridionale di M. Acuto, sezione B. strato MAb 0. zona a S. verrucosum.. Es. MAb 650. Fig. 9 - Idem Es. MAb 614. Fig. 10 -Idem. Es. MAb 652. Fig. Il- Olcostephanus guebhardi KILIAN, morfotipo querolensis BULOT. Sezione "La Valle", liv. a 25.80 m, zona a S. verrucosum bio-orizzonte a verrucosum Es. CC 587. Fig. 12 - Haploceras (Neolissoceras) extracomutum sp. n. Olotipo. Sezione "La Valle", liv. a 25.05 m, zona a S. verrucosum, bio-orizzonte a verrucosum. Es. CC 592. Fig. 13 - Idem. Paratipo. Raccolto in un affioramento isolato vicino alla sezione "La Valle". Es. Olof504. Fig. 14 - Idem. Paratipo. Sezione "La Valle", livello compreso fra i metri 23 e 28, zona a S. verrucosum zone, bio-orizzonte a verrucosum. Es. CC 644. F'ig. 15 - Idem. Paratipo. Affioramento diM. Alto. Es. BT486. Fig. 16- Neocomites (N.) gr. neocomiensis (D'ORBIGNY) sensu COMPANY. Versante meridionale di Monte Acuto, sezione B, strato MAb 0, zona a S. verrucosum. Es. MAb 615. Fig. 17 - Neocomites (N.) neocomiensis (D'ORBIGNY). Sezione "La Valle", liv. a 28.05 m, zona a S. verrucosum, bio-orizzonte a verrucosum. Es. CC 621. Fig. 18 - Idem Livello a 25.10 m. Es. CC 657. Fig. 19 - Oosterella gr. cultrata (D'ORBIGNY). Sezione "La Valle", livello a 10.00 m, zona a N. pachydicranus. Esemplare CC 599. Fig. 20 - Oosterella garciae (NìCKLES). Versante meridionale di Monte Acuto, sezione B, stratoMAb 8.20, zona a N. pachydicranus. Es. MAb 617. Fig. 21 - Oosterella aff. stevenini (NICKLES). Versante meridionale di Monte Acuto, sezione B, stratoMAb 5.40, zona a N. pachydicranus. Es. MAb 616. Fig. 22 - Oosterella cf. begastrensis COMPANY. Si noti l'apertura con il rostro ventrale. Versante meridionale di Monte Acuto, sezione B, strato MAb 0, zona a S. verrucosum Es. MAb 658. Fig. 23 - Bochianites neocomiensis (D'ORBIGNY) morfotipo goubechensis MANDOV. Versante meridionale di Monte Acuto, sezione B, stratoMAb 2.20. zona a N. pachydicranus. Esemplare MAb 655. Fig. 24 - Neocomites (Teschenites) sp. Impronta sul sedimento. Versante meridionale di Monte Acuto, sezione B, stratoMAb 9.10, passaggio Valanginiano-Hauteriviano. Esemplare MAb 618. Fig. 25 - Olcostephanus astieri (D'ORBIGNY). Affioramento diM. Alto. Esemplare BT 514. Fig. 26 - Neocomitide indeterminato (?M). Versante meridionale di Monte Acuto, sezione B, stratoMAb 9.10, passaggio Valanginiano-Hauteriviano. Esemplare MAb 619. Tutti gli esemplari sono figurati a grandezza naturale. Foto di Andrea BUSSOLETTI.
Mem. Descr. Carta Geol.d'It. LI (1995), pp. 59-63
Pulchellia (Heinzia) pallimi sp. n. e Pulchellia (Heinzia) provincialis (D'ORBIGNY): ammoniti del Barremiano superiore dell'Appennino Umbro-Marchigiano
Pulchellia (Heinzia) pallimi sp. n. and Pulchellia (Heinzia) provincialis (D'ORBIGNY): Upper Barremian Ammonites of Umbria-Marche Apennines
FABRIZIO CECCA (*)
RIASSUNTO - Viene istituita la nuova specie Pulchellia (Heinzia) ABSTRACT - The new species Pulchellia (Heinzia) pallina, of Late pallimi, riconosciuta in base ad esemplari raccolti in livelli del Barre Barremian age, A. vandenheckii zone, is defined in this paper. It is based miano superiore, zona a A. vandenheckii, dell'Appennino Umbro- on specimens collected in the Maiolica limestone outcropping in Umbria- Marchigiano. Sono inoltre descritti gli esemplari di Pulchellia (Heinzia) Marche Apennines. Specimens of the species Pulchellia (Heinzia) pro provincialis (D'ORBIGNY), specie di notevole interesse biostratigrafico. vincialis (D'ORBIGNY) are also described because of its biostratigraphic significance.
PAROLE CHIAVE: Ammoniti, Cretaceo inferiore, Barremiano, Pa KEY WORDS: Ammonites, Lower Cretaceous, Barremian, Palaeon leontologia, Biostratigrafia, Appennino umbro-marchigiano. tology, Biostratigraphy, Umbria - Marche Apennines.
(•) Servizio Geologico Nazionale, Largo S. Susanna, 13 00187 - Roma, ITALY 60 CECCA F.
1. - INTRODUZIONE 2. - DESCRIZIONI PALEONTOLOGICHE
La Famiglia Pulchelliidae è conosciuta grazie a nu I caratteri dimensionali sono espressi in millimetri. merose monografie paleontologiche dedicate sia alla Le abbreviazioni usate indicano: D=diametro; 0=am- descrizione di specie (NICKLÈS. 1890-1894; GERHARDT, piezza dell'ombelico; A= altezza del giro. Fra parentesi 1897) sia all'interpretazione filogenetica che alla revisio sono espressi i rapporti O/D e A/D. ne dei taxa appartenenti alla famiglia (HYATT, 1903; A causa del tipo di conservazione non è stato possibi DOUVILLÉ, 1911; GIGNOUX, 1920; BURGL, 1956; le misurare lo spessore del giro. KOTETICHVILl, 1980; VERMEULEN, 1980). Tutti gli esemplari studiati sono provvisoriamente L'interesse biostratigrafico di queste ammoniti è note conservati presso le collezioni dell'Autore. volissimo. VERMEULEN (1974; 1980) ha proposto una zonazione omofiletica unicamente basata su specie ap SUPERF AMIGLI A Desmocerataceae ZITTEL, 1895 partenenti a questa Famiglia. FAMIGLIA Pulchelliidae DOUVILLÉ, 1890 Alcuni degli indici zonali proposti da VERMEULEN sono inoltre stati confermati nella recente zonazione del In questo lavoro viene adottata la classificazione di Gruppo di Lavoro sui Cefalopodi del Cretaceo inferiore VERMEULEN (1980) che prevede la distinzione di due soli (HOEDEMAEKER & COMPANY, 1993). Inoltre, data la generi: Psilotissotia HYATT con Buergliceras ETAYO grande abbondanza di pulchelliidi in Colombia SERNA e Subpulchellia HYATT come sottogeneri e Pul (GERHARDT, 1897; BURGL, 1956), esistono notevoli chellia UHLIG di cui sono considerati sottogeneri Heinzia potenzialità di correlazioni a grande scala. SAYN, Coronites HYATT e Nicklesia HYATT. I rappresentanti di questa famiglia sono relativa mente frequenti nei sedimenti dell'Hauteriviano su- GENERE Pulchellia UHLIG, 1883 periore-Barremiano della formazione della Maiolica SPECIE TIPO: Ammonites galeatus VON BUCH, 1839 affiorante nell'arca Umbro-Marchigiana. Alcune forme sono già state figurate da CECCA & PALLINI (in II genere ingloba conchiglie di piccole dimensioni, invo stampa) ma le ricerche più recenti condotte in questa lute, con spire compresse ed anche molto spesse (Carstenia), regione hanno portalo alla scoperta di una nuova ornamentazione vigorosa con coste larghe, forti e, salvo nel specie nonché al ritrovamento di alcuni esemplari sottogenere Nicklesia, interrotte sull'area esterna. Sul margi appartenenti a Pulchellia (Heinzia) provincialis ne ventro-laterale possono svilupparsi davi o tubercoli e (D'ORBIGNY), specie di notevole interesse biostrati- doppi tubercoli nel gruppo di P. (Heinzia) provincialis. grafico nella nostra regione in quanto indica il Bar remiano superiore (VERMEULEN, 1974) e, data l'as SOTTOGENERE SAYN. 1891 senza del marker, consente di individuare la zona a A. Heinzia vandenheckii . SPECIE TIPO: Ammonites provincialis D'ORBIGNY, 1850
Spigolo ventrale Parallelogramma latero-ventrale Spigolo laterale Struttura laterale Spigolo interno
dis.V. Pannuti
Fig. 1 - Terminologia usala per la descrizione della costulazione delle ammoniti del genere Pulchellia (da VERMEULEN. 1980, modificato). - Terms used for the description of the ribbing characters in the ammonites of the genus Pulchellia (from VERMEULEN, 1980, modified). PULCHELLIA (HEINZIA) PALLINI! SP. N. E PULCHELLIA (HEINZIA) PROVINCIALIS (D'ORBIGNY). 61
Nota - SAYN (1891) non indicò una specie tipo per lazione non è così proiettata in avanti, come nell'esem Heinzia; questa fu designata da HYATT (1903) in H. plare precedente. L'esemplare VR 623 (Fig. 2 b) ha coste sayni, specie creata dallo stesso HYATT SU esemplari che radiali, proverse, biforcate a metà fianco. L'esemplare F SAYN (1891, tav. 1, fig. 16; tav. 2, fig. 7) figurò con il 175 (Fig. 2 c) è un frammento, determinato come P.(H.) nome di Pulchellia provincialis (D'ORBIGNY). Successi cf. provincialis, che però mostra chiaramente il caratte vamente (BURGL, 1956; VERMEULEN, 1980) è stato am ristico sdoppiamento del parallelogramma latero-ventrale piamente dimostrato che H. sayni è un sinonimo di in struttura laterale e spigolo latero-ventrale (Fig. 1). provincialis che, per priorità, è quindi la specie tipo di MATERIALE - Quattro esemplari: F 460, F 175, S 364, Heinzia. VR623. Rispetto a Pulchellia s. str. Heinzia racchiude forme DIMENSIONI con ombelico aperto. Nel gruppo di P. (Heinzia) heinzi (COQUAND) si hanno tubercoli sulla terminazione ventro- laterale delle coste, o parallelogrammi latero-ventrali esemplare D A O limitati da uno spigolo laterale secondo la terminologia F 460 22 9,5 (0,43) 5,5(0,25) di VERMEULEN (1980), mentre nel gruppo di P. (H.) S 364 23 10,5 (0,45) 5 (0,22) provincialis (D'ORBIGNY) si ha un caratteristico sdop VR 623 -21 - - piamento del parallelogramma latero-ventrale con l'in 19 9(0,47) 4(0,21) dividualizzazione di un tubercolo ventro-laterale e di un secondo tubercolo, detto anche "struttura laterale", ben delimitato da uno spigolo laterale e da uno interno (Fig. DISTRIBUZIONE STRATIGRAFICA E PROVENIENZA DEL MATERIALE - Tutti i dati della letteratura concordano nell'attribuire questa specie al Barremiano superiore, zona a A. vandenheckii . Il marker di questa zona non è Pulchellia (Heinzia) provincialis (D'ORBIGNY) mai stato rinvenuto, almeno finora, nell'area umbro- Fig. 2 a-e marchigiana; P. (H.) provincialis ha quindi una funzione di indicatore del Barremiano superiore, particolarmente 1850 Ammonites provincialis D'ORBIGNY; p.99. in quelle sezioni dove non si rinvengono altri elementi 1883 Pulchellia provincialis D'ORBIGNY; UHLIG, p. 125, tav.20, fig.2. biostratigraficamente caratteristici. In effetti, nella nostra 1891 Pulchellia provincialis D'ORBIGNY; SAYN, p. 35, tav.l, regione, si tende ad utilizzare la "zona a P. provincialis" fig. 16; tav. 2, fig.7. ma intesa in senso diverso da VERMEULEN (1974; 1980) 1903 Heinzia provincialis (D'ORBIGNY); HYATT, p. 131, tav. 15, in quanto, mantenendo distinta P. (H.) provincialis da P. figg. 19, 20. (H.) sartousi si riconosce la zona a P. (H.) sartousi, al di 1937 Ammonites provincialis D'ORBIGNY; COTTREAU, p. 19, tav. 77, fig. 18, 19. sopra di quella a A. vandenheckii. L'esemplare S 364 è 1967 Pulchellia provincialis D'ORBIGNY ; BACCELLE & LUŒHT stato raccolto nello strato 79 della sezione di Stirpeto; GARAVELLO, p. 148, tav. 3, fig. 8a-c. VR 623 nello strato 16 della sezione Tenetra VR; F 175 1970 Heinzia provincialis D'ORBIGNY; KOTEHCHVIU, p. 91, tav. nello strato 121 e F 460 nello strato 84 della sezione di 16, fig. 2. Gorgo a Cerbara. 1980 Heinzia (Heinzia) provincialis (D'ORBIGNY); KOTETICHVUI, p. 55, tav. 3, figg. 1-4. OSSERVAZIONI - I nostri esemplari sono chiaramente 1980 Pulchellia (Heinzia) provincialis (D'ORBIGNY); VER MEULEN, p.28, tav.4, figg. 5, 8-10. confrontabili con quelli noti figurati in letteratura e quindi la 1992 Heinzia provincialis (D'ORBIGNY); DELANOY, p. 37, tav. 6, loro identificazione specifica non pone problemi. figg. 1-4, 7. VERMEULEN (1980) propende per una visione molto DESCRIZIONE - Conchiglia evoluta con fianchi della ampia di H. provincialis nella quale dovrebbero essere spira leggermente bombati che ricadono sul giro prece inclusi come sinonimi anche P.(H.) sartousi P.(H.) dente senza formazione di muraglia ombelicale. Orna ouachensis. Il nostro materiale non consente ne di con mentazione forte, formata da coppie di coste radiali, fermare ne di smentire questa ipotesi. unite sul bordo ombelicale che sviluppano la caratteristi Tuttavia ci sembra importante sottolineare che P. (FI.) ca struttura laterale. Si tratta in effetti dello sdoppiamen provincialis si rinviene almeno nella sezione di Gorgo a to del tubercolo sviluppato poco sotto al margine ventro- Cerbara (CECCA & PALLINI, in press) mollo al di sotto di laterale. Si hanno anche coste semplici. P.(H.) sartousi e P.(H.) ouachensis e non abbiamo mai Nell'esemplare F 460 (Fig. 2 e) la struttura laterale è rinvenuto associati nello stesso strato esemplari corri sviluppata fino a 2/3 dell'ultimo giro mentre nell'ultima spondenti a questi tre tipi morfologici. Si mantengono parte si hanno più coste semplici, rare coste intercalari, e quindi distinte queste tre specie. P. (H.) sartousi si distin si osserva anche una costa biforcata a metà fianco. A gue da P. (H.) provincialis per l'assenza di strutture late questo punto le coste presentano una concavità verso rali e per una costulazione che sviluppa un più accentua l'apertura e sul margine ventro-laterale la struttura latera to aspetto spatuliforme delle coste. P.(H.) ouachensis ha le tende a scomparire mentre le coste sono nettamente una ornamentazione più fine di P.(H.) provincialis che proiettate in avanti. L'esemplare S 364 (Fig. 2 a) mantie inoltre è fortemente indebolita attorno alla parte media ne coste radiali fino alla fine dell'ultimo giro e la costu- del fianco della spira. 62 CECCA F.
P. (H.) aff. lindigii (KARSTEN) in UHLIG ha un ombe DEPOSITORIO - Collezione dell'Autore in attesa di collo lico molto più chiuso di P. (H.) provincialis ed anche cazione definitiva. coste più robuste. DIAGNOSI - Heinzia caratterizzata da ombelico relativa mente molto aperto, dalla perdita della "struttura latera Pulchellia (Heinzia) pallimi sp. n. le" sulla camera d'abitazione ornata da coste biforcate, Fig. 2 f-j semplici ed intercalari. DESCRIZIONE - Conchiglia evoluta, compressa, con DERIVATIO NOMINIS - La specie è dedicata al Paleontolo fianchi leggermente bombati. L'ornamentazione, fino alla go GIOVANNI PALLINI. prima metà dell'ultimo giro è formata da coste forti, OLOTIPO - S 363, Fig. 2 f. rilevate, biforcate al terzo esterno del fianco, e da coste PARATIPI - VR 622, VR 624. semplici. Nella seconda metà dell'ultimo giro si hanno LOCALITÀ TIPO - Stirpeto, nella valle del Fiume Bosso, coste semplici tra le quali si osservano coste intercalari vicino alla località Poggio le Guaine sul versante meri estese dall'area ventrale fino a metà fianco. dionale della struttura di Monte Nerone. Le coste biforcate nella prima metà dell'ultimo giro LIVELLO TIPO - Barremiano superiore, A. vandenheckii portano sul margine ventro-laterale la caratteristica zone. struttura laterale (Fig. 1). Quest'ultima non si osserva
Fig. 2 - Pulchellia (Heinzia) provincialis (D'ORBIGNY): a) esemplare S 364, sezione di Stirpeto, strato 79; b) es. VR 623, sezione Tenetra VR, strato 16; c) es. F 175, sezione di Gorgo a Cerbara, strato 121; d) es. VR 631, sezione Tenetra VR, strato 15; e) es. F 460, sezione di Gorgo a Cerbara, strato 84. Pul chellia (Heinzia) pallimi sp. n.: f) es. S 363, olotipo, sezione di Stirpeto, strato 76; g) es. VR 622, paratipo, sezione Tenetra VR, strato 16; h) es. VR 624, paratipo, sezione Tenetra VR, strato 15. P. (H.) cf. pallimi: i) es. VT 208, sezione Tenetra VT, strato 25; j) es. VR 656, sezione Tenetra VR, strato 15. Tutti gli esemplari sono riprodotti a grandezza naturale. Fotografie di Andrea Bussoletti. - Pulchellia (Heinzia) provincialis (D'ORBIGNY): a) specimen S 364, Stirpeto section, bed 79; b) sp. VR 623, "Penetra section VR, bed 16; c) sp. F175, Gorgo a Cerbara section, bed 121; d) sp. VR 631, Tenetra section VR , bed 15; e) sp. F 460, Gorgo a Cerbara section, bed 84. Pulchellia (Heinzia) pallina sp. n.: fi sp. S 363, holotype, Stirpeto section, bed 76; g) sp. VR 622, paratype, Tenetra section VR, bed 16; h) sp. VR 624, paratype, Tenetra section VR, bed 15. P. (H.) cf. pallimi: i) sp. VT208, Tenetra section VT, bed 25; j) sp. VR 656, Tenetra section VR, bed 15. AU figures natural size. Photos by Andrea Bussoletti. PULCHELLIA (HEINZIA) PALLINI! SP. N. E PULCHELLIA (HEINZIA) PROVINCIALIS (D'ORBIGNY). 63 sulla terminazione delle coste nella seconda metà dell'ul BÙRGL H. (1956) - Catalogo de las Amonitas de Colombia, parte I, timo giro. La costulazione dell'olotipo (Fig. 2 f) è relati Pulchelliidae. Inst. Geol. Nac., Boi. Geol., 4 (1): 1-119, 28 law., Bogota. vamente rigida e radiale mentre nei paratipi (Fig. 2 g, h) esse hanno un tracciato leggermente concavo. CECCA F. & PAT I INI G. - (in press) Latest Hauterivian-Barremian Gli esemplari VR 656 e VT 208 (Fig. 2 i, j), a causa ammonite biostratigraphy in the Umbria-Marche Apennines del loro insufficiente stato di conservazione, sono stati (Central Italy). In: L. BULOT & H. ARNAUD (Eds.): "Lower Creta ceous Cephalopod Biostratigraphy of the Western Tethys". Géologie determinati come P. (H.) cf. pallimi: il primo è deforma alpine, mém. spec. H. S., 20:, 1 pi. Grenoble. to mentre il secondo è un frammento. Entrambi mostrano i caratteri ornamentali della nuova specie descritta. COTTREAU J. (1937) - Les Types du Prodrome de paléontologie strati- graphique universelle de D'ORBIGNY. Ann. Pal., 26: 53-84, taw. 3-7, MATERIALE - Cinque esemplari: S 363, VR 622, VR Paris. 624, VR 656, VT 208. DIMENSIONI DELANOY G. (1992) - Les ammonites du Barrémien supérieur de Saint- Laurent de l'Escarène (Alpes-Maritimes), Sud-Est de la France. esemplare D A O Annales Muséum Hist. Nat. Nice, 9: 1-148, 4 figg., 1 tab., 40 taw. S 363 -38 D'ORBIGNY A. (1850) - Prodrome de Paléontologie stratigraphique 33,5 16 (0,48) 11 (0,33) universelle, 2° vol.: pp. 289, Masson, Paris.
I paratipi VR 622 e VR 624 non sono misurabili a DOUVILLÉ H. (1911) - Evolution et classification des Pulchellidés. Bull. causa della loro incompleta conservazione. Il loro diame Soc. Géol. France, 4e sér., 11: 285-320, Paris. tro si aggira attorno ai 32-33 mm. DISTRIBUZIONE STRATIGRAFICA E PROVENIENZA DEL GERHARDT K. (1897) - Beitrûge zur Kentniss der Kreideformation in MATERIALE - Barremiano superiore, zona a A. vandenheckii. Columbien. N. Jahr. fìir Min., 9: 119-208, 5 taw., Stuttgart. L'olotipo S 363 è stato raccolto nello strato 76 della sezione di Stirpeto, circa 1,5 metri sopra ad un livello contenente P. GIGNOUX M. M. (1920) - Les Pulchelliidés du Paléocrétacé. Mém. Expl. (H.) provincialis; VR 624 e VR 656 provengono dallo strato Carte Géol. France: 135-164, Paris. 15 e VR 622 dal 16 della sezione Tenetra VR; l'esemplare VT 208, determinato come P. (H.) cf. pallimi viene dallo HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. B., strato 25 della sezione Tenetra VT. AVRAM E., BOGDANOVA T. N., BUJTOR L., BULOT L., CECCA F., OSSERVAZIONI - La forma descritta non può essere DELANOY G., ETTACHFINI M., MEMMI L., OWEN H. G., RAWSON P. confrontata con nessuna delle specie descritte in lettera F., SANDOVAL J., TAVERA J. M., THIEULOY J.-P., TOVBINA S. Z. & VASICEK Z. (1993) - Ammonite zonation for the Lower Cretaceous tura. La presenza di una struttura laterale nella prima of the Mediterranean region; basis for the stratigraphie correla parte dell'ultimo giro la avvicina a Pulchellia (Heinzia) tions within IGCP-Project 262. Revista Espanda de Paleontologia, 8 provincialis, da cui si discosta nettamente per la succes (1): 117-120, 1 tab., Madrid. siva evoluzione della ornamentazione. Almeno nello strato 16 della sezione VR del Monte HYATT A. (1903) - Pseudoceratites of the Cretaceous. U. S. Geol. Tenetra, P. (H.) pallina sp. n. è stata rinvenuta associata Survey Monogr., 44: 1-250, 47 taw., Washington. a P. (H.) provincialis (D'ORBIGNY). Si potrebbe quindi ritenere che la nuova specie sia in realtà il corrisponden KOTEnCHVTLI E. V. (1970) - Stratigraphy and fauna of the Colchiditic te macroconco. DELANOY (1992) ha ipotizzato l'esistenza and adjacent horizons of Western Georgia. Trudy Geol. Inst. Tbilis di un dimorfismo in seno a P. (H.) provincialis, figuran si, (N. S.), 25, 1-115, 20 pl., Tbilissi. do alcuni esemplari, certamente appartenenti alla specie KOTETTCHVTLI E. V. (1980) - Famille des Pulchelliidae. Akad. Nauk. G. di D'ORBIGNY, ma di taglia superiore alla norma. Tutta C. C. P. Geol. Inst., 67: 1-110, 10 taw., Tbilissi. via, rispetto agli individui figurati da DELANOY (1992, tav. 6, fig. 1-3) gli esemplari di P. (H.) pallina sp. n. NICKLÈS R. (1890-1894) - Contributions à la Paléontologie du Sud-Est hanno un ombelico più aperto, un'ornamentazione meno de l'Espagne. Mém. Soc. Géol. France, 4; parte 1 (1890): 1-30, 34 forte e rilevata, biforcazioni delle coste più numerose e fig., tav. 1-4; parte 2 (1894): 31-59, 42 figg., taw. 5-10, Paris. definite e un minore sviluppo della struttura laterale. Si ritiene quindi che P. (H.) pallimi sp. n. non sia il SAYN G. (1891) - Description des Ammonites du Barrémien du Djebel corrispondente macroconco di P. (H.) provincialis Ouach près Constantine. Ann. Soc. Agric. Hist. Nat. et Arts utiles, sér. 6, 3 (1890): 135-208, 3 taw., Lyon. (D'ORBIGNY) e che quindi sia corretto considerare i due gruppi di forme come due specie distinte. UHLIG V. (1883) - Die Cephalopodenfauna der Wernsdorferschichten. Denk. K. Akad. Wissensch., 46: 1-166, 32 taw., Wien.
RIFERIMENTI BIBLIOGRAFICI VERMEULEN, J. (1974) - Sur une stratigraphie homophylétique basée sur la famille des Pulchelliidae. C. R. Acad. Se. Paris, sér. D, 278: 2885-2887.
BACCELLE L. & LUCCM GARAVELLO A. (1967) - Ammoniti dei livelli cretacici di La Stua (Cortina dAmpezzo). Ann. Univ. Ferrara, N. S., VERMEULEN, J. (1980) - Etude de la famille des Pulchelliidae. Thèse de sez. IX Se. Geol. e Paleont., 4 (9): 117-153, 1 fig., 2 tabb., 3 taw. l'Université de Nice: 1-92, 6 figg., 7 tabb., 4 taw. Mem. Descr. Carta Geol.d'It. LI (1995), pp. 65-101
About some significant ammonites from the Lower Aptian (Bedoulian) of the Angles-Barrême area (South-East France)
Su alcune ammoniti significative dell' Aptiano inferiore (Beduliano) nell 'area di Angles-Barrême (Sud-Est della Francia)
GÉRARD DELANOY (*)
IGCP Projects 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - The Lower Aptian (Bedoulian) from the stratotypical RIASSUNTO - L'Aptiano inferiore (Beduliano) nell'area dello stralolipo del region of the Barremian has given some significant ammonites belonging Barremiano ha fornito alcune ammoniti significative, appartenenti ai generi lo genera Deshayesites and Cheloniceras which are described and Deshayesites e Cheloniceras, descritte e figurate nel presente lavoro. In base a figured in this paper. On the basis of these new collected faunas, it is now queste nuove faune é possibile riconoscere in quest'area le zone a Deshayesites possible to recognize in this area the mediterranean Deshayesites tuarkyricus e a D. weissi, valide per la regioni mediterranee. Tuttavia, i limiti tuarkyricus and D. weissi Zones. Nevertheless their boundaries are still di queste zone sono ancora di difficile definizione. \JH zona a Deshayesites unclear. The Deshayesites deshayesi Zone could not have been revealed deshayesi non è stala riconosciuta, salvo forse la parte superiore. Il problema by the ammonites, except perhaps his upper part. The problem of the del limite Barremiano/Aptiano è discusso per quel che riguarda la sezione di Barremian / Aptian boundary is discussed in the Angles section. Angles.
KHY-WORDS - Biostratigraphy, Ammonites, Lower Aptian, Lower PAROLE CHIAVE: Biostratigrafia. Ammoniti, Aptiano inferiore. Cretaceous, South-East France. Cretaceo inferiore, Sud-Est della Francia.
(*) Laboratoire de Géochimie et Geologie Analytique and Laboratoire de Géologie Marine, Université de Nice,Parc Valrose, F 06108 Nice Cedex 2 Centre d'Etudes Méditerranéennes, Muséum d'Histoire Naturelle, 60 bis Bd Risso, F 06300, Nice 66 DEI ANO Y lì.
1. - INTRODUCTION Table 1 - Correlations between the Lower Aptian from England (CASEY, 1961a) and the mediterranean region The Lower Aptian from South-East of France (the (BOGDANOVA, 1983; HOEDEMAEKER & BULOT, 1990; so-called Bedoulian of TOUCAS, 1888) has been HOEDEMAEKER & COMPANY, 1993). subdivided in two zones by KILIAN & REBOUL (1915): a - Correlazioni fra l'Aptiano inferiore dell' Inghilterra (CASEY, lower zone with Parahoplites weissi, P. consobrinus and 1961a) e l'area mediterranea (BOGDANOVA, 1983; Procheloniceras albrechtiaustriae, and an upper zone HOEDEMAEKER & BULOT, 1990; HOEDEMAKKER & COMPANY, 1993). with Parahoplites deshayesi. This division of the Lower Aptian has been recognized by Rocii (1927) in his slratigraphical and paleontological study of La Bédoule Mediterranean region (the type-area of the Bedoulian). ogdanova, 1971 Hoedemaeker & Bulot, j During the Symposium on the Lower Cretaceous, 1990 (Lyon, September 1963) only one zone has been England 11 Hoedemaeker & maintained for the Bedoulian: the Deshayesites Casey, 1961 |§ Company, 1993 deshayesi Zone (FLANDRIN, 1965; anonymous, 1965), because of the too long range of the taxa used by KILIAN & Rocii (FABRE-TAXI et alii. 1965). Bowerbanki Furcata Later on, THOMEI. (1964) and MOULLADE (1966) have given to Puzosia matheroni the proéminent rank of index-species for all the Lower Aptian of the voconlian region. Deshayesi Deshayesi In 1984, BUSNARDO has proposed seven zonal subdi visions for the Lower Aptian of La Bédoule area, from bottom to lop the "Prodeshayesites", Pseudocrioceras coquandi. Ancyloceras matheroni, Roloboceras ham- brovi, Deshayesites grandis and Tropaeum bowerbancki Forbesi Zones. However, the author stressed the difficulties in Weissi using some of these zones out of the stratotype of La Bédoule. Because of their local use, the elements of these zonal scheme have not been maintained for the zonation Fissicostatus Tuarkyricus of the mediterranean province during the workshop of the Lower Cretaceous Working Group of IGCP 262 in Digne (July 1990) (HOEDEMAEKER& BULOT. 1990). The near Montélimar or La Bcdoulc near Marseille). On zones used in the Caucasian regions (Georgia, the other hand, the pelagic domain gives a less rich Turkmenistan) have been preferred (successively the Deshayesites tuarkyricus. D. weissi, D. deshayesi and fauna, especially the heleromorph ammonites, and the inherited taxa from the Barremian (Coslidiscus Dufrenoya furcata Zones) (Tabi. 1). recticostatus, Macroscaphites yvani, Pseudohaploceras One year later, a level containing some ammonites matheroni, Eulytoceras phestus,...) represent an which can be referred to the Prodeshayesites important part of the populations. Zone (CASEY, 1961a) was recognized in the fissicostatus The significant ammonites of genera Deshayesites voconlian area (DELANOY. 1991). and Cheloniceras are generally represented by poorly The proposal of HOEDEMAEKER & BULOT (1990) has preserved or fragmentary small specimens and it results been maintained during the second workshop of the that the specific determinations are very difficult, often Lower Cretaceous Working Group of IGCP 262 in Mula impossible. (July 1992) (HOEDEMAEKER & COMPANY, 1993). Thus, In addition, these two genera have been splitted in a the identification of this zonation in the Lower Aptian of great number of typologie species, sometimes without the vocontian area, especially in the Angles-Barrême- the knowledge of their precise stratigraphie position, or Caslcllane region, became very important. they have been diversely interpreted. Some genera The compilation of many works related to the Lower usually considered as aptian taxa appear in the Aptian from South-East France and my own researches uppermost Barremian and they can be used only with shows in advance the major difficulties to propose or to many precautions (Procheloniceras. Kutatissites. recognize a zonal scheme: the quantitative and Pseudocrioceras,...). qualitative disparities of the ammonite faunas between The research undertaken since some years in the the deeper part of the basin and its marginal areas. As a Upper Barremian and in the Lower Aptian of the matter of faci, the rich ammonite faunas described since Angles-Barrême-Caslellane area (DELANOY, in prep.) more than 150 years came essentially from the outer part providedt an interesting fauna of Deshayesites which of the shelves (the old quarries of l'Homme d'Armes allowed us to recognize the zones proposed for the AMMONITES FROM THE LOWER APTIAN OF SE FRANCE 67
mediterranean province (HOEDEMAEKER & BULOT, alternation of calcareous beds and marly inlerbeds. In 1990; HOEDEMAEKER & COMPANY, 1993). The results contrary, the upper part represents the base of the presented in the present paper are different but they Blues Marls Formation, the sudden change of lithology un complete the data previously published (DELANOY, derlining a stratigraphical hiatus recognized in the whole 1991). area (MOULLADE, 1966; COTILLON, 1971; FRIES et alii , 1984).
2.2. - THE BARREMIAN/APTIAN BOUNDARY 2. - STRATIGRAPHY
2.1. - THE STUDIED AREA The Barremian / Aptian boundary considered in this paper is not different than the one recognized so far BUSNARDO, 1965; DELANOY. 1991, 1992; 1994). In The studied area is located in the south-eastern 1965, BUSNARDO has fixed this boundary at the base of part of the Vocontian Basin (Fig. 1). In this area are bed 197, which was considered the level where Puzosia exposed Ihe best sections of the Barremian because it matheroni {^Pseudohaploceras matheroni) appears. is poorly affected by slumps and by the deformations Nevertheless, the author recognized the lack of of the alpine orogenesis (FERRY, 1988). It represents significant taxa in this part of the section (formation 15, also the reference area of the Barremian stage beds 197 to 204). (BUSNARDO. 1965). From a lithological point of view, in this area the greater part of the Bedoulian is in This fact has been stressed by many authors distinct from the Barremian. It is characterized by an (MOULLADE, 1966; ARNAUD. 1981; RAWSON. 1983). Recently the occurrence of Dcshayesilidae has been recognized at the top of the "formation 15" with the discovery of a level with "Prodeshayesites" (DELANOY, 1991). During the same time it has been proved that the genus Pseudohaploceras appeared in the Ilemihoplites feraudianus Zone and the species Pseudohaploceras matheroni occurred in the Martelites sarasini Zone (DELANOY. 1992, in press). The paleontological data obtained in the studied area prove indiscutably that the genus Deshayesites. represented by taxa of the Deshayesites luarkyricus Zone, occurs in the levels which are the equivalents of beds 201 b to 204 of the Angles section. These levels make a good lithologie landmark visible in the whole region (Fig. 7). They correspond to a bundle (the "thick bundle") of 3 or 4 thick (metric) beds in which are intercalated 1 or 2 thin beds and interpreted as a lowstand wedge (ARNAUD, JAQUIN & VAIL oral communication. 1990; ARNAUD & ARNAUD-VANNEAU. 1991). They represent the upper part of the "formation 15" (BUSNARDO, 1965) and they will be considered in this paper as the base of the Deshayesites luarkyricus Zone. In contrary, the occurrence of Dcshayesitidac in the lev els immediately below needs to be verified. The possible presence of genus Prodeshayesites in bed 200 of Angles road cited by KAKABAD/.E (oral com munication in DELANOY, 1991) could not have been confirmed by new collects. Consequently, because of the doubt concerning the FO of the Dcshayesitidac in the whole studied area, the Barremian / Aptian boundary is not shifted in the stratotypical section of Angles. The levels included between this boundary, which has been recognized in the other sections by means of sequential correlation, and the base of the Deshayesites luarkyricus
Fig. 1 - Geographical location of the area studied. Zone, as admitted in this paper (base of the "thick bun - Ubicazione dell 'area di studio. dle"), are named "non-characterized zone". 68 DELANOY G.
2.3. - SUCTIONS STUDIED made in incomplete sections of the same arca which are not described in this paper. The 5 sections described in this paper have been studied bed by bed near the following localities: 2.3.1. - The road of Angles section (ANG) (Fig.2) - Angles: the road of Angles and La Combe Lambert sections. The Aptian begins at the base of bed 197. The "thick bundle" is represented by beds 201 b to 204 (pi. 8, fig. - Saint-André les Alpes: Méouilles section. 1). The more significant taxa are Deshayesites sp. (-- - Morie/.: the Colle gully section near the farm of Prodeshayesites cf. tenuicostatus in DELANOY, 1991) in Trcmolies . bed 206 and Deshayesites sp. gr spathi/normani (= D. gr. primitivus/spathi in DELANOY, 1991) in bed 210. - Barrême: the Vignon's gully section. The top of the section is not exposed, because it disappears under the grass. The beds 217 to 219 The detailed location of these sections is published in described by BUSNARDO (1965) arc not now really DEI.ANO Y (in press). Some observations have been visible today. BUSNARDO (1965) has cited D. cf consobrinus (D'ORBIGNY) in bed 214 and D. deshayesi (D'ORBIGNY) in bed 217. In the Lower Greensand. Deshayesites closely related to D. consobrinus (D'ORBIGNY) occur in •z E the Deshayesites forbesi Zone (CASEY, 1963) and D a 3 a 5 deshayesi (D'ORBIGNY) is the index-species of the Deshayesites deshayesi Zone (Tabi. 2). According to »'• III.'. oSs BOGDANOVA (1971) D. consobrinus (D'ORBIGNY) occurs J in the Deshayesites luarkyricus and Deshayesites weissi ,U, 1 J ,1 ,1J j 213 •r l'r r r i S Zones and D deshayesi (D'ORBIGNY) is present in the I' I ' I ' I' I i upper part of the Deshayesites weissi Zone and in the S 210 whole Deshayesites deshayesi Zone (Tabi. 3). "B g I do not have found ammonites which may be S identified with these two species and. allough these citations do not deeply modify the zonal scheme proposed in the section, it should be interesting to see again the Deshayesites cited by BUSNARDO (as the specimens reported to the genus Cheloniceras too). n 5 Q 2.3.2. - La Combe Lambert section, near Angles (COM) (Fig. 3)
Il h The Aptian begins in the bottom of the stream with bed 100, which corresponds to the base of the "thick bundle". Deshayesites sp. Prodeshayesites cf. Barremian tenuicostatus in DELANOY, 1991) specimens occur in level 107. Deshayesites aff. euglyphus CASEY has been collected in bed 122 with Cheloniceras cornuelianum
11 ^ 11 Limesiones (D'ORBIGNY) and Ancyloceras sp. The lop of the limestones suddenly passes to the blue marls (pi. 10. fig. Maris 1). According to BUSNARDO (1965) this boundary was The road of Angles section pointed out by ferruginous deposits recalling a hard ground, which is not visible today. This section corresponds to the second section presented by BUSNARDO (1965) on his tabic 1 and which l'ig. 2 - Section of the Aptian of the road of Angles. Only the significant was described briefly by the same author at page 108. In identified ammonites have been documented. The total ranges of the most important genera based on specimens undeterminable at the specific level the upper part of the limestones BUSNARDO has cited are represented by grey columns. Deshayesites consobrinus (D'ORBIGNY), D. deshayesi - Sezione dell 'Aptiano della strada di Angles. Tra le ammoniti sono (D'ORBIGNY) and Dufrenoya cf. praedufrenoya CASEY. riportate solo quelle biostraligraficamente significative. Le barre in but I could not verify the occurrence of these species in grigio rappresentano le distribuzioni verticali dei generi più importanti, desunte in base ad esemplari indeterminabili a livello the section and draw the stratigraphical conclusions on specifico. the basis of their presence. AMMONITES H« M TI IH I XWLIR APTIAN OF Sii FRANCE 69
EN CE ES
3 a A
00 129 1 3 S 3 H 'L'I1 I' > 127 |I |I I| I H •S-
I 1 C '"•IL I H O 2 .3 S -I CI. D. 1 I N M • 9 Q U < 122 1 • 2 . I I1 I I I N 3 IL 1 1 1 1 1 ) a C 5 A. 5 L'I I I' .A 118 "3 U -C EU I I I U O Q "5. •A ET •C CI I ^1 •W ..MM) A III .1 °- 1 A 111 ft. CL. §•
109 5 O
3
105 S O >-> .* 103 U ES S H
100 PFF=
UN VISIBILITY
Limestones
Marls LA COMBE LAMBERT SECTION
Fig. 3 - Section ol'lhe Aptian of] a Combe Lambert near Angles (see Fig. 2 for explanation). - SEZIONE DELL APTIANO DI "LA COMBE LAMBERT", PRESSO ANGLES (VEDI DIDASCALIA RG. 2). 70 DBIANOYG. 2.3.3. - Méouillcs section, near St André les Alpes "thick bundle". D. aff. weissi formis BOGDANOVA (= (MHO) (Fig. 4) occurs in bed 200. The specimens of Deshayesites sp. ( Prodeshayesites cf. tenuicostatus in DKI.ANOY, 1991) The base of the Aptian is placed at the base of bed 194. have been collected in level 208. The possible Deshayesites oglanlensis BOGDANOVA has been appearance of genus Cheloniceras in bed 212 is Paradeshayesites gr. laeviusculus in DKLANOY, 1991) documented by a poorly preserved fragment. The lop of collected in bed 199. which represents the base of the the section is not exposed because of the vegetation.
jaes mc •« a es es ~ at .2«? = s x No Hes ea S V3 w 222 1 1 1 1 1 i i i i a nil ,1, S: 1 219 1, 1 J, cm Hi- •3 § -s —216 i i n nr 3 i 1 s- a O S I i 1 J ,1V 3 •o -2 .2C i i ri' J ft.85 a. '. 1 . 1 •m i 2 Ì* S Cl. c L. S s> •« 3c. * a1 Ciò *«3 ^ •c •s o •«Q •I 111 Q O I tu "3 Q U a ili i i m «U i i i i i i a -ac <3 u I
Barremian
I ^ 11 Limestones
Maris The Méouilles section
Fig. 4 - Section of the Aptian of Méouilles, near Saint André les Alpes (see lig. 2 for explanation). - Sezione dell 'Aptiano di Méouilles. presso Saint-André les Alpes (vedi didascalia Fig. 2). AMMONITIiS FROM Tllli 1.1 IWUR APTIAN l »F SI: FRANCU 71
I'ïg. 5 - Section of the Aptian ol'lhe Colle gully under the farm of Tremolies, near Moriez (see fig. 2 for explanation). - Sezione dell 'Aptiano del "Ravin de la Colle", presso la fattoria di Tremolies. Moriez (vedi didascalia Fig. 2). 72 DELANOY G.
es as x CCJ H
"a
3 •s es. Q 's U h. 3 J! u 00 4!
g 3 e •3 a o •S B 3
•C B .2 a f <
c Ci.
It O «s a i. «> u « a. s». Q •«S
a
I
Barremian
I I * I I Limestones
Marls The Vignon's gully section
Fig. 6 - Section of the Aptian of the Vignon Gully, near Barrême (see fig. 2 for explanation). - Sezione dell 'Aptiano del "Ravin du Vignon". presso Barrême (vedi didascalia Fig. 2). AMMONITES FROM THIi LOWER APTIAN OF Sii FRANHÌ 73
2.3.4. - La (vile gully section near the farm of 2.3.5. - The Vignon's gullv section, near Barrême (I Id) Tremolies, near Moriez (TRE) (Fig. 5; pi. 10, fig. 2) (Fig. 6)
The section begins with bed 240, i. e. the base of The Aptian begins with bed 472 and the "thick bundle" the "thick bundle". In one place, the upper part of with bed 476 (pi. 8. fig. 2), the section showing the whole this bundle shows slumps. Deshayesites are present succession of the aptian limestones and the transition with in the whole of the section but always represented by the blue marls. In the level 482 has been collected loo fragmentary and undeterminable specimens. A Deshayesites sp. (= Prodeshayesites cf. tenuicostatus in specimen of Deshayesites gr. spathi I normani has DELANOY, 1991). The two others significant Deshayesites been collected in a fallen bock. The level with discovered in this section are D. aff. callidiscus CASEY and Deshavesiles sp. ( Prodeshayesites cf. tenuicostatus D. aff. evolvens LUPPOV, respectively in beds 486 and 493. in DFI.ANOY, 1991) has been recognized in bed 248. The genus Cheloniceras appears in bed 490 and C. gr. Generally, this section seems relatively poor in cornuelianum has been collected in bed 496. The lop of the relatively well preserved ammonites authorizing a last limestone bed is remarkable because of its perforated good specific determination. Costidiscus aff. surface which underlines the slratigraphical hiatus (pi. 9. nodososlriatus (UHLIG) has been found in bed 262. fig. 1. 2). The base of the marls is covered by grass and The transition from Ihc limestones to the marls limestone detritus but the double bed is well visible about 4 appears more progressive than in the other studied m after the limestone/marl boundary. Cheloniceras kiliani sections. The section seems more complete in his (KOENEN) has been collected in the second bed of this upper part and needs more important investigations. guide-level.
en N
9 ...
•} --
TTTW
St O
9
La Combe Lambert La Colle Gully
Méouilles Vignon gully Road of Angles
Fig. 7 - Correlations belween the studied sections. - Correlazioni fra le sezioni studiale 74 DHIAN0YG.
2.4. - STRATIGRAPI IICAI. INTERPRETATION At least, the correlations between the zonal scheme defined in England (CASEY, 1961a) and that defined in The "non-characteri/cd zone'" is represented by some Turkmcnia (BOGDANOVA, 1971), as already considered beds in which the FO of the Deshaycsitidae is not well by BOGDANOVA et alii (1983), seems to be confirmed documented (viz the occurrence of ? Prodeshayesites in (Tabi. 1). bed 200 of the section of the road of Angles according to K.AKABADZE). The lower boundary has been defined by BUSNARDO ( 1965) in the Angles section and it has been recognized 3. - PALAEONTOLOGICAL STUDY in the other sections by means of sequential correlation. The upper boundary corresponds to the base of the GENUS Deshayesites KASANSKY, 1914 "thick bundle" (Fig. 7), which is considered in this TYPE SPECIES: Ammonites deshayesi LEYMERIE in paper as the base of the Deshayesites luarkyricus Zone. D'ORBIGNY The Deshayesites tuarkyricus Zone is materialized by Deshayesites oglanlensis BOGDANOVA and D. aff. Deshayesites oglanlensis BOGDANOVA. 1983 weissiformis BOGDANOVA, which arc two characteristic PI. 2, fig. la, b species of this zone in Turkmenistan (BOGDANOVA, 1971. 1983) (Tabi. 3). The lower boundary of this zone 1983 Deshayesites oglanlensis BOGDANOVA, p. 136.pl. 1. fig. 1- corresponds to the base of the "thick bundle". On the 9; text-figs. 5, 6. other hand it is not possible to identify the upper boundary. DESCRIPTION - An incomplete and compressed The Deshayesites weissi Zone is materialized by specimen with its body chamber. A part of the ribbing of Deshayesites gr. spathilnormani. D. aff. callidiscus the phragmocone is well preserved on the left side of the CASEY. D. aff euglyphus CASEY and Cheloniceras ammonite. The ribbing is palmate, fasciculate. The ribs cornuelianum (D'ORBIGNY) according to the fact that make peri-umbilical bullae and after they broaden out the Deshayesites to which the collected specimens considerably, but their relief is weaken in the middle arc compared occur in the Deshayesites forhesi Zone part of the sides. In the upper part of the flanks they of England (CASEY, 1961a. 1963) (Tabi. 2) and in form 5 to 6 secondary ribs often united in 2 bundles. On the Deshayesites weissi Zone of Turkmenistan the body chamber, the primary ribs show a well marked (BOGDANOVA. 1971, 1983) (Tabi. 3). D. aff evolvens peri-umbilical bullae and they strongly broaden out LUPPOV is considered as a form of this zone with before to bifurcate in the middle parts of the flanks. doubt. The boundaries of this biostratigraphic unit Each secondary rib bifurcates at new in the third upper arc also difficult to establish. As in Turkmenistan part of the sides. (BOGDANOVA, 1971) (Tabi. 3) and other adjacent regions, the genus Cheloniceras HYATT appears MATERIAL - Specimen 28653 Coll. DELANOY. Lower sooner in South-East of France than in northern Aptian, Deshayesites tuarkyricus Zone, Méouilles Europe The lower boundary is temporarily located at section, Saint-André les Alpes. the lop of the level with the Deshayesites sp. (= DISCUSSION - Because of its evolute coiling and its Prodeshayesites cf. tenuicostatus in DELANOY, ribbing, this Deshayesites belongs to the group of D. 1991), although the upper boundary is always tuarkyricusloglanlensis. The density of the ribbing being impossible to define. Perhaps it is included in the more important in D. tuarkyricus BOGDANOVA, the slratigraphical hiatus which exists at the contact studied sample is related to D. oglanlensis BOGDANOVA. between the limestones and the Blue Marls OCCURRENCE - Deshayesites oglanlensis Bogdanova, Formation in the whole basin ? is a characteristic form of the Deshayesites tuarkyricus Zone (BOGDANOVA. 1971, 1983) (Tabi. 3). The sample The Deshayesites deshayesi Zone has not been described above has been collected in the bundle (the materialized by ammonites. This zone is probably "thick bundle") near the base of the Aptian of the represented at the base of the Blue Marls Formation, this Méouilles section. rapid change in sedimentation coinciding with the disappearance of the urgonian limestones on the pcrivocontian shelves (ARNAUD, 1981; RUBINO, 1988). Deshayesites aff. weissiformis BOGDANOVA, 1983 The problem of the lower boundary is the same than the PI. 5. fig. 2 upper boundary of the D. weissi zone. The upper boundary should correspond to the base of the doublc- bed where Cheloniceras kilian! (KOENEN) was found in 1991 Paradeshayesites gr. laeviusculus (KoFiNEN); Dlil.ANOY. p. the Vignon's gully section and which is considered as 439, fig. 2d. the lower boundary of the Dufrenoya furcata Zone (= base of the Tropaeum bowerbancki Zone in RUBINO. DESCRIPTION - The specimen is preserved as an 1988; MAGNIEZ-JANIN, 1991). impression and represents a relatively involute form. AMMONITES FROM TI IH l.OWHR AFI'IAN OF Si I'ftANCLs 75
Tabic 2 - Stratigraphical distribution of Prodeshayesites, Deshayesites and Cheloniceras (Cheloniceras) in the Lower Aptian from England according to CASEY (1961b, 1963). - DISTRIBUZIONE STRATIGRAFICA DI Prodeshayesites, Deshayesites E Cheloniceras (Cheloniceras) NELL'APLIANO INFERIORE DELL' INGHILTERRA SECONDO CASI;Y ( 1961 B, 1963).
CASEY, 1961b, 1963
FISSICOSTATUS FORBESI DESHAYESI BOWERBANCKI TAXA *^«^^ Prodeshayesites fissicostatus germanicus 1
jacksoni 1 • ' lestrangei pseudotiliani bodei falcatus laeviusculus obsoletus Deshayesites primitivus forbesi pygmaeus fìttoni grapesi cf. consobrinus topleyi kiliani euglyphus spathi normani punfieldensis callidiscus gracilis mirabilis saxbyi E - deshayesi involutus multicostatus consobrinoides geniculatus vectensis wiltshirei grandis planus (C)Cheloniceras cornuelianum crassum kiliani disparile minimum proteus parinodum Idkaldyi quadrarium meyendorfii mackensoni cf. gotshei 76 DEIANOY G.
The ribbing is sinuous, constituted by primary ribs affinities really exist with some evolute Deshayesites with discrete peri-umbilical bullae ; the ribs split into described and figured by BOGDANOVA et alii (1979) as the middle of the flanks in bundles of 3 to 4 well marked D. formosus BOGDANOVA, KVANTALIANI & SHARIKA- ribs. The point of splitting is sometimes pointed out by a DZE, D. michailovae BOGDANOVA, KVANTALIANI & thickened primary rib. MATERIAl-Specimen 28579 Coll. SHARIKADZE. D. rarecostatus BOGDANOVA. KVAN DELANOY, Lower Aptian, Deshayesites tuarkyricus TALIANI & SHARIKADZE, D. bahaschensis BOGDANOVA Zone, Méouilles, Saint-André les Alpes. and D. dechyi PAPP, all these Deshayesites presenting DISCUSSION - The sculpture of this Deshayesites also remarkable convergences with the Prodeshayesites (sinuous fasciculate ribs, relatively narrow umbilicus) of the group bodei (KOENEN). D. planus CASEY is a allows us to include it in the group of D. tuarkyricus small species which ornamentation is similar to the BOGDANOVA. D. oglanlensis BOGDANOVA shows thicker Deshayesites sp. of the vocontian area, but the coiling is secondary ribs and D. tuarkyricus BOGDANOVA is a less evolute. D. luppovi BOGDANOVA shows a ribbing more involute form. Thus this specimen, which was strongly prorsiradiate in the lower part of the flanks. previously identified as Paradeshayesites gr. laeviu- OCCURRENCE - Considered as Prodeshayesites, the sculus (KOENEN) (DELANOY. 1991) is now compared stratigraphie position of these ammonites was easy to with D. weissiformis BOGDANOVA. precise. All the Prodeshayesites of Great Britain and Germany have been indeed collected in the first zone of OCCURRENCE - According to BOGDANOVA (1971. 1983) Deshayesites weissiformis BOGDANOVA occurs the Aptian (Prodeshayesites fissicostatus Zone in Great only in the Deshayesites tuarkyricus Zone of Britain (Tabi. 2), Prodeshayesites tenuicostatus Zone in Turkmenistan (Tabi. 3). The specimen described above Germany) (CASEY, 1961a. 1963; KEMPER 1967,1976; has been found in the "thick bundle" of the Aptian in KEMPER et alii, 1974) which may be correlated with the the Méouilles section. Deshayesites tuarkyricus Zone as it has been suggested by BOGDANOVA et alii (1983). But, if these ammonites arc true Deshayesites, it is more difficult to precise now Deshayesites sp. their stratigraphie position. D. planus CASEY is a species PI. 2, fig. 2, 3, 4: pi. 6. fig. 3, 6 of the Deshayesites forbesi Zone (CASEY, 1963) (Tabi.
1991 Prodeshayesites cf. tenuicostatus (KOENEN); DELANOY, p. 2). In Turkmenistan, BOGDANOVA (1971) has cited D. 439. fig. 2b, 2c. planus CASEY and D. dechyi PAP? in the Deshayesites weissi Zone while D. luppovi BOGDANOVA in the DESCRIPTION - This taxon is represented by Deshayesites tuarkyricus and Deshayesites weissi Zones compressed and poorly preserved little ammonites. The (Tabi. 3). The species from Central Dagestan described shell is evolute with a wide umbilicus. The and figures by BOGDANOVA et alii (1979) came from a ornamentation is constituted by numerous sigmoid ribs Deshayesites dechyi - Deshayesites deshayesi Zone or which can be single or, mostly, bifurcate were reworked in levels of an Epicheloniceras approximatively in the middle part of the flanks. subnodosocostatum - Colombiceras crassicostatum Zone. MATERIAL - Specimens 28580 Coll. DELANOY, La Waiting for a belter preserved material which could Colle gully, Moriez; 28581 Coll. DELANOY, Vignon elucidate the laxonomic problem raised by these gully section. Barrême; 28640 Coll. DELANOY, ammonites, the level containing these Deshayesites is Méouilles section. Saint André les Alpes ; 28641 Coll. considered arbitrarily and temporarily as the lop of the DELANOY. Angles road section; 28643 Coll. DELANOY, La Combe Lambert section, Angles and many Deshayesites tuarkyricus Zone. unregistered and fragmentary samples, all from the Lower Aptian, top of the Deshayesites tuarkyricus Zone. Deshayesites sp. gr. spathi /normani DISCUSSION - These ammonites have been at first Pl. 1, fig. 2 interpreted as Prodeshayesites gr. fissicostatus I tenuicostatus (DELANOY, 1991), whith which they 1991 Deshayesites gr. primitivus/spathii; DliLANOY, p. 440, fig. present great ornamental and morphological affinities. 2a. They arc very probably conspecific with the Deshayesites from the Nice area figured by AUTRAN & DESCRIPTION - The specimen is incomplete and DELANOY (1987). represented by about half a whorl. The whorl section is However, the discovery of true Deshayesites strongly compressed. The internal whorls are partly characteristic of the Deshayesites tuarkyricus Zone in visible and show primary, convexe ribs, probably the underlying levels set at new the problem of their bifurcate in the upper half of the sides. identification. According to RAWSON (oral and written When the whorl height reaches 16 mm, the communication), who has seen these ammonites and ornamentation is constituted by thick sinuous primary shown the specimen of the Nice area to CASEY and ribs, raising from the umbilical margin. The rib section DEAN, these Deshayesitidae represent an evolute is rounded and the ribs broaden in the middle part of the Deshayesites. Some ornamental and morphological flanks before bifurcating or trifurcating. All the ribs AMMONITES FROM THE LOWER APTIAN OF SE FRANCE 77 cross the venter where their thickness is maximum. On DESCRIPTION - Two small incomplete specimens the last preserved part of the shell, the ribs thicken and which show the succession of two ornamental stages. Up trifurcations arc replaced by short intercalatory ribs. to a whorl height of about 14-16 mm the ribbing is made MATERIAL - Specimen 28592 Coll. DELANOY, Lower of sinuous primary ribs, sligthly raised in the middle Aptian, Deshayesites weissi Zone, the road of Angles part of the flanks just below the regular bifurcation in section. Angles. the upper part of the flanks. Intercalatory ribs or DISCUSSION - The sculpture of this Deshayesites trifurcations appear progressively, allough irregularly. shows affinities whith that of some Deshayesites of the From this whorl height, the ribbing become more Deshayesites forbesi Zone (CASEY, 1961a) like D. irregular and fasciculate. Now the ribs bear small, little spathi CASEY or D. normani CASEY. D. primitivus peri -umbilical bullae and become thicker and give rise CASEY from the Prodeshayesites fissicostatus Zone to a group of 3 to 5 secundary ribs of variable thickness. seems to be more evolute. This specimen is quite similar Further subdivisions of the ribs appear inside the to the Deshayesites ex gr. involutus SPATI I of the Lower bundle. All of them cross the venter forming a gentle arc Aptian from Slovakia figured by VASICEK el alii in towards the aperture and becoming weaker. 1983. MATERIAL - Specimens 28615 and 28853 Coll. OCCURRENCE - Some species with an ornamentation DELANOY , Lower Aptian, Deshayesites weissi Zone, similar to this sample (D. kiliani CASEY, D. topleyi Vignon's gully section, Barrême. SPA ru and D. normani CASEY) have been cited by DISCUSSION - These two ammonites arc closely BOGDANOVA (1971) in the Deshayesites weissi Zone related to Deshayesites callidiscus CASEY. The sample from Turkmenistan (Tabi. 3). According to CASEY 28615 shows ornemental affinities with the sample SM (1961a, 1963) these Deshayesites occur in the B. 27057 (Coll. WILTSHIRE) figured by CASEY (1961a. Deshayesites forbesi Zone (Tabi. 2). Deshayesites cf. 1963) from the Alherfield Clay Series. Nevertheless, normani has been reported from the "Bedoulian " of they are different because of the weaker ribbing on the Rumania (PATRULIUS & AVRAM, 1976) venter, without the strong curvature of the ribs observed An other specimen comparable to this group has in the british specimens. been collected in the Tremolies section near Moriez, but OCCURRENCE - In Great Britain, Deshayesites ils stratigraphie position is unfortunately unclear callidiscus CASEY occurs at the top of the Deshayesites (specimen 28850 Coll. DELANOY, pl. 1, fig. 5). forbesi Zone (CASEY. 1961a, 1963) (Tabi. 2) and characterizes the Deshayesites callidiscus Sub-zone. In Deshayesites aff. euglyphus CASEY, 1963 the Lower Aptian from Turkmenistan. D. callidiscus PI. 1. fig. 4; pi. 4, fig. 4 CASEY has been cited in the Deshayesites weissi Zone by BOGDANOVA (1971) (Tabi. 3) and also in the Lower DESCRIPTION - The sculpture is well visible since a Aptian (Deshayesites deshayesi Zone) of Bulgaria whorl-heigh of about 6 mm. The ribbing is sinuous, (DIMITROVA, 1967). In Rumania the species of CASEY regular, formed by some rounded primary ribs (9-10 per occurs in the Deshayesites Zone (PATRULIUS & AVRAM, whorls), which are bifurcate just above or just below the 1976). mid flank. Rarely, an intercalatory rib appears in the area of the bifurcations and gives the impression of Deshayesites aff'. evolvens LUPPOV, 1952 trifurcation. All ribs cross the venter with their PI. 3. fig. 1 maximun of thickness. MATERIAL - Specimens 28634 and 28690 Coll. DESCRIPTION - This taxon is represented by a single, DELANOY. Lower Aptian, Deshayesites weissi Zone, La poorly preserved and compressed adult specimen. Only Combe Lambert section, Angles. the last whorl (end of the phragmocone and the body DISCUSSION - On the basis of Iheir dimensional chamber) is visible. characters and mode of ribbing these two specimens The end of the phragmcone bears relatively broad, show affinities with Deshayesites euglyphus described flexuous ribs, well marked as early as the umbilical by CASEY in 1963, according to him a species closely margin. These ribs are bifurcate or, more rarely, allied with D. kiliani SPATH . trifurcate in the upper half of the flanks. On the body OCCURRENCE - In the Lower Greensands, chamber, the ribbing changes. On the first half there are Deshayesites euglyphus CASEY occurs in the intercalatory, single and bifurcate strong, broad, sinuous Deshayesites forbesi Zone (CASEY, 1963) (Tabi. 2). ribs. On the second half of the chamber, the bifurcate BOGDANOVA (1971) has reported this species at the top ribs disappear progressively and on the end of the of the Deshayesites tuarkyricus Zone and in the preserved part subsist only single, less sinuous, distant Deshayesites weissi Zone of Turkmenistan (Tabi. 3). ribs, strongly elevated on the venter. MATERIAL - Specimen 28852 Coll. DELANOY. Lower Deshayesites aff. callidiscus CASEY, 1961 Aptian, Deshayesites weissi Zone ?, Vignon gully, Pl. 1, fig. 1 and 3 a, b Barrême. 78 DIÏIANOYG.
DISCUSSION - This Deshayesites shows great less thick than the primary ribs in the lower half of the affinities with the ammonite figured by KIUAN & flanks, of the same thickness than the secondary ribs in REBOUL (1915) as Parahoplites weissi NEUMAYR & the upper part of the flanks and on the venter. UHLIG and considered later by LUPPOV (1952) as a MATERIAL - Specimens 28695 and 28696 Coll. representative of his new species D. evolvens. The DELANOY, Lower Aptian, Deshayesites weissi Zone, La body chamber is also very similar to the one of the Combe Lambert section, Angles. lectotype of D. consobrinus (D'ORBIGNY) but, unfortunately, the inner whorls of this species arc DISCUSSION - These ammonites show the typical unknown. ornamentation of the species created by D'ORBIGNY in 1841. The rare presence of tubercles on the intercalatory OCCURRENCE - The exact slratigraphical position ribs on one side of one specimen prove the great of Deshayesites evolvens LUPPOV is not know in ornamental variation of this taxon as KEMPER (1964) has Turkmenistan (Deshayesites Zone in LUPPOV, 1952) already considered. and the species is not cited by BOGDANOVA (1971). DIMITROVA (1967) describes and figures a specimen OCCURRENCE - The stratigraphie position of the collected in the Lower Aptian of Bulgaria without genus Cheloniceras HYATT, 1903 has already been any indications of its precise slratigraphical position. discussed by CASEY (1961a, b) and KEMPER (1964). PATRULIUS & AVRAM (1976) have cited Deshayesites In the Lower Greensand, C. cornuelianum aff. evolvens LUPPOV in the Deshayesites Zone of (D'ORBIGNY) occurs in the Deshayesites deshayesi Rumania. Its ornamental affinities with D. weissi and Tropaeum bowerbancki Zones (CASEY, 1961a, b) (NEUMAYR & UHLIG) and D. consobrinus (Tabi. 2). (D'ORBIGNY), two species of the Deshayesites weissi In northern Germany, the species has been Zone and the collect of the specimen described some reported in the Cheloniceras latispinosum Zone of beds above a level with D. aff. callidiscus CASEY KEMPER (1964) which corresponds to a part of the seems to indicate that it occurs in the same position. Deshayesites deshayesi Zone (KEMPER, 1964). In Turkmenistan the genus Cheloniceras H Y ATT is reported from earlier strata than in the north of the GENUS Cheloniceras HYATT. 1903 Europe, viz. in the Deshayesites weissi Zone TYPE SPECIES: Ammonites cornuelianus D'ORBIGNY (BOGDANOVA, 1971) (Tabi. 3).
Cheloniceras cornuelianum D'ORBIGNY. 1841 PI. 6, fig. 1 a,b and 2 Cheloniceras sp. PI. 5, fig. 1 a, b 1841 Ammonites cornuelianus D'ORBIGNY. p. .164, pl. 112. fig. 1 cl2 1924 Cheloniceras cornuelianum (D'ORBIGNY); Sl'ATII, p. 79. 1961b Cheloniceras (Cheloniceras) cornuelianum (D'ORBIGNY); DESCRIPTION - An incomplet specimen with a CASIÌY, p. 198. pi 33, Fig. 7 a-b; pi. 34, fig. 1 a-b. 9 a-b; pi. subcircular depressed whorl section. Two ornemental 35, fig. 1 a-b, 2, 3; lext-fig. 60 a-c, 61, 62, 61e-[(cum syn.). stages can be distinguished. 1964 Cheloniceras cornuelianum (D'ORBIGNY); KHMPER, p.46, pi. 4, fig. 3 a-b; pi. 5, fig. 3; pi. 7 (cum syn.) 1) Up lo a diameter of about 55 mm, the primary tuberculate ribs alternate with 5 non-tuberculate intercalatory ribs per interval. The former show a gentle DESCRIPTION - The species is well represented by peri-umbilical tubercle and, in the middle of the flanks, slightly compressed and incomplete specimens. The a stronger lateral tubercle which is the point of sculpture is similar to the one of the typical form. There bifurcation or sometimes trifurcation are two types of ribbing. The secondary ribs cross the venter where their 1) The thick primary ribs which originate at the base thickness is maximum. Intercalatory ribs do not bear of the umbilical wall, which they cross rursiradiate. tubercles except an angular swelling in the middle part They develop a first big tubercle on the umbilical of the flanks. margin, and a second tubercle just above the upper third 2) From this diameter until the end of the preserved of the flanks stronger than the umbilical one (those of part of the ammonite, the number of intercalatory ribs specimen 28695 are flatter and more proéminent, thus decreases (2-3). They are sometimes bifurcate in the recalling the subspecies latispinosum). From this middle part of the sides. The primary ribs are a few tubercle start two secondary ribs which cross radially the stronger than the intercalatories, the lateral tubercles are venter in their maximum of thickness. moderate sized, angular, the bifurcations disappear. 2) The non-tuberculate intercalatory ribs (except MATERIAL - Specimen 28684 Coll. DELANOY. Lower some rare case of umbilical lubcrculation in the internal Aptian, Deshayesites weisii Zone , Vignon 's gully whorl on one side of specimen 28696). These ribs are section, Barrême. AMMl INITliS I-'Rl 1M 'Il Ili I.( 1WI-R API1AN ( >F Sii FRANŒ 79
Tabic 3 - Slratigraphical distribution o/Deshayesites and Cheloniceras in the Lower Aptian of Turkmenistan according to BOGDANOVA (1971). - Distribuzione stratigrafica di Deshayesites e Cheloniceras nell'Aptiano inferiore del Turkmenistan secondo Bogdanova ( 1971 ).
BOGDANOVA, 1971
"""""""^^^Zones Tuarkyricus Weissi Deshayesi Furcata Taxa "^^^ Deshayesites antiquus tuarkyricus weissiformis oglanlensis luppovi consobrinus planicostatus euglyphus weissi planus subsimilis normani inflatus kiliani pappi topleyi dechyi levigatus callidiscus latilobatus pygmaeus kudriavzevi consobrinoides deshayesi kasanskii terminalis Cheloniceras seminodo sum cornuelianum 80 DELANOY O.
DISCUSSION - This Cheloniceras differs from the ACKNOWLEDGEMENTS forms of the cornuelianum group in its less proéminent I thank F. CECCA (Rome) for the interest and the ornamentation and its greater number of intercalatory encouragements that he has given during the realization ribs in the inner whorls. Some affinities exist with the of this paper, P RAWSON (London) and P. Cheloniceras figured by SINZOW (1906, pl. 1, fig. 1) as HOEDEMAEKER (Leiden) for their very useful comments C. cornuelianum (D'ORBIGNY) which was considered by on the manuscript. I also thank Mrs. R. CASANOVA, G. LUTPOV (1952) as variety sinzowi. However the THOMEL, M. MOULLADE (Nice), Mrs H. ARNAUD, IP. tuberculation of the latter is stronger and the number of THIEULOY (Grenoble) and G. CONTE (Nîmes) for their intercalatories is smaller. varied assistance. A great aknowlegment to Mr. A. OCCURRENCE - Cheloniceras sp. has been collected MAGNIN (Grenoble) for his help during the field-work. in the upper part of the aptian limestones of the Barrême section, a few beds below the level i which Deshayesites aff evolvens has been found (top of the Deshayesites REFERENCES weissi Zone ?). ANONYMOUS (1965) - Conclusions générales du Colloque in Colloque sur le Crétacé inférieur (Lyon, Septembre 1963). Mémoire du Cheloniceras kiliani (KOENEN, 1902) Bureau de Recherches Géologiques et Minières, 34: 292-296, Paris. PI. 4, fig. 2 ARNAUD H. (1981) -De la plate-forme-urgonienne au bassin vocontien: le Barrémo-Bédoulien des Alpes occidentales entre \902 Acanthoceras kiliani KOENliN, p. 406, pi. 33. fig. 3-6. Isère et Buech (Vercors méridional, Diois oriental et Dévoluy. 1921 Cheloniceras kiliani (V. KOENEN); SPATH, p. 314. Géologie Alpine, 12 (1): 1-311, Grenoble. 1961b Cheloniceras (Cheloniceras) kiliani (V. KOENEN); CASEY, p. 213, pi. 33, fig. 3-6 ; text-fig. 67a-d.. ARNAUD H. & ARNAUD-VANNEAU A. (1991) - Les calcaires urgoniens des massifs subalpins septentrionaux et du Jura. Géologie Alpine, DESCRIPTION - Up to a diameter of about 50 mm, the 67: 63-79, Grenoble. ribbing is similar to that of the cornuelianum group. It is AUTRAN G. & DELANOY G. (1987) - Mise en evidence d'un niveau à composed by thick primary ribs, which are tuberculated ammonites aptiennes dans la basse vallée du Var (Alpes on the umbilical margin and in the upper third of the Maritimes, France). Conséquences palèogeographiques. Geobios, flanks, from where they bifurcate, and by 1-2 non 20 (3) : 415-422, Lyon. tuberculate intercalatory ribs per interval. After this BOGDANOVA T.N. (1971) - The Lower Aptian and these boundaries in diameter the primary ribs suddenly disappear and the the western and southern Turmenistan. Thesis Laboratory of ribbing is only made of inerm ribs, simple or more Geology of the University of Moscow: 1-29, Moscow (in russian). rarely bifurcate from the umbilical margin. BOGDANOVA T.N. (1983) - Deshayesites tuarkyricus Zone: the MATERIAL - Specimen 28682 Coll. DELANOY (leg. lowermost Aptian of Turkmenistan. Ezhcgodnik Vses Palcont. ARNAUD-VANNEAU), Lower Aptian, top of the Obsh., 26: 128-147 (in russian). Deshayesites deshayesi Zone/base of the Dufrenoya furcata Zone, Vignon gully section, Barrême. BOGDANOVA T.N., KVANTALIANI I.V. & SHARIKADZE M.Z. (1979) - Some early Aptian Deshayesitidae from Central Dagestan. DISCUSSION - This ammonite is very similar to the Geologica Balkanica, 9 (3): 3-12, Sofia. form described by KOENEN (1902) as Acanthoceras kiliani. The main feature of this species is the fast BOGDANOVA T.N., LOBACHEVA S.V. & PROZOROVSKY V.A. (1983) - The Barremian - Aptian boundary. Abstract - Symposium on change of ornamentation ( loss of the tuberculation) at a Cretaceous stage boundaries: 26-29, Copenhagen. small diameter. BUSNARDO R. (1965) -Le stratotype du Barrémien. Lithologie et OCCURRENCE - Cheloniceras kiliani (KOENEN, 1902) macrofaune in Colloque sur le Crétacé inférieur (Lyon. Septembre has been described from the Aptian from Ahaus, in 1963). Mém. B. R. G.M..34: 101-116, Paris. Germany. According to CASEY (1961a, b) the species occurs in the top of the Deshayesites deshayesi Zone BUSNARDO R(1984) - Ammonites in Chapitre Crétacé inférieur. Synthèse Géologique du Sud-Est de la France. Mém. B. R. G.M., {grandis Subzone) and in the Tropaeum howerbancki 125: 292-294, Orléans. Zone (meyendorffi Subzone) (Tabi. 2). CASEY R. (1961 a) - The slratigraphical palaeontology of the Lower Greensand. Paleontology, 3 (4) :487-621, London.
5. - CONCLUSIONS CASEY R. (1961 b) - The Ammonoidea of the Lower Geensand, Pari III. Palaeont. Soc: 119-216, London.
This work is only a stage in the knowledge of the CASEY R. (1963) - The Ammonoidea of the Lower Geensand, Part V. ammonite fauna of the Lower Aptian of the Angles- Palaeont. Soc.: 289-398, London Barrcme area. There is no doubt that future collects of ammonite will modify the results presented in this COTILLON P. (1971) - Le Crétacé inférieur de l Arc subalpin de Castellane entre VAsse et le Var. Mém. B. R. G.M., 68: 1-313. paper. The figuration of the most significant Paris. ammonites collected up today in this area will permit, in any case, a better comparison with the DELANOY G. ( 1991 ) - Sur la présence du genre Prodeshayesites CASPY. 196] (Ammonoidea) dans lAptien inférieur du BassinVoconiien. faunas of the other regions. Cretaceous Research, 12 : 437-441, Ixindon. AMMONITES FROM THE LOWER APTIAN OF SE FRANCE 81
DEI ANO Y G. (1992) - Les ammonites du Barrémien supérieur de Saint- LUPPOV (1952) - Lower Cretaceous deposits of the Northwest of Laurent de l'Escarène (Alpes-Maritimes, Sud-Est de la France). Caucasus and their fauna. Trud. Vses. Nell. Nauchno. Issled. Geol. Ann Mus. Hist. Nat. de Nice: 1-148, Nice. Razved, 65: 1-238, Moscow (in russian).
DELANOY G. (in press) - Les zones à Feraudianus, Giraudi et Sarasini MAGMEZ-JANIN F. (1991) - Renouvellements de Foraminifères et du Barrémien supérieur de la région stratotypique d'Angles- séquence de dépots dans le Crétacé inférieur du Bassin vocontien Barrême Castellane. Géologie Alpine, Grenoble. (SE de la France). Bull. Soc. Géol. France, 162 (5): 887-895, Paris.
DIMTTROVA N. (1967) - Les fossiles de Bulgarie. IV Crétacé inférieur : MASSE J.P. & THIEULOY J.P. (1975) - Données nouvelle sur la Cephalopoda (Nautiloidea et Ammonoidea). Publications de biostratigraphie et la paléogéographie de l'Aptien inférieur de l'Académie Bulgare des Sciences: 1-236, Sofia. Basse Provence occidentale. C. R. Acad. Sciences Paris, 280: 1337- 1339, Paris. FERRY S. (1988) - Contrôle eustatique de la resédimentation calcaire en fosse vocontienne (Mésozoique, Sud-Est de la France). In: S. FERRY & J. L. RUBINO et alii (Eds.): "Eustatisme et séquence de MOULLADE M. (1966) - Etude stratigraphique et micropaléontologique dépôts dans le Crétacé du Sud-Est de la France". Géotrope, 1: 32- du Crétacé inférieur de la "Fosse Vocontienne". Doc. Lab. Géol. 51, Lyon. Fac. Sciences Lyon, 15: 1-369, Lyon.
FABRE-TAM S., MOLJLLADE M. & THOMEL G. (1965) - Le Bédoulien ORBIGNY A. D' (1840-42) - Paléontologie Française. Terrains Crétacés, dans sa région type, la Bédoule-Cassis.in Colloque sur le Crétacé Céphalopodes. Massonéd.: 1-662, Paris. inférieur (Lyon, Septembre 1963). Mém. B. R. G.M., 34: 173-199, Paris. PATRULIUS D. & AVRAM E. (1976) - Stratigraphie et corrélation des terrains nèoeomiens et barrèmo-bédoulien du Couloir de FLANDRLN J. (1965) - Rapport sur l'étage Aptien in Colloque sur le Dimbovicioara (Carpathes orientales). Dari de Seama aie Sedint., Crétacé inférieur (Lyon, Septembre 1963). Mém. B. R. G.M., 34: 42: 135-160, Bucuresti. 222-234, Paris.
FRIES G.. BEAUDOIN B., JOSEPH P. & PATERNOSTER B. (1984) - Les RAWSON P.F. (1983) - The Valanginian to Aptian stage. Current grès de Rosans et les slumpings aptiens associés: restitution definitons and outstanding problems. Zitteliana, 10: 493-500, paléomorphologiques. Bull. Soc. Géol. France, sér. 7,. 26 (4): 693- Mûnchen. 702, Paris. ROCH E. (1927) - Etude stratigraphique et Paleontologique de l'Aptien HOEDEMAEKER P. & BULOT L. (1990) - Preliminary ammonite zonation inférieur de la Bédoule. Mém. Soc. Géol. France, 4: 5-37, Paris. for the Lower Cretaceous of Mediterranean fteg/on. Géologie Alpine, 66: 123-127,Grenoble. RUBINO J.L. (1988) - Organisation des séquence de dépôts de la plate forme au bassin dans l'Aptien et l'Albien du assin Vocontien.. In S. HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. B„ FERRY & J. L. RUHNO et alii (Eds.): "Eustatisme et séquence de AVRAM E., BOGDANOVA T. N„ BUJTOR L., BULOT L., CECCA F., dépôts dans le Crétacé du Sud-Est de la France". Géotrope, 1: 53- DELANOY G., ETLACUFINI M., MEMMI L., OWEN H. G., RAWSON P. 73, Lyon. F., SANDOVAL J., TAVERA J. M., THIEULOY J.-P., TOVBINA S. Z. & VASICEK Z. (1993) - Ammonite zonation for the Lower Cretaceous SINZOW I. (1906) - Die Beschreibung einiger Douvilleicerasv4r(en aus of the Mediterranean region; basis for the stratigraphie den oberen Neokom Russlands. Verh. russ. -kais Min. Ges. St. correlations within IGCP-Project 262. Revista Espanda de Petersb., 2 (44):157-197, St Petersbourg. Paleontologia, 8 (1): 117-120, 1 tab., Madrid.
KEMPIÌR E. (1964) - Einige Cephalopoden aus den Apt des Westlichen SPATH L.F.(1921) - On Cretaceous Cephalopoda from Zululand. Ann. Norddeutchland. Fortschr. Geol. Rheinid. u. Westf., 7: 31-66, South African Mus. 12 (16): 217-321, Cape Town. Krefeld. SPATH L.F.(1924) - On the ammonites of the Speeton Clay and the KEMPER E. (1967) - Die atteste Ammoniten-Fauna im Aptium subdivisions of the Neocomian. Geological Magasine, 7: 73-89, Nordwest-Deutchlands.Palâont. Z., 41:119-131, Stuttgart. London.
KEMPER E. (1976) - Geologisher Fiirher durch die Grafschaft THOMEL G. (1964) - Les zones d'ammonites de VAptien du Sud-Est des Bentheim und die angrezenden Gebiete mit einem Abri ss der Basses-Alpes. C. R. Acad. Sciences Paris, 258: 4308-4310, Paris. emslàndischen Unterkreide. Das Bentheimer Land, 64: 1-206, Bentheim. TOUCAS (1888) - Note sur le Jurassique supérieur et le Crétacé inférieur de la vallée du Rhone. Bull. Soc. géol. France, 16: 903- KEMPER E., RAWSON P.F., SCHMID F. & SPAETH C. (1974)- Die 927, Paris. megafauna der Kreide von Helgoland und ihre biostratigraphische Deutung. Newsl. Strat., 3 (2):121-137, Leiden. VASICEK Z. (1972) - Ammonoidea of the Thesin-Hradiste Formation (Lower Creatceous) in the Moravskoslezske Beskydy Mts. Vydal KILIAN W.& REEOUL (1915) - Contribution à l'étude des faunes Ustreni uslav Geologicky, Praha, y Acad. Naklad. Ceskosslov. Akad. paléocrétacées du Sud-Est de la France; 1: la faune de l'Aptien de ved: 1-103, Prague. Montelimar (Drame). Mem. Carte Géol. détaillée France: 1-221, Paris.
VASICEK Z, MICHALLK J & BORZA K. (1983) - To the "Neocomian" KOENEN A. VON (1902) - Die Ammoniten des norddeutschen Neocom biostratigraphy in the Krizna-Nappe of the Strazovske Vrchy (Valanginien, Barrémien und Aptien). Abh. Kôn. Preuss. Geol. Moutains (Northwestern Central Carpathians). Zitteliana, 10 : 467- Landcsandst, N. F., 24: 1-451, Berlin. 483, Mûnchen. 82 DELANOY Q.
PLATE 1
Fig. 1 - Deshayesites aff. callidiscus CASEY, 1961: specimen 28615 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (VIG 486), Vignon's gully section, Barrême. Fig. 2 - Deshayesites gr. spathi/normani: specimen 28592 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (ANG 210), Angles road section, Angles. Fig. 3a, b - Deshayesites aff. callidiscus CASEY, 1961: specimen 28853 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (VIG 486),Vignon's gully section, Barrême. Fig. 4 - Deshayesites aff. euglyphus CASEY, 1963: specimen 28690 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (COM 122), La Combe Lambert section. Angles. Fig. 5 - Deshayesites gr. spathilnormani: specimen 28850 Coll. DELANOY, Lower Aptian, level unknown, Trcmolies section, Moriez. All figures natural size.
TAVOLA 1
Fig. 1 - Deshayesites aff. callidiscus CASEY, 1961: esemplare 28615 Coll. DEIANOY, Aptiano inferiore, Zona a Deshayesites weissi (VIG 486), sezione di "Ravin du Vìgnon",presso Barrême. Fig. 2 - Deshayesites gr spathi/normani: esemplare 28592 coll. DEIANOY, Aptiano inferiore, zona a Deshayesites weissi (ANG 210), sezione della strada di Angles, presso Angles. Fig. 3a, b - Deshayesites aff. callidiscus CASEY, 1961: esemplare 28853 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (VIG 486), sezione di "Ravin du Vignon ", Barrême. Fig. 4 - Deshayesites aff. euglyphus CASEY, 1963: esemplare 28690 coll. DEIANOY, Aptiano inferiore, zona a Deshayesites weissi (COM 122), sezione di "La Combe Lambert", Angles. Fig. 5 - Deshayesites gr. spathi/normani: esemplare 28850 coll. DEIANOY, Aptiano inferiore, livello sconosciuto, sezione di "Ravin de la Colle", presso la fattoria di Tremolies, Moriez. Tutte le figure sono a grandezza naturale. AMMONITES FROM THE LOWER APTIAN OF SE FRANCE 83 84 DELANOY G.
PLATE 2
Fig. la, b - Deshayesites oglanlensis BOGDANOVA. 1983: specimen 28653 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (MEO 199), Méouilles section, Saint-André les Alpes. Fig. 2 - Deshayesites sp. : specimen 28580 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (TRE 248), La Colle Gully section near the farm of Tremolies, Moriez Fig. 3 - Deshayesites sp. : specimen 28643 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (COM 107), La Combe Lambert section, Angles. Fig. 4 - Deshayesites sp. : sample 28640 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (MEO 208), Méouilles section, Saint André les Alpes. All figures natural size.
TAVOLA 2
lug. la, h - Deshayesites oglanlensis BOGDANOVA, 1983: esemplare 28653 coll. DELANOY, Aptiano inferiore, zona a Deshayesites tuarkyricus (MEO 199), sezione di "Méouilles", Saint-André les Alpes. Fig. 2 - Deshayesites sp. : esemplare 28580 coll. DELANOY, Aptiano inferiore, zona a Deshayesites tuarkyricus (TRE 248), sezione di "Ravin de la Colle", presso la fattoria di Tremolies, Moriez Fig. 3 - Deshayesites sp.: esemplare 28643 coli. DEIANOY, Aptiano inferiore, zona a Deshayesites tuarkyricus (COM 107), sezione di "La Combe Lambert", Angles. Fig. 4 - Deshayesites sp. : esemplare 28640 coli. DEIANOY, Aptiano inferiore, zona a Deshayesites luarkyricus (MEO 208), sezione di "Méouilles", Saint-André les Alpes. Tutte le figure sono a grandezza naturale.
DELANOY G. 86
PLATE 3
Fig. 1 - Deshayesites aff. evolvens LUPPOV, 1952: specimen 28852 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (VIG 493), Vignon gully section, Barrême. All figures natural size.
TAVOIA 3
Fig. I - Deshayesites aff. evolvens LUPPOV, 1952: esemplare 28852 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (VIG 493), sezione di "Ravin du Vignon ", Barrême. Tutte le figure sono a grandezza naturale.
DELANOY O.
PLATE 4
Fig. 1 - Ancyloceras sp.: specimen 185 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (COM 122), La Combe Lambert section, Angles. Fig. 2 - Cheloniceras kiliani (KOENEN, 1902): specimen 28682 Coll. DELANOY leg. ARNAUD-VANNEAU, Lower Aptian, base of Dufrenoya forcata Zone (VIG 498b), Vignon gully section, Barrême. Fig. 3 - Pseudohaploceras liptoviense (ZEUCHNER, 1856): specimen 28691 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (COM 119), La Combe Lambert section, Angles. Fig. 4 - Deshayesites aff. euglyphus CASEY, 1963: specimen 28634 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (COM 122), La Combe Lambert section, Angles. All figures natural size.
TAVOLA 4 lug. 1 - Ancyloceras sp.: esemplare 185 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (COM 122), sezione di "La Combe Lambert", Angles. Fig. 2 - Cheloniceras kiliani (KOENEN, 1902): esemplare 28682 coll. DEIANOY, Aptiano inferiore, zona a Dufrenoya furcata (VIG 498b), sezione di "Ravin du Vignon ", Barême. Fig. 3 - Pseudohaploceras liptoviense (ZEUCHNER, 1856): esemplare 28691 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (COM 119), sezione di La Combe Lambert, Angles. Fig. 4 - Deshayesites aff. euglyphus CASEY, 1963: esemplare 28634 coll. Delanoy, Aptiano inferiore, zona a Deshayesites weissi (COM 122), sezione di "La Combe Lambert", Angles. Tutte le figure sono a grandezza naturale.
90 DELANOY G.
PLATE 5
Fig. la. b - Cheloniceras sp.: specimen 28681 Coll. DELANOY. Lower Aptian. Deshayesites weissi Zone (VIG 490), Vignon gully section, Barrême. Fig. 2 - Deshayesites aff. weissiformis BOGDANOVA, 1983: specimen 28579 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (MEO 200), Méouilles section, Saint André les Alpes. Fig. 3 - Ancyloceras ? gr. matheroni D'ORBIGNY. 1842: specimen 28686 Coll. DELANOY. Lower Aptian, Deshayesites weissi Zone (VIG 490), Vignon Gully section, Barrême. All figures natural size.
TAVOLA 5
Fig. I a,h - Cheloniceras sp.: esemplare 28681 coll. DEIANOY, Aptiano inferiore, zona a Deshayesites weissi (VIG 490), sezione di Ravin du Vignon, Barrême. Fig. 2 - Deshayesites aff. weissiformis BOGDANOVA, 1983: esemplare 28579 coll. DEIANOY, Aptiano inferiore, zona a Deshayesites tuarkyricus (MEO 200), sezione di "Méouilles", Saint-André les Alpes. Fig. 3 - Ancyloceras ? gr. matheroni D 'ORBIGNY, 1842: esemplare 28686 coll. DEIANOY, Aptiano inferiore, zona a Deshayesites weissi (VIG 490), sezione di "Ravin du Vignon", Barrême. Tutte le figure sono a grandezza naturale.
92 DEIANOY G.
PLATE 6
Fig. la, b - Cheloniceras cornuelianum (D'ORBIGNY), 1841: specimen 28696 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (COM 122), La Combe Lambert section, Angles. Fig. 2 - Cheloniceras cornuelianum latispinosum (NlKTHlCH, 1915): specimen 28695 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (COM 122), La Combe Lambert section, Angles. Fig. 3 - Deshayesites sp.: specimen 28641 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (ANG 206b), Angles road section, Angles. Fig. 4 - Deshayesites sp. : specimen 28581 Coll. DELANOY, Lower Aptian, Deshayesites tuarkyricus Zone (VIG 482), Vignon gully section, Barrême. Fig. 5 - Costidiscus recticostatus (D'ORBIGNY, 1841): specimen 28639 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (VIG 497), Vignon gully section, Barrême. Fig. 6 - Costidiscus aff. nodosostriatus (UHLIG, 1883): specimen 28630 Coll. DELANOY, Lower Aptian, Deshayesites weissi Zone (TRE 262), La Colle gully section near the farm of Tremolies, Moriez. All figures natural size.
TAVOLA 6 lug. la, h - Cheloniceras cornuelianum (D 'ORBIGNY, 1841): esemplare 28686 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (COAL 122), sezione di "La Combe Lambert", Angles, lug. 2 - Cheloniceras cornuelianum latispinosum (NlKTHlCH, 1915): esemplare 28695 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (COM 122), sezione di "La Combe Lambert", Angles, lug. 3 - Deshayesites sp.: esemplare 28641 coll. DELANOY, Aptiano inferiore, zona a Deshayesites tuarkyricus (ANG 206b), sezione della strada di Angles, Angles. Fig. 4 - Deshayesites sp.: esemplare 28581 coll. DELANOY, Aptiano inferiore, zona a Deshayesites tuarkyricus (VIG 492), sezione di "Ravin du Vignon ", Barrême. Fig. 5 - Costidiscus recticostatus (D'ORBIGNY, 1841): esemplare 28639 coll. DEIANOY, Aptiano inferiore, zona a Deshayesites weissi (VIG 497), sezione di Ravin du Vignon, Barrême. Fig. 6 - Costidiscus aff. nodosostriatus (UHLIG, 1883): esemplare 28630 coll. DELANOY, Aptiano inferiore, zona a Deshayesites weissi (TRE 262), sezione di "Ravin de la Colle ", presso la fattoria di Tremolies, Moriez. Tutte le figure sono a grandezza naturale.
94 DELANOY G.
PLATE 7
Fig. 1 - Procheloniceras alhrechtiaustriae (UHLIG, 1883): unregistered specimen Coll. MAGNIN-BÈCU, Lower Aptian, Deshayesites tuarkyricus Zone (COM 109), La Combe Lambert section, Angles. All figures natural size.
TAVOIA 7
Fig. I - Procheloniceras alhrechtiaustriae (UHLIG, 1883): esemplare non catalogato coll. MAGNIN-BÈCU, Aptiano inferiore, zona a Deshayesites weissi (COM 109), sezione di "La Combe-Lambert", Angles. Tutte le figure sono a grandezza naturale.
56 DELANOYO.
PLATE 8
Fig. 1 - The "thick bundle" of the Deshayesites tuarkyricus Zone in the road of Angles section, Angles. Fig. 2 - The "thick bundle" of the Deshayesites tuarkyricus Zone in the Vignon's gully section, Barrême.
TA VOI A 8
Fig. 1 - Il "thick bundle" della zona a Deshayesites tuarkyricus nella sezione della strada di Angles, Angles. Fig. 2-11 "thick bundle" della zona a Deshayesites tuarkyricus nella sezione della strada di "Ravin du Vignon", Barrente.
98 DELANOYG.
PLATE 9
Fig. 1 - The top of the bedoulian limestones in the Vignon's gully section. Fig. 2 - The perforated surface of the top of the bedoulian limestones in the Vignon's gully section.
TAVOIA 9
Fig. 1 - La sommità dei calcari bedouliani nella sezione di "Ravin du Vignon", Barrême. Fig. 2 - La superfìcie sommi tale perforata dei calcari bedouliani nella sezione di "Ravin du Vignon", Barrême.
100 DELANOY G.
PLATE 10
Fig. 1 - The top of the bedoulian limestones and the beginning of the Blue Marls in La Combe Lambert section. The double bed (beds n° 131-132) is considered as the base of the Dufrenoya furcata Zone. Fig. 2 - The double bed of the base of the Dufrenoya furcata Zone (bed 271) in La Colle gully section near the farm of Trcmolies.
TA VOI A 10
Fig. I - La sommità dei calcari bedouliani e l'inizio della Formazione delle "Marnes Bleues" nella sezione di "La Comb e Lambert", Angles. Il doppio strato (strati 131-132) è considerato come la base della Zona a Dufrenoya furcata. Fig. 2-11 doppio strato della base della Zona a Dufrenoya furcata (strato 271) nella sezione di "Ravin de la Colle", presso la fattoria di Tremolies, Moriez.
Mem. Descr. Carta Geol d 'It. LI (1995), pp. 103-108
New data on the Upper Barremian biostratigraphy of the Georgian region (Caucasus)
Nuovi dati sulla biostratigrafia del Barremiano superiore della regione georgiana (Caucaso)
MIKHAIL KAKABADZE (*) & ELISO KOTETISHVILI (*)
IGCP Projects 343 : Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - The type section is selected for the Upper Barremian of RIASSUNTO - E' stata selezionala una sezione tipo per il Barremiano Georgia. Besides the four previously established ammonite zones of superiore della Georgia. Oltre alle quattro zone ad ammoniti definite in Heinzia matura. Hemihoplites feraudianus, fmerites giraudi and Col- lavori precedenti (Heinzia matura Hemihoplites feraudianus. Imerites chidites securiformis, two new Horizones - Ancyloceras vandenheckii giraudi e Colchidites securiformis), vengono proposti due nuovi oriz (lowermost Upper Barremian) and Pseudocrioceras waagenoides zonti: Ancyloceras vandenheckii (parte basale del Barremiano superiore) (uppermost Upper Barremian) are proposed. e Pseudocrioceras waagenoides (tetto del Barremiano superiore).
KEY-WORDS: Biostratigraphy, Upper Barremian, Correlation, Zone, PAROLE CHIAVE: Biostratigrafia, Barremiano superiore, correlazione, Horizon, Ammonites, Western Georgia. zona, orizzonte, ammoniti, Georgia occidentale.
(*) A. Djanelidze Geological Institute of Academy of Sciences of Georgia, Z. Roukhadze str. 1/9, 380093 Tbilisi, Republic of Georgia. |()4 KAKABADZIi M. - Kl ffl ill SIIVI!.I li.
1. - INTRODUCTION proposed here as the type section for the Georgian Upper Barremian (Fig. 1, 2). A summary description of this The problem of Global biostratigraphical correlation section was published recently (ADAMIA el alii, 1988), of the Cretaceous is currently under active investigation. but it is now apparent that the range of Upper Barremian Two IGCP Projects (343 and 362), concerned with inter has to be expanded significantly and its biostratigraphi regional correlation within the Tethys as well as between cal interpretation to be modified. the Tethyan and Boreal regions, have started simultane This section is situated to the north of Tvishi village ously. Hence new data on the Cretaceous biostratigraphy on the right bank of the river Rioni, along the Kutaisi- of any individual region is important. Oni road. Above the massive Urgonian limestones are: Until recently the biostratigraphical scheme of Upper Barremian of Georgia consisted of 4 zones: 1) Heinzia 1. Spontaneously outcropping, medium-bedded whitish matura, 2) Hemihoplites soulieri (wc believe that Ilemi- limestones (17m). hoplites feraudianus, instead of Hemihoplites soulieri, 2. Similar limestones with brachiopod debrics (7 m). should be regarded as index-species for this Zone, de The sequences can be followed along the Lakhephisl- spite its relatively rare occurence in Georgia), 3) Imer- skali (the right tributary of the Rioni). ites giraudi and 4) Colchidites securiformis. New data 3. While limestones with rather abondant ammonites - from the lowermost and uppermost Upper Barremian of Ancyloceras vandenheckii AsiTER, A. sp. ind., Pseu Western Georgia allows the Upper Barremian bios docrioceras ex gr. waageni (ANTHUI.A), Eulytoceras tratigraphic scheme to be supplemented here. phestum (MATHF.RON) (0.4 m). 4. (In the flood plane) white limestone with Spitidiscus 2. - AVAILABLE DATA sp. ind.. Paracrioceras rondishiense KAKAHADZE (0.8 m). Both the lowermost and uppermost Barremian arc 5. Limestone layer with Heinzia costata KOTETISIIVILI, well represented at Tvishi village, and this locality is //. sp. ind. (0.6 m).
Eig. 1. Schematic map of Lower Cretaceous outcrops in Western Georgia. - Carta schematica degli affioramenti del Cretaceo inferiore nella Georgia occidentale. UPPER BARREMIAN BIOSTRATIGRAPHY IN GEORGIA 105
Zone D. weissi
Beds with "Acrioceras" sp.sp.
Horizon P. waagenoides
Zone C. securiformis
Zone I. giraudi
Zone Hem. feraudianus
Zone H. matura
Horizon A. vandenheckii
Undivided Lower Barremian
Fig. 2. Biostratigraphical subdivision of the Upper Barremian deposits in the village of Tvishi (Western Georgia). - Suddivisione biostratigrafica dei depositi del Barremiano superiore nel villaggio di Tvishi (Georgia occidentale).
6. White limestone with Hemihoplites sp. (0.4 m). (ROUCHADZE), Heteroceras sp., Opis rionensis 7. Light grey limestones containing Imerites giraudi ROUCHADZE (5 m). (KlLlAN), Imerites /avrei ROUCHADZE, Eristavia di- 11. Similar to 9 with "Acrioceras" sp. ind. in the up choloma (ERISTAVI), Triplasia georgsdorfensis permost part of the layer (4 m). (BART. & BRUND.), Lenticulina praegaultina BART., BEIT, ET BOLLI, Conorotalites intercedens (BETT.), 12. Grey, compact, medium-bedded marly limestones Ganelinella barremiana BETT., etc. (5.9 m). with "Acrioceras" ex gr. furcatum D'ORBIGNY, "A." sp. ind., Costidiscus cf. recticostatus 8. Medium-bedded grey, compact limestones with Col- D'ORBIGNY (1 m). chidites securiformis (SlMONOViCH, BACEVICH, SOROKIN), C. ratshensis ROUCHADZE, Paraimerites 13. Thin-bedded compact grey limestones with Deshay sp., Dasmiopsis sp. (6.3 m). esites weissi NEUMAYR & UHUG. Cheloniceras sp., Opis rionensis ROUCHADZE (7 m). 9. Whilish-grcy, inedium-bedded marly limestones con taining Colchidites securiformis (SlMONOViCH, In the absence of ammonites bed 1 is provision BACEVICH, SOROKIN), C. sp. ind. (13.7 m). ally referred to the Lower Barremian, and bed 2 to the 10. Similar to 9 but without Colchidites. Pseudocrio- Upper Barremian. So, because of the lack of palacon- ceras waagenoides (ROUCHADZE), P. sahoriense tological data, the Lower/Upper Barremian boundary 106 KAKABADZEM. - KOTETTSHVUJ E.
can only be placed between these beds provisionally. of these limestones shows that among them there are no Beds 3 and 4 contain typical late Barremian ammonites genera or species whose stratigraphical ranges are lim and together with the bed 2 correspond to the lowermost ited only to the Lower Barremian substage. Most of Upper Barremian Ancyloceras vandenheckii Horizon. them have a more extensive stratigraphical distribution, Bed 5 is referred to the Heinzia matura Zone and bed 6 but Mesohibolites beskidensis (UHLIG), and Toxaster corresponds to the Hemihoplites feraudianus Zone. Bed argilaceous D'ORBIGNY are known only in the Upper 7 is well characterized by typical ammonites of Imerites Ban-emian and Aptian. It should also be noted that giraudi Zone, while the beds 8, 9 belong to the Colchid- Paracrioceras rondishiense KAKABADZE is typical repre ites securiformis Zone. Bed 10 still belongs to the Upper sentative of the group of P. barremense KILIAN. Based Barremian. It is impossible to determine a reliable age on stratigraphical position (directly under the Heinzia for beds 11 and 12 (see Discussion). Bed 13 contains D. matura Zone) and the above mentioned fossil composi weissi (NEUMAYR & UHLIG) and corresponds to the tion, these beds in the Gelaveri and Rondishi sections Lower Aptian Deshayesites weissi Zone. should also be attributed (opinion of M.K.) to the low ermost Upper Barremian and regarded as equivalent to the Ancyloceras vandenheckii Horizon of the Tvishi 3. - DISCUSSION section. However, in order to prove fundamentally this point of view it is necessary to make more detailed bios It must be noted first that descriptions and bios tratigraphical investigation of the Gelaveri and Rondishi tratigraphical interpretations of the characteristic Lower sections, as well as of other Barremian sections in Cretaceous deposits and fossils of the Heinzia matura Georgia. Zone, as well as of the other Upper Barremian Zones This stratigraphical level with A. vandenheckii (Hemihoplites feraudianus, Imerites giraudi, Colchidites ASTIER in Georgia is considered only as a Horizon, since securiformis) are already published (ROUCHADZE, 1933, its precise boundary with the Lower Barremian Hol 1938; ERESIAVI, 1952, 1955, 1964; KOTETISHVILI,1958, codiscus caillaudianus Zone is still impossible to trace. 1970, 1980, 1987; KAKABADZE, 1971, 1981, 1987, 1989) As to its upper boundary, limestones of ine, Ancyloceras and hence, in order to avoid repetition, a detailed ac vandenheckii Horizon in the Tvishi section are con count of these zones is omitted here, and only problems formably overlain by the limestones layer of the Heinzia of lowermost and uppermost of Upper Barremian bios matura Zone and the boundary between them is clearly tratigraphy are considered. determined. We conclude that only after a detailed study of the lower boundary problem, as well as the wider geo 3.1. - LOWERMOST UPPER BARREMIAN graphic recognition of the A. vandenheckii Horizon, might it be considered to rank as a Zone. According to the specific ammonite assemblage As to the Heinzia matura Zone, recently redeter (Ancyloceras vandenheckii ASTIER, A. sp. ind., Pseudo mined as Upper Barremian (KAKABADZE, 1987; 1989). it crioceras ex gr. waageni (ANTHULA), Eulytoceras is remarkable to note that among its various late Barre phestum (MATHERON), Paracrioceras rondishiense mian ammonite species, representatives of Heinzia KAKABADZE, Spitidiscus sp. ind.) and to the ouachensis (COQUAND), H. provincialis (D'ORBIGNY), stratigraphical position (directly under beds of the Upper H. lindigi (KARSTEN), H. sartousiana (D'ORBIGNY), etc. Barremian Heinzia matura Zone) beds 3 and 4 and pre (i.e. characteristic species of lowermost Upper Barre sumably bed 2 are ascribed to the lowermost Upper Bar mian of SE France) are frequent. remian. It is notable that a lowermost Upper Barremian Thus, the Ancyloceras vandenheckii Horizon and ammonite complex with A. cf. vandenheckii ASTIER, A. Heinzia matura Zone comprise the lowermost Upper ex gr. mojsisovicsi HAUG, ? Heinzia sp. ind., Hibolites Barremian scheme of Georgia. Owing to the above jaculum PHILLIPS, //. subfusiformis RASPAIL has been mentioned ammonite species association and to the collected also in the Gagra section (Western Georgia, stratigraphical position, the two stratigraphical levels Abkhazia). in Georgia correspond to the "Emericiceras" barre In relation to this question it is necessary to note that mense Zone of SE France (of the scheme by in some other sections of Western Georgia, such as BUSNARDO, 1984), as well as to the Ancyloceras Gelaveri and Rondishi, directly under the beds of the vandenheckii and Heinzia sartousiana Zones of SE Heinzia matura Zone, limestones with concretions of Spain (COMPANY et alii, 1992). chert arc exposed. Biostratigraphical analysis of the fossils (Paracrioceras rondishiense KAKABADZE, Bar remites sp., Mesohibolites beskidensis UH- 3.2. - UPPERMOST UPPER BARREMIAN UG,Cymatoceras sp., Grammatodon securis major LEYMERIE, Amphidonta sp. ind., Turnus cf. dallasi (WALKES), Neithea alava ROEMER, Panope cf. gurgitis In the Tvishi section, above the limestones (20 m) BROGNIART, Spondylus sp., Camptonectes cf. cottaldinus with characteristic species of the Colchidites securi D'ORBIGNY, Barbatia cf. aptiensis PlCTET & CAMPICHE, formis Zone, there follow 10 m of limestones, the lower Toxaster argilaceous (D'ORBIGNY), T. exilis (LORIOL)) part (bed 10; 5 m) of which contains Pseudocrioceras UPPER BARREMIAN BIOSTRATIGRAPHY IN GEORGIA 107
waagenoides (ROUCHADZE) and P. sahohense monites are also absent. In the stratotype section (ROUCHADZE). The uppemost part of the overlying marly (Angles) the Barremian-Aptian boundary is drawn at the limestones (beds 11 and 12; 5 m) is characterized by base of bed 197, where Pseudohaploceras matheroni "Acrioceras" ex gr. furcatum D'ORBIGNY, "A." sp. ind., D'ORBIGNY was found (BUSNARDO, 1965). It is now Costi discus cf. recticostatus D'ORBIGNY known that P. matheroni appears earlier (in the Upper The considered level (beds 10, 11, 12), situated be Barremian) and, unfortunately, until today there are no tween the Upper Barremian Colchidites securiformis sufficient supplementary data to prove this boundary. and the Lower Aplian Deshayesites weissi Zones, is well Recent discoveries (DELANOY, 1991) of Paradeshaye- traced only in those sections (Tvishi, Bethlevi, Skhvava, sites gr. laeviusculus and Prodeshayesites gr. fissicosta- Khashupse, etc.) where the uppermost Barremian- tus/tenuicostatus in the pelagic Lower Aptian of the Vo- lowermost Aptian sequences are represented by com contian Basin delineate the Prodeshayesites fissicostatus paratively deep neritic facies without hiatuses. In the Zone in the SE France. Moreover, the finds of ? shallower marine facies there is a hiatus at the Barre- Prodeshayesites in bed 206 and Deshayesites sp. gr. mian-Aptian boundary in several sections. In the spathi/normani in bed 210 (DELANOY, this volume) are Tskhetidjvari section (periphery of Dzirula massif) there very important for the Lower Aptian biostratigraphical are no uppermost Barremian-lowermost Aptian zonation in the Angles section. On the other hand, after (including D. weissi Zone) sediments, but in some sec- the recent find (by J. WIEDMANN and M. KAKABADZE, in lions (e. g. Godogani section) only the sediments corre 1989) of a fragment of ? Prodeshayesites sp. ind. in bed sponding to the uppermost part of the Colchidites securi- 200, we can conclude that in the Angles section the /orw/s-lowermosl part of the Deshayesites weissi Zones Lower Aptian begins at least from bed 200. are absent. It is obvious that for precise zonal Thus, until today there are no finds of zonal Upper (biostratigraphical) purposes such sections are less im Barremian or Lower Aptian ammonite species at least in portant (while in sequence stratigraphy research they are beds 194 up to 199; therefore the suggested Barre of great value). mian/Aptian boundary at the base of bed 197 in the An There is a similar situation in SE France, where only gles section has still to be considered as a lithos- sections in the pelagic deposits (facies) are convenient tratigraphical and not a biostratigraphical boundary. for detailed biostratigraphic purposes. In the Barremian- Nevertheless, we suppose that until definite sufficient Aptian transitional beds of this region the zonal am supplementary biostratigraphical data are received, the
ANGLES (Stratotype)
I I I I TVISHI (Georgia)
ZONE D. WEISSI
BEDS WITH "ACRIOCERAS" SP.SP.
HORIZON P. WAAGENOIDES
ZONE C. SECURIFORMIS » r 111 H "•'I'I'I'I'.'
Fig. 3. Supposed correlation of uppermost Upper Barremian - lowermost Lower Aptian interval of the Angles (SE France) and Tvishi (Georgia) sections. - Presunte correlazioni dell'intervallo Barremiano superiore - Aptiano basale nelle sezioni di Angles (SE della Francia) e di Tvishi (Georgia). 108 KAKABADZEM. - KOTETISHVTLI E. boundary at the base of bed 197 still has to be respected ERISTAVI M. S. (1952) - The Georgian block in the Lower Cretaceous. Geol. Inst. Acad. Sci. GSSR, monogr. VI (XI): 137-210, Tbilisi (in (i. c. it has to be remained unchanged). Russian). Having such insufficient data, it is obvious that the uppermost Barremian - lowermost Aptian correlation of ERISTAVI M. S. (1955) - Lower Cretaceous fauna of Georgia. Geol. Inst. the Angles and Tvishi sections is very provisional. We Acad. Sci. GSSR, monogr. n 6: pp. 224, Tbilisi (in Russian). suppose (Fig. 3) that the Pseudocrioceras waagenoides Horizon (bed 10 of the Tvishi section) should be corre ERISTAVI M. S. (1964) - Lower Cretaceous. In: "Geology of USSR". Georgian SSR X (1) - Geological description, "Nedra": 112-142, lated with the beds 194-196 of the Angles section, and Moscow (in Russian). beds 11 and 12 of theTvishi section with beds 197-206 (perhaps also beds 207-209) of the Angles section. HOEDEMAEKER P., COMPANY M. (Reporters) and AGUIRRE-URRETA M. As to correlation of the uppermost Barremian- B., A VRAM E., BOGDANOVA T. N., BUJTOR L., BUTJOT L., CEŒA F., lowermost Aptian of Georgia with the North Caucasus DELANOY G., ETTACHFINI M., MEMMI L., OWEN H. G., RAWSON P. F., SANDOVAL J., TAVERA J. M., THEULOY J. P., TOVBINA S. Z. & and Middle Asia, we can conclude that the Pseudocrio VASICEK Z. (1993) - Ammonite zonation for the lower Cretaceous ceras waagenoides Horizon should be regarded as of the Mediterranean region; Basis for the stratigraphie correla equivalent to the Turkmeniceras turkmenicum Zone of tions within IGCP-Project 262. Rev. Esp. Paleont., 8 (1): 117-120, Turkmenistan (Middle Asia) and of the "Matheronites" Madrid. ridzewskyi Zone of North Caucasus, but there are insuf ficient palaeontological data to solve this problem with KAKABADZE M. V. (1971) - The Colchidites and their stratigraphical confidence. As to the stratigraphical position of bed 12, significance. Trudy Geol. Inst. Acad. Sci. GSSR, new ser. 26: pp. 118, Tbilisi (in Russian, summary in English). we can only conclude the following. "Acrioceras" furca- tum D'ORBIGNY, as well as Costidiscus recticostatus KAKABADZE M. V., (1981) - Ancyloceratids of the south of the USSR D'ORBIGNY, found in the Tvishi section (bed 12) is and their stratigraphical significance. Trudy Geol. Inst. Acad. Sci. known from the Upper Barremian and Lower Aptian of GSSR, new ser. 71: pp. 195 Tbilisi (in Russian, summary in English). the Caucasus and therefore until definite Lower Aptian ammonites (i.e. Prodeshayesites, Deshayesites, etc.) are KAKABADZE M. V. (1987) - On the stratigraphical position of the found, the stratigraphical position of beds 11 and 12 of Heinzia matura Zone (Barremian. Georgian SSR). Bull. Acad. Sci. GSSR, 126, (3): 577-580, Tbilisi (in Russian, summary in English). the Tvishi section remains questionable.
KAKABADZE M. V. (1989) - The Barremian biostratigraphical subdivi sion of Georgia (USSR) and comparison with some western Medi REFERENCES terranean regions. In: J. WEDMANN (Ed.): "Cretaceous of the West ern Tethys. Proceedings 3rd Intern. Cretaceous Symposium". Tubin gen 1987, E. Schweizererbart'sche Verlagsbuchhandlung: 551-560, ADAMTA S. A., GAMBASHIDZE R. A, KAKABADZE M. V., KVANTALIANI I. Stuttgart. V., KOTETlSfTVTLI E. V., SHARKADZE M. Z. (1988) - Guide-Book of field trips in Georgia. Project 262 IGCP - UNESCO, 10-16 Novem KOTETISHVUJ E. V. (1958) - Stratigraphy of Cretaceous deposits of the ber: pp. 56, Tbilisi. Shkmeri syncline. Acad. Sci. GSSR: pp. 40, Tbilisi (in Georgian, summary in Russian). BUSNARDO R. (1965) - Le stratotype du Barrémien. Lithologie et macrofaune. Colloque sur le Crétacé inférieur (Lyon, 1963). Mém. B. R. G. M., 34: 99-116. Paris. KOTETISHWJ E. V. (1970) - The Stratigraphy and fauna of the Colchid ites and adjacent horizons of the Western Georgia. Trudy Geol. Inst. Acad. Sci. GSSR, new ser. 25: pp. 116, Tbilisi (in Russian). BUSNARDO R(1984) - Ammonites in Chapitre Crétacé inférieur. Synthèse Géologique du Sud-Est de la France. Mém. B. R. G.M., KOTE'LTSIRVTLI E. V. (1980) - The family Pulchelliidae H. DOIMUÊ 125: 292-294, Orléans. (from the Lower Cretaceus of south USSR). Trudy Geol. Inst. Acad. Sci. GSSR, new ser. 67: pp. 110, Tbilisi (in Russian). COMPANY M., SANDOVAL J., TAVERA M. (1992) - Secuencias deposi- cionales en el Barremiense-Aptiense Inferior de la Sierra del KOTETISHVE.I E. V. (1987) - Zonal stratigraphy of the Lower Creta Corque (Cordillera Betica): consideraciones paleogeograficas. ceous of Georgia and palaeozoogeography of the early Cretaceous Rev. Soc. Geol. Espana, 5 (3-4): 55-63, Madrid. basins of the Mediterranean province. Trudy Geol. Inst. Acad. Sci. GSSR, new ser. 91: pp. 160, Tbilisi (in Russian). DELANOY G. (1991) - Sur la présence du genre Prodeshayesites CA SEY,1961 (Ammonoidea) dans l'Aptien du Bassin Vocontien. Creta ROUCHADZE J. (1933) - Les Ammonites Aptiennes de la Géorgie occi ceous Research 12: 437-441, London. dentale. Bull. Inst. Géol. Géorgie, 1 (3): pp. 273, Tbilisi.
DELANOY G. (this volume) - About some significant ammonites from the ROUCHADZE J. (1938) - Quelques Céphalopodes nouveaux ou peu con Lower Aptian (Bedoulian) of the Angles-Barrême area (South-East nus de lAplien de la Géorgie. Bull. Inst. Géol. Géorgie, 3 (2): pp. France). 157, Tbilisi (in Georgian, summary in French and Russian). Mem. Descr. Carta Geol. d 'It. LI (1995), pp. 109-120
Biostratigrafia dell'Aptiano in Tunisia nord-orientale. Considerazioni stra tigrafiche sull'Aptiano e l'Albiano in Tunisia
Aptian biostratigraphy of northeastern Tunisia. A stratigraphical ap proach of Aptian and Albian of Tunisia
LUCIA MEMMI (*)
IGCP Projects 343 : Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
RIASSUNTO - NelPApliano la Tunisia era una vasta piattaforma in queste aree di sedimentazione le diverse associazioni ad ammoniti permet stabile più o meno subsidente, collegata a sud al Oratone sahariano, che tono di identificare le zone a: Mortomceras (M.) mflalum, Albiano s'immergeva a nord verso la Tetidc. Tre principali aree di sedimentazione superiore s.s.; Stoliczkaia (S.) dispar, parte alta dell'Albiano superiore erano presenti: a) un bacino marino aperto ("Sillon tunisien") a nord; b) (=Vraconiano). una piattaforma carbonatica localizzata in Tunisia centrale e meridionale nella quale sono distinte: una zona di scarpata ed una piattaforma aperta PAROLE CHIAVE: Biostratigrafia, Ammoniti, Aptiano, Albiano, Tu verso NW nella quale sono localmente presenti costruzioni a rudiste sui nisia, Paleoambienti. paleoalli; una piattaforma intema a facies urgoniana. Neil'Aptiano sono state distinte diverse unità biostratigrafiche ad ammoniti. 1. Nel "Sillon ABSTRACT - During the Aptian times the territory of Tunisia was an tunisien" si caratterizzano dal basso verso l'alto, le zone a: Deshayesites unstable shelf, irregularly subsiding, belonging to the Saharian cralon to deshayesi. Aptiano inferiore (Beduliano); Aconeceras nisum, Aptiano the South and deepening northward to the Tethys. Three distinctive supcriore pars (Gargasiano inferiore); Epicheloniceras subnodosocosta- depositional paleoenvironments are identified: a) an open marine basin in lum. Aptiano superiore pars (Gargasiano superiore); Diadochoceras the North; b) a shallow carbonate platform in the central and southern nodosocostalum. Aptiano superiore pars (Clansayesiano inferiore). 2. Tunisia with a shelf-slope and an external platform open to the NW with Zona di scarpala della piattaforma: le ammoniti sono rare e riferite alle localised rudist buildups on paleohighs; an internal shelf with urgonian zone a: Deshayesites deshayesi, Aptiano inferiore (Beduliano); Para facies. In the Aptian different biostratigraphic units based on ammonites hoplites melchioris. Aptiano superiore (Gargasiano). 3. Deshayesites e have been distinguished. 1. In the northern "Sillon tunisien" basin the Dufrenoyia sono slate scoperte nel bacino intracratonico degli "Chotts". following zones are recognized from bottom to top: Deshayesites des La larga distribuzione geografica di questi generi evidenzia l'ingressione hayesi, Lower Aptian (Bedulian); Aconeceras nisum: Upper Aptian della l'elide sulla sponda settentrionale del Cratone sahariano. Al limite (Lower Gargasian); Epicheloniceras subnodosocostatum: Upper Aptian Aptiano/Albiano, un'intensa fase tettonica ha dislocato la piattaforma. (Upper Gargasian); Diadochoceras nodosocostatum, Upper Aptian Molle aree risultano emerse e sottoposte all'erosione. I sedimenti dell'Al- (Lower Clansayesian). 2. In the shelf-slope zone of the platform, a limited biano superiore sono trasgressivi sull'Aptiano, più o meno eroso. Contem number of ammonites are referred to the zones: Deshayesites deshayesi, poraneamente a nord-ovest, il bacino Fahdène era un'area di rapida Lower Aptian (Bedulian); Parahoplites melchioris. Upper Aptian subsidenza dove sono presenti ammoniti delle zone a: Douvilleiceras (Gargasian). 3. Deshayesites and Dufrenoyia were recorded from the mammillatum, parte alla dcll'Albiano inferiore; Puzosia mayoriana, intracratonic basin of the Chotts. Their large geographical distribution Albiano medio. Nell'Albiano superiore, una grande trasgressione ha means the ingression of the Tethys on the northern continental margin of ricoperto gradualmente la Tunisia, sino al Paleoalto permiano. Si eviden the African Craton. Near the Aptian-Albian boundary time, the carbonate ziano tre paleoambienti: a) il bacino marino aperto Fahdène, a nord-ovest; platform was broadly folded, tilted and then eroded. The Upper Albian b) la piattaforma carbonatica Zebbag in Tunisia meridionale; c) una zona rests unconformably on eroded Aptian while an open marine rapid subsi di transizione a sedimentazione bioclastica ed a lenta subsidenza. In dence setting (Fahdène basin) occurred in NW Tunisia. Merc the fol-
(*) D.G.M., Ministore de l'Economie Nationale 17, avenue Khéreddine Pacha. 1002 - Tunis. Tunisia 110 MEMMIL. lowing ammonite zones have been identified: Douvilleìceras mammilla- subsidence rate was slow. In these depositional areas, various ammonite lum, upper part of the Lower Albian, Puzosia mayoriana: Middle Albian. associations allow us to identify the following Upper Albian zones: During Late Albian lime a major transgression reached gradually the Mortoniceras (M.) inflation, Upper Albian s.s.; Sloliczkaia (S.) di spar, territory of Tunisia down to the Permian High. Three distinctive deposi- uppermost Albian (=Vraconian). tional environments were established: a) in the NW, the open marine Fahdène basin; b) the southern carbonate Zebbag platform; c) a transitio KEY-WORDS: Biostratigraphy, Ammonites, Aptian, Albian, Tunisia, nal zone with mostly bioclastic carbonate deposition where the Paleoenvironmems.
1. - INTRODUZIONE 1.2. - STUDI PRECEDENTI
In Tunisia si usa la terminologia "Beduliano" per Nel Barremiano superiore e nell'Aptiano la Tunisia Aptiano inferiore, "Gargasiano" e "Clansayesiano" per era una vasta piattaforma instabile, più o meno subsiden- l'Aptiano superiore. Gli autori delle specie non saranno, te, collegata a sud al Oratone sahariano, che s'immerge di seguito, ripetuti dopo la prima indicazione. va a nord verso la Tetide. La prima suddivisione dell'Apuano in Tunisia setten Il quadro paleogeografico e la distribuzione delle as trionale è stata proposta da JOLEAUD (1901) che ha sociazioni faunistiche sono in relazione con diversi distinto dalla base: fattori (MEMMI, 1989) fra i quali: - marne e calcari a Phylloceras guettardi RASPAIL e - il conflitto tra ingressioni della Tetide Desmoceras enterici RASPAIL; (approfondimento delle aree di sedimentazione, paleo - marne a Belemnites semicanaliculatus DE correnti, rinnovo delle faune...) e Oratone sahariano BLAINVILLE. (ruolo aridificante, apporti detritici...); Nel 1907 PERVINQUIÈRE ha illustrato i cefalopodi dei - l'instabilità dei fondi marini, da mettere in relazio terreni mesozoici e ha caratterizzato due associazioni: ne col ruolo determinante della tettonica: importante - la prima, di età bedulo-gargasiana con Oppelia nisus tettonica locale (aree di subsidenza attiva, fenomeni (D'ORBIGNY), Parahoplites gargasensis (D'ORBIGNY). P. diapirici). attività tettonica regionale (sollevamenti, crassicostatus (D'ORBIGNY) e Puzosia getulina basculamenti, strutturazione ad "horsts" e "grabens"), (COQUAND); ruolo della tettonica globale (rotazione antioraria della - la seconda, del limite Aptiano-Albiano o del Clan Placca Africana, conseguenze eustatiche dell'apertura sayesiano collocato dall'autore nell'Albiano basale, con dell'Atlantico); Phylloceras late-umbilicatum PERVINQUIÈRE, Ptychoce- - i fattori climatici e la posizione intertropicale che ras cf. laeve MATHERON, Hoplites matho PERVINQUIÈRE, favorivano l'istallazione delle facies di scogliera. Douvilleiceras bigoureti SEUNES e Puzosia getulina. SOLIGNAC (1927) ha riconosciuto tre livelli, dal basso verso l'alto: marne a Silesites seranonis interposilus 1.1.- AREE DI SEDIMENTAZIONE (COQUAND) e belemniti; - marne e arenarie a Parahoplites crassicostatus e Nel nord della Tunisia, era impostato un bacino ma Puzosia getulina; rino aperto o "Sillon tunisien", a forte subsidenza ed a - marne e calcari marnosi a Douvilleiceras martini sedimentazione marnosa con intercalazioni di calcari e (D'ORBIGNY), D. bigoureti e Puzosia angladei SAYN. di apporti detritici provenienti dal sud-ovest. Nello studio dell'Atlante tunisino orientale CAST ANY La Tunisia meridionale faceva parte dell'area crato- (1951) ha dato un'elenco delle faune dell'Aptiano, nel nica sahariana, spesso emersa, indeformata dopo la fase quale sono però raggruppate ammoniti del Barremiano, tettonica ercinica che causò il sollevamento del Paleoalto dell'Aptiano e dell'Albiano inferiore. Il Beduliano non è permiano (Môle du Tebaga). caratterizzato mentre il Gargasiano è suddiviso, dal Una piattaforma carbonatica, transizione tra area basso verso l'alto, in due livelli a: cratonica e bacino, si approfondiva gradualmente trami - Aconeceras nisus e Hoplites furcatus SOWERBY; te una serie di faglie E-W, a gradinata ed era divisa da - Douvilleiceras subnodosocostatum SlNZOW, D. una zona alta, instabile, di direzione meridiana o "Axe buxtorfi JACOB e Belemnopsis semicanaliculatus. Nord-Sud" (BEN FERJANI et ahi, 1990). Il Clansayesiano è presente con Douvilleiceras nodo- Si distinguono da sud a nord: socostatum (D'ORBIGNY) e D. bigoureti. In seguito allo studio paleontologico di varie sezioni - una piattaforma interna con un bacino intracratoni- del Cretaceo inferiore della Tunisia nord-orientale, co in procinto di colmarsi o Bacino dei Chotts, furono stabilite le suddivisioni regionali per una parte dell'Aptiano (MEMMI, 1981): - una piattaforma esterna aperta verso NW, - marne verdastre con intercalazioni di calcari mar - una zona di scarpata. nosi a Pseudohaploceras matheroni (D'ORBIGNY) e APTIANO E ALBIANO IN TUNISIA 111
Deshayesites deshayesi (LEYMERIE): zona a Deshayesi Tunisia settentrionale e ciò denota un periodo di calma tes deshayesi (Beduliano); tettonica. Verso la base è presente, nell'anticlinale dell'Oued Bazi- - marne e calcari con Cheloniceras (C.) martini, na (Fig. 1), una fauna con Costidiscus recticostatus Aconeceras nisum, "Dufrenoyia" matho, Gargasiceras (D'ORBIGNY), Leptocerasfragile UHLIG, Barremites (B.) sp., gargasense: zona a Aconeceras nisum (Gargasiano Silesites seranonis (D'ORBIGNY) che indicano il Barremiano inferiore); superiore. A Gebel Mecella, si trovano Macroscaphites - argille con sottili intercalazioni di arenarie e di cal yvani Puzos e Costidiscus sp. A Est di Gebel Fkirine, la cari sabbiosi a Valdedorsella getulina e "Puzosia" eme fauna a Pseudohaploceras liptoviense (ZEUSCHNER), P. ri ci: zona a Epicheloniceras subnodosocostatum matheroni indica l'Aptiano inferiore (Beduliano). (Gargasiano superiore). Al di sopra, è presente un'alternanza di marne ver L'Aptiano terminale non è stato studiato. dastre e calcari marnosi grigi (70 a 85 m) con a Gebel Mecella, Deshayesites deshayesi, D. consobrinus, (D'ORBIGNY), Cheloniceras (C.) cornuelianum (D'ORBI 2. - L'APTIANO IN TUNISIA GNY). Con queste specie, caratteristiche dell'Aptiano inferiore, a Gebel Kemkine (regione di Gebel Fkirine), si trovano Cheloniceras (C.) seminodosum (SiNZOW) e 2.1.- PALEOAMBIENTI DI TIPO BACINO APERTO Procheloniceras albrechtiaustriae (HOHENEGGER in 2.1.1. - La serie delTAptiano della Tunisia nord-orientale UHLIG). La microfauna dei livelli marnosi è caratterizza ta dalla comparsa di Schakoina cabri SIGAL e S. pustu- Il passaggio Barremiano - Apuano è rappresentato lans BOLLI. nel bacino aperto o "Sillon tunisien", da calcari sottil Segue una serie più marnosa (da 100 a 160 m), con mente stratificati e bituminosi che indicano un ambiente marne grigio verdastre e sottili intercalazioni (10 cm al di sedimentazione euxinico. Questi calcari (da 5 a 30 m massimo) di calcari verdastri e di calcari marnosi. I di spessore) costituiscono un livello bene individuato in fossili sono abbondanti (ammoniti e rari bivalvi piritiz-
Fig. 1 - Tunisia nord-orientale: località citate. - North-eastern Tunisia: location map. 112 MEMML.
zali e rostri di belemniti). A Gebel Bou Kornine 2.1.2.2. - Facies a serie condensate (Potinville), nei dintorni di Gebel Zaghouan (Gebel Ech Chama) o di Gebel Fkirine (Gebel Ech Chenannafa), si A sud - est, a Gebel Mdeker e Hammam Djedidi. trovano Phylloceras baborense (COQUAND), Holco- la serie è molto condensata (BIELY et ahi, 1973), phyllocerasguettardi, Aconeceras nisum, Valdeldorsella l'Aptiano è rappresentato da uno strato (da 0,10 a angladei, Epicheloniceras martini, Gargasiceras garga- 0,30 m) di calcare brunastro, detritico con glauconiti, sense, "Dufrenoyia" matho ecc., che indicano l'Aptiano noduli fosfatici ed un "hard - ground" nella parte superiore pars (Gargasiano inferiore). La microfauna superiore. Sono stati ritrovati vari fossili: Macro- con Hedbergella cf. infracretacea (GLAESSNER) e Cla- scaphites striatisulcatus (D'ORBIGNY), M. yvani, vihedbergella simplex (MORROW), indica la stessa età . Procheloniceras albrechtiaustriae, Cheloniceras (C.) La serie, spessa da 60 a 100 m, diventa più argillosa e si cornuelianum, C. (C.) seminodosum, Epicheloniceras osservano sottili intercalazioni di calcari arenacei e di martini occidentalis (JACOB), Pseudohaploceras arenarie ferruginose. Nelle marne sono state ritrovate ricche matheroni, Melchìorites emerici strìgosa FALLOT, faune ad ammoniti, bivalvi e gasteropodi piritizzati, Deshayesites deshayesi, Dufrenoyia furcata, Dufre belemniti, brachiopodi, echinidi: Phylloceras aptiense noyia lurensis KILIAN ecc., gasteropodi, brachiopodi, SAYN, Holcophylloceras lateumbilicatum, Valdedorsella echinodermi, coralli. Le ammoniti rappresentano una getulina, "Puzosia" ibrahìm (COQUAND), Zuercherella fauna polizonale dell'Aptiano inferiore (Beduliano) e zuercheri JACOB, Epicheloniceras subnodosocostatum dell'Apuano superiore pars (Gargasiano). Questa (SINZOW), E. tschernyschewi (SINZOW) indicano l'Aptiano condensazione indica una sedimentazione sul margi superiore pars (Gargasiano superiore). Nella microfauna si ne della piattaforma o sopra un paleoalto ("horst" caratterizzano le tre zone, a Globigerinelloides ferreolensis Mdeker - Bou Ficha) collegato all' "Axe Nord - Sud" MOULLADE, G. algeriana CUSHMAN & TEN DAM e Hedber a scarsa sedimentazione. Su queste serie condensate gella trocoidea (GANDOLFI) dell'Apuano superiore sono trasgressivi i sedimenti dell' Albiano superiore. (OUAHCHI et olii, 1993). Le serie dell'Aptiano e dell' Albiano riscontrate nei A Gebel Oust, la sedimentazione è ridotta e si trova pozzi d'Enfidaville e del Cap Bon presentano simili no faune dell'Apuano inferiore associate a faune del riduzioni di spessore e lacune (VITERBO, 1983). l'Apuano superiore pars (Gargasiano). La successione continua con una sedimentazione di marne grigio verdastre (da 16 m a 50 m) intercalate da due 2.1.2.3. - Serie di transizione (Tunisia nord-occidentale) livelli di calcari marnosi. Questa successione si osserva solo nei "paleograben". A Gebel Oust, le ammoniti indicano il Clansayesiano inferiore: Gabbioceras jaubertianum Nel Barremiano superiore, l'influenza del Cratonc (D'ORBIGNY), Ptychoceras laeve hamaimense PERVTN- sahariano si manifesta coll'aumenlo dei sedimenti sab QUIÈRE, Melchìorites ouachensis JOLEAUD, Hypacanthopli- biosi che invadono tutta la serie di Gebel Rhazouane. Le les traulscholdi SlMONOWITSCH, BAZEWITSCH & SORONINE, marne sabbiose verdi formano alternanze con arenarie Acanthoplites nolani SEUNES. A. bigoureti ecc. Questa quarzose, calcari arenacei, lumachelle con Exogyra, fauna indica la parte alta dell'Apuano superiore Orbitolina, Choffatella decipiens ScilLUMBERGER, (Clansayesiano inferiore) e si osserva la comparsa di Pla- Ostracodi, ecc. nomalina cheniourensis (SlGAL). In questo periodo, si sono verificate risalite diapiri- che del Trias evaporitico che hanno creato rilievi e de pressioni più profonde nella morfologia del fondo mari 2.1.2. - Variazioni laterali no (Fig. 2). Nell'Aptiano inferiore, la sedimentazione è caratte rizzala da un "arco" di biocostruzioni (Knoll - reef) 2.1.2.1- Facies profonda sull'orlo esterno dei paleoalti (Gebel Slata) o da lenti di calcari compatti, in grossi banchi talvolta oolitici, con Nella regione di Tunisi (Henchir Sfiane, Colline di alghe, foraminiferi {Orbitolina, Choffatella) rudiste e Sedjoumi, Gebel Amar, Gebel Naheli...), le facies sono localmente coralli, in alternanza con livelli più detritici. più marnose e le ammoniti senza ornamentazione Nelle depressioni prevalgono le marne scure o verdastre (Phylloceratidae, Lytoceratidae, Desmoceratidae) abbon a Orbitolinidae (MASSE, 1984). danti. Nell'Apuano superiore si caratterizzano le zone a: Un sollevamento rapido (risalita diapirica) ha provo - Protetragonites oblìquestrangulatum (KILIAN) e cato la distruzione degli organismi costruttori, il rima Diadochoceras pretiosum (D'ORBIGNY) del Gargasiano neggiamento e la sedimentazione dei frammenti di fos inferiore; sili costruttori. Infatti, in vari punti della Tunisia nord - Argonauticeras depereti (KlLIAN) e Melchìorites occidentale, si osservano calcari bioclastici (Formazione melchioris (TiETZE) del Gargasiano superiore. Serdj) con Ovalveolina reicheli DE CASTRO, Paracoski- Questa biozonazione è stata stabilita da THOMEI, nolina tunesiana PEYBERNÈS, Orbitolina (Mesorbìtolina) (1964) per le facies marnose "de type oriental" delle texana (ROEMER), O. (M.) minuta DOUGLASS, rudiste e Basses-Alpes (Sud -Est della Francia). Exogyra latissìma LAMARK. APTIANO E ALBIANO IN TUNISIA 113
Sopra la Formazione Serdj riposano alternanze di 2.2. - PALEOAMBIENTI DI TIPO PIATTAFORMA CAR argille scure, di marne sabbiose, di calcari bioclastici a BONATICA Orbitolina (M.) minuta e O. (M.) parva DOUGLASS e di calcari arenacei nerastri con Colombiceras crassicosta- Alla fine del Barremiano e nell'Apuano inferiore, la tum, C. discoidalis SlNZOW, Parahoplites melchioris che piattaforma s'instaura sulla Tunisia centro -meridionale indicano l'Aptiano superiore (Gargasiano). e progredisce verso nord (Fig. 3). L'Aptiano continua con una serie (75 m a Gebel Hame- ima, 300 m nel "paleograben" di Mellègue) di marne scure, 2.2.1. - La piattaforma esterna a rare intercalazioni di calcari marnosi a frattura aciculare, neri e ricchi in pirite. Sono stali rinvenuti Acanthoplites Nell'area centrale, la facies è di piattaforma esterna bigoureti, A. aschiltaensis, A. nolani SEUNES, Diadochoce- aperta (Formazione Serdj) mentre nella zona di scarpata, ras nodosocostatum che indicano il Clansayesiano inferiore. episodi calcari a rudiste, rari coralli ed alghe alternano La microfauna indica il Clansayesiano: Falsogaudryinella con livelli più detritici (Gebel Serdj, Gebel Trozza). A cf. alta (MAGNIEZ - JANNIN), Valvulineria gracillima TEN Gebel Djerissa affiorano: DAM & SlGAL e Epistomina colomi DUBOURDIEU & SIGAL - le alternanze inferiori (150 m): marne grigie a in (ZGIIAL, 1994). tercalazioni di calcari bioclastici talvolta arenacei con
DEVELOPMENTAL MODEL FOR THE TUNISIAN ATLAS
TRIASSIC- EARLY JURASSIC Crustal attenuation Rifling and sabkha-type evaporiles
basemen*
MIDDLE JURASSIC TO EARLY CRETACEOUS Crustal foundering Pelagic sediments, turbidiles and slumps Shelf carbonates
MID-CRETACEOUS TO LATE EOCENE Gradua, basin infilling Growth of evaporile diapirs/salt walls
LATEST OLIGOCENE TO MIDDLE MIOCENE Crustal shortening drives folding of Mesozoic-Ter tiary cover
ran Platform J I i i
Fig. 2 - Modello di evoluzione dell'Atlante tunisino (after BEN FERJANI et ahi, 1990). - Developmental model for the Tunisian Atlas (after BEN FERJANI et ahi, 1990). 114 MEMMI L.
Tab. 1 - APTIANO: Associazioni caratteristiche ad ammoniti nei paleoambienti evidenziati in Tunisia. - APTIAN: Characteristic ammonite assemblages in the depositional paleoenvironments identified in Tunisia.
ETÀ' ZONAZIONE PROPOSTA : TUNISIA BACINO SCARPATA e PIATTAFORMA PIATTAFORMA ESTERNA INTERNA ?Gap Gap ? Diadochoceras nodosocostatum Acanthoplites nolani. A. aschiltaensis. Hiatus ?: il Vraconiano è stato A. bigoureti, D. nodosocostatum , caratterizzalo sopra la piattaforma HIATUS (Clansayesiano - Gabbioceras jaubertìanum a depositi recitali a Rudiste Albiano interiore e medio) ?
E. subnodosocostatum .E.tschernyschewi ? Epicheloniceras Valdedorsella getulina, Zurcherella zurcheri, "Puzosia " ibrahim
superior e subnodosocostatum Piatlalorma carbonatica del Serdj e episodi a Rudiste calcari con fauna a (Agriopleura darderi Polyconites, Orbitolina e Nerinea Aconeceras nisum A nisum , Epicheloniceras martini Radiolitidae ), Nerinea, Orbitolinidi APTIAN O occidentalìs, Gargasiceras gargasense, "Dufrenoyia" matho, V.angladei Colombiceras crassicostatum
bcatrente, D. callidiscus, D. deshayesi, D. consobrinus , Deshayesites D. weissi , Dufrenoyia Pseudohaploceras matheroni, furcata e D. et. planus
Ferior e Deshayesites deshayesi Cheloniceras (C.) seminodosum, C.cornuelianum, Procheloniceras piattaforma di tipo urgoniano albrechti - austriae impostala dal Barremiano
Deshayesites weissi NEUMAYR & UHLIG, Aetostreon gr. (CALZADA), echinidi, alghe e i foraminiferi Palorbitoli aquila (BRONGNIART), Plicatula, Palorbitolina lenticu- na lenticularis, Orbitolinopsis, Mayncina, e qualche laris (BuiMENBACH), Praeorbitolina cormyi corallo. Questo membro della Formazione Orbata o ScilROEDER, Choffalella decipiens; "membro Berrani", ha una vasta estensione geografica. - calcari duri (100 m), ricristallizzati, con frammenti Infatti, si estende fino ai confini del Sahara c poggia sul di rudiste (Pachyodonta, Requieniidae, Toucasia canna Paleoalto permiano del Tebaga (BUSSON, 1972); ta MATHERON), coralli, echinidi. alghe melobesiae, - sopra, al Gebel Bir Oum Ali, si ha l'alternanza di Orbitolinidae e rare ammoniti (Deshayesites deshayesi, calcari bioclastici, calcari marnosi a Orbitolina, dolomie D. consobrinus); e marne gessose. Nei calcari marnosi, sono state ritrova - le alternanze superiori (350 m): si osserva la base te le ammoniti Deshayesites callidiscus CASI-;Y, D. pla della serie in una lunga depressione scavata nei calcari nus CASEY, D. weissi, Dufrenoyia furcata SOWERBY che sottostanti. Si tratta di marne nerastre in alternanza con indicano l'Aptiano inferiore (Beduliano medio). Sono rari calcari dolomitici a Orbitolina (Kiesorbitolina) associate a molluschi (Trigonia, Nerinea), ad echinidi minuta e Ovalveolina reicheli e con calcari bioclastici a (Tetragramma dubium GRAS, Toxaster collegnoi rudiste (Agriopleura darderi ASTRE, Polyconites gr. SISMONDA, Heteraster peroni FICHER) ed ai foraminiferi verneuili BAYLE, Radiolitidae), Exogyra, gasteropodi, Choffatella decipiens e Orbitolina (M.) minuta; echinodermi, e foraminiferi. - la serie continua con calcari grigi a Orbitolina (Ivi.) Le ammoniti sono rare. Colombiceras crassicosta texana, Mayncina bulgarica LAUG, PEYBERNÈS & REY e tum c C. tobleri JACOB & TOBLER. Charentia cuvillieri NEUMANN che indicherebbero l'Ap tiano superiore (Gargasiano). Alla parte superiore, si osserva una discontinuità (hard ground) che è conosciuta 2.2.2. - La piattaforma interna regionalmente. Questa "Barre aptienne" materializza la prima in- In Tunisia meridionale, la facies è di piattaforma in gressione della Tetide sul Continente africano dalla sua terna di tipo urgoniano (Formazione Orbata), impostata emersione nell'Oxfordiano superiore. sin dal Barremiano superiore. Nella catena settentrionale degli "Chotts", a Gebel Berrani, si osservano (BEN YOUSSEF et alii, 1985): 2.3. - BIOSTRATIGRAFIA DELL'APTIANO IN TUNISIA - dolomie e calcari con rari livelli marnosi a rudiste, Toucasia praecarinata DOUVILLÉ, T. compressa Nel bacino nord-orientale, è stato effetuato uno PAQUIER, Matheronia munieri PAQUIER, i brachiopodi studio paleontologico sulle serie del Cretaceo inferio Sellithyris sella (SOWERBY), Loriolithyris crusafonti re (MEMMI, 1981, 1989). Le specie di ammoniti APTIANO E ALBIANO IN TUNISIA 115 identificate in varie sezioni hanno permesso di stabi ne: E. subnodosocostatum, E. tschernyschewi, Valdedor- lire una succesione di unità biostratigrafiche mentre, sella getulìna, Zuercherella zuercheri, "Puzosia" ibra- nei paleoambienti di piattaforma carbonatica, solo him, ecc. qualche livello è fossilifero e le ammoniti sono spo 4) Zona a Diadochoceras nodosocostatum (caratte radicamente presenti. rizzata solo localmente), Aptiano superiore pars (Clansayesiano inferiore). Associazione : Acanthoplites bigoureti, A. aschiltaensis, A. uhligi, A. ouenzaensis, 2.3.1. - Paleoambienti di bacino aperto della Tunisia Nolaniceras rigidus, ecc. settentrionale ("Sillon tunisien") (Tab. 1) 2.3.1.2. - "Grabendi Tunisi" 2.3.1.1. - Regione nord-orientale
Nell' area dei "Massifs jurassiques" (Gebel Za- Nel "graben di Tunisi" (Gebel Amar, Gebel Naheli, ghouan, Gebel Fkirine ecc.), si caratterizzano le seguenti Sedjoumi), a sedimentazione di mare più profondo, è zone, dal basso verso l'alto. utilizzata per il Gargasiano la biozonazione di THOMEL 1) Zona a Deshayesites deshayesi, Aptiano inferiore (1964). (Beduliano). Associazione: D. deshayesi, D.consobrinus, 1) Zona a Protetragoni tes obliquestrangulatum e Procheloniceras albrechtiaustriae, Cheloniceras (C.) Diadochoceras pretiosum, Aptiano superiore pars cornuelianum, C. (C.) seminodosum, Pseudohaploceras (Gargasiano inferiore). Associazione: oltre alle specie matheroni, ecc. indicative, Phylloceras subseresitense, Eogaudryceras 2) Zona a Aconeceras nisum, Aptiano superiore pars numidum, Eotetragonites duvali, Melchìorites emerici (Gargasiano inferiore). Associazione: A. nisum, Epiche strigosa, ecc. loniceras martini occidentalis, Gargasiceras gargasen- 2) Zona a Argonauticeras depereti e Melchìorites se, "Dufrenoyia" matho, ecc. melchioris, Aptiano superiore pars (Gargasiano superio 3) Zona a Epicheloniceras subnodosocostatum, Ap re). Associazione: oltre alle specie indicative, Holco- tiano superiore pars (Gargasiano superiore). Associazio phylloceras lateumbilicatum, Hemitetragonites strangu-
Fig. 3 - Correlazione dell'Aptiano e dell'Albiano in Tunisia centrale (after BEN FERJANI et alti, 1990). - Correlation chart of Aptian andAlbian units in Central Tunisia (after BEN FERJANI et ahi, 1990). 116 MEMMIL.
Tab. 2 - APTIANO E ALBIANO: Associazioni caratteristiche ad ammoniti dei paleoalti e della piattaforma carbonatica. - APTIAN AND ALBIAN: Characteristic ammonite assemblages in the paleohighs and carbonate platform.
ZONAZIONE PROPOSTA: TUNISIA BACINO PIATTAFORMA ESTERNA PIATTAFORMA INTERNA
(Fahdène) (Zebbag ini.) S. (S.) dispar, S. (S.) africana, S. (S.) dispar, S. (S.) africana Mariella bergeri, Osllingoceras Mortoniceras (D.) perinflatum NON CARATTERIZZATO Stoticzkaia (S.) dìspar puzosianum, Submantelliceras s/z a M. (D.) perinflatumsuzannae Anisoceras armatum, Hamites M. (M.) pachys, M. (C.) minor.Engonoceras saadense, s/z a M. (M.) rostratum (S.j virgulatus, Scaphites hugardianusM.(D.) postini'latum, EngonocerasE. toussainti + Knemiceras saadense aegyptiacum
M. (M.) inflatum, Hysteroceras carinatumM. (M.) inflatum, Hysteroceras"COUCHE S À KNEMICERAS S.S." o H. orbignyi, Dipoloceras cristatum,carinatum, Kn. aegyptiacum Kn. gracile, Kn. aegyptiacum O "E « Mortoniceras inflatum Z &> • M.(P.) pricei, Elobiceras elobiense Kn. syriacum.Eopachydiscus < 3 S/Z A Dipoloceras cristatum 5 < Puzosia mayoriana Tetragonites timotheanum, Latidorsella latidorsata , Puzosia mayoriana •5 ? Gap ? ? GAP ? L. flandrini, Beudanticeras dupinianum oriz. a Lyelliceras flandrini africana (APTIANO SUPERIORE pars - ALBIANO INFERIORE E MEDIO) Beudanticeras revoili, B. dupinianum . Douvilleiceras mammillatum ' Parahoplites " numidicus, Ptychoceras laeve hamaimense
Gap GAP
latum, Melchìorites melchioris alpina, M. emerici alpi 3.1. - RISTRUTTURAZIONE DELLO SPAZIO: RIVOLUZIONE na, Uhligella seguenzae. APTIANA E CRISI ALBI AN A
2.3.2. - Paleoambienti di piattaforma carbonatica della Al limite Aptiano/Albiano si osserva un'improvvisa Tunisia centrale e meridionale (Tab. 1 e Tab. 2) variazione nel panorama paleogeografico della Tunisia che risulta da un'importante attività tettonica (o 1) Zona a Deshayesites deshayesi, Aptiano inferiore "rivoluzione aptiana") e da una fase regressiva (o "crisi ("Beduliano"). Associazione, in più della specie indica albiana"). tive, Deshayesites callidiscus, D. weissi, D. planus, Nell'Aptiano superiore (Fig. 2) si verifica un'in Dufrenoyia furcata, Cheloniceras (C.) cornuelianum, tensa fase tettonica estensiva che si manifesta colla ecc. fratturazione della piattaforma carbonatica centro- 2) Zona a Parahoplites melchioris, Aptiano superiore meridionale da faglie del basamento di orientazione (Gargasiano), caratterizzata soltanto in Tunisia centrale. WNW-ESE, riattivate. Queste faglie hanno provocato Associazione: Colombiceras crassicostatum, C. tobleri, una strutturazione "a tegole" del margine della piatta C. discoidalìs, Epicheloniceras martini, Parahoplites forma che s'immergeva a scatti, mentre le zone emer campichei, P. melchioris. genti erano sottoposte all'erosione. A Est dell' "Axe Nord-Sud", nell'area Pelaga si osservano eruzioni vulcaniche nella serie sedimentaria. La sedimenta 3. - CONSIDERAZIONI SULL'ALBI ANO IN TUNISIA zione era controllata da un altro fattore, i movimenti verticali dell' "Axe Nord-Sud". Se nell'Apuano inferiore il dominio marino ha rico A nord-ovest, la tettonica locale provocava fenomeni perto una gran parte della Tunisia, nell'Albiano superio diapirici che modificavano la palcomorfologia dell'im re è iniziala l'ingressione principale della Tetide sul pianto sedimentario, creando ambienti euxinici nel Continente africano. bacino (Fig. 2). La massima estensione è stata raggiunta nel Ceno- Tutti questi movimenti hanno conferito una ristruttu maniano superiore quando il mare sommerse il basa razione dello spazio in aree sollevate ("horsls") e bacini mento palezoico del Sahara centrale. isolati ("grabens"). APTIANO E ALBIANO IN TUNISIA 117
Tab. 3 - ALBIANO: Associazioni caratteristiche ad ammoniti nei paleoambienti evidenziati in Tunisia. - ALBIAN: Characteristic ammonite associations in depositional paleoenvironments identified in Tunisia.
BIOZONE (Tetide) PALEOALTI E ZONA DI SCARPATA PIATTAFORMA ESTERNA PIATTAFORMA INTERNA (Company e al , 1993) (Tunisia centro-settentrionale) (Tunisia centrale) (Tunisia meridionale) S. (S.) dispar, S. (S.) africana, S.(S.) clavigera S. (S.) dispar. S. (S.) africana Mariella bergeri, Ostlingoceras puzosianum . Mortoniceras (D.) perinflatum CALCARI DOLOMITICI
S. (S.) dispar Anisoceras armatum, Hamites (S.} virgulatus. M.(D.) postinflatum , M. (M.) pachys,Engonoceras saadense, H.(S.) venetzianus, Scaphites hugardianus Engonoceras saadense E afl. jezzinense, E. toussainti + Knemiceras aeavotiacum M. (M.) inflatum , Hysteroceras carinatum M. (M.) inflatum . Hysteroceras "couches à Knemiceras s.s. " H. orbignyi, Elobheras ebbiense, Hamites sp. carinatum Kn. gracile, Kn. aegyptiacum, z < M. inflatum Kn. syriacum.Eopachydiscus X s/zona a Dipohxeras cristatum mardanus
< Puzosia mayoriana, Tetragonites, timotheanum, E. lautus Latidorsella laditorsata •5 E. loricatus ?Gap? H. dentatus HIATUS APTIANO SUPERIORE pars e onz. a Lyeiliceras flandrini, B.dupinianum africana ALBIANO INFERIORE E MEDIO
D. mammilatum Beudanticeras dupinianum, B. revoili, " Parahoplites " numidicus Ltaideiwcata ?Gap? H. jacobi ?Gap ? A. nolani A. aschitiaensis, A. bigoureti. O Nolaniceras ouenzaensis z fauna nerica senza ammoniti, < P. melchioris Colombiceras crassicostatum , C. tobleri , Perinea paulì, N.byzacenica , Tylostoma CALCARI DOLOMmCI DI P. melchioris' E.martin (+ Ovalveolina reicheli ) nxhatianum ,Harpagordes desori, FACIES URGONIANA B. Natica coauandiana.... < Deshayesites weissi. D. callidiscus, Cheloniceras Dufrenoyia furcata. Deshayesites D. deshayesi (C.) cornuelianum CALCARI BICCLASTICI deshayesi, D. weissi, D. planus calcari bicclaslid di tades urgoniana
E' opinione di VITERBO (1983) che "l'intensità di (sensu OWEN in HANCOCK, 1990). Tra i foraminiferi sono questa fase può trovare una logica spiegazione nei con abbondanti Hedbergella planispira (TAPPAN) e //. infracre- comitanti movimenti delle Placche...africana e iberica." tacea (GLAESSNER) (ZGHAL, 1994). Ncll'Albiano inferiore si verifica un'importante fase I sedimenti dell'Albiano medio costituiti da calcari bi regressiva o "crisi albiana", molte aree della Tunisia tuminosi con qualche intercalazione di marne nerastre o risultano emerse e sottoposte ad un'attiva erosione, ad "calcaires de l'Allam", sono presenti nel bacino Fahdène una forte carsificazione e dolomitizzazione (BEN (Fig. 3) e nel "graben" di Tunisi. Il ritrovamento a Gebel FERJANI et olii, 1990). Djerissa, di Lyeiliceras flandrini DliBOURDlEU indica l'Al- Questo hiatus sedimentario, che sarebbe generale nei biano medio pars mentre nei bacini settentrionali è stala mari della "Provincia Gondwaniana" (OWEN. 1984), identificata la zona a Puzosia mayoriana (D'ORBIGNY) corrisponde all'Aptiano superiore pars -Albiano inferio dell'Albiano medio terminale. La microfauna è caratterizza re elevato nei bacini settentrionali. In Tunisia centro- ta dai foraminiferi Ticinella primula PREMOLI SILVA e meridionale, i sedimenti dell'Albiano superiore poggiano Hedbergella rischi MOULLADE (ZGHAL. 1994). (Fig. 3) sull'Aptiano più o meno eroso o talvolta su formazioni più antiche come nell' "Axe Nord-Sud" o sul 3.2. - LATRASGRESSIONE DELL'ALBIANO SUPERIORE (Fig. 3) "Môle du Tebaga". La "rivoluzione" aptiana ha infatti un' origine tetto nica mentre la "crisi albiana" è di origine eustatica Nell'Albiano superiore, si evidenziano tre paleoam- (ABDALLAH, 1989). bienli: - i bacini marini aperti della Tunisia nord 3.1.1. - Cenni biostratigrafia sulT Albiano inferiore e occidentale e dell'off-shore orientale erano aree di rapida medio subsidenza dove si depositavano argille scure, con inter calazioni di calcari marnosi e bituminosi ("calcaires A nord-ovest del bacino Fahdène. le rare faune ad am feuilletés du Mouelha" della Formazione Fahdène); moniti piritizzate di Gebel Hameima (PERVINQUIÈRE, 1907; - una piattaforma carbonatica interna, la Piattaforma DUBOURDIEU, 1956) rappresenterebbero la parte alta del Zebbag, instauratasi nell'Albiano superiore sull'area l'Albiano inferiore, zona a Douvilleiceras mammillatum emersa dalla fine dell'Aptiano; 118 MEMMIL.
- VMA ZOVVA ÀI\ VÎMVSYZAOTAC A ÎAC\ES D\ P\A\YAFOIMA "ì ."i . - B\OSTRA.T\Q\\AFV/\ OTAAM AMANO CSLEMA POCO SUBSVDETWC E CAIATLERIZ:/.ALA DA SED\MEI\VA- zione bioclastica. 3.3.1. - Paleoambienti di tipo bacino aperto Fahdène) Nei bacini settentrionali la sedimentazione è conti nua dall'Albiano medio al superiore; le marne scure e i Solo alcuni livelli sono fossiliferi e una biozonazione calcari neri sottilmente stratificati denotano, però, un provvisoria è stata stabilita (Tab. 3). ambiente euxinico a scarsa circolazione. L'Albiano 1) Zona a Douvilleiceras mammillatum: parte alta superiore s.s. è riconosciuto in base ai foraminiferi Biti- dell'Albiano inferiore. Associazione: Beudanticeras cinella breggiensis (GANDOLFI) e Rotalipora gr. tici- revoili, B. dupinianum, "Parahoplites" numidicus, Pty- nensìs (GANDOI.FI), il Vraconiano da Planomalina bux- choceras laeve hamaimensìs. lorjì (GANDOI.FI) e Rotalipora appenninica RENZ. (ZGIIAL,1994). 1 a) Orizzonte a Lyellicerasflandrini, Albiano medio La paleogeografia della Tunisia centro-meridionale pars. Associazione: L.flandrini, Beudanticeras cambiò dopo la "crisi albiana". Era un'estesa area crato- dupinianum africana. nica, emersa per un lungo periodo di tempo (fine Aptia- 2) Zona a Puzosia mayoriana, Albiano medio pars. no-Albiano medio), peneplanata dall'erosione e talvolta Associazione: P. mayoriana, Latidorsella latidorsata, dolomilizzata e silicizzata (Fig. 3). Tetragonites timotheanum, Elobiceras elobiense, Idio- Nel sud, nell'Albiano inferiore, ingenti fiumi traspor hamites gr. alternatus. tavano il materiale di dilavamento del Sahara, arenarie e 3) Zona a Mortoniceras (M.) inflatum, Albiano su sabbie con frustoli vegetali, resti di coccodrilli e di dino periore s. Associazione. M. inflatum, Dipoloceras sauri delle Formazioni Foum el Argoub e Chenini cristatum, Beudanticeras beudantì, Kossmatella rencu- (BUSSON, 1972). relensis, Silesites lamberti, ecc. La Tetide sommerse gran parte di quest'area a 4) Zona a Stoliczkaia (S.) dispar, Albiano superiore morfologia peneplanata e si instaurò un ambiente di (Vraconiano); piattaforma carbonatica (Piattaforma Zebbag), di 4 a) subzona a Pervinquieria rostrata, Vraconiano scarsa profondità, circa 10 m. La sedimentazione è inferiore; Associazione: Hamites (Hamites) vìr- bioclastica nell'Albiano superiore ss., con ammoniti gulatus, H. (H.) venetzianus, Scaphites (Knemiceras), alghe verdi, grandi foraminiferi e hugardianus, Puzosia subplanata, Mortoniceras ostracodi. Le "couches à Knemiceras" rappresentano (Cantabrigites) subsimplex, ecc.; la fase trasgressiva mentre i calcari dolomitici com 4 b) subzona a Mortoniceras (Durnovarites) perinfla patti del Vraconiano denotano caratteristiche regres tum, Vraconiano superiore; Associazione: Ma sive (ABDALLAH & MEMMI, 1994). riella (M.) bergeri, Ostlìngoceras puzosianum, La transizione fra piattaforma e bacino si realizza Hypoturrilites mantelli, Stoliczkaia (S.) dispar, attraverso un margine caratterizzato da una strutturazio S. (S.) africana, S. (S.) clavigera, Puzosia cf. ne con blocchi ruotati ("tilted blocks") (BOLTENHAGEN, furnitana. 1985). A Gebel Trozza, nell'Albiano superiore s.s., sono 3.3.2. - Paleoambienti di Piattaforma esterna aperta presenti marne con rare intercalazioni di calcari grigi (Tab. 2 e Tab. 3) con Hysteroceras carinatum SPATH, radiolari, foramini feri (Hedbergella) e rari ostracodi. Solo l'Albiano superiore è caratterizzato e trasgredi Il Vraconiano è più calcareo: si hanno calcari sce sull'Apuano, più o meno eroso. grigi con sottili intercalazioni marnose e nella parte 1) Zona a Mortoniceras (M.) inflatum, Albiano su superiore, calcari grigi più compatti, talvolta dolomi periore s. s. Associazione: M. (M.) inflatum, M. (P.) tici e con noduli di selce. Nella parte inferiore, i pricei, Hysteroceras orbignyi, H. carinatum, H. varico- calcari presentano sezioni di belemniti, echinidi c sum, Hamites (S.) subvirgulatus; bivalvi (BATIK et alii, 1987). Le marne sono ricche di 2) Zona a Stoliczkaia (S.) dispar, Albiano superiore echinidi (Holaster laevìs BRONGNIART, //. nodulosus (Vraconiano); GOLDIUSS, Epiaster ricordeaui (D'ORBIGNY), Pseu- 2 a) subzona a Pervinquieria rostrata, Vraconiano dananchys algira COQUAND) e di ammoniti: Morto inferiore; Associazione: Mortoniceras (M.) pa niceras (M.) pachys SEELEY, M. (Cantabrigites) chys, M. (Durnovarites) postinflatum, M. minor SPATH e, a Gebel Mrhila, Engonoceras (Cantabrigites) minor, Engonoceras saadense; saadense THOMAS & PERON del Vraconiano inferiore. 2 b) subzona a Mortoniceras (Durnovarites) perinfla Nella parte superiore, Stoliczkaia (S.) dispar tum, Vraconiano superiore; Associazione: Os (D'ORBIGNY), S. (S.) africana PERVINQUIÈRE, S. (S.) tlìngoceras puzosianum, Mortoniceras clavìgera NEUMAYR e Mortoniceras (Durnovarìtes) (Durnovarites) subquadratum, M. (D.) perinfla perinflatum SPATH caratterizzano il Vraconiano su tum, Stoliczkaia (S.) dispar, S. (S.) africana, S. periore. (S.) clavigera. APTIANO E ALBIANO IN TUNISIA 119
3.3.3. - Mari superficiali della Piattaforma Zebbag le all'Albiano inferiore pars nel bacino Fahdène e sino (Tab. 2 e Tab. 3) all'Albiano medio sulla piattaforma Zebbag. Durante quest'epoca, l'erosione ha peneplanato il paesaggio e 1) Zona a Mortoniceras (M.) inflatum, Albiano su facilitato l'ingressione marina sul Oratone sahariano. La periore .s\.s'. Associazione: Eopachydiscus marcianus, trasgressione dell'Albiano superiore s. s. segna l'inizio Knemiceras gracile, K. aegyptiacum, K. compressum, K. della trasgressione maggiore sul Sahara centrale, avve syriacum, ecc. nuta nel Cenomaniano superiore. 2) Zona a Pervinquieria rostrata, Vraconiano inferiore. In Tunisia centro-meridionale, l'ingressione marina Associazione: Engonoceras saadense, E. jezzinense, E. pone fine alla sedimentazione detritica osservata durante toussainti, Parengonoceras, Knemiceras syriacum. il Cretaceo inferiore e potrebbe essere l'indice di cam biamenti geochimici e sedimentari (abbondanza di glau- conite e fosfati) in seguito allo spostamento verso sud, 4. - CONCLUSIONI delle zone di apporto. L'originalità di questa trasgressione è dovuta alla 4.1.- APTIANO INFERIORE comparsa, grazie a comunicazioni marine, di faune particolari. Nei bacini settentrionali sono segnalate I paleoambicnti c i sedimenti denotano una profondità forme cosmopolite (Kossmatella, Beudanticeras, Puzo che diminuisce da nord-ovest a sud-est. A NW, si hanno sia, Oxytropidoceras, Mariella) associate ad elementi carbonati e sedimenti circalittorali di mare aperto ad am gondwaniani (Mortoniceras, Elobiceras). Nei paleoam moniti cosmopolite. A SE si hanno biocostruzioni e calcari bienti infralittorali della piattaforma Zebbag, prevalgono bioclastici mentre a sud, la facies è di ambiente littorale ammoniti a conchiglia compressa, debole ornamentazio ristretto (calcari dolomitici e dolomie) di tipo urgoniano. La ne e linea lobale "neoceratitica" (Knemiceras, Engono distribuzione areale delle ammoniti Deshayesites e Dufre ceras), adattale ai mari epiconlinentali. noyia, evidenzia un'omogeneità della temperatura delle Sarà la grande trasgressione del Cenomaniano a li acque che ha agevolato la migrazione e l'adattabilità di vellare questo provincialismo ed a uniformare le faune queste faune sulla sponda meridionale della Tetide. Livello delle sponde settentrionale e meridionale della Tetide. guida morfologico, la "barre aptienne" rappresenta la prima ingressionc della Tetide sul Oratone sahariano dopo quella del Calloviano. E' conosciuta come livello guida morfologi RINGRAZIAMENTI. co e stratigrafico nell' Atlante sahariano (Monts de Batna e du Hodna) e in Algeria orientale (GUIRAUD, 1973). Verso Il manoscritto è stato letto dal Dott. F. CECCA Est, affiora in Libia settentrionale e nel Deserto occidentale (Servizio Geologico d'Italia) al quale esprimo la mia egiziano (BUROLLET & BUSSON, 1983). riconoscenza per i suoi commenti e per l'aiuto datomi nel correggere i "francesismi". I miei vivissimi ringra ziamenti alla signora Rafika FENNICHE e al Dott. Habib 4.2. - APTIANO SUPERIORE BENSALEM (Servizio Geologico di Tunisia) per l'aiuto editoriale. Gli errori restanti sono miei. L'intensa fase tettonica ha fratturato e sollevato la piattaforma che è slata sottoposta ad erosione. Il rima neggiamento di rudiste e di altri organismi ha agevolato episodi di "bioaccumulazioni" alternati a sedimenti RIFERIMENTI BIBLIOGRAFICI sabbiosi. La sedimentazione è pressoché continua nei grabens. Ammoniti del Caucaso e della Penisola di ABDALLAH II. (1989) - Les transgressions du Crétacé moyen entre les Mangyshlak (Turkmenia) sono rinvenute associate a jeux tectoniques et les montées eustatiques (Sud tunisien). Géobios, Mém. spéc. 11: 83 - 94, 5 figg., Lyon. forme endemiche dell'Atlante sahariano. Queste asso ciazioni denolano l'esistenza di correnti superficiali da ABDALLAH H. & MEMMI L. (1994) - Sur l'âge des couches à Est, che hanno favorito la dispersione delle larve o delle "Knemiceras" de Tunisie méridionale. Caractérisation de TAlhien forme nectobentoniche ornamentate. supérieur (zone à Inflatum et s/zone à Suhstuderi). C. R. Acad. Sci. Sulla scarpata della piattaforma, mareggiate, correnti Paris, 319, II: 337-340, 2 figg., Paris. e tempeste hanno determinato una scarsa sedimentazio ne con fauna polizonale mentre nel graben di Tunisi, di BATIK P., DONZE P., GILALI A., MAAMOURI A.L. & MEMMI L. (1987) - Les dépôts crétacés dans le secteur du Jebel Trozza. Notes Serv. ambiente più profondo, si sedimentavano marne e cal Géol. Tunisie, 54: 5 - 24, 3 figg.. Tunis. cari ad ammoniti senza ornamentazione (Leiostraca).
BEN FERJANI A., BUROLLET P. F. & MEJRI F. (1990) - Petroleum Geo logy of Tunisia. Mém. Entreprise Tunisienne d'Activités Pétrolières, 4.3. - ALBIANO SUPERIORE 1: 194 pp., 75 figg., 23 fotog., Tunis.
BEN YOUSSEF M., BEL Y A. & MEMMI L. (1985) - La formation La "crisi albiana", d'origine eustatica, ha determinato Orbala en Tunisie méridionale. Précisions biostratigraphiques una lacuna sedimentaria ("hiatus") dall'Aptiano termina nouvelles. Notes Serv. Géol. Tunisie, 51: 105 - 120, 4 figg., Tunis. 120 MEMML.
BIELY A., MEMM L. & SALAJ J. (1973) - Le Crétacé inférieur de la MASSE J.P. (1984) - Données nouvelles sur la stratigraphie de l'Aptien région d'Enfidaville. Découverte d'Aptien condensé. Livre Jubilaire carbonate de la Tunisie centrale, conséquences paléogéographi M. SOJJGNAC, Ann. Mines & Géol. Tunis, 26: 169 - 178, 3 figg., ques. Bull. Soc. Géol. France, sér.7. 26: 1077-1086, 4 figg., Paris. Tunis. MEMMI L. (1981) - Biostratigraphie du Crétacé inférieur de la Tunisie BOLTENHAGEN C. (1985) - Paléogéographie du Crétacé moyen de la nord - orientale. Bull. Soc. Géol. France, sér.7, 23: 175 - 183, 3 Tunisie centrale. Actes 1er. Congr. nat. Sci. Terre, Tunis 1981. Ann. taw., Paris. Mines & Géol. Tunis, 31: 97 - 114, 5 figg., Tunis. MEMMI L. (1989) - Le Crétacé inférieur (Berriasien - Aptien) de Tuni BUROLLET P.F. & BUSSON G. (1983) - Plate - forme saharienne et sie. Biostratigraphie, Paléogéographie et Paléoenvironnements. Mésogée au cours du Crétacé. Notes et Mém. C. F. P., 18: 17 - 26, Thèse Doct. d'Etat ès-Sci. Univ. Lyon I: pp. 158, 58 figg., 1 vol. alle 6 figg., Paris.BUSSON G. (1972) - Principes, méthodes et résultats gati. d'une étude stratigraphique du Mésozoïque saharien. Mém. Mus. nat. dliist. naturelle (C), 26: pp. 441 140 figg., 8 labb., 2 carte, Paris. OUAHCHI A., BISMUTH H. & TURKI M.M. (1993) - Nouvelles données sur le Crétacé et l'Eocène des environs de Grombalia (Tunisie nord CASTANY G. (1951) - Etude géologique de l'Atlas tunisien oriental. - orientale). Géologie Méditerranéenne, 20 (1): 25 - 43, 10 figg., Ann. Mines & Géol. Tunis, 8: pp. 662, 248 figg,con atlante, Tunis. Marseille.
DUBOURDEU G. (1956) - Etude géologique de la région de l'Ouenza OWEN H.G. (1984) - Albian stage and substage boundaries. Bull. geol. (Confins algéro - tunisiens). Pubi. Serv. Carte géol. Algérie, 10: pp. Soc. Denmark, 33 (1-2): 183 - 189, Kobenhaven. 659, 89 figg.,conallante, Alger. PERVINQUIÈRE L. (1907) - Etudes de Paléontologie tunisienne. 1- GUIRAUD R. (1973) - Evolution post - triasique de l'avant-pays de la Céphalopodes des terrains secondaires. Dir. génér. Travaux Pu chaîne alpine en Algérie d'après l'étude du Bassin du Hodna et des blics (Carte géol. Tunisie): pp. 438, 158 figg., con atlante: 27 taw., régions voisines. Thèse Doct. Etat ès-Sci. Univ. Nice: pp. 270. de Rudeval, Paris.
HANCOCK J.M. (1991) - Ammonites scales for the Cretaceous system. SOLiaNAC M. (1927) - Etude géologique de la Tunisie septentrionale. Cretaceous Research, 12: 259 -291, London. Dir. génér. Travaux Publics (Serv. Mines): pp. 756, 231 figg., Tunis.
HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. B., A VRAM E., BOGDANOVA T. N., BUJTOR L., BULOT L., CECCA F., THDMEL G. (1964) - Les zones d'ammonites de l'Aptien des Basses- DELANOY G., ETTACHFINI M., MEMMI L.. OWEN H. G., RAWSON P. Alpes. C. R. Acad. Sci. Paris, 258: 4308 - 4310, Paris. F., SANDOVAL J., TAVERA J. M., THEULOY J.-P., TOVBINA S. Z. & VAS1CEK Z. (1993) - Ammonite zonation for the Lower Cretaceous VITERBO I. (1983) - Evoluzione paleogeografica della Tunisia centro- of the Mediterranean region; basis for the stratigraphie correla settentrionale dal Trias inferiore al Quaternario. Studi palcogeo- tions within IGCP-Project 262. Rev. Esp. Paleontologia, 8 (1): 117- grafici sull'area mediterranea: 52, 13 figg., Bari. 120, 1 tab., Madrid. ZGHAL I. (1994) - Etude microbiostratigraphique du Crétacé inférieur JOLEAUD A (1901) - Contribution à l'étude de l'Infra - Crétacé à faciès de la Tunisie du Centre Ouest (Régions de Kasserine - Sbeitla et de vaseux pélagique en Algérie et en Tunisie. Bull. Soc. Géol. France, Tadjerouine). Thèse Doct. Géol.- Biostratig., Univ. Tunis II. 2 vol.: sér. 4,1: 113-146, Paris. pp. 382, 43 figg. 42, 12 Taw., Tunis. Mem. Descr. Carta Geol. d'lt. LI (1995), pp. 121-130
The "Boreal" Early Cretaceous (Pre-Aptian) ammonite sequences of Nw Europe and their correlation with the western Mediterranean faunas
Le successioni ad ammoniti "Boreali " del Cretaceo inferiore (Pre- Aptiano) dell 'Europa Nord Occidentale e loro correlazione con le faune mediterranee occidentali
PETER F. RAWSON (*)
IGCP Projects 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - Pre-Aptian ammonite faunas of the northern hemisphere RIASSUNTO - Le faune ad ammoniti pre-Aptiane dell'emisfero nord fall into two distinct realms, Tethyan and Boreal. The NW European ricadono in due dominii distinti, Tetideo e Boreale. I,e faune dell'Europa faunas belong to the West European Province of the Boreal Realm. They nord occidentale appartengono alla Provincia Europea Occidentale del show a strong Tethyan influence at times, which is reflected in the current Dominio Boreale. Esse mostrano, a tratti, una forte influenza tetidea che biostratigraphic schemes. Some Tethyan immigrants gave rise to endemic si riflette negli attuali schemi biostratigrafici. Alcuni immigranti tetidei genera through allopatric speciation. Others quickly became extinct. The diedero vita a generi endemici attraverso speciazioni allopatiche mentre occurrence of immigrant forms means that NW Europe is a key area in altri si estinsero velocemente. La presenza di forme immigranti dimostra correlation between Boreal and Tethyan realms. che l'Europa nord occidentale è un'area chiave nella correlazione tra i dominii Boreale e Tetideo.
KEYWORDS - Ammonites, Lower Cretaceous, Boreal-Telhyan corre PAROLE-CHIAVE - Ammoniti. Cretaceo inferiore, correlazione Borea- lation, NW Europe. le-Telide, Europa nord occidentale.
(*) Department of Geological Sciences, University College London, Gower Street, London WC1E 6BT, UK RAWSON P. F. 122
1. - INTRODUCTION rises in sea level (RAWSON, 1993a; 1994). In addition, Boreal ammonites are found at some levels in the West Mediterranean Province. Thus Valanginian to Hauteri In the northern hemisphere there were two distinct vian zonations can be correlated with the West Medite- faunal phases during Early Cretaceous times (RAWSON, ranean scheme with some confidence, Barremian ones 1981). During Bcrriasian to early Barremian times the more questionably (Fig. 2). Boreal and Tethyan Realms were clearly differentiated. The following account is essentially an expansion of The former was characterised by perisphinctacean am two recent contributions to IGCP Project 362 (Tethyan- monites, the latter by a much more varied fauna inclu Boreal Cretaceous) - a short account of the NW Euro ding phylloceratids, lytoceratids and heteromorphs. pean ammonite zonations in Newsletter 1 and a talk During the Early Barremian the sea withdrew from with abstract on Tethyan immigrants to eastern England many high boreal (Arctic) areas and the pattern broke down. Aptian and Albian faunas show only limited given at the first meeting of Project 362 at Coimbra differentiation. (RAWSON, 1993b. c). For each stage I firstly discuss the zonally important genera and then summarise the occu This review deals with the earlier, Berriasian to Bar rence of Tethyan immigrants, especially those that are remian, phase, when the North Sea and contiguous important for correlation. North German basins formed a major Early Cretaceous depocentre which lay on the southern margin of the Boreal Realm and maintained at least intermittent con 2. - THE FAUNAL SEQUENCES nections with western Tethys (Fig. 1). The ammonite sequence is well known and often quoted as a standard for the Boreal Realm. The ammonite zonation of the West European Pro vince currently used has evolved over the last hundred But this is rather misleading as the faunas show a years and owes much to work in the first quarter of this strong Tethyan influence, sufficient to merit the reco century by Koenen. Spath and Stolley. More detailed gnition of a distinct West European Province (RAWSON, collecting over the last 30 years has refined the sequence 1981, 1993a). In fact the first ammonite ever described considerably but much work remains to be done. from the province. Ammonites rotula (SOWERBY, 1827) from the Speeton Clay, became type species of the typi cally Te.thyan genus Spitidiscus. Other Tethyan forms 2.1. - THE RYAZANIAN SEQUENCE were figured from Speeton by YOUNG & BIRD (1828) and PHILLIPS (1829), so that as early as 1838 AGASSIZ NW Germany was non-marine at this time, but ma (in D'ARCHIAC, 1838) was able to compare the fossils of rine sediments extend over much of the North Sea Basin the Speeton Clay with the Neocomian beds of the Jura. into eastern England (RAWSON, 1992, map. 1). The The standard stage names developed during the 19th Ryazanian (approximately equivalent to the Late Ber century were based on sequences in the West Mediterra riasian) ammonites are exclusively boreal, identical with nean Province. They were first applied to NW Europe by or close to species from East Greenland and the Russian KOENEN (1902) who, like some of his predecessors, Platform. figured some typical Tethyan taxa in his monograph. The eastern England succession was described by The occurrence of all the Valanginian to Hauterivian CASEY (1973). Unfortunately the sequence consists Tethyan and Tethyan derived forms so far known from mainly of thin, often condensed sands and the ammoni the West European Province was reviewed by Kemper, tes were collected mainly from temporary sections, no RAWSON & THIEULOY (1981). longer visible. The zonation based on this record is Since then, DOYLE (1989) and RAWSON (this volu (from top to bottom): me) have added important new records from the Speeton Clay of eastern England. Further material from Germa Peregrinoceras albidum ny has been figured by KEMPER & WIEDENROTH (1987), Surites (Bojarkia) stenomphalus KEMPER (1992), QUENSEL (1988) and MUTTERLOSE Surites (Lynnia) icenii (1992). The former two papers also refigured many of Hectoroceras kochi the specimens previously figured by KEMPER (1976) or Runctonia runctoni KEMPER et alii (1981). Altogether a large number of immigrant forms have now been figured in these and East Greenland is the type area for the kochi Zone, earlier publications. Norfolk or south Lincolnshire for the remaining zones. The Tethyan migrants often became extinct quickly, The earliest known Tethyan immigrant is the nucleus of but sometimes gave rise through allopatric specialion to a Neocomites? cf. trezanensis from the base of the thriving endemic genera. None are known from the Claxby Ironstone of Lincolnshire, figured by KEMPER el Ryazanian but they occur at several levels through the alii (1981). This came from a transgressive horizon that Valanginian to Barremian sequence, generally close to contains very late Peregrinoceras of latest Ryazanian or, clearly defined sequence boundaries that represent rapid more likely, earliest Valanginian age. The appearance BOREAL AND MEDITERRANEAN AMMONITES 123
Fig. 1. The palaeogeographic framework - connections between the West European Province and adjacent regions. - // quadro paelogeografico e le connessioni tra la provincia europea occidentale e le regioni adiacenti.
of this form may predate that of Platylenticeras in North gaps in the proven succession. Nor have type sections Germany. been formally named. In the literature, individual loca lities were often associated with a particular assemblage (zone). 2.2. - THE VALANGINIAN SEQUENCE But as more than one locality may be associated with A marine transgression at the beginning of the Va a single zone while some localities span a zonal bounda langinian brought the sea back to North Germany, whe ry, the table below indicates the "locus typicus" of the re thick mudrocks with marginal sands began to accmu- index species rather than a type locality for the zone lale in the Lower Saxony Basin. A detailed zonation has (based on information in KEMPER, 1961, 1978 and evolved which provides a standard for NW Europe. In JELETZKY & KEMPER, 1988). practice the zones effectively represent individual as Unfortunately even in some of the most recent pa semblages from scattered brickpits that were placed into pers (e.g. KEMPER, 1992) the horizon of figured am sequence. Thus the zonal limits often are not monites is generalised rather than being referred to a well defined and it is possible that there are still specific zone. This makes it difficult to assess the exact RAWSONP. F. 124
horizon of sonic immigrant ammoniles.Thc English lis, was poorly known and that many of the ammonites Valanginian sequence is thin and incomplete, but a formerly assigned to it belong to a new species, P. simplified version of the German zonalion can be ap hapkei, which therefore became the zonal index. plied (RAWSON et alii, 1978). 3. The index species of the D. bidichotomus Zone The German zonal scheme is (from top to bottom): was renamed D. bidichotomoides by KEMPER (1978).
OLD DIVISION ZONE "LOCUS TYPICUS" Astierien Sch. Olcostephanus densicostatus (T) Arnoldien Sch. Dicostella tuberculata (T) Ottensen Dichotomites bidichotomoides (B) Ottensen Dichotomites triptychoides (B) Hasslage-Nord Dichotomiten Schichten Dichotomites crassus (B) Varlheide, Sud Prodichotomites polytomus (B) Stadthagen Prodicholomiles hollwedensis (B) Twiehausen, near Hollwcdc Polyptychites hapkei (B) Hollwede Polyptychites clarkei (B) Lindhorsl Polyptychiten Schichten Polyptychites multicostatus (B) Lindhorst) Polyptychites pavlowi (B) Osterwald Platylenticeras involutum (T?) Buckeburg Platylenliceras Schichten Platylenticeras heteropleurum (T?) Barsinghauscn Platylenticeras robustum (T?) Gronau
(T) = of Tethyan origin, (B) = of Boreal origin
The lowest zonal genus, Platylenticeras, appeared in QUENSEL (1988) later suggested splitting the bidichoto Germany with the initial marine transgression and moides Zone into two zones, bidichotomoides. below established a long-lived population there. The dispute and ivanovi above. Quensel's divisions are regarded here over its Tethyan or Boreal origin was discussed by as subzones of the original bidichotomoides Zone. The RAWSON (1993a, p. 234), who favoured the former. The last Prodichotomites occurs in the tuberculata Zone. zonation of the Platylenticeras beds follows KEMPER Tethyan immigrants appeared alongside the Polypty (1961, as modified 1973, table 1). Equivalent beds in chitinae on several occasions. The first horizon is at the eastern England are thin and incomplete, but Platylenti base of the hollwedensis Zone. Here large, inflated Ol ceras never appears to have successfully replaced the costephanus appear, forming STOLLEY'S (1937) already established boreal lineage, represented early in "Proastieria" fauna. A single specimen was figured by the Valanginian by Costamenjaites and allied late Cra- KEMPER et alii (1981, pi. 35, figs 1. 2) as O. (O.) sp.. spcditinae. and later identified by BULOT (1990. p. 87) as O. (O.) Boreal Polyptychitinae spread over the whole of NW guebhardi KILIAN. Europe later in the Early Valanginian, first appearing in These inflated Olcostephanus survived to the middle north Germany in the upper part of the Platylenticeras of the hollwedensis Zone, when a whole group of Tethyan genera invaded the area - Bochianites, Sayno- beds. After Platylenticeras died out polyplychitinids ceras, Valanginites, Karakaschiceras and Neohoploce- dominated the faunas of the whole West European Pro ras. Most spread across the whole region but Saynoce- vince till very late in the Valanginian, when they began ras and Valanginites were filtered out before reaching to peter out as Tethyan immigrants occupied the region. England. Many examples of this distinctive fauna have The initially broad zonal subdivision of the polypty- been figured by KEMPER et alii (1981) and earlier wor chine sequence (e.g. KOF.NEN, 1902; STOLLEY, 1937) kers, KEMPER & WIEDENROTH (1987), KEMPER (1992) has been much modified by KEMPER in a series of im and MUTTERLOSE (1992). portant papers, starting in 1971. The present-day ver Both these and later Valanginian ammonites are sion dates from KEMPER (1976, table 6), tabulated 2 known from England only from condensed or remanie years before some of the index species were formally Upper Valanginian beds. But in the thick Upper Va named. There have been minor subsequent modifica langinian succession in north German there are other tions, as follows: important immigration horizons higher in the sequence. 1. JELETZKY & KEMPER (1988) placed the former The majority of immigrants were neocomitids and olco- zonal index Polyptychites euomphalus in synonymy stephanids, but rarer heteromorphs occur with P. pavlowi and therefore renamed the zone. The neocomitid Varlheideites peregrinus (RAWSON 2. JELETZKY & KEMPER (1988) showed that the in & KEMPER, 1978) was described from the crassus Zone dex for the highest Polyptychites Zone, P. sphaeroida- of Varlheide, where a single Oosterella aff. cultrata was BOREAL AND MEDITERRANEAN AMMONITES 125
discovered too (KEMPER et alii, 1981, p. 302, pi. 37, figs German succession. Examples were illustrated for the 9-10). Varlheideites or a similar neocomitid is known first time by KEMPER et alii (1981) and further material also from the bidichotomoides Zone (QUENSEL, 1988). was figured by MUTTERLOSE (1992) (refigured by A mass occurrence of Bochianiles neocomiensis in KEMPER, 1992). Because the species were left in open core samples from the western margin of the Lower nomenclature in KEMPER et alii's (1981) review the Saxony Basin is less well dated but lies somewhere zone remained unnamed. within the polytomus ? to triptychoides Zones (KEMPER It was subsequently called the "Olcostephanus spp." et alii, 1981, p. 266). Zone (RAWSON, 1983). QUENSEL (1988) then named it Crioceratites-like heteromorphs first appear in the the paucinodum Zone, based on the identification of a triptychoides Zone, together with the apparently ende minor element of the fauna as "cf. Eleniceras paucino mic heteromorph Juddiceras. They are quite common at dum", an enigmatic species first described by NEUMAYR this level (KEMPER et alii, 1981) while through the & UHLIG (1881). remainder of the Valanginian there are only spasmodic The choice of such a poorly understood taxon as zo records of fragmentary specimens. nal index is inappropriate. Olcostephanus has long been KEMPER (1992) figured two from the "Upper Va recognised as the characteristic ammonite of this level, langinian" of the Mitteland Canal while both QUENSEL and now that some forms have been firmly identified (1988, pl. 11.1/3) and MUTTERLOSE (1992, pi. 7, figs 1- (BULOT in MUTTERLOSE, 1992) and illustrated as Olco 2) illustrated fragments from the tuberculata Zone. The stephanus densicostatus I am proposing to use thai fragments figured by KEMPER et alii (1981, pi. 34, figs. species as the zonal index. O. densicostatus is a widely 16-17), QUENSEL (1988, pl. II 1/3, fig. 1 and MUT distributed form characteristic of one of the TERLOSE (1992, pi. 7, figs 1-2) have all been assigned to "chronoclines" recognised by BULOT (1990, p. 128). a new taxon. Criohimantoceras gigas, by THIEULOY & BULOT (1993). with MUTTERLOSE'S specimen as the Because of the supposed basal Hauterivian age of holotype. However, this specimen is much less curved Eleniceras QUENSEL (1988) placed this zone in the than the triptychoides Zone material figured and recor Hauterivian. Eleniceras is actually recorded from the ded by KEMPER et alii (1981) so at least two taxa are Late Valanginian too (e.g. THIEULOY, 1977; THIEULOY probably represented. et alii., 1990). Conversely, typical earliest Hauterivian A second neocomitid genus. Dicostella, first appears Acanthodiscus first appear in the overlying Endemoce- in the middle of the bidichotomoides Zone where seve ras beds (see below). ral species occur (KEMPER et alii, 1981; QUENSEL, 1988 - ivanovi Subzone). It provides the zonal index for the overlying tuberculata Zone, named by KEMPER et alii 2.3. - THE HAUTERIVIAN SEQUENCE (1981) following their reidentification of the index spe cies of KEMPER'S (1971) Dicostella pitrei Zone, which in turn had been proposed for the "Arnoldien Schichten" Thick mudrocks continued to accumulate in north of former workers. Ottensen was the main locality for Germany and there is a well-developed succession in the these faunas. Speeton Clay of eastern England. The faunal sequence Other ncocomilids also occur as rarities in the upper is similar in both areas so that a common zonation can part of the Valanginian. KEMPER et alii (1981) figured be applied to most of the sequence. The modern zona several examples, most from the tuberculata Zone or tion dates from RAWSON'S (1971a, 1971b) study of the just beneath. Speeton Clay sequence of eastern England, which drew A form similar to their Neocomites sp. A occurs in on earlier published work including THIERMANN'S the transgression horizon at Sarstedt (KEMPER, 1992, pi. (1963) recognition of the amblygonium and noricum 37. fig. 3), associated with Dicostella aff. tuberculata. Zones in north Germany. Other ncocomilids from just above the transgression North Germany is therefore the type area for these horizon have been assigned to Eleniceras and Neocomi lowest two zones and the coastal section at Speeton is tes (KEMPER & WIEDENROTH, 1987, pi. 7, figs 2-3; the type locality for the remainder, with two exceptions. KEMPER, 1992, pi. 37, fig. 1), supposedly of Hauterivian When KEMPER & RAWSON (in KEMPER, 1973) expanded age but probably latest Valanginian. KEMPER (1992, pi. the "English" zonation to north Germany they used S. 37. fig. 5) also figured a more involute Neocomites from staffi as an alternative to .S'. speetonensis and S. (C). the Valanginian/ Hauterivian boundary at Niederme- discofalcatus as an alternative to S. marginatus and C. hnen. variabilis, reflecting differences in the abundance of the This specimen looks close lo N. f/'eschenites) of the Simbirslcites species. The inversum Zone was first used jlucticulus group. An Oosterella aff. villanovae came in North Germany by KEMPER (1976, table 7). from the same level (KEMPER, 1992, pi. 33, fig. 3). At Speeton the base of each zone was defined by the The highest Valanginian densicostatus zone was first appearance of the index species. formerly known as the "Astierien Schichten" - the level where a second wave of Olcostephanus appeared in the The zonation, from top to bottom, is: 126 RAWSON P. F.
ENGLAND GERMANY S. (Simbirskites) marginatus S. (C.) discofalcatus (pars) Simbirskites (Craspedodiscus) gottschei S. (Milanowskia) speetonensis S. (M.) staffi Simbirskites (Speetoniceras) inversum Endemoceras regale Endemoceras noricum Endemoceras amblygonium
The ammonite faunas show considerable diversity which first appears immediately above this level and for and include typical Tethyan species at some levels. a short while became the dominant ammonite across the Endemoceras is the characteristic and dominant genus whole NW European area: English Aegocrioceras were of the first three zones. It is an endemic neocomitid monographed by RAWSON (1975) and German examples apparently derived by allopatric speciation from a illustrated by KEMPER & WIEDENROTH (1987) and Tethyan-derived Neocomi tes (Teschenites). In Germany KEMPER (1992). Acanthodiscus appeared with Endemoceras. Much pri A second invasion of Crioceratites is marked by zed by collectors it is a quite rare genus though relati common examples of the nolani/duvali group high in vely abundant in collections! Few of the museum speci the inversum Zone in both England and Germany (e.g. mens have an accurate horizon recorded but it is known KEMPER et alii, 1981, pi. 34, fig. 3, 4; KEMPER. 1992, from the upper part of the amblygonium Zone and the pi. 55-57). noricum Zone (KEMPER et alii, 1981; QUENSEL, 1988). From then upwards it occurs scattered through the Compared with the French material, the German forms Upper Hauterivian sequence though these younger are fairly advanced A canthodiscus with a broad siphonal forms remain poorly known. In the middle of the spee band characteristic of the middle part of the radiatus Zone (BULOT et alii, 1993, p. 39). So the previous pro tonensis Zone at Speeton Spitidiscus reappeared briefly, visional correlation of the base of the underlying am represented by the type species, S. rotula. Similar forms blygonium Zone with the base of the underlying radia occur in the upper part of the Gildehauser Sandstone of tus Zone (THIERMANN, 1963; RAWSON, 1971b) still north Germany and the nearby Losser Sandstone in the appears the best approximation. Netherlands (KEMPER et alii, 1981; KEMPER, 1992, pis 55-57). Acanthodiscus failed to reach eastern England, whe re the equivalent beds are condensed but very fossilife- rous. However, younger Early Hauterivian faunas are best known from England (Speeton Clay) where the 2.4. - THE BARREMIAN SEQUENCE regale Zone faunas are better developed than in the poorly fossilferous German sections. Here olcostepha- nids reappear in the upper part of the regale Zone where Barremian sequences occur in both Germany and Olcostephanus of the sayni group, Jeannoticeras jean- England, mainly in mudrock or calcareous mudrock noti and the apparently endemic micromorph form Pa- facies. The zonation currently used is based mainly on rastieria peltoceroides all occur (KEMPER et alii, 1981; KOENEN'S (1902, 1908) and STOLLEY'S (1908) work in DOYLE, 1989). north Germany, as modified slightly by KEMPER (1976, Spitidiscus pavlowi appeared briefly at the top of the p. 75). As with the Valanginian, the zonation was zone. Immediately afterwards there was a major mid established by placing individual faunas from scattered Hauterivian faunal turnover, coinciding with a sequence sections into sequence. boundary that marks an important sea level rise of glo Unfortunately, although rich horizons are sometimes bal extent (RAWSON, 1993a). found (e.g. IMMEL & MUTTERLOSE, 1980), ammonites Boreal Simbirskites (Speetoniceras) replaced Ende are rare or absent at many levels and no detailed, bed- moceras at the base of the inversum Zone. An evolving by-bed sequence has been established. Thus the strati- plexus of Simbirskitinae then occupied the whole West graphic accuracy of the zonation remains uncertain. European Province until very early in the Barremian. The lower part of the zonation (variabilis to lower With the earliest forms came high Arctic Homolsomites denckmanni zones) has been proved in outline at Spec- and rare Tethyan Crioceratites and ?Megacrioceras -all ton, though once again identifiable forms are scarce and in the same thin bed (C7H) at the base of the inversum fragmentary (RAWSON & MUTTERLOSE, 1983). The Zone at Speeton. bidentatum Zone is more fossiliferous there, but the This first Crioceratites gave rise by allopatric spe intervening upper denckmanni to stolleyi zones are ciation to the endemic heteromorph Aegocrioceras difficult to identify due to poor exposure. BOREAL AND MEDITERRANEAN AMMONITES 127
The lowest Barremian zone has a different simbir- next firm tie between the two regions is not until the skitid index in each area. base of the hollwedensis Zone. Here, large, sphaeroidal Olcostephanus of the guebhardi group occur through The zonation, from top to bottom, is: the lower part of the zone, indicating a correlation with
ZONE TYPE LOCALITY* Parancyloceras bidentatum Sarstedt (Moorberg) Simancyloceras stolleyi Behrenbostel Simancyloceras pingue!/"Ancyloceras" innexum Mellendorf Paracrioceras denckmanni Mellendorf Paracrioceras elegans Hildesheim "Hoplocrioceras " fissi costatum Hildesheim "Hoplocrioceras" rarocinctum Querum Simbirskites (Cr.) variabilis ( = S. (C.) discofalcatus Speeton, England (pars) in Germany)
•based mainly on KOENEN (1902)
Very early in the Barremian (end of the variabilis/ the upper campylotoxum Zone. The Lower/Upper Va discofalcatus Zone) the simbirskitids died out and the langinian boundary lies in about the middle of the NW European Barremian faunas became almost exclu hollwedensis Zone, where Saynoceras verrucosum ap sively heteromorph, consisting of Tethyan or Tethyan- pears (KEMPER et alii, 1981). derived endemic species whose exact biogeographical Varlheideites peregrinus (RAWSON & KEMPER, affinities are difficult to interpret; the problem is discus 1978), first described from the north German crassus sed in detail by RAWSON (this volume). Zone, has now been found in the upper part of the ver The later Barremian heleromorphs show a more rucosum Zone of the south-east of France, where it obvious Tethyan connection, apparently linked to a forms a distinct peregrinus Horizon (Bui .or et alii, possible sea level rise that is marked at Speeton by a 1993). Crassus Zone dichotomitids occur there at the sharp facies changes from somewhat calcareous mu- same level. drocks lo a dark, pyritic shale at the base of the bidenta tum Zone. This was accompanied by the appearance of Correlation of the younger Valanginian beds is more numerous Aconeceras nisoides, Toxoceratoides, the tenuous. BULOT et alii (1993) correlated the top of the apparently endemic Parancyloceras and, more remar crassus Zone with the base of the nicklesi Horizon be kably, small Heteroceras (RAWSON, this volume). With cause of the occurrence in the latter of Dichotomies the exception of Heteroceras all these forms are recor petschi and D. evolutus. However, at least one of these ded also from north Germany, from where KEMPER taxa is now known to extend into the basal triptychoides (1973) has also described Spinocrioceras, a distinctive Zone in Germany (MUTTERLOSE, 1992). It appears more trituberculatc crioceratitid from the lower part of the appropriate to provisionally correlate the base of the bidentatum Zone. latter zone with the base of the nicklesi Horizon as crio ceratitid hetermorphs (Himantoceras group) first appear at this level in both areas. Occurrences of the related genus Criohimantoceras led BULOT et alii (1993) to 3. CORRELATION WITH THE WEST MEDITERRA correlate the upper triptychoides, bidichotomoides and NEAN FAUNAS lower tuberculata Zones with the furcillata Horizon. Unfortunately, Criohimantoceras is so rare and poorly In addition to the Tethyan ammonites recorded here known that its scattered records in north Germany and from north-west Europe, boreal or even Tethyan-derived France are of very limited stratigraphie value. Dicostel forms occasionally migrated in the opposite direction, to la also gives little help. It is not common in France, marginal areas of the West Mediterranean Province. where occurrences in SE France and the Paris Basin This happened almost exclusively in the Valanginian were reviewed by THIEULOY et alii (1990). It appears to unless some poorly known Barremian heteromorphs be another neocomitid that reached its peak of deve also followed the same trend. The migrant forms give lopment in the West European Province. Hence the several tie-points where faunas from the two realms can correlation of the beds above the triptychoides/nicklesi be correlated (Fig. 2). The Mediterranean zonation is level shown in Fig. 2 is very provisional: an approxima based on a recent revision by HOEDEMAEKER, COMPANY te correlation of the densicostatus Zone with the et alii (1993) on behalf of IGCP Project 262. "callidiscus" Zone of BULOT et alii (1993) (= callidiscus Platylenticeras comparable with early German forms and overlying unnamed horizons in Fig. 2) is based on (robustum Zone) appear very high in the otopeta Zone the occurrence of "Eleniceras" and common Olcostpha- of south-eastern France (KEMPER et alii, 1981), but the nus densicostatus in both areas (BULOT et alii. 1993). 128 RAWSON P. F.
ZONE SUBSTAGE West European Province West Mediterranean region sarasini bid en tatù m giraudi stolleyi UPPER feraudianus BARREMIAN pingue / innexum sartousiana denckmanni vandenheckii ? elegans caillaudianus fissicostatum LOWER nicklesi rarocinctum BARREMIAN hugii variabilis disco marginatus falcatus angulicostatus gottschei balearis UPPER speetonensis /staffi ligatus HAUTERIVIAN inversum sayni nodosoplicatum regale loryi LOWER noricum HAUTERIVIAN radiatus amblygonium densicostatus callidiscus Hor. tuberculata pachy- furcillata Hor. dicranus bidichotomoides UPPER triptychoides nicklesi Hor. VALANGINIAN crassus peregnnus Hor verrucosum polytomus hollwedensis hapkei clarkei campylotoxus multicostatus LOWER pavlowi VALANGINIAN involutum pertransiens heteropleurum robustum otopeta
Fig. 2. The zonation of the West European Province and ils correlation with the Mediterranean Region. Dashed lines indicate an approximate correlation with the West European Province, dashed lines and ? indicate greater uncertainty. - Zonazione della Provincia Europea Occidentale e correlazione con la regione mediterranea. Le linee tratteggiate indicano una correlazione approssimativa con la Provincia Europea Occidentale, tratteggi e ? indicano maggiore incertezza. BOREAL AND MEDITERRANEAN AMMONITES 129
This leaves the intervening bidichotomoides and tuber- BULOT L., THIEULOY J.-P., BLANC E. & KLEIN J. (1993) - Le cadre straligraphique du Valanginien supérieur et de VU auterivien du culatus Zones to correlate approximately with the furcil- Sud-Est de la France: Définition de biochronozones et caractéri- lata Horizon. sation de nouveaux biohorizons. Géologie Alpine. 68 (1992): 13- The base of the Hauterivian is conditionally placed 56, Grenoble. at the base of the amblygonium zone, as discussed abo CASEY R. (1973) - The ammonite succession at the Jurassic- ve. Very close correlations can be made between the Cretaceous boundary in eastern England. In: R. CASEY & P. F. Speeton (England) and French mid Hauterivian sequen RAWSON (Eds.):"The Boreal Lower Cretaceous". Geol. Jl. Spec. Iss.. ces (BULOT et alii, 1993; BIILOT & RAWSON. in prep). 5: 193-266, Liverpool. The occurrence of Jeannoticeras jeannoti in the upper CECCA F. & LANDRA G. (1994) - Late Barremian-Early Aptian am part of the Speeton regale Zone gives a firm tie to the monites from the Maiolica formation near Cesano lìrianza upper loryi Zone, the base of the nodosoplicatum Zone (Lombardy basin, Northern Italy). Riv. II. Pai. Strat., 100 (3): correlates with the base of the inversum Zone while 395-422, Milan. BULOT et alii's (1993) redefined sayni Zone corresponds D'ARCWAC A. (1838) - Mémoire sur les étages inférieurs de la forma to the upper part of the inversum Zone. tion crétacée dans le nord de la France et en Angleterre. Bull. Soc. KEMPER et alii (1981) took the first (and only) ap géol. France, 9: 259, Paris. pearance of Crioceratites (Paracrioceras) spathi at the DELANOY G. ( 1992) - Les ammonites du Barrémien Supérieur de Saint- base of the variabilis Zone at Speeton to mark the base Laurent de l'Escarène (Alpes-Maritimes, Sud-Est de la France). of the Barremian there. This coincides with a horizon in Ann. Mus. Hist. Nat. Nice, 9: 1-148, Nice. about the middle of the German discofalcatus Zone. There a related form, C. (P.) strombecki (KOENEN), is DOYLE J. C. (1989) - The stratigraphy of a late Lower Hauterivian horizon in the Speeton Clay formation (l^ower Cretaceous) of East close to the Tethyan "E. " emerici group. However, in Yorkshire. Proc. Geol. Assoc.. 100: 175-182. London. the Mediterranean area such forms range from the upper part of the angulicostata Zone (top Hauterivian) through HOEDEMAEKER J., COMPANY M. (Reporters) and AGU1RRE-URETA M. B., A VRAM E., BOGDANOVA T. N.. BlUTOR I.., BULOT L, CECCA much of the Lower Barremian. Thus the correlation F., DELANOY G., ETTACTiFTNl M., MEMMI L., OWEN H. G., shown in Fig. 2 is only tentative. The same is true for RAWSON P. F„ SANDOVAL J., TAVERA J. M., THIEULOY J.-P., the Lower/ Upper Barremian boundary, which is based TOVBINA S. Z. & VASICEK Z. (1993) - Ammonite zonation for the on the superficial resemblance of the coarsely-ribbed, Lower Cretaceous of the Mediterranean region; basis for the stra tigraphie correlations within IGCP-Project 262. Revisla Espanola trilubcrculatc inner whorls of some denckmanni Zone de Paleontologia, 8 (1): 117-120, 1 lab., Madrid. crioccratilids to the barremense group at the base of the French Upper Barremian (RAWSON, 1994). Possibly the JELETZKY J. A. & KEMPER E. (1988) - Comparative paleontology and boundary should be drawn slightly lower, in or at the stratigraphy of Valanginian Polyptychitinae and Simbirskitinae in Sverdrup Basin (Arctic Canada) and Lower Saxony Basin base of the elegans Zone. (Northwest Germany). Geol. Surv. Can. Bull., 377: 355 pp., 67 pis, Spinocrioceras of the lower bidentatum Zone was Ottawa. originally regarded as a "boreal" heteromorph. It is now KEMPER E. (1961) - Die Ammomtengattung Platylenticeras (y- Gamie- known from SE France (DELANOY, 1992), northern Italy ria). Geol. Jb., 47: 1-195, Hannover. (CECCA & LANDRA. 1994) and the Caucasus (KOTETISIIVILI, 1970) and probably originated in the KEMPER E.(1973) - The Valanginian and Hauterivian stages in north West Mediterranean Region. There it occurs in the west Germany. In: R. CASEY & P.F. RAWSON (Eds.): "The Boreal feraudianus and giraudi Zones. Together with Hetero- Lower Cretaceous". Geol.JI. Spec. Iss., 5: 327-344, Liverpool.
ceras from the bidentatum Zone at Speeton, this record KEMPER E. (1976) - Geologischer Fuhrer durch die Grafschaft Bent- and the evidence of a sea-level rise at about the base of heim und die angrenzenden Gebiete. mit einem Abriss der the giraudi Zone suggests a provisional correlation of emslandischen Unterkreide (5th edition): p.205. Nordhom, Bent- the giraudi and sarasini Zones with the bidentatum heim. Zone. KEMPER E.(1978) - Einige neue biostratigraphisch bedeutsame Arten The Aconeceras of the bidentatum Zone are regar der Ammoniten-Gattung Dichotomites (NW-Deutschland. Oberva- ded as "Tethyan" immigrants, but the genus is not langin). Geol. Jb., A 45: 183-253, Hannover. known from adjoining areas of Tethys at this time. Hen ce RAWSON (this volume) has suggested that its appea KEMPER E. (1992) - Die Tiefe Unterkreide im Vechte-Dmkel-Gebiel. rance in the West European Province may represent Het Staringmonument te Losser: pp. 95, 66 pis., Ix>sser immigration from the eastern Pacific via a proto-Gulf KEMPER E., RAWSON P. F. & THIEULOY J.-P. (1981) - Ammonites of Stream through the opening North Atlantic. Tethyan ancestry in the early Lower Cretaceous of north-west Eu rope. Palaeontology, 24: 251-311, I^ondon.
KEMPER E. & WIEDENROTH K. (1987) - Klima und Tier-Migrationen REFERENCES am Beispiel der fr&he-kretazischen Ammonilen. Geol. Jb., A 96: 315-363, Hannover. BULOT L. (1990) - Evolution des Olcostephaninae (Ammonitine!, Ce phalopoda) dans le contexte palèobiogèographique du Crétacé KOENEN A. VON (1902) - Die Ammonitiden des Norddeutschen Neo- inférieur (Valanginien-H auterivien) du Sud-Est de la France. kom (Valanginien, Hauterivien, Barremien und Aptien). Abh. Thèse, Université de Bourgogne: pp. 178, Dijon (unpublished). preuss. geol. Landesanst., N.F., 24: 1-451, 55 pis; Berlin. 130 RAWSON P. F.
KOENEN A VON (1908) - Bemerkungen zur gliederung der unteren Abstracts of the 1st meeting of IGCP Project 362: Tcthyan/Boreal Kreide. Zentralbl. Min. Geol. Pal., Jg. (1908): 289-293, Stuttgart. Correlation, Coimbra, Portugal.
KOTETISHWI E. V. (1970) - Stratigraphy and fauna of the colchiditic RAWSON P. F. (1994) - Sea level changes and their influence on am and adjacent horizons of Western Georgia. Trudy Geol. Institute, monite biogeography in the European Lower Cretaceous. Atti 111° Tbilisi, 67: 1 -115 (in Georgian), Tblisi. Conv. Int. "Fossili, Evoluzione, Ambiente", Pergola 1990. Paleope- lagos, spec, pubi., 1: 317-326 Roma. MUTTERLOSE J. (1992) - Migration and evolution patterns of floras and faunas in marine Early Cretaceous sediments ofNW Europe. RAWSON P. F. (this volume). Biogeographical affinities of NW Euro Palacogeog., Palaeoclim., Palaeoecol., 94: 261-282; Amsterdam. pean Barremian ammonite faunas and their palaeogeographical implication. NEUMAYR M. & UHLIG V. (1881) - Ueber Ammonitiden aus den Hil- sbildungen Norddeutschlands. Palaeontographica, 27: 129-203, RAWSON P. F., CURRY D., DILLEY F. C, HANCOCK. J.M., KENNEDY W. Cassel. J., NEALE J. W„ WOOD C. J. & WORSSAM B. C. (1978) - A corre lation of Cretaceous rocks in the British Isles. Geol. Soc. Ix>ndon, QUENSEL P. (1988) - Die Ammonitenfauna im Valangin-Hauterive- Special Report, 9: pp. 70, London. Grenzbereicht vom Mittelandkanal bei Pollhagen. Berliner geowiss. Abhl., A94: 15-71, Berlin. RAWSON P. F. & KEMPER E. (1978) - Varlheideites, n. gen. (Ammonoidea, Neocomitinae) aus dem Obervalangin NW- RAWSON P. F. (1971a) - Lower Cretaceous ammonites from north-east Deutschlands: Geol. Jb., A 45: 163-181, Hannover. England: the Hauterivian genus Simbirskites. Bull. British Mus. nat. Hist. (Geology), 20: 25-86, London. RAWSON P. F. & MUTTERLOSE J. (1983) - Stratigraphy of the Lower B and basal Cement Beds (Barremian) of the Speeton Clay, Yorkshi RAWSON P. F. (1971b) - The Hauterivian (l^ower Cretaceous) biostra re, England. Proc. Geol. Ass., 94: 133-146. tigraphy of the Speeton Clay of Yorkshire, England. Newsl. Strat., 1: 61-76, Leiden. SOWERBY J. DE C. (1827) - The Mineral Conchology of Great Britain 6: pis. 546-580, London. RAWSON P. F. (1975) - Lower Cretaceous ammonites from north-east England: the Hauterivian heteromorph Aegocrioceras. Bull. British STOLLEY E. (1908) - Die Gliederung der norddeutschen unteren Mus. nat. Hist. (Geology), 26: 129-159, London. Kreide. III. Oberneocom (Barreme). Zentralbl. Min. Geol. Pal., Jg. (1908): 162-175, Stuttgart. RAWSON P. F. (1981) - Early Cretaceous ammonite biostratigraphy and biogeography. In: M. R. House & J. R. Senior (Eds.): "The STOLLEY E. (1937) - Die Gliederung des norddeutschen marinen Ammonoidea". Systematics Assoc. Spec. Vol., 18: 499-529. Aca Unterneocoms. Zentralbl. Min. Geol. Pal. Abt B, 11: 434-456; 12: demic Press, London. 497-506, Stuttgart.
RAWSON P. F. (1983) - The Valanginian to Aptian stages - current THJERMANN A. (1963) - Die Ammonitengattung Endemoceras n. g. aus definitions and outstanding problems. Zitteliana, 10: 493-500, dem Unter-Hauterive von Nordwest-Europa. Geol. Jb., 81: 345- Munchen. 412, Hannover.
RAWSON P. F. (1992) -Early Cretaceous. In J.C.W. Cope, J. K. Ingham THIEULOY J.-P. (1977) - Les ammonites boréales des formations Néo- & P. F. Rawson (Eds.): "Atlas of Palaeo-geography and Lithofacies". comiennes du sud-est Français (Province Subméditerranéenne). Geol. Soc, London, Mem. 13, 131-137, London. Geobios, 10: 395-461, Lyon. RAWSON P. F. (1993a) - The influence of sea level changes on the migration and evolution of Lower Cretaceous (pre-Aptian) am THIEULOY J. - P. & BULOT L. (1993) - Ammonites du Crétacé Inférieur monites. In M. R. House (Ed.): "The Ammonoidea: environment, du Sud-Est de la France: I. Nouvelles espèces à valeur strati ecology and evolutionary change". Systematics Assoc. Spec. Vol. 47: graphique pour le Valanginien et l'Hauterivien. Géologie Alpine. 227-242, Oxford. 68 (1992): 85-103, Grenoble.
RAWSON P. F. (1993b) - NW European "Boreal" Lower Cretaceous THIEULOY J.-P., FUHR M. & BULOT L. (1990) - Biostratigraphie du ammonite biozones. TBC Newsletter 1, Utrecht. Crétacé inférieur de l'Arc de Castellane (S.E. de la France). 1: Faunes d'ammonites du Valanginien supérieur et âge de l'horizon RAWSON P. F. (1993c) - The occurrence of Tethyan ammonites in the dit de "La Grande Lumachelle". Géologie Méditerranéenne 17: 55- "Boreal" pre-Aptian sequendces of Eastern England: A review. 99, Marseille. Mem. Descr. Carta Geol. a"It. LI (1995), pp. 131-136
Biogeographical affinities of NW European Barremian ammonite faunas and their palaeogeographical implications
Affinità biogeografiche delle faune ad ammoniti del Barremiano dell'Europa nord occidentale e loro implicazioni paleogeografiche
PETER F. RAWSON (*)
IOCF Projects 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - Closure of the Danish-Polish furrow in latest RIASSUNTO - La chiusura del solco danese-polacco nell'I Iautenviano Hauterivian times led to increased isolation of the NW European basins terminale portò a un crescente isolamento dei bacini dell'Europa nord during the Barremian. For much of the Barremian the ammonite fauna occidentale durante il Barremiano. Per gran parte del Barremiano le consisted almost exclusively of apparently endemic heteromorph faunas faune ad ammoniti consistevano quasi esclusivamente di ammoniti that had evolved from Tethyan-derived Hauterivian ancestors. However, eteromorfe apparentemente endemiche, cvolutesi da antenati hauterìviani during the mid Barremian desmoceratids appeared briefly. Then in latest di origine telidea. Durante il Barremiano "medio" i desmoceratidi Barremian limes there was an influx of the normally coiled ammonite apparvero per un breve periodo. Nel Barremiano superiore, si verificò Aconeceras together with the distinctive late Barremian heteromorph l'arrivo di Aconeceras, ammonite ad avvolgimento normale, insieme al genus Heteroceras, recently discovered in the Aconeceras beds at genere eteromorfo Heteroceras, scoperto recentemente negli strati ad Speeton (eastern England). The appearance of these Tethyan forms shows Aconeceras a Speeton (Inghilterra orientale). La comparsa di queste that there was at least intermittent Tethyan influence in NW Europe forme dimostra che durante il Barremiano in Europa occidentale ci fu during the Barremian, probably via a seaway through the North Atlantic. un'influenza telidea, per lo meno intermittente, probabilmente attraverso Aconeceras may have arrived in the area from the eastern Pacific via a il braccio di mare dell'Atlantico settentrionale. Gli Aconeceras proto-Gulf Stream. potrebbero essere dal Pacifico orientale attraverso una proto-corrente del Golfo.
KEY-WORDS - Lower Cretaceous, ammonites, biogeography, PAROLE-CHIAVE - Cretaceo inferiore, ammoniti, biogeografia, palaeogeography, ocean currents. paleogeografia, correnti oceaniche.
(*) Department of Geological Sciences, University College London, Gower Street, London WC1E 6BT, UK 132 RAWSON P. F.
1. - INTRODUCTION Parancyloceras bidentatum Simancyloceras stolleyi UPPER BARREMIAN Until the beginning of the Aptian, the Early Simancyloceras pingue/"Ancyloceras" innexum Cretaceous ammonite faunas of NW Europe (England, Paracrioceras denckmanni the North Sea Basin and North Germany) belonged to Paracrioceras elegans the West European Province of the Boreal Realm "Hoplocrioceras" fissicostalum (RAWSON, 1981; in press). The Berriasian ammonites LOWER BARREMIAN "H oplocrioceras " rarocinctum were exclusively boreal but through Valanginian and Simbirskites (Craspedodiscus) Hauterivian times there was a marked Tethyan influence variabilis (KFMPFR et alii 1981). The influx of Tethyan forms took place mainly, though not exclusively, at times of rapid sea level rise (KEMPER et alii, 1981; RAWSON, 1993, 3. - BIOGEOGRAPHICAL AFFINITIES OF THE NW 1994). Occasionally a Tethyan immigrant gave rise, EUROPEAN FAUNAS through allopatric speciation, to major endemic faunas that gave the West European Province a distinctive The simbirskitid ammonites of the earliest Barremian character (Platylenticeras, Endemoceras, Aegocrioce- are typical Boreal perisphinctaceans. The heteromorphs ras). A similarly strong Tethyan influence during the are of Tethyan origin but their exact relationships are Valanginian and Hauterivian is seen in other fossil difficult to determine. KOENEN'S (1902) monograph of groups, such as the belemnites (MUTTERLOSE, 1983), the German faunas is still the most complete review brachiopods (MIDDDLEMISS, 1979), foraminifera available. KEMPER (1973), IMMEL (1978) and IMMEL & (MICHAEL, 1974) and nannoflora (MUTTERLOSE, 1992). MUTTERLOSE (1980) added further information. SPATH The immigrant Tethyan organisms were all forms (1924) listed the English fauna and RAWSON (1975) and that lived in western Tethys, from Spain to the Caucasus. RAWSON & MUTTERLOSE (1983) have reviewed English There was a direct immigration route from the Lower Barremian occurrences. These various works Carpathians through the Danish-Polish furrow to the indicate that by the beginning of the Barremian the NW European basins, and possibly a second route heteromorphs of the West European Province had linking the Jura with the Lower Saxony Basin via the diverged considerably from their mid-Hauterivian Rheinische Senkungszonc (MIDDLEMISS, 1976; RAWSON, Tethyan ancestors. in press, fig. 1). By the end of the Hauterivian these Unfortunately it is difficult to compare these "boreal" seaways had apparently closed and NW Europe was no forms with the classic Tethyan faunas of SE France, longer open to direct Tethyan influence. Thus the monographed by SARKAR (1955) and THOMEL (1964). A Barremian has been regarded as an interval of increasing plethora of species names has been proposed from both cndemicity among many fossil groups (RAWSON, 1973, areas, but there is hardly a name in common between the 1981; MICHAEL. 1979; MIDDLEMISS, 1979; two. This excessive monographic "splitting" of both the MUTTERLOSE, 1983, 1992). However, the recent German and French faunas helps to obscure their true discovery in the Speeton Clay at Speeton (eastern taxonomic relationships, as does the fragmentary England) of a Barremites in the mid Barremian and of preservation of many specimens in a group that shows several examples of the distinctive Tethyan heteromorph considerable morphological change during ontogeny. In Heteroceras in the highest Barremian beds have France only the early to intermediate growth stages are prompted a reappraisal of the biogeographical usually preserved, while it is often the mid to later stages relationships and palaeogeographical setting of the that are best preserved in NW Europe. Barremian faunas. Because of these taxonomic problems the biogeographical affinities of the Barremian 2. - COMPOSITION AND BIOSTRATIGRAPHY OF heteromorphs of the West European Province are THE NW EUROPEAN FAUNAS difficult to interpret. While Tethyan species definitely occurred there during the Hauterivian (KEMPER et alii, During the Late Hauterivian the West European 1981), the Barremian faunas may have diverged from Province ammonite faunas were dominated by the late those of Tethys in response to the increasing perisphinctacean genus Simbirskites, but heteromorph geographical isolation of the NW European basins ammonites occurred too. Very early in the Barremian (RAWSON 1973; in press). However, the divergence may Simbirskites died out, leaving an almost exclusively have been slight for there are some interesting parallels heteromorph fauna through the remainder of the in the development of faunas in the two areas. For Barremian. However, normally coiled ammonites example, for the Lower Barremian KEMPER et alii (1981, occasionally reappeared alongside the heteromorphs, p. 261) recognised close similarities between especially in latest Barremian times when Aconeceras Crioceratites (Paracrioceras) spathi (Boreal) and invaded the province in significant numbers. "Emericiceras" of the thiollierei group (Tethyan), C. (P.) The biostratigraphy of the Barremian ammonites strombecki (B) and the "E. " emerici group (T), and C. requires further research (RAWSON, this volume). The (P.) ftssicostatum (B) and the "Binelliceras" binelli zonation currently used is: group (T). BIOOEOGRAPHICAL AFFINITIES OF NW EUROPEAN FAUNAS 133
I;ig 1-3 - Ammonites from the PARANCYLOCERAS BIDENTATUM Zone (Upper Barremian); Upper B Beds, Speeton Clay Formation, Speeton, North Yorkshire. UK. All specimens are in the author's collection at University College London. 1): ACONECERAS sp.(nucleus), x 7 (actual diameter 6 mm); 2): HETEROCERAS sp. - 2a lateral view of a slightly distorted specimen, x 1.5 - 2b distorted earliest whorls of the same specimen, showing the characteristic curvature of the ribs over the venter at the helical stage, x 2.7; 3): HETEROCERAS sp., helical earliest whorls, x 5. - AMMONITI DELLA ZONA PARANCYLOCERAS BIDENTATUM (BARREMIANO SUPERIORE); "UPPER B BEDS" DELLA FORMAZIONE SPEETON CLAY, SPEETON, YORKSHIRE SETTENTRIONALE. GRAN BRETAGNA. TUTTI GLI ESEMPLARI APPARTENGONO ALLA COLLEZIONE DELL 'AUTORE, UNIVERSITY-COLLEGE DI LONDRA. 1): ACONECERAS SP. (NUCLEO), X 7 (DIAMETRO EFFETTIVO 6 MM); 2): VISIONE LATERALE DI UN ESEMPLARE DI HETEROCERAS SP. - 2A LEGGERMENTE DISTORTO, X 1.5 - 2B SPIRALI INIZIALI DISTORTE DELLO STESSO ESEMPLARE, CON LA CARATTERISTICA CURVATURA DELLE COSTE SULL'AREA VENTRALE NELLO STADIO AD AVVOLGIMENTO ELICOIDALE, X 2.7; 3): HETEROCERAS SP.. SPIRALI ELICOIDALI INIZIALI, X 5.
The new discoveries at Speeton coupled with a re- MUTTERLOSE, 1980) and C. (P.) denckmanni (KOENEN) evaluation of some of the North German faunas suggest from the Caucasus (KAKABADZE, 1981, pi. 2, fig. 1). The thai whatever the uncertainties in interpeting the specimens certainly look very similar to the NW systematics and biogeographical relationships of many of European forms and indicate the possibility of southward the heteromorphs, NW Europe must have retained at as well as northward migration at that time. least intermittent connection with "Tethyan" areas. A second, more clearly defined invasion of Tethyan There appear to have been two main intervals when such ammonites occurred in NW Europe very late in the connection occurred. Barremian. The oppeliid genus Aconeceras suddenly The first was at about the middle of the Barremian appears in the highest Barremian beds of both Speeton (elegans-denckmanni zones), when desmoceratid and north Germany (KOENEN, 1902, 1908). In the ammonites appeared in NW Europe. In North Germany Hildesheim area it is sufficiently common that ils they appear to be quite common (e.g. Lange collection, horizon was referred to as the Oppelia nisoides beds Hamburg). KOENEN (1902) recorded his "Desmoceras" (e.g. at Hoheneggelsen: BRANDES collection, Hamburg). (^Callizoniceras) plicatulum from the elegans and German published records (e.g. STOLLEY, 1908; denckmanni zones, while his "Desmoceras" KEMPER, 1976, table 8) indicate that Aconeceras first (Callizoniceras) hoyeri occurs in the upper appears at the base of the stolleyi Zone. However, new denckmanni to lower pingue zones, according to KEMPER collecting at Speeton suggests that in eastern England il (1976, table 8; KOENEN originally recorded it from the first appears higher in the sequence, at the base of the top of the Barremian). The horizon is also represented in bidentatum Zone (though ammonites are very rare in the England, where Mr J. C. DOYLE has recently collected a immediately underlying beds). It is common at several single Barremites from bed LB IB (probably basal levels in that zone, though easily overlooked as often elegans Zone) at Speeton. This supplements an earlier only the earliest whorls, up to 2 mm diameter, are record of desmoccratids from unknown horizons in the preserved (Fig. 1). Speeton Barremian, based on two small specimens More remarkable is the recent (1992) discovery at collected in the last century by J. W. JUDD (British Speeton of the distinctive heleromorph Heteroceras, Geological Survey, nos. 30973 and 30974). These were which first appears with the first Aconeceras at the base recorded by SPATH (1924, p. 78) as "Pseudosaynella of the bidentatum Zone. Heteroceras has an initial plana (PHILLIPS, non MANTELL)" but reidentified by helical spiral followed by a straight or curved shaft and a CASEY (1954, p. 268) as true desmoceratids, "belonging recurved crozier. Both small and very large forms are to the Barremian group of Barremites strettostoma". known, but at Speeton only the helix and fragments of It is at about mid Barremian times that "Boreal" shaft of a diminutive form of the //. elegans ROUCHADZE crioceratitids may have spread into western Tethys. - H. baylei REYNES group have been found (author's Crioceratites (Paracrioceras) of the elegans group arc collection). The material will be described in full in a recorded from Morocco (ROCH, 1930; IMMEL & revision of the Speeton Late Barremian heteromorphs 134 RAWSON P. F.
(RAWSON, in preparation), but two specimens are of the Hauterivian, severing connections between NW illustrated here (Figs 2-3). Heteroceras is of latest Europe and the Carpathian area. However, some of the Barremian age and achieved a remarkably wide sandstones within the furrow show limited evidence of distribution, from Japan and South Africa, through marine conditions (glauconite, agglutinated western Tethys to Colombia, Patagonia and Canada foraminifera). so it is possible that there were brief (AOUIRREURRETA&KLINGER, 1986, p. 322). spillovers of Tethyan waters into NW Europe during the This sudden spread of "Tethyan" Heteroceras and Barremian. On the other hand, if this were the migration common Aconeceras in the latest Barremian may route then there should be records of the appropriate indicate another rapid sea level rise, not previously ammonites in the Barremian of adjacent parts of western documented in NW Europe. This could link with a Tethys, from the Caucasus, through the Carpathians to similar event recently recognised at about the base of the SE France. While desmoceratids and Heteroceras giraudi Zone of SE France (ARNAUD-VANNEAU & certainly occur in those areas, Aconeceras is not ARNAUD, 1990). recorded (e.g. DRUSHCHITS & KUDRYAVTSEVA, 1960; BRESKOVSKI, 1975; AVRAM, 1983) and thus appears to have reached NW Europe by another route. 4. - PALAEOGEOGRAPHICAL IMPLICATIONS The most likely alternative route by which Barre mian Tethyan ammonites would have reached NW While the exact biogeographical affinity of the NW Europe was through the North Atlantic (Fig. 4), where a European Barremian heteromorphs remains a matter of connection from western Tethys to East Greenland was debate, the appearance of desmoceratids in the mid first inferred to explain Valanginian faunal links Barremian and of Aconeceras together with Heteroceras between the two areas (DONOVAN, 1957; AGER, 1971; very late in the Barremian points firmly at intermittent RAWSON, 1973). This has also been suggested as the Tethyan connection. This is also indicated by Tethyan route by which "boreal" crioceratitids migrated to elements in the dinocysls (MUTTERLOSE & HARDING, Morocco (IMMEL & MUTTERLOSE, 1980) and Tethyan 1987) and possibly the nannoplankton. microflora reached the North German Basin The position of the connection is problematic. The (MUTTERLOSE & HARDING. 1987) during the Barremian. Danish-Polish furrow had apparently closed by the end It could easily explain the appearance of desmoceratids
Fig. 4 - Late Barremian palaeogeography and possible migration routes. - Paleogeografia del Barremiano superiore e probabili vie di migrazione. BI0GEOGRAPH1CAL AFFINITES OF NW EUROPEAN FAUNAS 135 and Heteroceras in the West European Province. DRUSHCHJTS V. V. & KUDRYAVTSEVA M. P. (1960) -Atlas of the Lower Cretaceous faunas of the Caucasus and Crimea. Pp. 701, Moscow However, the ultimate origin of Aconeceras is more (in Russian). problematic. Both CASEY (1954) and RAWSON (1981) thought that the Oppeliidae may have been open ocean IMMEL H. (1978) - Die Crioceratiten (Ancyloceratina, Ammonoidea) dwellers, the latter author suggesting that they possibly des mediterranen und borealen Hauterive-Barreme (Unterkreide). Palaeontographica, A 163: 1-85, Stuttgart. lived in the Pacific area. In that case Aconeceras may have migrated from the eastern Pacific, through the IMMEL H. & MUTTERLOSE J. (1980) - Barreme-Cephalopoden aus dem central Atlantic and to the west of the British Isles - kretazischen Untergrund des Stadtgebietes von Hannover (NW- following a proto-Gulf Stream (AGER, 1971). Recent Deutschland). Palaont. Z., 54: 241-266, Stuttgart. reconstructions of mid Cretaceous surface ocean currents KAKABADZE M. (1981) - The ancyloceratids of the south of the USSR (BARRON & PETERSON, 1989) support this interpretation, and their stratigraphical significance. Trudy Geol. Inst. Tbilisi, 71: though they represent a slightly later time interval and a 1-196, Tbilisi (in Russian, with English summary). slightly higher sea level. Such a route could also explain KEMPER E. (1973) - Die Unterkreide im Untergrund der Gerdener the earlier (Late Hauterivian) curiously disjunct Berge und in der Deister-Mulde. Ber. Naturhist. Ges., 117: 29-54, distribution of a forerunner of Aconeceras, Prota- Hannover. coneceras -known mainly from a thin horizon in the KEMPER E. (1976) - Geologischer Fiihrer durch die Grafschaft gottschei Zone at Speeton and from Patagonia, Bentheim und die angrenzenden Gebiete, mit einem Abriss der Argentina. emslandischen Unterkreide (5th edition). Pp. 205: Nordhorn, Bentheim. ACKNOWLEDGEMENTS KEMPER E., RAWSON P. F. & THIEULOY J.-P. (1981) - Ammonites of I am grateful to Dr. Misha KAKABADZE (Tbilisi) who Tethyan ancestry in the early Lower Cretaceous of north-west Europe. Palaeontology, 24: 251-311, London. first recognised two tiny fragments of Heteroceras in my collections, to Gérard DELANOY (Nice) for additional KOENEN A. von (1902) - Die Ammonitiden des Norddeutschen Neokom comments on the material, and to Jack DOYLE (Hertford) (Valanginien, Haulerivien, Barrémien und Aptien). Abh. preuss. for allowing me to quote his new record of a Barremites geol. Landesanst., N.F. 24, 1-451, Berlin. from Speeton. Dave RUTLEDGE (UCL) commented on KOENEN A. von (1908) - Bemerkungen zur Gliederung der unteren the manuscript while Mike GRAY (UCL) photographed Kreide. Zentralbl. Min. Geol. Pal., Jg. 1908: 289-293, Stuttgart. the ammonites. MICHAEL E. (1974) - Zur Palaokologie und Faunenfuhrung des norddeutschen Unterkreide-Meeres. Geol. Jb., A 19: 1-68. Hannover.
REFERENCES MICHAEL E. (1979) - Mediterrane Fauneneinflusse in den borealen Unterkreide-Becken Europas. besonders Nordwestdeutschlands. In: J. WLEDMANN (Ed): "Aspekle der Kreide Europas", IUGS Ser. A 6: AQER D. V. (1971) - Space and time in brachiopod history. In: F. A. 305-321, Stuttgart. MIDDLEMISS, P. RAWSON & G. NEWALL (Eds.): "Faunal Provinces in Space and Time". Geol. J. Spec. Iss., 4: 95-110, MIDDLEMISS F. A. (1976) - Lower Cretaceous Terebratulinida of Liverpool. Northern England and Germany and their geological background. Geol. Jb., A 30: 21-104, Hannover. AGUIRRE URRETA M. B. & KLÏNGER H. C. (1986) - Upper Barremian Heteroceratinae (Cephalopoda, Ammonoidea) from Patagonia and MIDDLEMISS F. A. (1979) - Boreal and Tethyan brachiopods in the Zululand, with comments on the systematics of the Subfamily. Ann. European Early and Middle Cretaceous. In: J. WEDMANN (Ed.): S. Afr. Mus., 96: 315-358, Cape Town. "Aspekte der Kreide Europas", IUGS Ser. A 6,: 305-321, Stuttgart. AVRAM E. (1983) - Barremian ammonite zonation in the Carpathian MUTTERLOSE, J. (1983) - Phylogenie und Biostratigraphie der area. Zitteliana, 10: 509-514, Mûnchen. Unterfamilie Oxyteuthinae (Belemnitida) aus dem Barrane (Unter- Kreide) NW-Europas. Palaeontographica, A, 180: 1-90, Stuttgart ARNAUD-VANNHAU A. & ARNAUD H. (1990) - Hauterivian to Lower Aptian carbonate shelf sedimentation and sequence stratigraphy in the Jura and northern Subalpine chains (southeastern France and MUTTERLOSE J. (1992) - Migration and evolution patterns of floras and Swiss Jura). Spec. Pubs int Ass. Sediment., 9: 203-233. faunas in marine Early Cretaceous sediments of NW Europe. Palaeogeog., Palaeoclim., Palaeoecol., 94: 261-282, Amsterdam. BARRON E. J. & PETERSON W. FI. (1989) - Model simulation of the Cretaceous Ocean circulation. Science, 1989: 684-686, MUTTERLOSE J. & HARDING I. (1987) - The Barremian Blatterton: an Washington. Anoxic Warm Water Sediment of the Lower Saxony Basin. Geol. Jb., A 96: 187-207, Hannover. BRESKOVSKI S. (1975) - Les zones et sous-zones ammonitiques dans l'étage Barrémien en Bulgarie du Nord-Est. Geol. Balcanica, 5: 47- RAWSON P. F. (1973) - Lower Cretaceous (Ryazanian-Barremian) 66, Sofia. marine connections and cephalopod migrations between the Tethyan and Boreal Realms. In: R. CASEY & P. F. RAWSON (Eds): CASEY R. (1954) - Falciferella, a new genus of G ault Ammonites, with a "The Boreal Lower Cretaceous". Geol. J. Spec. Iss., 5: 131-144, review of the family Aconeceratidae in the British Cretaceous. Proc. Liverpool. Geol. Assoc., 65: 262-277, London. RAWSON P. F. (1975) - The interpretation of the Lower Cretaceous DONOVAN D. T. (1957) - The Jurassic and Cretaceous systems in East heteromorph ammonite genera Paracrioceras and Hoplocrioceras Greenland. Medd. om Gronland, 155 (4): 1-214, Kobenhavn. SPATH, 1924. Palaeontology, 18: 275-283, London. 136 RAWSON P. F.
RAWSON P. F. (1981) - Early Cretaceous ammonite biostratigraphy and Clay, Yorkshire, England. Proc. Geol. Ass., 94: 133-146, biogeography. In: M. R. HOUSE & J. R. SENIOR (Eds.): "The London. Ammonoidea". Syslematics Assoc. Spec, 18: 499-529, London. ROCH E. (1930) - Etudes géologiques dans la région méridonale du RAWSON P. F. (1993) - The influence of sea level changes on the Maroc occidental. Pp. 542, Paris. migration and evolution of Lower Cretaceous (pre-Aptian) ammonites. In: M. R. HOUSE (Ed.): "The Ammonoidea: SARKAR S. S. (1955) - Révision des ammonites déroulées du Crétacé environment, ecology and evolutionary change". Syst. Ass. Spec, 47: inférieur du sud-est de la France. Mém. Soc. géol. Fr., N.S. 34: 1- 227-242, London. 176, Paris.
RAWSON P. F. (1994) - Sea level changes and their influence on SPATH L. F. (1924) - On the ammonites of the Speeton Clay and the ammonite biogeography in the European Lower Cretaceous. Atti subdivisions of the Neocomian. Geol. Mag., 61: 73-89, Cambridge. III Conv. Int. "Fossili, Evolutione, Ambiente", Pergola 1990. Palaeopelagos, spec. pubi. 1: 317-326, Roma. STOLIJ3Y E. (1908) - Die Gliederung der norddeutschen unteren Kreide. III. Oberneocom (Barreme). Zentralbl. Min. Geol. Pal., Jg. 1908: RAWSON P. F. (this volume) - The "boreal" Early Cretaceous (pre- 162-175, Stuttgart. Aptian) ammonite sequences of NW Europe and their correlation with the Western Mediterranean faunas. THOMEL G. (1964) - Contribution à la connaissance des Céphalopodes Crétacés du sud-est de la France. Note sur les ammonites RAWSON P. F. & MUTTERLOSE J. (1983) - Stratigraphy of the déroulées du Crétacé Inférieur Vocontien. Mém. Soc. géol. Fr., N.S. Lower B and basal Cement Beds (Barremian) of the Speeton 101: 1-78, Paris. Mem. Descr. Carla Geol. d'il. M (1995). pp. 137-165
Implications of variation in coiling in some Hauterivian (Lower Creta ceous) heteromorph ammonites from the Vocontian basin, France
Implicazioni della variabilità dell'avvolgimento in alcune ammoniti ete romorfe dell'Hauteriviano (Cretaceo inferiore) del bacino voconziano, Francia
PIERRE ROPOLO (*)
1GCT Projects UNESf 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - In many groups of ammonites that await revision, la- sono distinti soltanto in base al modo di avvolgimento della conchiglia e xonomic divisions are often still based on morphology alone. Among the dunque appartengono, secondo la sistematica in uso, a generi diversi, heteromorph ammonites, for example, the genera Crioceratites, Suba- nonostante l'ornamentazione e le linee di sutura siano simili e, soprattut sptnoceras, Aspinoceras and Acrioceras are separated from each other to, la loro associazione negli stessi strati e nelle stesse località. Sulla base by their type of coiling, even if they are found together in the same bed di recenti lavori sulT Hauteriviano medio si è cercato di dimostrare che and have identical sculpture and suture lines. Recent work on the mid la maggior parte delle forme spiralate di tipo Crioceratites evolvevano Hauterivian suggested firstly that most species of Crioceratites evolved nelle Zone a L. nodosoplicatum e a S. sayni verso una disposizione tri lo a subaspinoceratid or an aspinoceratid type of coiling; secondly, that partita di tipo aspinoceratitica o acrioceratitica della conchiglia e che the old idea ol'scxual dimorphism could profitably be examined further. l'idea di un eventuale dimorfismo avesse fondamento e quindi dovesse New material collected bed-by-bed, seems to confirm that in the Haute certamente essere presa in considerazione. Nuovo materiale, slraligrafi- rivian, the association of Crioceratites with Subaspinoce- camente localizzalo con la più grande precisione, sembra confermare che rasi'Acrioceras and the morphological similarities between their early nel!' Hauteriviano questa trasformazione di struttura della conchiglia, whorls, constitute a phenomenon of dimorphism which persists at least dalla disposizione spiralata alla disposizione tripartita con asta ed unci up to the Barremian. 'The stratigraphie position of each species is clearly no, appartenga spesso ad un fenomeno di dimorfismo riconoscibile al slated New dimorphic pairs are described. meno lino al Barremiano. La posizione stratigrafica delle specie è chia ramente illustrata e nuove coppie dimorfiche sono descritte. Il valore KEY-WORDS: Heteromorph ammonites, morphology, dimor tassonomico dei generi a conchiglia tripartita dell' Hauteriviano Acrio phism, Hauterivian. biostratigraphy. ceras, Subaspinoceras e Protacrioceras è ridiscusso. E' proposta la loro collocazione in sinonimia col genere Crioceratites che ha la priorità RIASSUNTO - In numerosi gruppi di ammoniti, che non sono stati nomenclalurale. oggetto di revisioni recenti, le delimitazioni tassonomiche si basano spesso su criteri morfologici. Tra le ammoniti eteromorfe, per esempio, i PAROLE-CHIAVE: Ammoniti eteromorfe, morfologia, dimorfismo. morfotipi Crioceratites, Subaspmoceras, Aspinoceras e Acrioceras Hauteriviano, biostratigrafia.
(*) Centro d'études méditerranéennes - M.H.N. - 60 Bd. Risso 06300 Nice - France 138 ROPOIJO P.
1. - INTRODUCTION 2. Emericiceras SARKAR. 1955 - type species: Eme- The number and the variability of Lower- riciceras enterici (LÉVEILLÉ, 1837) - crioceratitid coi Cretaceous heteromorph ammonites seems to defy all ling, strongly tuberculate forms, major ribs tritubcrcu- attemps at classification. Moreover, phenomena of con late separated by variable intermediaries that themsel vergence and sometimes of dimorphism must be added, ves may bear tubercles. thus making the problem more difficult. 3. Acrioceras s. s. HYATT, 1900 - type species: Ammonite palaeontologists of the last century de Acrioceras tabarelli (ASTIER, 1851) - acrioceratid coi limited species and genera according to morphological ling, major ribs triluberculate. criteria, referring only to an index-species, without 4. Acrioceras (Paraspinoceras) BREISTROFFER, considering the stratigraphical position of the taxa. 1952 - type species: A. (Paraspinoceras) pulcherrimum Present-day authors emphasize biostratigraphical (D'ORBIGNY, 1840) - acrioceratid coiling, major ribs, if analysis and also consider phyletic links and geograph present, non-tuberculate. ical distribution. Over the last few years, the study of 5. Acrioceras (Paraspinoceras) ANDERSON, 1938 - those data has made considerable progress, particularly type species: Aspinoceras hamlini, (ANDERSON, 1938) - concerning the Jurassic ammonites. Biometrie methods aspinoceratid coiling, major ribs non tuberculate. allow us to appreciate more precisely the morphologi 6. Acrioceras (Protacrioceras) SARKAR, 1955 - type cal variability of the shells. Biostratigraphical investi species: A. (Protacrioceras) ornatum (D'ORBIGNY, gations enable us to estimate better the life span of dif 1850) - aspinoceratid coiling, major ribs trituberculate. ferent species and their geographical areas. Zonal schemes are now commonly used, and recently the new Today, we know that though Emericiceras has a terms "Biozones" (THIEULOY, 1977; BUSNARDO, 1984) distinct crioceratid coiling, some specimens uncoil in and "Biohorizons" (BULOT, 1990; THIEULOY et alii, the adult stage and may even form a recurved hook. 1990; BULOT & THIEULOY in BULOT et alii, 1992; The result of this classification, still in common use BULOT, 1993; BULOT & THIEULOY in HOEDEMAKER & and modified, but never simplified, by various subse COMPANY, 1993), were introduced in the Upper Va quent authors was a multiplication of genera and spe langinian / Hauterivian ammonite scale, to facilitate cies. THOMEL (1964), BRESKOVSKI (1966), DIMITROVA the interpretation of the successive associations and to (1967), IMMEL (1978) did not clarify the interpretation clarify better the chronostratigraphical zonation. of those populations which might have some importan Unfortunatly, Hauterivian and Barremian system ce in biostratigraphical scales, in spite of the disappea atic palaeontology has not always made the same prog rance of Crioceratites duvali as index species (Col ress. The evolution of some families, such as Ancylo- loque sur le Crétacé Inférieur - Lyon 1963 - France) ceratidae, for example, is still badly known. The dis IMMEL (1978) recognised five Mediterranean and tinction between the Hauterivian taxa Crioceratites three Boreal species groups in Crioceratites, but never (LÉVEILLÉ, 1837), Acrioceras (HYATT, 1900), Aspi considered morphological development nor intermedia noceras (ANDERSON, 1938), Paraspinoceras, tes and never referred to dimorphism, in spite of (BREISTROITER, 1951), Protacrioceras, (SARKAR, RAWSON'S (1975) views, who three years before discus 1955) and Sub aspinoceras (THOMEL et alii, 1987) is sed .."generic distinction on coiling alone..." (p. 282) still established according to morphological data and and suggested that ..."forms with aspinoceratid / ancy- more precisely according to the differences in coiling loceratid coiling may be dimorphs of larger criocera patterns, although similarities in the early-whorls titid forms..." (p. 275). (ornamentation and suture lines) are clearly visible. The existence of dimorphism within ammonite po A full discussion on taxonomic divisions must be pulations was suggested in the middle of XlXth centu supported by good biostratigraphical analysis and ma ry, (DUCROTOY DE BLAINVILLE, D'ORBIGNY, WAAGEN, terial precisely collected bed-by-bed. This was not the REYNÈS, QUENSTEDT). MUNIER-CHALMAS (1892) was case with SARKAR (1955), who proposed unsatisfactory the first to interpretate it as sexual. This hypothesis, loo subdivisions, many of them poorly defined on the stra poorly argued at that time, was abandoned until the se tigraphical level. His monograph, based on public and cond part of the XXth century. private collections, did not consider morphologically New indisputable facts allowed MAKOVSKI (1962), intermediate forms and gave the impression that crio- TINTANT (1963), CALLOMON (1963) and WESTERMANN ccratitid populations had phylogenetic positions di (1964) to propose the issue of sexual dimorphism again. stinct from other genera of heteromorphs, often defined Those authors distinguished "microconch" and "macro- as successive grades: crioceratitid coiling evolving gra conch" forms in dimorphic pairs. According to them, in dually through time, according to him, to other types of almost all cases, the smaller adult microconch has stronger coiling perhaps by way of the aspinoceratic lineage. sculptures up to the body chamber aperture;thc macro- His scheme was as follows: conch has a larger size the ornamentation fades away at 1. Crioceras LÉVEILLÉ, 1837 - type species: Crioce- the end of the phragmocone and on the body chamber. ras duvali LÉVEILLÉ, 1837 - crioceratitid coiling, major Recent studies on the Lower-Cretaceous hetero ribs mono-bi- or triluberculate. morphs : Macroscaphites I Costidiscus (AVRAM, 1984) COILINO VARIATIONS LN IlAUTERTVIAN HETEROMORPH AMMONITES 139
- Colchidites (AGUIRRE-URRETA & KLINGER, 1986) - HAUIERI VI AN Lytocrioceras (DELANOY & POUPON, 1992), Crioce ratites / Acrioceras (KLINGER & KENNEDY, 1992), Cri oceratites / Sub aspinoceras (ROPOLO, 1991; ROPOLO & ZONES SUBZONES HORIZONS SALOMON, 1992), and others on the Upper-Cretaceous (LANDMAN & WAAGE, 1993), provide good evidence of H7 P.angulicostata P. catulloi dimorphism, just as clearly demonstrated as for the Ju aucl. P. angulicostala auct. rassic period. H6 B. balearis
The recognition of this phenomenon seems to be ve H5 P. ligalus ry important at the taxonomic level, because if we ac cept dimorphic pairs, we have to unite the subfamilies H4 S. sayni Crioceratitinae and Ancyloceratinae and regard Crio C. cruasensc H3 L. nodosoplicatum ceratites. Aspinoceras and Acrioceras as synonyms, the oldest name, Crioceratites (LÉVEILLÉ, 1837) having H2 C. loryi O (J) j calinoli priority. C. loryi HI A. radiatus
2. - STRATIGRAPHY HI - H4: Lower Hauterivian H5 - H7: Upper Hauterivian It was essential to clarify the stratigraphical appea rance of the different type of coiling and their deviation through lime. We have chosen to use the Hauterivian Fig. 1 - Hauterivian zonation according to the last works of the 2nd Workshop of the Lower-Cretaceous Cephalopod Team of IGCP ammonite zonation of the 2nd Workshop of the Lower Project 262 - Mula (Spain), July 1992. Cretaceous Cephalopod Team of IGCP project 262, - Scala biostratigrafica dell' Hauteriviano secondo gli ultimi lavori (Mula, SE of Spain, July 1992). (Fig. 1) del 2nd Workshop of the Lower-Cretaceous Cephalopod Team of IGCP Project 262-Mula (Spagna), luglio 1992. To support our research we have drawn up, bed by bed, the vertical distribution of heteromorphic ammoni tes and dimorphic pairs that we found in the Vocon- In the early Balearis Zone of Le Poët, we discovered tian-Basin : two specimens of Megacrioceras jourdani (ASTIER). - on the North side of the Mont-Ventoux (Ravin du One of them is very large and the presence in the same Croc - Ravin du Cave de Diou); horizon of a smaller form with a different juvenile part - at Cumier (Radiatus zone to Nodosoplicatum zone); of coiling might suggest a possible dimorphism. - al Le Poët-en-Pcrcyp, near Buis-les-Baronnies. From the end of the Ligatus Zone, we noted the on In these sections, we paid special attention to the set of the inversion of the uncoiling phenomenon. At investigation of the microconch/macroconch morpho- first the shells are again moderately evolute, planispi- lypes within each species and we noted that : rally coiled with non touching whorls (Binelliceras bi- - in the Lower Hauterivian there first appears a di nelli ASTIER, Crioceratites pseudoangulicostatum mensional dimorphism (Crioceratites loryi SARKAR - SARKAR). Then, the spiral tightens up with touching Crioceratites matsumotoi SARKAR: cf. pl. 1 and 2); whorls (Pseudothurmannia angulicostata D'ORBIGNY - - this is followed by a morpho-dimensional dimor Pseudothurmannia grandis BUSNARDO). Aspinoceratid phism starting from the early Nodosoplicatum Zone. shapes become progressively rarer and the first Mega- crioceras/Garroniceras appear (Garroniceras serin The Heteromorph microconchs seem to show at first gue! ASTIER - Megacrioceras jourdani ASTIER - Mega during their ontogeny a peculiar coiling of the spiral crioceras doublieri JAUBERT). with a tendency to a tripartite structure. Slratigraphically higher, we collected some uncoi led specimens which form a shaft and a recurved hook (Crioceratites curnieri ROPOLO, Crioceratites sornayi 3. - LOCATION OF THE SECTIONS STUDIED SARKAR. C. duvali LÉVEILLÉ, Cmajoricensis NOLAN, C.shibaniae SARKAR, C.shibaae SARKAR...; cf. pl. 3, 4, 5, 6). All these taxa are associated in the same beds and 3.1. - RAVIN DU CROC - RAVIN DU CAVE DE DIOU, sometimes in the same nodules with larger crioceratitid NORTH OF MONT VENTOUX (Fig. 2) partners (macroconchs). We could clearly establish for the species Protacri- oceras ornatum D'ORBIGNY, Protacrioceras alpinum The Northern side of Mont-Ventoux, in front of SARKAR and Protacrioceras puzosianum D'ORBIGNY, Brantes and of the more western Mont-Serein, is very an onlogenic development from a crioceratitid type of sheer. There is a continuous succession of beds along coiling lo a tripartite type of coiling, always at the same the forest road of the "col de Comte". Going up from stratigraphical levels. (ROPOLO & SALOMON, 1992) this road in the ravines (Ravin du Croc, Ravin du Cave KOPOIJOP.
1 20 P^eudoihunmannia AimioneAcui SARU.
P^eudoihunmannia anguticoàifid '0RB.) SLUMP Acniocenaò Ap. Binetticena* Linetti (AS7IE.R)
X Bateaniie* Hateani* (NOLAN)
O Bateaniie* Ap. 110 N T Cnio cenaiiieA majon.icenòiò( NOLAN) > (Cniocenaiiiid and a4fti.noce.sial.ld S3 /.ornaci ) « PteòioApiiidiòcu.* n.ei.outi(KILIAN)
O 5= Cnio cenaiiieA Ah.jJLa.ae. SARKAR O (Cniocenaiiiid and inipaniiie -f.onm.0) •< 100 i-J fa Pte4Ì0 4piiidÌ4cu.-i tA.gai.UA (d'ORB.) —' SuLtaynetta mimica 7H.ILU.L. and BILL.
Cniocenaiiieò duuati LS.VLILLE. O M (Cn.iocen.aiJ.Hd and in.iftan.iiie -f-onmA) « SuLtaynetta tayni (PAÛUIE.R) Cniocenaiiie* AniHaniae AenAu. IfiCiLL W 90 (Cniocenaiiiid and in.ipan.iiie JLon.m.0 ) A SpiiidiAcuA inienmediuA Aen-òu.
w 7H.It~U.L0y non d'ORBIÇNtj > u Pn.oiacn.iocena* ftuz.oóianum (d'ORB.) 85 0 teoriepnana A uaniegaiuò PAQ.LLIE.R LyiicocenaA gn. nodosopticaium. Q (KILIAN and REB0U.L) Pnoiacniocenaò gn.. atftinum SARK. C. cunnieni R0P0L0 (Cniocenaiiiid Z M and AufLaApinocenaiid -£onm.A) > OS 2-eannoiicena* jeannoii (d'ORB.)
CniocenaiiieA tonyi SARKAR . 30 ÇJ o OtcoAÌephanu.0 òp. AS CJ
u 75 Bneiòino {.genetta ca-òiettanenàià u (d'ORBIQNy) Z M > < AcanihodiàcuA nadiaiuA (BRU.Q. ) 70
Fig. 2 - Slratigrtaphical distribution of the Hauterivian heteromorph ammonites and dimorphic pairs in the North of Mont-Ventoux (Sii. of France). - Distribuzione stratigrafica delle ammoniti eteromorfe e delle coppie dimorfiche nel versante nord del Mont- Ventoux (S.E. della Francia). COILING VARIATIONS IN HAUTERIVIAN HETEROMORPH AMMONITES 141
dc Diou), il is possible lo observe, from 750 m to 1150 sappear, and an abrupt cliff does not allow us to collect m, strata of Hauterivian age. more fossils, but the lithology and the stratigraphy in Over a distance of roughly 50 m, the Radiatus Zone dicate the top of Hauterivian. (HI) shows calcareous decimetric beds separated by schistose clays. A major fault cuts off these strata, 3.2. - CURNIER (Fig. 3 ) which form a sort of anticlinal. The collected fauna (Teschenites aff. paraplesius, Acanthodiscus radiatus, The geographical location and the biostratigraphy Breistrofferella castellanensis) is characteristic of the of the Valanginian / Hauterivian section of Curnier we basal Hauterivian. re given in previous articles (ROPOLO, 1991 ; BULOT & Decimetric strata grouped together in bundles of 2 FUHR, 1990 in BULOT et alii, 1992). New investiga to 7m thick constitue the top of the Radiatus Zone and tions and new precisely located material allows us to the base of the Loryi Zone. A synsedimentary landslip complete the palaeontological survey of this section. provides a marker for the new starting point of the sec The visible strata of the Radiatus Zone (HI) begin tion in the "Ravin du Cave de Diou". Limestone beds in the thalweg made by the drained banks of the Ar- are separated by dark blue calcareous clays. gence brook. Over a thickness of 20 metres we col Crioceratites loryi, Olcostephanus sp., ieannotice- lected: Teschenites flucticulus, Teschenites pachydi ras jeannoti and Saynella clypeiformis were collected cranus, Breistrofferella varappensis and Breitrofferella (beds 80-83), indicating the Loryi Zone (H2). castellanensis, which characterize the first lower Hau In the lower Nodosoplicatum Zone (H3), appear terivian biohorizon. We could not individualize the crioceratitid and subaspinoceratid forms of Criocerati Buxtorfi biohorizon defined for the first time by BULOT tes curnieri with early specimens of Olcostephanus et alii, 1992. (Beds 250-253). Other species of lesser variegatus and of Protacrioceras gr. alpinum - (beds significance are Neolissoceras grasi and Spitidiscus gr. 84-86). rossfeldensis-menghini. The Nodosoplicatum Zone (120 m) (H3) contains a In three decimetric calcareous beds we collected very rich fauna: Lyticoceras gr. nodosoplica- numerous Crioceratites loryi, microconchs and macro tum/cryptoceras, Protacrioceras puzosianum, Spitidi conchs (beds 254-255), Oosterella cultrata - Phyllopa- scus intermedius, Protacrioceras ornatum, Criocerati chyceras winckleri - Crioceratites nolani. tes quenstedli, Crioceratites gr. nolani/sablieri. As at The thicker bed 256 (0,40 - 0,50 m thick) furnished Curnier, many morphological intermediates within the Crioceratites loryi, Olcostephanus astierianus, Olco same species can be found in temporal and geographic stephanus gr. lamberti, Olcostephanus sayni and associations. These intermediates all present similar Saynella gr. neocomiensis. sculpture in the early spiral whorls but differ in the ty Bed 259-260-261 are grouped with thin interbeds. pe of coiling. They represent the Jeannoti biohorizon with, Crioce The Sayni Zone (90 m) (H4), shows the typical ratites matsumotoi (dimorphic pairs) and Jeannotice- Hauterivian ribbon development; clays here are very ras jeannoti, Spitidiscus aff. rotula, Crioceratites dark. In the directly overlying strata were discovered quenstedti. At the top of this horizon appears Saynella many very interesting dimorphic pairs and particularly: clypeiformis, which marks together with Spitidiscus gr. Crioceratites shibaniae (bed 92) and, in the same no pavlowi/mikadiensis and Abrytusites thieuloyi, the dules, Crioceratites duvali (presumed macroconch boundary between the Loryi and the Nodosoplicatum form) with a smaller tripartite shell which we suppose Zones. to be the microconch of this species (bed 95) (see e.g. Taxonomy and Systematics). The faults in the Curnier area follow the eastern si de of the Condorcet diapir. The very thick Nodosoplica Over the next 50 metres calcareous blocks form a tum Zone seems to be the consequence of a flattened succession of beds. This is the Ligatus Zone (H5), fold and the repetition of the same beds would explain yielding Plesiospitidiscus ligatus and Crioceratites the exceptional abundance of fossils. shibaae (crioceratitid and aspinoceratid forms) (bed 103). - Beds 264-265: Lyticoceras nodosoplicatum, Ol Over 70 metres, we could collect Plesiospitidiscus costephanus variegatus, Crioceratites elegans. rebouli and many dimorphic specimens of Criocerati - Beds 266-267: Lyticoceras nodosoplicatum, Crio tes majoricensis (beds 108-110). ceratites curnieri, Protacrioceras alpinum (criocera In the beds 112-113, the Balearis Zone (H6) is mar titid and tripartite forms), Olcostephanus ked by Balearites balearis and Balearites sp. In three variegatus and Protacrioceras ornatum (= gignouxi slumped levels (113,114,116) we noted the presence of form, sensu SARKAR). Binelliceras binelli and Acrioceras ind. - Beds 268-269: Crioceratites quenstedti, Lyticoce Accès to the outcrops now becomes difficult. After ras gr. cryptoceras. the last slump we found the Pseudothurmannia Zone - Beds 270-274: Crioceratites curnieri (crioceratitid (H7) with Pseudothurmannia angulicostata (117) and and tripartite forms). Crioceratites quenstedti, Olco Pseudothurmannia gr. simionescui (120). Interbeds di stephanus variegatus and Abrytusites juliannii. 142 ROPOLO P.
LSedA 1 2 0 284
ClioceiatiteA joli£.oÌAÌ SARKAR - AtLiytuAiteA Ap. 5pJ.tXdU.ic.uA inteimediuA AenAu 7H.ILU.L0y 1 1 0 CiioceiatiteA aff. majoiicenAiA (NOLAN)(Ciioceiatitid and tni.pan.Li.Le. foimA) - Pn.0Lacn.i0ce.1aA puzosianum (d'ORBIQNy)(elliptic coiling, pn.oLacn.iocen.aLid foimA) - C. nolani KILIAN - C. AaHlieii (AS7I6.R) 1 0 0 ti 280
CiioceiatiteA aff. majoiicenAiA (NOLAN)(CiiaceiaLiLid and AuHaApino- 3 I
-c.en.atid foimA) - SpiLidiAcuA faAcigei 7H.ILU.L0y - C. Aat-lieii (AS7ILR)t 9 0 z ce n Pn.oLacn.iocen.aA oin.aLu.rn ( d'ORBIQNy)( Clio ceiatitid/pio tacito ceiatid foimA) - ClioceiatiteA Aomayi SARK. (C1Ì0ceiaLiLid and Liipaitite 8 0 O /01mA ) - 0. vaiiegatuA PAOJULR ^_ X
CiioceiatiteA cu.1n.ie1i ROPOLO (Clioceiatitid and tiipaitite foimA) C-^ ID C. quenitedti (00S7LR) - 0. vaiiegatuA PAQRILR Q AliyLuAiLeA julianii (HONORAT BAS7IDL) 7 0 L. aff. ciypLoceiaA (d'ORBIQNy) 270 L. nodoAoplicatum (KILIAN and RLBOUL)- C. cuinieii ROPOLO 6 0 0. vaiiegatuA PAÛUILR - P. alpinum SARKAR (Ciioceiatitid and tiipaitite /.01mA) - Piotac. oinatum (gignouJci /.01m) PARTE ) 5 0 O L. nodoAoplicatum (KILIAN and RLBOUL)- 0. vaiiegatuA PAQUILR ce 265 C. eleganA SARKAR - Saynella clypeif.01n.iA (d'ORBIQNy) a. JeannoticeiaA jeannoti (d'ORBIQNy) 4 0 2-eannoticeiaA jeannoti (d'ORBIQNy) - S. aff. lotula (KILIAN) Ciio ceiatiteA matAumoLoi ( micioconch, macioconch.) SARKAR 260 3 0 CM CiioceiaLiLeA loiyi SARKAR COUP E z OlcoAtephanuA aALieiianuA d'ORBIQNy - 0. cf. lamleiLi KILIAN 2 0
CiioceiaLiLeA loiyi SARKAR (micioconch., macioconch.) 1 0 255 CiioceiaLiLeA loiyi SARKAR - C. nolani KILIAN B. caALellanenAiA (d'ORB.) B. vaiappenAiA (BAUPIB.) 7. pachydicianuA THILULOy I 7. flucticuluA 7HltlLLOy 250
Fig. 3 - Stratigraphical distribution of the Lower Hauterivian heteromorph ammonites at Cumier (Vocontian Basin, France). - Distribuzione stratigrafica delle ammoniti eteromorfe nelTHauteriviano inferiore di Curnier (Bacino Voconziano. Francia).
- Bed 275: Crioceratites quenstedti, Crioceratites study of the different Hauterivian biostratigraphical le curnieri (microconch). vels, from the Loryi Zone to the Angulicoslata Zone. - Beds 276-277: Olcostephanus variegatus, Crioce As in the above sections we collected what arc pro ratites sornayi (crioceratitid and tripartite forms). bably dimorphic pairs for the following species Crioce - Beds 278-279: Protacrioceras ornatum (crioceratitid ratites loryi, Crioceratites curnieri, Protacrioceras and protacrioceratid forms), Crioceratites sornayi. alpinum, Crioceratites shibaniae and Crioceratites - Beds 280-282: Spitidiscus fasciger, Crioceratites majoricensis. gr. nolani/sablieri. Crioceratites sornayi, (crioceratitid In the first part of the Loryi Zone (H2), (beds 76- and aspinoceratid forms).- Bed 283: Crioceratites aff. 77-78) we collected in the decimetric calcareous beds majoricensis (crioceratitid and aspinoceratid forms), many compressed macroconchs and microconchs of Protacrioceras puzosianum (elliptically coiled and Crioceratites loryi, together with small Olcostephanus protacrioceratid forms), Crioceratites nolani, Crioce cf. sayni. ratites gr. nolani/sablieri. In the Jeannoti Subzone, appears Saynella clypei - Bed 284: Crioceratites joliboisi, Abrytusites sp. formis (bed 82), with numerous small Spitidiscus gr. Spitidiscus intermedius sensu THIEULOY. pavlowi and Abrytusites thieuloyi (bed 83-84). The first appearance of L. nodosoplicatum (bed 85) 3.3. - LE POËT-EN-PERCYP (Fig. 4) marks the base of the following biozonc. Wc found Protacrioceras gr. alpinum (crioceratitid and tripartite On the southern flank of the "Montagne de la Lou- specimens: beds 87-88), Crioceratites quenstedti, Cri be". just above the D.152 departmental road, east of oceratites curnieri, (dimorphic pairs) together with Buis-les-Baronnies, the Le Poët deposit allows a good numerous Olcostephanus variegatus. COILING VARIATIONS IN HAUTERIVIAN HETEROMORPH AMMONITES
P Aeudothunmannia AimioneAcui SARKAR P A eudo thunmannia a££. gnandiA BUSNARDO 145 PAe.udoth.iL/imannia angulicoAiata (d'ORBIQNy) CO W Poeudoi.hu/tmannia ajL/.. angulicoAiata (d'ORB.) M 2 140 BinellicenaA k/ienkeli (SARKAR) 2 BinellicenaA Lineili (ASTIER) O BaleaniteA cf.. moncluAenAÌA UIEDPÎANN H6 BaleaniteA Ap. < BaleaniteA LaleaniA (NOLAN) 3 C/iiocenatiteA majonicenAÌA (NOLAN) CO 130 ( c/iio ce/iatitid and alpinoce/iatid /.onmA ) W BaleaniteA LaleaniA (NOLAN) hJ FlegacniocenaA joundani (ASTIER) BaleaniteA LaleaniA (NOLAN) CO H H5: 120 CniocenatiteA AhiLaae SARKAR =3 ta 3=S (C/iioce.natitid and tn.ipan.tite /.onmA J I I u I 1 < PleAioApitidiAcuA ligatuA (d'ORBIQNy)
Fig. 4 - Slraligraphical distribution oflhe Hauterivian heteromorph ammonites and dimorphic pairs in the Le Poët deposits (I>ome, Voconlian Basin, France). - Distribuzione stratigrafica delle ammoniti etermorfe e delle coppie dimorfiche a Le Poët (Drame, bacino Voconziano, Francia). 144 ROPOLO P.
- Beds 97-98: Protacrioceras puzosianum and Pro tion. However as extreme variation in sex-ratio may be tacrioceras ornatum. caused by environmental conditions, by preservation, or - Bed 101: Spitidiscus intermedius sensu THIEULOY by various processes of fossilization, (.."The stale of is the last taxon collected in this biohorizon. preservation of an ammonite may be greatly influenced The Sayni Zone (H4) starts at beds 104 -105 with Sub- by its absolute size, or by not yet clearly established saynella sayni and Crioceratites gr. nolani/sablieri. other reasons"... MAKOWSKI, 1962), such a criterion - Beds 110-113: Crioceratites duvali, Crioceratites cannot be regarded as conclusive for the acceptance of joliboist and what we believe to be a badly preserved dimorphism. Subsaynella. In the Taxonomy and Systematics' section we use - Bed 117: Plesiospitidiscus ligatus and four di standard morphological terms: morphic specimens of Crioceratites shibaae (beds 120- D = Shell diameter 121) are the only ammonites collected in the Ligatus H = Height of whorl biozone. U = Width of umbilicus The Balearis Zone (beds 128-141) again shows suc H/D and LVD ratios characterize the shell coiling cessive strata with interbeds. The fauna is more abun scheme. dant here, containing: I = Hiatus between the initial whorls and the oral - Bed 128: Balearites balearis, Crioceratites majo- part. ricensis, Megacrioceras jourdani, (two specimens). - Bed 130-131: Balearites balearis, Crioceratites 4.2. - TAXONOMY AND SYSTEMATICS majoricensis (crioceratidid and aspinoceratid forms). - Beds 135-136: Balearites sp. and Balearites ORDER Ancyloceratida WIEDMANN, 1966 montclusensis. SUPERFAMILY Ancylocerataceae MEEK, 1876 - Beds 140-141: Binelliceras krenkeli and Binelli- FAMILY Ancyloceratidea MEEK, 1876 ceras binelli. SUBFAMILY Crioceratitinae WRIGHT, 1952 Two biohorizons are clearly visible in the Anguli- GENUS Crioceratites LÉVEILLÉ, 1837 SUBGENUS Crioceratites LÉVEILLÉ, 1837 costata zone: TYPE SPECIES: Crioceratites duvali LÉVEILLÉ, 1837 - Beds 142-145 with many Pseudothurmannia an- gulicostata, sometimes in the same nodule. TAXA Macroconch Microconch Strut, level - Beds 146-150 with Pseudothurmannia cf. grandis, C. loryi Crioceratitid Crioceratitid Loryi Zone Pseudothurmannia simionescui, both characterizing the SARKAR, 1955 coiling coiling lop of the Hauterivian. C. matsumotoi Crioceratitid Crioceratitid Loryi Zone SARKAR, 1955 coiling coiling C. curnieri Crioceratitid Aspinoceratid Nodosoplicatum ROPOLO, 1991 coiling coiling Zone 4. - PALAEONTOLOGY C. sornayi Crioceratitid Aspinoceratid Nodosoplicatum SARKAR, 1955 coiling coiling Zone C. duvali Crioceratitid Aspinoceratid Sayni Zone LÉVEILLÉ, 1837 coiling coiling 4.1- POSSIBLE DIMORPHIC PAIRS C. shibaniae Crioceratitid Subaspinoceralid Sayni Zone SARKAR, 1955 coiling coiling C. majoricensis Crioceratitid Subaspinoceratid Balearis Zone It is not always easy to identify dimorphic pairs NOLAN, 1894 coiling coiling within heteromorph ammonite populations with absolu tely objective criteria. Some species have little or no detectable shell dimorphism. Certain microconchs Crioceratites (C.) loryi SARKAR, 1955 change the orientation of the shell during their ontoge PI. l,fig. 1-4; pi. 2, fig. 3 ny and different stages of growth can be collected from the crioceratitid type of coiling to the aspinoceratid ty 1955 Crioceras loryi SARKAR, p. 40, pi. 5, fig. 2. pe of coiling. Others microconchs may be confused 1955 Balearites koechliniformis SARKAR, p. 147, pi. 10, fig. 7. with macroconch juvenile or incomplete forms. For all 1955 Balearites tuberculatus SARKAR, p. 146, pl. 11, fig. 3. those reasons identification must be based on : 1955 Balearites cf balearis NOLAN; SARKAR, p. 142, pi. 6, fig. 14. - Material collected in one biostratigraphical hori 1964 Crioceratites (Crioceratites) duvali loryi SARKAR; zon of one section. THOMEL, p. 12. 1964 Crioceratites (Crioceratites) barrabei SARKAR: Tl-CMEL, -This material must be composed of adult and p. 27, pi. 4, fig. 1. complete specimens, with similar initial whorls and 1967 Crioceratites arci DIMTTROVA, p. 43. pi. 16, fig. 4. identical suturai lines. 1972 Crioceratites (Crioceratites) loryi SARKAR; 1TÏÏEULOY, p. 41, pi. 5, fig. 1,5, fig. 4q, r,s,t. - A possible numerical ratio between the two suppo 1976 Crioceratites (Crioceratites) loryi SARKAR; MANDOV, pi. sed sexes can be introduced to confirm the above solu 6, fig. 3. COILING VARIATIONS IN HAUTERIVIAN HETEROMORPH AMMONITES 145
1978 Crioceratites (Crioceratites) loryi SARKAR; IMMEL, p. 42, Crioceratites (C.) matsumotoi SARKAR, 1955 pl. I, fig. 4; pi. 4, fig.2 . PI. 2, fig.1 , 2 1986 Crioceratites (Crioceratites) loryi SARKAR; VASICEK & MICIIALK, p. 459, pl.l, fig.4 . 1955 Crioceras matsumotoi SARKAR, p. 74, pl.3, fig.2. 1962 Crioceratites (Crioceratites) matsumotoi SARKAR; DESCRIPTION - All specimens are of medium size, WEDMANN, pi. 8, fig.2 . well preserved and not deformed, which is rare in the 1964 Crioceratites (Crioceratites) matsumotoi SARKAR; Vocontian-Basin. Crioceraticonically coiled shells THOMEL, p. 14. which have the three ornamental phases typical of this 1964 Crioceratites (Crioceratites) krishnaae SARKAR; species: THOMEL, pl. 1; fig. 4-5. INITIAL STAGE - Thin flexuous fasciculated ribs, someti 1967 Crioceratites matsumotoi SARKAR; DlMLTROVA, pi. 17, mes with little median tubercles which disappear at the fig.3. end of the first whorl. Short spines are periodically ob 1976 Crioceratites (Crioceratites) villiersianum bitubercula- servable on the perimeter (one every 4 or 5 ribs). tum SARKAR; MANDOV, pi. 6; fig. 4. INTEIMEDIATE STAGE - Umbilical tubercles correspon 1976 Crioceratites (Crioceratites) rodighieri DIMTTROVA; MANDOV, pi. 6, fig. 5-6. ding to spine bases appear on major ribs, which are se parated by a variable number of intermediaries (4 to 7). 1978 Crioceratites (Crioceratites) matsumotoi SARKAR; IMMEL, p. 37, pi.2, fig 5-6. All ribs are interrupted on the venter by a smooth si- 1992 Crioceratites matsumotoi SARKAR; BULOT et alii, Tabi. phonal band. 10, p. 37; Tabi. 13, p. 48; Tabi. 14, p. 49. THE ADULT STAGE - Intermediate ribs tend to become as strong as main ribs which nevertheless remain more prominent. Bituberculation is now clearly visible. The DESCRIPTION main ribs bear variably developed ventro-lateral and umbilical tubercles. The latter are particularly promi PRESUMED MACROCONCH SPECIMEN - A crioceraticoni nent on the gently rounded umbilical rim. On the cally coiled shell of relatively modest size (D = apertural part the whorl is as wide as high and the sec 63,91mm), moderately compressed, with flat or gently tion subquadratc. rounded flanks and a subrectangular section. The bitu- DIMORPHISM - It is not always easy to discern dimorphic berculate spiral has a characteristically fine ornamen pairs within the crioceratitid populations of the Loryi tation. On the inner whorls the sculpture consists of Zone. Dimorphic shell differences are barely detectable thin, flexuous intermediate ribs (2-8) between slightly because inner whorls of microconchs and macroconchs thicker main ribs. On the perimeter short spines appear arc indistinguishable. However, the presence of adult periodically. Then the major ribs, which up to D = specimens of different size in the same levels and the 63 mm remained very discreet, gradually become more differing ratios between shells of larger size and those prominent. The three last ones are particularly strong of modest size, justify the hypothesis of a dimensional at the end of the spiral. They are separated by 12-13 dimorphism, probably of a sexual origin. We note that : intermediate ribs. Five strong tubercles are preserved - generally the ornamentation of the microconch seems on the ventral edge. Suturai lines are clearly visible on finer than that of the macroconch; the phragmocone. - at the end of the last whorl, the microconch often PRESUMED MICROCONCH SPECIMEN - This ammonite shows more numerous (5-6) and more flexuous inter differs from the other figured specimen by its smaller mediate ribs than the macroconch (3-4); size and its peculiar involution. If the intermediate rib - while the growth rate of inner whorls tends to remain density is the same, the main ribs seem stronger on the the same in both types, the height of the microconch phragmocone. The space between the aperture and the increases more quickly than the height of the chamber inner whorls is greater and the last whorl forms a sort of its dimorphic partner. This fact means probably that of short shaft, which gives the impression of slight un : "...macroconchiate females took longer to mature coiling. than their microconchiate males..." (WESTERMANN, 1990). Because of its long range (Loryi to Sayni Zones) Crioceratites matsumotoi is of no value as an index MATERIAL - Four specimens: macroconchs, pl. 1, fossil. fig. 2-4; microconchs, pl. 1, fig. 1-3: Loryi zone, bed 83 - Ravin du Cave de Diou, North side of Mont- MATERIAL - Two specimens (1.- macroconch - 2- Ventoux, France. microconch) from the Loryi Zone, Jeannoticeras jean- noti biohorizon, bed 124 - Curnier, Drôme - France. MEASUREMENTS MEASUREMENTS Specimen D H U H/D U/D Pl. Lfig. 1 65 20.3 44 0.312 0.676 Specimen D H U H/D U/D PI. l,fig. 2 72,94 22.35 48.8 0.306 0.669 PI. 2, fig. 1 63.91 19.4 41.27 0.303 0.645 PI. 1, fig. 3 55.2 16.47 33.52 0.302 0.607 PI. l.iig. 4 74.1 20 50 0.269 0.674 PI. 2, fig. 2 45.07 14 28.10 0.299 0.623 146 ROTOLO P.
Crioceratites (C.) curnieri ROPOLO, 1991 The specimen of pi. 3, fig. 2 has a badly preserved Pl. 3, fig. 1, 2, 3 aspinoceratid shell. It presents on the crioceratiform spiral, the hook and the straight shaft, the characteri stic sculpture of Crioceratites curnieri with flexuous 1991 Crioceratites (Crioceratites) curnieri ROPOLO, p. 65, pi. 1, fig.A , B; pi. 2, fig. A, B; pi. 3, fig.A-C . intermediate ribs and stronger bituberculate major ribs. The whorl height is low and increases very slowly. The 1992 Crioceratites (Crioceratites) curnieri ROPOLO; ROPOIjO & SALOMON, p. 196, pi. 4, fig. 1-7. flanks are moderately compressed with a subrectangu non 1992 Crioceratites curnieri ROPOLO; BULOT et alii, p.42. lar whorl section. The well preserved specimen of pi. 3, fig. 3 has a better visible sculpture than the 2nd one, with prorsi DESCRIPTION radiate to rectiradiate intermediate ribs (6 to 10). The PRESUMED MACROCONCH SPECIMEN - The specimen of height of the last whorl increases moderately quickly pi. 3, fig. 1 is a crioceraticonically coiled shell with the and the terminal hook-shaped part is less curved than typical three stages of ornamentation. that of the previous specimen. The whorl section is su On the initial whorl, which is not entirely preser brectangular. ved, fine parallel ribs are visible. At diameter D = MATERIAL - Three specimens (pi. 3, fig. 1- macro 25mm appear the first main ribs with a ventral and conch; pi. 3, fig. 2, 3 microconchs) Nodosoplicatum umbilical tuberculation. On the body chamber, major Zone, bed 140 - Curnier (Drôme, France). ribs and intermediates tend to become similar. MEASUREMENTS On the second and on the third ornamental stage there are 6 to 10 intermediate ribs between the main Specimen D II U H/D U/D ribs; they can be radiate or flexuous. Major ribs bear PI. 3, fig. 1 121 32 79 0.264 0.652 fine ventral and umbilical tubercles. Flanks are flat or PI. 3, fig. 2 79.2 20 31 0.252 0.391 gently curved. The section is subrectangular. PI. 3, fig. 3 78 20 35.5 0.256 0.455 Certain macroconch specimens tend to a tripartite structure with a marked space between the juvenile whorls and the last one. Crioceratites (C.) sornayi SARKAR, 1955 In spite of some ornamental similarities, Criocerati PI. 3, fig. 4, 5 tes curnieri differs from Crioceratites quenstedti (OOSTER, 1860, sensu IMMEL, 1978) by its whorl sec 1955 Crioceratites (Crioceratites) sornayi SARKAR, p. 50, pl. 1, tion, its more evolute coiling and by its dimensional fig. 7. ratios: 1955 Crioceras sornayi var. densicostata SARKAR. p. 51, pi. 4, fig. 8. 1955 Crioceras sornayi var. tuberculata SARKAR, p. 51, pi. 4, fig. 15. Crioceratites curnieri, holotype (N° 1990/45 Muséum d'Histoire Natu- non 1978 Crioceratites (Crioceratites) basseae SARKAR; IMMEL, p. relle, Marseille) 50, fig. c; p. 48. I H/D = 0,259 I 1 = 8,9 | U/D = 0,530 ~| 1992 Crioceratites (Crioceratites) sornayi SARKAR; ROPOm & SALOMON, p. 196, pi. 5, fig. 1-5.
Crioceratites curnieri, topotype (N° 1990/46 Muséum d'Histoire Natu- rclle of Marseille) DESCRIPTION I H/P = 0,269 I I--9,7 | U/D = 0,544 PRESUMED MACROCONCH SPECIMEN (pi. 3. fig. 4) - A crioceraticonically coiled shell with a tritubcrculate ju Crioceratites quenstedti, holotype ( in IMMEL, 1978, pl. 1, fig.3 ) venile part up to the early last whorl; here the sculpture 1 H/D = 0,357 I I-4 I U/D = 0,446 I changes and the major ribs become bituberculate; the lateral tubercle disappears on the body chamber and the Crioceratites quenstedti ( in IMMEL, 1978, pi. 3, fig. 1) intermediate ribs (4 to 8) tend to become as strong as I H/D = 0,366 I 1 = 6 I U/D = 0,500 | the main ribs. The section is oval, the flanks are gently curved. The whorl height increases moderately quickly
PRESUMED MICROCONCH SPECIMENS - The group of though the whorls remain well separated, the last one small ancyloceratids variously referred to as Acrioce- being more evolute and forming a sort of incurved ras, Aspinoceras or Subaspinoceras by previous aut hook. hors is generally interpreted to have developed from PRESUMED MICROCONCH FORM (pi. 3, fig. 5) - This spe crioceratiform ancestors. Therefore it seems surprising cimen has a small but complete and well preserved to collect tripartite shapes with similar sculpture and shell. The first whorls (juvenile stage) are planispirally suture lines associated with crioceratitid partners. This coiled whilst the gerontic part consists of an incurved fact suggests that the tripartite and crioceratitid forms shaft and of a sort of opened hook resulting in a suba- may constitute dimorphic pairs. spinoceratid type of coiling. On the phragmocone ma- COILING VARIATIONS IN IIAIJTEPJVIAN HETEROMORPH AMMONITES 147 jor ribs bear three small tubercles. Then, on the body thin intermediate ribs of uniform type are visible (6 to chamber, triluberculate ribs progressively bituberculate, 14) between strong bituberculate major ribs. As in the the lateral tubercle disappearing. Intermediate ribs (4 to specimen of pi. 4, fig. 1, this specimen corresponds en 10), often flexuous or concavely curved adorally; tend tirely to SARKAR'S description. to be as strong as the major ribs on the terminal part. PRESUMED MICROCONCH SPECIMEN (pi. 4, fig. 2) - A The whorl height increases moderately quickly, the complete and well preserved subaspinoceratid shell flanks are gently curved. The section is subquadrate to with a juvenile spirally coiled part, a short shaft and a oval. curved hook. The sculpture shows 17 major ribs with MATERIAL - Two specimens (pi. 3, fig. 4 macro- gently flexuous intermediates (6 to 12). The sutures are conch;pl. 3, fig. 5 microconch), Nodosoplicatum Zone, indistinguishable from those of the dimorphic partner. bed 142 - Curnier (Drôme - France). On the shaft and on the hook the same furrows dou MEASUREMENTS bling the major ribs are particularly pronounced. The main ribs bear umbilical and ventral tubercles. The Specimen D H U H/D U/D flanks are flat. On the spire the whorl height increases PI. 3, fig. 4 133 34 84 0.255 0.631 moderately quickly in relation to diameter, but dimi nishes at the end of the phragmocone. PI. 3, fig. 4 72 19.2 42.5 0.266 0.590 MATERIAL - Three specimens (pi. 4, fig. 1 and 3 macroconchs;pl. 4, fig. 2 presumed microconch form) Crioceratites (C.) duvali LÉVEILLÉ, 1837 Sayni Zone - bed 95 - Ravin du Cave de Diou, North Pl. 4, fig. I, 2, 3 side of Mont-Ventoux, France. MEASUREMENTS 1837 Crioceratites duvali LEVIiH.II>, p. 313, pi. 22, fig. 1, 2. 1878 Crioceras duvali LEVIilLI Ji: BAYTJ: & ZIÏILER, pi. 97, fig Specimen D H U H/D U/D 1 PI. 4, fig. 1 140 44.55 89.1 0.318 0.636 1902 Crioceras duvali LÉVEILLÉ; SARASIN & PI. 4, fig. 2 75 27 44.55 0.36 0.594 SCHONDELMAYER, p. 105, pi. 12, fig.1 . 1919 Crioceras duvali LEVEILLE; RODIGHIERO, p. 110, pi. 5, PI. 4, fig. 3 156.6 47.25 99.9 0.301 0.637 fig 4, 11. 1955 Crioceras duvali LÉVEILLÉ; SARKAR, p. 33, pl. 1, fig.3 ; pi. 7, fig.4 . Crioceratites (C.) shibaniae SARKAR, 1955 1955 Crioceras duvali LÉVEIL1.H sp. var. sarasini SARKAR, p. 36. PI. 5; fig.1- 4 1955 Crioceras cf. duvali LÉVEII.UÌ sp. (forme n°l); SARKAR p. 36, pi. 5, fig. 6 and text fig. 4 A. 1955 Crioceras shibaniae SARKAR, p. 49. fig. 9 and text. fig. 8 1955 Crioceras baylei SARKAR, p. 36 and Textfig. 4B. E. 1955 Crioceras vishnui SARKAR, p. 68, pi. 3, fig. 5. 1955 Crioceras nowaki SARKAR, p. 49, pi. 4, fig.1 1 and text, 1964 Crioceratites (Crioceratites) duvali LÉVEILLÉ; THOMEL, fig- 8 B. p. 10,pl. I, fig.1,2 . 1955 Crioceras karakashi SARKAR, p. 48. pi. 4, fig.1 3 and text, 1978 C. (Crioceratites) duvali LÉVEILLÉ; IMMEL, p. 36. fig. 8 A. 1989 Crioceratites duvali LEVEILLE; AUIRAN, p. 211, pi. 13, 1955 Crioceras vialii SARKAR, p. 44, pi. 4. fig.1 9 and text. fig. fig. 7. 6 D. 1955 Crioceras slahleckeri SARKAR, p. 43, pl. 1, fig. 5 and text. fig6C. DESCRIPTION 1978 C. (Crioceratites) shibaniae SARKAR, in IMMEL, p. 51 and text. fig. d; p. 48.
MACROCONCH FORM (pi. 4, fig. 1) - The interpretation of Crioceratites duvali is beset with many difficulties, DESCRIPTION the holotype of LÉVEILLÉ being losl. SARKAR (1955) and TIIOMEL (1964) revised and figured this species PRESUMED MACROCONCH SPECIMEN (pi. 5, fig. 1) - A again and we refer to them for identifying our speci crioceraticonically coiled shell of medium size with flat mens. flanks and a narrow rounded venter. On the juvenile whorls of the spire up to a diameter of 52 mm the ma A crioceraticonically coiled shell, moderately com jor ribs are trituberculate; the lateral tubercle is closer pressed with well preserved sculpture and sutures. Or to the ventral one. At the end of the phragmocone, the namentation shows 23 major ribs with thin intermedia lateral tubercle disappears and the main ribs become te ribs (6 to 12): all are gently flexuous. Just before the bituberculate. They are doubled by furrows on the body end of the phragmocone, furrows appear which double chamber. Intermediate ribs (6 to 12) are gently the main ribs. 8 ventral tubercles are clearly visible on flexuous. The whorl height increases moderately quic the 12 main ribs of the last whorl. This specimen corre kly on the phragmocone but diminishes on the body sponds to SARKAR'S description of Crioceratites duvali. chamber. The macroconch specimen of pi. 4, fig. 3 is a well preserved crioceraticonically coiled shell, larger than SUPPOSED MACROCONCH SPECIMEN (pi. 5, fig. 2) - This the specimen of pi. 4, fig. 1. On the juvenile whorls, crioceraticonically coiled shell is smaller than that of 148 ROPOLO P.
fig. 1 and presents a peculiar coiling which shows a DESCRIPTION faint tendency to aspinoceratid type of coiling because CRIOCERATITES MAJORICENSIS NOLAN CE. REMANEI the increase of the whorl height is rather quick on the WIEDMANN (pi. 6, fig. 1), MACROCONCH - This crioce phragmocone but diminishes on the body chamber. raticonically coiled shell of medium size (D= 116mm) This is interpreted as a macroconch characteristic. forms an evolute spire, each whorl being more and mo SUPPOSED MICROCONCH SPECIMENS (pi. 5, fig. 3, 4) - re detached from the preceding one in relation with the The specimen of pi. 5, fig. 3 is a subaspinoceratid coi diameter. This open crioceratitid coiling corresponds to led shell with a juvenile crioceratiform part which NOLAN'S (1894) pi. 10, fig. 3 b, c. Three ontogenetic lends to uncoil. The gerontic part forms a kind of short stages are clearly visible: 1) on the juvenile stage the curved shaft. The whorl height increases moderately strongly trituberculate main ribs are separated by 4 to 5 quickly On the spire the major ribs bear three strong flexuous intermediate ribs. 2) on the middle stage the tubercles: at the end of the phragmocone. they become lateral tubercle disappears and the umbilical one beco bituberculate and rarer. They are doubled by a furrow mes more pronounced. Intermediates are biconcave to on the body chamber, whilst the number of intermedia wards the aperture; 3) on Ihe adult stage only a strong te ribs (6 to 20) between two main ribs increases. ventral tubercle persists. The specimen of pi. 5, fig. 4 is a badly preserved CRIOCERATITES MAJORICENSIS MAJORICENSIS NOLAN (pi. aspinoceratid form has the same ornamental characte 6, fig. 2), MACROCONCH - This crioceraticonically ristics as the previous specimen. The flanks are flat and coiled specimen bears exactly the same type of sculptu moderately compressed. On the straight shaft and on re as the preceding one. but the form of the spiral dif the hook the imperfectly preserved ribs are rather faint fers; the whorl height increases more quickly than the and indistinct, but become strong on the terminal part. specimen of pi. 6, fig. 1 and the section is subrectangu- MATERIAL - Four specimens (pi. 5. fig. 1; 2 macro lar. conchs; pi. 5, fig. 3, 4 microconchs) Sayni Zone - bed CRIOCERATITES MAJORICENSIS CF'. REMANEI (pi. 6, fig. 3), 92 - Ravin du Cave de Diou. North side of Mont Ven PRESUMED MICROCONCH - Hook shaped aberrant shell toux, France. with juvenile part coiled in free crioceratiform spire. The first ornamental stage (trituberculate major ribs MEASUREMENTS with 4 to 5 inserted ribs) is here more pronounced and continues up to the end of the phragmocone on the Specimen D H U H/D U/D early stage of the curved shaft. The next two main ribs PI. 5, fig. 1 96 30 58.2 0.312 0.606 are bituberculate and finally tubercles disappear on the PI. 5, fig. 2 78.9 28.3 49.8 0.358 0.631 hook, where the intermediate ribs lend to become as PI. 5, fig. 3 90 27 53 0.300 0.588 strong as the major ribs. The whorl height increases PI. 5, fig. 4 81 22 39 0.271 0.481 slowly on the phragmocone and more quickly on the hook. CRIOCERATITES MAJORICENSIS MAJORICENSIS (pi. 6. fig. Crioceratites (C.) majoricensis NOLAN. 1894 4), PRESUMED MICROCONCH - An acrioceratiform spe PI. 6, fig. 1-5 cimen with a juvenile crioceratiform spire , a shaft and a curved hook. The sculpture shows the three typical 1894 Crioceras picleti var. "majoricensis" NOLAN, p. 192, pi. stages of C. majoricensis (trituberculate, bituberculate, 10, fig. la, lb, Id. monotuberculate major ribs). On the hook, there is a 1894 Crioceras angulicostatum D'ORBIGNY; NOI AN, p. 195, pi. 10, fig. 3 b, c. section of alternating simple and dichotomous ribs. The 1902 Crioceras quenstedti OOSTER; SARASIN & whorl section is subquadrate. SCHÒNDELMAYER, p. 109, pi. 12, fig. 4-7. CRIOCERATITES MAJORICENSIS CF. REMANEI (pi. 6, fig. 5), 1919 Crioceras quenstedti OOSTER; RODIGHIERO, p. 113, pi. PRESUMED MICROCONCH - This tripartite shell has 12, fig. 2. 1955 Crioceras nolani vai. "majoricensis" NOLAN; SARKAR, p. major trituberculate ribs separated by 4 to 5 intermedia 45. tes on the spiral. On the straight shaft and on the cur 1955 Crioceras seitzi SARKAR; p. 70, pi. 3, fig. 3. ved hook the bituberculate and the monotuberculate 1955 Crioceras rogeri SARKAR; p. 42, pi. 4, fig. 14 and text. fig. 6A. stages are developed. At the transition of the shaft to 1962 Crioceratites (Crioceratites) majoricensis remanei the terminal hook occur ribs that bifurcate at medium NOLAN; WIEDMANN, p. 118, pi. 8, fig. 3. flank height. 1962 Crioceratites (Crioceratites) majoricensis, NOLAN; WIEDMANN, p. 121, pi. 8, fig. 4; pi. 9, fig. 2. MEASUREMENTS 1964 Crioceratites (Crioceratites) majoricensis NOLAN; Specimen D H U H/D U/D THOMEL, p. 19, pi. 3, fig. 1. 1976 Crioceratites (C) majoricensis majoricensis NOLAN; PI. 6, fig. 1 116 29 68 0.25 0.586 MANDOV, pi. 4, fig. 1-3. PI. 6, fig. 2 101.2 28 58 0.276 0.583 1976 Crioceratites (C) majoricensis WIEDMANN; MANDOV, pi. PI. 6, fig. 3 94.2 28 50 0.297 0.530 5, fig. 4. PI. 6, fig. 4 92 25.5 49 0.277 0.532 1978 C. (Crioceratites) majoricensis NOLAN; IMMEL, p. 49 and text. fig. b, p. 48. PI. 6, fig. 5 94 26 42 0.276 0.446 COILING VARIATIONS IN HAUTERIVIAN HETEROMORPH AMMONITES 149
OCCURRENCE -_A11 the specimens : Balearis Zone - KENNEDY, 1992) would certainly mark a progress, be (pi. 6, fig. 1, 3, 5~bed 110; pi. 6, fig. 2, 4, bed 111) cause it seems evident now that conspecific large and Ravin du Cave dc Diou - North side of Mont-Ventoux, small forms differing in sex must be assigned to the France. same genus or even the same species, and that generic separation based on criteria such as differences in coi ling is untenable.
5. - TAXONOMIC IMPLICATIONS AND GENERAL CONCLUSIONS ACKNOWLEDGEMENTS
The aim of this paper is to demonstrate that the I would like to thank my good friend, Roland phenomenon of dimorphism is a reality within hetero GONNET (Avignon, France) for allowing me to use morph ammonite populations. The species described specimens of his collections in this paper, for discus here reveal, for the same time and in the same beds, sing certain aspects of the present research and for his Iwo structural types. technical assistance. P. RAWSON revised the cnglish The first, larger, structure with crioceratitid coiling version of the manuscript. is probably the female of the species. The second, smaller, structure with subaspinocera- lid or aspinoceratid coiling would seem to correspond REFERENCES to the male. AGUIRRE - URRIi'IA M. B. & KIJNGER II. C (1986) - Upper- However as our recent study suggests (ROPOLO & Barremian Heleroceralinae (Cephalopoda, Ammonoidea) from SALOMON. 1992) the variation of coiling or uncoiling Patagonia and Zululand, with comments on the systematics of the docs not seem to be reflect dimorphism alone, it takes Subfamily. Ann. South Afr. Mus., 96 (7): 271-274, Cape Town. on a second aspect. AVRAM E. (1984) - Correspondent species of the genera Macroscaphi- Some species (C. nolani KILIAN var. sahlieri tes MEEK and Costidiscus UHLIG. Spec. vol. "75 years lab. pa- leonl": 67-80. Bucuresti. ASTIER. C. elegans, D'ORBIGNY. C. joliboisi, SARKAR, etc.) reveal variations of coiling over time. These mor AUTRAN G. (1989) - L'évolution de la marge NE provençale (Arc de phological transformations (a kind of biological Castellane) du Valanginien à l'Hauterivien à travers l'analyse "crisis") seem to correspond to transgressive or regres biostratigraphique de la région de Peyroides: séries condensées, sive periods with sea level variations (TINTANT et alii discontinuités et indices d'une tectogénèse distensive. Thèse Univ. Nice: pp 232, Nice. 1982; MARCHAND et alii, 1985; MARCHAND, 1992; DELANOY & MAGNIN, 1994). BAYLE E. & ZELLER R. (1878) - Explication de la Carte géologique de Alternatively they could be explained by colder and la France. Serv. Carte Géol. France, Paris. warmer periods in which glacio-eulalism reached its BRESKOVSKI S. (1966) - Biostratigraphie du Barrémien au sud du maximum (KEMPER & WIEDENROTII, 1987). According village deBrestak, dans la région de Varna. Trav. géol. Bulg., ser. to BULOT (1993. cum hibl.), recent investigations on Palaeont., 8: 71-121, Sofia (in bulgarian). bryo/.oan distribution and carbon isotopes seem to con firm this last hypothesis. BULOT L. (1990) - Evolution des Olcostephaninae (Ammonitina, Ce A further study to be published will include mor- phalopoda) dans le cadre paléobiogéographique du Crétacé in phofunclional and biostratigraphic analyses in order to férieur (Valangimen-Hauterivien) du SE de la Prance. D.S.E.R. Univ. Dijon: pp. 172, Dijon. clarify our understanding of this second aspect of "uncoiling". In any case the appearance of morphologi cal dimorphic differences or variations during evolu BULOT L. (1993) - Stratigraphie implications of the relationships between ammonites and fades: examples taken from the Lower- tion of the coiling seems to constitute a genetic respon Cretaceous (Valanginian-Hauterivian) of the Western Tethys. In: se to physical and ecological changes induced by ocea M.R. House (Ed): "The Ammonoidea: Environment, Ecology and nic or climatic events. Evolutionary Change". Systematics Assoc., spec, vol., 47: 243-266. Clarendon Press, Oxford. The recognition of sexual dimorphism in Ancyloce- ralidac and of coiling evolution within heteromorph BULOT L. ARNAUD-VANNEAU A, BLANC E., ARNAUD II. & THIEULOY ammonites calls for a revision of the classification of J. P. (1992) - Basin type successions; biostratigraphic tools, stra the Lower Cretaceous genera and species. There is now tigraphie gaps and reworked sediments, transition from Platform no serious objection to uniting in the same genus large to Basin. In: A. ARNAUD-VANNEAU (Ed.): "The Subalpine forms with crioceratitid coiling and smaller forms with chains:Platform margins." Symposium Guide-book: 25-41, Greno ble. subaspinoceratid / aspinoceratid or acrioceratid coiling. From a taxonomic point of view, a new classification suggested for many years by numerous eminent authors BUSNARDO R. (1984) - Crétacé inférieur: échelles biostratigraphi- ques in Synthèse géologique du SE de la France.Mém. B.R.G.M., (MAKOWSKI, 1962; RAWSON, 1975; KLINGER & 125:291-294, Orléans. 150 ROTOLO P.
CALLOMON J. H. (1963) - Sexual dimorphism in Jurassic Ammonites. OOSTER W. A. (1860) - Catalogues des Céphalopodes fossiles des Trans. Leicester, lit. phil. Soc, 57: 21-56, London. Alpes Suisses. Nouv. Mém. Soc. Hclv. Sci. Nat., 18: pp. 100, Ge nève.
DHIANOY G. & POUPON A. (1992) - Sur le genre Lytocrioceras SPATH, RAWSON P. F. (1975) - The interpretation of the Lower-Cretaceous 1924 (Ammoidea. Ancyloceratina). Geobios, 25 (3): 367-382, heteromorph ammonite genera "Paracrioceras" and Lyon. "Hoplocrioceras", SPATH, 1924. Palaeontology, 18 (2): 275-283, London. DELANOY G. & MAGNTN A. (1994) - Evolution de l'enroulement des ammonites héléromorphes avec les événements marins. C. R. RODIGHŒsRO A. (1919) - // sistema cretaceo del Veneto occidentale Acad. Sci. Pans, 318, sér. 2: 843-848, Paris. compresso fra l'Adige e il Piave con speciale riguardo al Neo- comiano dei Sette Comuni. Palaeont. Italica, 25: 39-125, Pisa.
DlMLTROVA N. (1967) - Les fossiles de Bulgarie IV. Crétacé inférieur. Cephalopoda (Nautiloidea et Ammonoidea). Bulg. Acad. Sci. ROPOLO P. (1991) - "Crioceratites cumieri" nov. sp., une nouvelle (Palaeontology), 4: pp. 1-236, Sofia. espèce d'ammonite hétéromorphe préfigurant l'acquisition des coquilles tripartites de l'flauterivien inférieur, (Ammonoidea, An cyloceratina). Mésogée, Bull. Mus. Hist. Nat. Marseille, 51: 65-73, HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. Marseille. B., AVRAM E.. BOGDANOVA T. N., BUJTOR L., BULOT L., CECCA F., DELANOY G., ETTACHFINI M., MEMMI L, OWEN H. G., RAWSON P. F., SANDOVAL, J., TAVERA J. M., THIEULOY J.-P., ROPOLO P. & SALOMON M. (1992) - Evolution du déroulement, pas TOVBINA S. Z. & VASICEK Z. ( 1993) - Ammonite zonation for the sage du stade criocératique au stade subaspmocératique ou Lower Cretaceous of the Mediterranean region; basis for the protacriocèralique chez certaines populations d'ammonites hélé stratigraphie correlations within IGCP-Project 262. Rev. romorphes de l'Hauterivien moyen (Zone à Nodosplicatum et Espanda Paleont., 8 (1): 117-120, 1 tabi, Madrid. à Sayni). Géologie Méditerranéenne, 19 (3): 189-227, Marseille.
MME1. H. (1978) - Die Crioceratiten (Ancyloceratina, Ammonoidea) SARASIN C. H. & SCHÔNDELMAYER CH. (1901) - Etude monographi der medilerranen und borealen Hauterive Barreme (Unterkreide) que des ammonites du Crétacique inférieur de Châtel-Saint- Paleontographica A, 163: 1-85, Stuttgart. Denis. Mém. Soc. Pal. Suisse, 28: pp. 91, Genève.
KEMPER E. & WlEDENROTH K. (1987) - Klima und Tier-Migrationen SARKAR S. S. (1955) - Révision des ammonites déroulées du Crétacé am Beispiel der fruhe-kretazischen Ammoniten. Geol. Jb., A 96: Inférieur du SE de la France.. Mém. Soc. géol. France, 72: 1-176, 315-363, Hannover. Paris.
KLINGER H. C. & KENNEDY W.J. (1992) - Cretaceous faunas from THIEULOY J. P., (1972) - Biostratigraphie des lentilles à pérégrinelles Zululand and Natal. South-Africa; Barremian representatives of (Brachiopodes) de l'Hauterivien de Rottier (Drôme. France). the Ammonites family, Ancyloceratidae, Gill (1871). Ann. South Geobios, 5(1): 5-53, Lyon. Afr. Mus: 71-138, Cape Town.
LANDMAN N. II. & WAAGE K.M. (1993) - Scaphitid ammonites of the THIEULOY J. P. (1977) - La zone à Callidiscus du Valanginien supé Upper Cretaceous (Maastrichtian) Fox-Hills formation in S. Da- rieur Vocontien (SE de la France), Lithostratigraphie, ammonito- kola and Wyoming. Bull. Amer. Mus. Nat. Hist., 215: 1-257, New- faune, limite Valanginien-Hauterivien. corrélation. Géol. Alpine, York. 53: 83-143, Grenoble.
LEVEILLE C. (1837) - Description de quelques nouvelles coquilles THIEULOY J. P., FUHR M. & BULOT L. (1990) - Biostratigraphie du fossiles du Département des Basses-Alpes. Mém. Soc. Géol. Fran Crétacé Inférieur de l'Arc de Castellane (SE de la France), fau ce, 2: 313-315, Paris. nes d'ammonites du Valanginien supérieur et âge de l'horizon dit de la "Grande Lumachelle". Géologie Méditerranéenne, 17: 55-99, Marseille. MAKOVSKI H. (1962) - Problem of sexual dimorphism in Ammonites. Acta palaeontol. poi., 12: pp. 92, Warszawa. THOMEL G. (1964) - Contribution à la connaissance des Céphalopo MANIXiV G. (1976) - L'étage llauterivien dans les Balkanides occi des crétacés du SE de la France. Note sur les ammonites dé dentales, Bulgarie de l'Ouest, et sa faune d'ammonites. Ann. roulées du Crétacé inférieur - Mém. Soc. Géol. France (ns) 43 (2), Univ. Sofia, géol. géogr., 67: 11-99, Sofia. pp. 1-80, 12 pl., Paris.
MARCHAND D. (1992) - Ammonites et paléoprofondeur - les faits, les THOMEL G., DELANOY G. & AUTRANG. (1987) - Valeur taxomonique, interprétations . Paléovox, 1: 49-68, Dijon. position stratigraphique et relations phylétiques des genres d'ammonoidea "Acrioceras" (HYATT, 1900) et "Aspinoceras" (ANDERSON, 1938) au cours des temps Hauieriviens, ainsi que MARCHAND D., THIERRY J., TINTANT H. (1985) - Influence des seuils leurs dérivés. C. R. Acad. Sci., Paris, 305,sér. 2: 215-219, Paris. et des hauts-fonds sur la morphologie et l'évolution des Ammo- noidés. Min. Educ. Nat., Com., trav. hist, scient., Bull. Sect. Sci., 9: 191-202, Dijon. TINTANT H. (1963) - Les Kosmoceratidés du Callovien inférieur et moyen d'Europe occidentale. Pubi. Univ. Dijon, 64: pp. 500, Di jon. MUNIER-CHALMAS E. (1892) - Sur la possibilité d'admettre un dimor- phisme sexuel chez les Ammonitidés. C. R. somm. Soc. géol. Fran ce. 14: 170-174, Paris. TINTANT H., MARCHAND D., MOUTERDE R. (1982) - Relations entre les milieux marins et l'évolution des Ammonoidés: les radiation NOLAN H. (1894) - Sur les Crioceras du groupe du Crioceras duvali. adaptatives du Lias. Bull. Soc. Géol. France, sér. 7, 24 (5-6): 951- Bull. Soc. géol. France sér. 3, 22: 183-196, Paris. 961, Paris. COLLLNQ VARIATIONS LN HAUTERIVIAN HETEROMORPH AMMONITES 151
VASICEK Z., MICHAIJK J. (1986) - Some heteromorphic ammonites WESTERMANN G. E. G. (1990) - New developments in Ecology of Ju from Polomec (Hauterivian-Barremian, Central Western Car rassic-Cretaceous ammonoids. In: G. PALLINI, E. CECCA, S. pathians, Czechoslovakia). Geologicky sbom., 39 (6): 655-674, CRESTA & M. SANTANTONIO (Eds.): "Fossili, Evoluzione, Ambien Bratislava. te". Atti 11° Convegno Intemazionale Pergola, 1987: 459-478.
WlìSTERMANN G. E. G. (1964) - Sexual dimorphism and taxonomy in Jurassic ammonitina: a revision of the Otoitidae (including WIEDMANN J. (1962) - Unterkreide-Ammoniten von Mallorca. I, Lyto- Sphaeroceratinae). Geol. Soc. Amer., spec, papers, 76: 178-179, ceratina, Aptychi. Abh. Akad. Wiss. Lit., math-naturwiss. Kl. Washington. (Mainz), 1: 1-148, Wiesbaden. 152 ROPOLO P.
PLATE 1
Supposed dimensional dimorphism. Fig. 1,3- Crioceratites loryi SARKAR, 1955, microconchs - Loryi Zone, Ravin du Cave de Diou section (Northern side of Mont-Ventoux, France), bed 83. Fig. 2, 4 - Crioceatites loryi SARKAR, 1955, macroconchs - Loryi Zone, same section and bed. Collection GONNET - Avignon. Photos P. ROPOLO. X 1,5 An arrow indicates the beginning of the body chamber.
TAVO I A 1
Dimorfismo dimensionale presunto. Fig. 1,3- Crioceratites loryi SARKAR, 1955, microconchi - Zona a Lory, sezione di "Ravin du Cave de Diou" (versante settentrionale del Mont-Ventoux), strato 83. Fig. 2, 4 - Crioceatites loryi SARKAR, 1955, macroconchi - Zona a Loryi, stessa sezione, stesso strato. Collezione GONNET - Avignon). Foto P. ROPOLO, X 1,5 La freccia indica l'inizio della camera d'abitazione.
154 Ropomp
PLATE 2
Dimensional dimorphism - Loryi Zone. Fig. 1 - Crioceratites matsumotoi SARKAR, 1955. macroconch. Fig. 2 - Crioceratites matsumotoi SARKAR, 1955, microconch. Fig. 3 - Dimorphism in a same nodule - Crioceratites loryi SARKAR, 1955, microconch and macroconch. Fig. 1 and 2 Collection ROPOLO; fig. 3 Collection POUPON (Bed 124, Curnier section). Photos P. ROPOLO, X 1
TAVOIA 2
Dimorfismo dimensionale - Zona a Loryi. Fig. 1 - Crioceratites matsumotoi SARKAR, 1955, macroconco. Fig. 2 - Crioceratites matsumotoi SARKAR, 1955, microconco. Fig. 3 - Esempio di dimorfismo nello stesso nodulo - Crioceratites loryi SARKAR, microconco e macroconco. Fig. 1 e 2 Collezione ROPOLO; fig. 3 Collezione POUPON (strato 124, sezione dì Curnier ). Foto P. POPOLO, X 1
L56 ROTOLO P.
PLATE 3
Morpho-dimensional dimorphism. Fig. - 1 Crioceratites curnieri ROPOLO, 1991, macroconch - Nodosoplicatum Zone, Curnier (Drôme, France), bed 140 Fig. 2, 3 - Crioceratites curnieri ROPOLO, 1991, microconchs - Nodosoplicatum Zone, Curnier (Drôme, France), bed 140. Fig. 4 - Crioceratites sornayi SARKAR, 1955, macroconch - Nodosoplicatum Zone, Curnier (Drôme, France), bed 142. Fig. 5 - Crioceratites sornayi SARKAR, 1955, microconch - Nodosoplicatum Zone, Curnier (Drôme, France), bed 142. Fig. 1 - 3: Collection GONNET - Avignon; fig. 4, 5: Collection SALOMON, Musée de Mormoiron, (Vaucluse, France). Photos R. GONNET, x 1
TA VOLA 3
Dimorfismo morfo-dimensionale. lug. - I Crioceratites curnieri ROPOLO, 1991, macroconco - Zona a Nodosoplicatum, sezione di Curnier (Drôme, Fran eia), strato 140. Fig. 2, 3 - Crioceratites curnieri ROPOLO, 1991, microconchi - Zona a Nodosoplicatum, sezione di Curnier (Drôme, Francia), strato 140. lug. 4 - Crioceratites sornayi SARKAR, 1955, macroconco - Zona a Nodosoplicatum, sezione di Curnier (Drôme, Fran cia), strato 142. lug. 5 - Crioceratites sornayi SARKAR, 1955, microconco - Zona a Nodosoplicatum, sezione di Curnier (Drôme, Fran eia), strato 142. Fig. I - 3: Collezione GONNET - A vignon; fig. 4, 5: Collezione SALOMON, Museo dì Mormoiron (Vaucluse, France). Foto R. GONNET, x 1
158 ROPOLO P.
PLATE 4
Morpho-dimensional dimorphism. Fig. 1, 3 - Crioceratites duvali LÉVEILLÉ, 1837, macroconch - Sayni Zone, Ravin du Cave de Diou section (Northern side of Mont-Ventoux, France), bed 95. Fig. 2 - Crioceratites duvali LÉVEILLÉ, 1837 microconch - Sayni Zone, same section and bed. Collection GONNET - Avignon. Photos R. GONNET, X 0,70
TAVOLA 4
Dimorfismo morfo-dimensionale. Fig. 1, 3 - Crioceratites duvali LÉVEILLÉ, 1837, macroconchi - Zona a Sayni, sezione di "Ravin du Cave de Diou" (versante settentrionale del Mont-Ventoux, Francia), strato 95. Fig. 2 - Crioceratites duvali LÉVEILLÉ, 1837, microconchi - Zona a Sayni, stessa sezione, stesso strato. Collezione GONNET - Avignon. Foto R. GONNET, x 0,70
160 ROPOLO P.
PLATE 5
Morpho-dimensional dimorphism Fig. 1,2- Crioceratites shibaniae SARKAR, 1955, macroconchs - Sayni Zone, Ravin du Cave dc Diou section (Northern side of Mont-Ventoux, France), bed 92. Fig. 3, 4 - Crioceratites shibaniae SARKAR, 1955, microconchs - Sayni Zone, same section and bed. Collection GONNET - Avignon. Photos R. GONNET, X 1
TA VOI A 5
Dimorfismo morfo-dimensionale. Fig. 1, 2 - Crioceratites shibaniae SARKAR, 1955, macroconchi - Zona a Sayni Zone, sezione di "Ravin du Cave de Diou" (versante settentrionale del Mont-Ventoux, Francia), strato 92. Fig. 3, 4 - Crioceratites shibaniae SARKAR, 1955, microconchi - Zona a Sayni, stessa sezione, stesso strato. Collezione GONNET - Avignon. Foto R. GONNET, x I
162 ROPOLO P.
PLATE 6
Morpho-dimensional dimorphism. Fig. 1,2- Crioceratites majoricensis NOLAN, 1894, macroconch - Balearis Zone. Fig. 3, 4, 5 - Crioceratites majoricensis NOLAN, 1894, microconchs - Balearis Zone. Fig. 1, 3, 5 from bed 110; fig. 2 and 4 from bed 111, Ravin du Cave de Diou section (Northern side of Mont-Ventoux, France). Collection GONNET - Avignon. Photos R. GONNET, X 1
TAVOLA 6
Dimorfismo morfo-dimensionale. Fig. 1,2- Crioceratites majoricensis NOLAN, 1894, macroconchi - Zona a Balearis. Fig. 3, 4, 5 - Crioceratites majoricensis NOLAN, 1894, microconchi - Zona a Balearis. Fig. 1, 3, 5 strato 110, fig. 2, 4 strato 111 della sezione di "Ravin du Cave de Diou" (versante settentrionale del Mont- Ventoux, Francia). Collection GONNET - Avignon. Foto R. GONNET, x 1
164 ROPOLO P.
PLATE 7
Possible morpho-dimensional dimorphism: Megacrioceras jourdani (ASTIER). Fig. 1. - microconch (RG/1127) - Balearis Zone, Le Poët-en-Percyp section (Drôme, France). Fig. 2. - macroconch (RG/1231) - Balearis Zone, same section. Photos R. GONNET, X 2/3
TAVOLA 7
Dimorfismo morfo-dimensionale presunto: Megacrioceras jourdani (ASTIER). Fig. 1. - microconco (RG/1127) - Zona a Balearis, sezione di "Le Poët-en-Percyp" (Drôme, Francia). Fig. 2. - macroconch (RG/1231) - Zona a Balearis, stessa sezione. Foto R. GONNET, X 2/3
Mem. Descr. Carta Geol.d'It. LI (1995), pp. 167-171
Aptian and Albian ammonites in the Western Carpathians (the Czech and Slovak Republics)
Ammoniti aptiane ed albiane nei Carpazi occidentali (Repubbliche Ceca e Slovacca)
ZDENEK VASÎCEK (*)
IGCP Projects 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - Deposits of the Aptian and Albian age in the Western Mediterranean fauna! province. MARCINOWSKI & WIEDMANN stated that Carpathians reflect the tectonic disturbance heralding the gradual there were boreal hoplitides that penetrated into the Tatric during the development of palaeoalpine orogenesis at the end of the Lower Middle Albian. Cretaceous. With few exceptions, the Aptian and Albian successions in both the Outer and the Central Western Carpathians are KEY WORDS: Czech and Slovak Republics, Western Carpathians, macrofaunislically much poorer than the deposits in the lower part of the Aptian, Albian, ammonites. IjOwer Cretaceous. Fossiliferous deposits from the Outer Carpathians are known from the Silesian Unit (the upper part of the Tesin-flradiste RIASSUNTO - I depositi dell' Aptiano e dell'Albiano nei Carpazi Formation). They belong almost excusively to the lowermost Aptian occidentali riflettono l'attività tettonica che annuncia il graduale sviluppo (Procheloniceras albrechtiausthae), exceptionally to the Upper Aptian dell'orogenesi paleoalpina alla fine del Cretaceo inferiore. Tranne poche (Acanthohoplites nolani). From the Klippen Belt only sporadically eccezioni, le successioni aptiane ed albiane, sia nel Carpazi occidentali occurring Lower Albian ammonites are known. Quite new relatively esterni che centrali, sono macrofaunisticamente molto più povere dei abundant ammonite finds from the Upper Albian flysch deposits in the depositi della parte più bassa del Cretaceo inferiore. Si conoscono Klape Unit of the Klippen Zone include the subzonal species Dipoloceras depositi fossiliferi dei Carpazi esterni dall'Unità Silesiaca (parte cristatum and Hysteroceras orbignyi. In the Central Carpathians superiore della FormazioneTesin-Hradiste). Essi appartengono quasi ammonites occur sporadically in the marly deposits of the Pâmica esclusivamente all'Aptiano basale (Procheloniceras albrechtiaustriae), Formation in the Lower Aptian (probably Deshayesi Zone), in a tectonic eccezionalmente all'Aptiano superiore (Acanthohoplites nolani). Dal unit of higher order called Fatric. The base of the Zabijak Formation in "Klippen Belt" sono solo sporadicamente segnalate ammoniti the Tatric Unit has an exceptional position. From this condensed horizon dell'Aptiano inferiore. Ritrovamenti relativamente recenti, e frequenti, di came PASSENDORFER's collection, from which MARCINOWSKI & ammoniti nel flysch dell'Albiano superiore nell'Unità Klape, nella zona WIEDMANN described approximately 60 species corresponding to the dei Klippen, include gli indici subzonali Dipoloceras cristatum e ammonite zones of Floridum up to Altonense (the middle part of the Hysteroceras orbignyi. Nei Carpazi centrali si trovano sporadicamente Lower Albian up to the higher part of the Upper Albian). From the ammoniti nei depositi marnosi della Formazione Pàmica dell'Aptiano palaeobiogeographical point of view, the bulk of the Aptian and Albian inferiore (probabilmente Zona a Deshayesi), in un'unità tettonica di deposits in the Western Carpathians contains only ammonites of the ordine più alto, chiamata Fatricum. La base della Formazione Zabijak
(*) Department of Geology, Mineralogy and Geochemistry, University of Mining and Metallurgy of Ostrava, Tr. 17. listopadu, CZ-708 33 Oslrava-Poruba, the Czech Republic VASlCEKZ. 168 nell'Unità Tatrica è in una posizione eccezionale. Da questo orizzonte occidentali contiene solo ammoniti della provincia faunistica condensato proviene la collezione PASSENIXJRFER, da cui mediterranea. MARCINOWSKl & WIEDMANN stabilirono l'esistenza di MARCINOWSKl & WIIÏDMANN descrissero approssimativamente 60 hoplitidi boreali che penetrarono nel dominioTalrico durante l'Albiano specie corrispondenti ad un intervallo che va dalla Zone a IToridum medio. fino alla Zona a Altonense (parte media dell'AJbiano inferiore fino alla parte più alta dell'Albiano superiore). Dal punto di vista PAROLE CHIAVE: Repubbliche Ceca e Slovacca, Carpazi paleobiogeografico, la massa dei deposili Aptiani ed Albiani nei Carpazi occidentali, Aptiano. Albiano, ammoniti.
1. - INTRODUCTION Silesian Unit and in the Klippen Belt. In the former unit sedimentation occurred in an increasingly deep The Western Carpathians extend mainly over the basin, while the previous tendency towards deposition territory of the Slovak Republic and reach the of dark coloured, predominantly pelitic rocks continued neighbouring territory of the Czech and Polish (MENCÌK et alii, 1983, VASICEK et ahi, 1994). With the Republics (Fig. 1). They belong to the Middle- gradual loss of carbonate content also ammonites European Alpine mountain bell with a complicated disappeared very quickly from these deposits. The nappe structure. The one from supposed palinspastic lowermost Aptian is the best known here, with the situation of sedimentary basins at the end of the Lower index species Procheloniceras albrechtiaustriae Cretaceous (before Alpine movement and nappe (UHLIG), the rare occurrence of hitherto only shifting) is illustrated in Fig. 2. The present surface imperfectly known représentants of Prodeshayesites structure, with the basic divisions of the Western Casey and Costidiscus microcostatus (SiMONOViCH, Carpathians including the position of the Aptian and BACEVICH & SoROKIN), Procheloniceras pachy- Albian ammonite localities discussed here, are shown stephanum (UHLIG), Cheloniceras aff. seminodosum in Fig. 3. (SlN/.ow), Deshayesites borowae (UHLIG), Acrioceras karsteni (UHLIG) etc. (localities Verovice, Kuncicc, Kozlovice. Ostravice, Hradiste etc. - VASICEK, 1972, 1973). One locality (below the Pindula saddle) has yielded the Upper Aptian ammonites Acanthohoplites nolani exiquecostatus EGOIAN. Tetragoniles duvalianus (D'ORBIGNY), Nodosohoplites moravicus VASICEK and N. difftcilis VASÏCEK (VASÌCEK. 1981). The specimen of Acanthohoplites ex gr. bigoureti (SEUNES) recorded by LIEBUS & UHLIG (1902) no longer exist in the collections. Albian ammonites are still not known in the Silesian Unit. In the Klippen Bell, deposition of Aplian-Albian pelagic carbonates periodically gave way lo thai of l'ig. 1 - The geographical position of the Western Carpathians in the Central Europe. pelitic sediments and later of flysch. In the last few -IM posizione geografica dei Carpazi occidentali nell'Europa centrale. decades there have been no new discoveries of Aptian and Lower Albian ammonites. STUR (1860, 1868) recorded Leymeriella tardefurcata (LEYMERIE) and It was the concurrent tectonic rearrangement of the Douvilleiceras mammillatum (Scui.OTHElM) from the complex system of Carpathian sedimentary basins which Lower Albian at one or two localities (Tvrdosin) of the influenced the development of the Aptian and Albian Klippen Belt in the Orava valley. These too have since stages in the whole Western Carpathians (VASICEK et alii, disappeared from the collections. 1994). This is seen outstandingly both in the character of the sedimentation and in ammonite occurrences and Upper Albian ammonites have been recently in preservation. Generally it may be staled that in the found the flysch of the Klape Unit of the Klippen Belt, Western Carpathians continuous sequences of strata do at Povasky Chlmec (VASICEK & RAKLIS, 1993). The occur, but there is a shortage of fossiliferous deposits that prevailing species here is Puzosia ex gr. mayoriana could be utilized at least as type profiles supported (D'ORBIGNY). Other species include Phylloceras minimally by two or three biozones of ammonites (Hypophylloceras) ex gr. velledae (MICHELIN), occurring immediately one after another. Kossmatella cf. muhlenbecki (FAI,LOT), K. schindewolft WIEDMANN & DIENI, Hamites (H.) compressus SOWERBY, 77. (Metahamites) passendorferi MARCI- NOWSKI & WIEDMANN, Hemiptychoceras ex gr. 2. - AMMONITE ASSOCIATIONS gaultinum (PlCTET), Hysteroceras carinatum SPATII, Prohysteroceras (Goodhalites) cf. delabechei SPATH In the Outer (Flysch) Western Carpathians the and slratigraphically important forms such as Aptian and Albian period is best documented in the Dipoloceras (D.) cristatum (DELUC) and Hysteroceras APTIAN AND ALBIAN AMMOMTES IN THE WESTERN CARPATHIANS 169
Fig. 2 - The supposed palinspastic situation of Carpathian sedimentary basins during the Albian stage (after VAsiCEfCer alii, 1994). - La presunta collocazione palinspastica dei bacini sedimentari dei Carpazi nell'Albiano (VAsICF.K et alti, 1994).
orbignyi (SPATH). These prove the lower part of the Fatric Unit at Medziholie may be regarded as an Upper Albian (Inflatum Zone). exception, for from here ANDRUSOV (1931) recorded At Skalica. sporadic fragments of ammonite molds minute pyritized ammonites, now lost. During the last have been collected from a conglomeratic breccia survey HASKO & POLÂK (1979) rediscovered the consisting predominantly of limestone pebbles and horizon but found only a few fragments of ammonites, fragments of Urgonian type with glauconitic sandy marl among which VASICEK & RAKI'JS (this volume) matrix (the slope deposits of the Manin Unit in the zone determined the following species: Phylloceras passing between the Klippen Belt and the Central (Hypophylloceras) cypris cypris (FALLOT & TFRMIER), Carpathians in the Vâh valley). Macroscaphites striatisulcatus (D'ORBIGNY), Acanthohoplites SINZOW indicates the Upper Aptian, Costidiscus tenuistrialus (REPELIN), Deshayesites sp., while the sole mold of Phylloceras (Hypophylloceras) Melchìorites cf. enterici (RASPAIL) and Toxoceratoides moreti (MAHMOUD) is of Albian age (MICIIAIJK & sp. However, they could not confirm ANDRUSOV'S VASÏCEK, 1984). (1931) record of Cheloniceras cornuelianum During the Aptian-Albian interval the Central (D'ORBIGNY). Western Carpathians were more affected by the Nevertheless, his identification can be accepted, reconstruction of sedimentary basins then the Outer especially as VASICEK et alii (1994) found Carpathians. Usually already during the Barremian Cheloniceras cf. cornuelianum in a similar set of massive limestone of Urgonian type developed on deposits at another locality in the Zâzrivka valley, near newly occurring carbonate platforms, instead of the Zâzrivâ. So the Medziholie locality belongs to the former marly limestone facies (Neocomian) which may Lower Aptian, most probably to the Deshayesi Zone. also be replaced by marly and later by flysch deposits in In the High Tatra region of the Central Western Ihc deeper zones. In these facies ammonites are lacking Carpathians, at the Slovak-Polish border, grey-green or only very rarely seen. Aptian marly deposits in the glauconitic limestones form the base of the Zabijak 170 VASlCEKZ.
Fig. 3 - The present structure of the Western Carpathians. The position of the main Aptian and Albian ammonite localities is shown by the black circles. - L'attuale struttura dei Carpazi occidentali. La posizione delle principali località ad ammoniti aptiane ed albione è evidenziata dai cerchi neri.
Formation (Tatric Unit). From a condensed horizon other Aptian and Albian Carpathian deposits only characterized among others by phosphatisation of Mediterranean ammonites are known. This shows organic remains, based on Passendorfer made a that boreal elements penetrated the Tatric region of collection, from which MARCINOWSKI & WIEDMANN the Central Carpathians in the Middle Albian for a (1990) described about 60 ammonite species indicating short period. the Floridum to Altonense Zones (the middle part of According to the data and the sketch by the Lower Albian up to the higher part of Upper MARCINOWSKI & WIEDMANN (1985, 1988, 1990 - Albian). Fig. 1) during the Middle Albian the hoplitids The stratigraphically most important species in migrated from Western Europe through the platform the fauna are: Douvilleiceras mammillatum areas of Poland (from the north and northwest to the (SCHLOTHEIM) from the Lower Albian, Hoplites (H.) southeast) through the Danish-Polish Trough to the dentatus (SOWERBY) and Anahoplites splendens Russian Platform and via Lwow area into the (SOWERBY) from the Middle Albian, and Carpathian region. Dipoloceras cristatum (DELUC) and Hysteroceras orbignyi (SPATH) from the Upper Albian. New collections from Mokrâ Diera Cave in Slovakia (RAKÛS et alii, in press) have added the species ACKNOWLEDGEMENTS . Tegoceras gladiator (BAYLE), Sonneratia cf.dutempleana (D'ORBIGNY) and ?Rossalites sp. The author is much indebted to the ALEXANDER Especially from the palaeobiogeographical point VON HUMBOLDT Foundation for supporting my of view it is interesting to note that together with research work at the University of Tubingen and to Mediterranean ammonites also hoplitids occur in Prof. Dr. P. F. RAWSON (London) for his comments to the Middle Albian of the High Tatra area while in my manuscript and valuable advices. APTIAN AND ALBIAN AMMONITES IN THE WESTERN CARPATHIANS 171
REFERENCES position of the "Skalica Breccia". Geol. Zbor. Geol. carpalh. 35: 559-581, Bratislava.
ANDRUSOV D. ( 1931 ) - Sur la subdivision stratigraphique du Crétacé RAKÙ5 M., VAsÌCEK Z. & PAVLARCÌK S. (in press) - Albian ammonites inférieur de la nappe subtatrique inférieure de la Slovaquie from the Mokrâ diera Cave in Javorovà Valley (Tatric. High centrale. Vest. St. geol. Ûst. Cs. Republ. 7: 152-160, Praha [in Taira). Miner, slov., Bratislava. Czech wiOi French summary], STUR D. (1860) - Bericht tiber die geologische Ùbersichtaufnahme IlAsKO J. & POIAK M. (1979) - Explanations to the geological map of des Wassegebietes de Waag und Neutra. Jb. K.-k. geol. the Kysucké vrchy Hills and Krivân part of the Mala Fatra Mts. Reichsanst. 11:17-151, Wien. D. Slur's Geol. Inst.: 1-145, Bratislava [in Slovak with English summary]. STUR D. (1868) - Bericht iiber die geologische Aufnahme im oberen Waag- und Gran-Thale. Jb. K.-k. geol. Reichsanst. 18: 337-425, I.IEBUS A. & UHLIG V. (1902) - Ober einige Fossilien aus der Wien. karpathischen Kreide. Beitr. Palàont. Geol. Òsterr.-Ung. 14: 113- 130, Wien - Leipzig. VAsÌCEK Z. (1972) - Ammonoidea of the Tisin-Hradisti Formation (Lower Cretaceous) in the Moravskoslezské Beskydy Mts. Rozpr. MARCINOWSKI R. & WIEDMANN J. (1985) - The Albian ammonite Uslr. List. geol. 38: 1-103, Praha. fauna of Poland and its paleogeographical significance. Acta geol. polon. 35: 199-219, Warszawa. VAsÌCEK Z. (1973) - Zur Barreme-Apt-Grenze in der Schlesischen Einheit. Sbor. ved. Praci Vys. Sk. bàò., R. hom.-gcol. 18: 101-107, MARCINOWSKI R. & WIEDMANN J. (1988) - Paleogeographic Ostrava. implications of the Albian ammonite faunas of Poland. In: Wiedmann J. & Kullmann J. (eds.) Cephalopods - Present and Past: VAstCEKZ., MICHALÌK J. & REHÀKOVÂ D. (1994) - Early Cretaceous 491-504, Stuttgart. stratigraphy, paleogeography and life in the Western Carpathians. Beringeria, 10: 3-169, Wurzburg. MARONOWSKI R. & WIEDMANN J. (1990) - The Albian ammonites of Poland. Palaeont. polon. 50: 3-94, Warszawa - Kraków. VAsÌCEK Z. & RAKÙS M. (1993) - Upper Albian Ammonoidea from MhTJCIK E. (Ed.) et alii (1983) - Geology of the Moravskoslezské the PovaOsky Chlmec locality near Dilina (Klape Unit. Klippen Heskydy Mts. and the Podbeskydskà pahorkatina Upland. Zone, Slovakia). Zâpad. Karpaty, Sér. Paleonl. 17: 41-56, Acadcmia: 1-304, Praha [in Czech with English summary]. Bratislava.
MKT I AI. JK J. & VASÌCEK Z. (1984) - On the early- and mid-Cretaceous VAsÌCEK Z. & RAKÙS M. (this volume) - Lower Aptian ammonites in West Carpathian development: the age and environmental Medziholie locality (the Mala Fatra Mts., Slovakia). Mem. Descr. Carla Geol. d 'It. 1.1(1995), pp. 173-183
Lower Aptian Ammonites from the Medziholie locality (the Mala Fatra Mountains, Slovakia)
Ammoniti delVAptiano inferiore della località di Medziholie (Monti Mala Fatra, Slovacchia)
ZDENEK VASICEK (*) & MILOS RAKÛS (**)
IGCP Projects 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - During the last geological mapping in the Mala Fatra RIASSUNTO - Nel corso dell'ultima campagna di cartografia geologica Mountains in Hie region of Medziholie Saddle, a macrofaunistic horizon in nelle Montagne Mala Fatra, nella regione della Sella Medkiholie, è stalo the marly deposits of the Pâmica Formation, which was reported earlier by riscoperto un orizzonte con macrofauna nei depositi marnosi della ANDRUSOV, has been rediscovered. Except for tiny gastropods and Formazione Pâmica. precedentemente descritto da ANDRUSOV. Salvo bivalves found on the Medziholie locality, also ammonites (often with piccoli gasteropodi e bivalvi, rinvenuti nella località Medkiholie. sono preserved suture-lines) occur here more frequently. Among ammonites we frequenti anche le ammoniti (spesso con le suture conservate). Fra le were able to identity Phylloceras (Hypophylloceras) cypris cypris, ammoniti sono state identificate le specie Phylloceras (Hypophylloceras) Macroscaphites striatisulcatus, Costidiscus tenuistriatus, Melchiorites cypris cypris, Macroscaphites striatisulcatus, Costidiscus tenuistriatus, cf. emerici and Deshayesites sp. Most probably M. striatisulcatus and C. Melchiorites cf. emerici e Deshayesites sp. Molto probabilmente, M. tenuistriatus form a dimorphic pair. The determined ammonite striatisulcatus e C. tenuistriatus costituiscono una coppia dimorfica. association is richer than the assemblage cited by ANDRUSOV except for L'associazione ad ammoniti determinata è più ricca di quella citata da Cheloniceras cornuelianum which occurrence was not verified. The ANDRUSOV, con l'eccezione di Cheloniceras cornuelianum, la cui locality mentioned here is the unique Lower Aptian ammonite locality in presenza non è stata verificata. La località in esame è l'unica, nell'intera the whole Central Western Carpathians. parte centrale dei Carpazi occidentali, dove sono presenti ammoniti dell'Aptiano inferiore.
KEY-WORDS. Slovakia, Central Western Carpathians, Fatric, PAROLE CHIAVE: Slovacchia. Carpazi occidentali centrali, Fatricum. I ,ower Aptian, ammonites, taxonomy. Aptiano inferiore, ammoniti, tassonomia.
(*) Katedra geologie, mineralogie a geochemie, VSB, Tr. 17. listopadu, 708 33 Ostrava-Poruba, the Czech Republic; (»*) GÛDS. Mlynskâ dolina 1, 817 04 Bratislava, the Slovak Republic 174 VASÌCEK Z. - RAKIJSM.
1. - INTRODUCTION Pârnica Formation (HAUER, 1872) which are very poor in macrofossil content. The succession of the whole Building new forest approaches from the valley in strata in the Krizna Nappe ends in the flysch deposits the direction from Velkâ Lucivnâ (the north of Pârnica) belonging to the Albian. in the Mala Fatra Mountains (the Western Carpathians) From the Pârnica Formation, however, without any to the burned-out chalet in the Medziholie Saddle below precise localization under the name Medziholie the Velky Rozsutec Mount, a significant nearly complete ANDRUSOV (1931) mentioned the occurrence of profile through the KriLlna Nappe was discovered. macrofauna especially of pyritized ammonites. Predominantly Triassic and Jurassic carbonate deposits Cheloniceras cornuelianum (D'ORBIGNY), the guide of the Krizna Nappe (belonging to the Fatric tectonic species of the Lower Aptian. has the highest unit in the central part of Western Carpathians) around stratigraphical value among all ammonites cited by the Jurassic\Crelaceous boundary pass into marly Andrusov (Costidiscus recticostatus microcostatus limestone succession of strata, formerly simply (SIMONOVICH, BACEVICH & SOROKIN), Macroscaphites designated as Neocomian. On the basis of the data yvani afra SAYN, Desmoceras (Puzosia) sp.). However, available so far (VASICEK, 1991) the prevailing part of these ammonites have never been described more these deposits belongs to the fossiliferous Mràznica precisely or at least figured and that have most probably Formation. In the profile under study the Mràznica got lost during the time. SCHEIBNEROVÂ (1962) studied Formation ends below the Medziholie saddle in the the benlhic and planctonic foraminiferas of this locality Upper Barremian, which is proved by the occurrence of and proposed the same age for these deposits. Costidiscus recticostatus (D'ORBIGNY) and Barremites Similar new occurrences of bivalves, gastropods and sp. in the last limestone layers. The Mràznica Formation ammonites of small dimensions found during geological is in overlying stratum gradually replaced by a set of mapping in the Medziholie area are given by HASKO & dark-grey deposits which are bare in numerous erosion- POLAK (1979). The layer with fossils is situated in one of rills and gullies in the wider surroundings of the above the erosion-rills on the Pârnica Formation, which mentioned chalet. These deposits correspond to the topographical position is indicated in Fig. 1. It is
Fig. 1 - Location of the Medziholie locality. An asterisk indicates the location of the fossiliferous layer. - Ubicazione della località Medziholie. La posizione dello strato fossilifero è indicata dall'asterisco. LOWER APTIAN AMMONITES FROM SLOVAKIA 175 situated approximately 850 m SE of key point 1610 (the stage any tetraphylloid saddles, which are typical of Velky Rozsutec Mount). It is either identical or at least adult shells of the given phylloceratid group. near to the ANDRUSOV'S locality (1931). The present OCCURRENCE - The mentioned subspecies ranges paper describes the ammonites of the HASKO & POLÂK from the Aptian up to the Upper Albian. (1979) collection, which predominantly contains fragments and often also partly deformed fine ORDER Lytoceratida HYATT, 1889 limonitized molds, frequently with preserved suture- SUBORDER Lytoceratina HYATT, 1889 lines. SUPERFAMILY Lytocerataceae NEUMAYR, 1875 FAMILY Macroscaphitidae HYATT, 1900
2. - TAXONOMY GENUS Macroscaphites MEEK, 1876 TYPE SPECIES: Scaphitesyvani Puzos, 1831 The following abbreviations are used for the dimensional parameters of the ammonite shells Macroscaphites striatisulcatus (D'ORBIGNY, 1841) (measured in mm): D = diameter, H = whorl height, W PI. 1. fig. 3-7
= whorl width, O = umbilical diameter. The suture 1841 Ammonites striatisulcatus ÛOimaNY, P. 153, PI. 49, FIG4-7 . symbols arc used according to WEDEKIND'S suture 1976 Macroscaphites yvani striatisulcatus (D'ORBIGNY); terminology (see KULLMANN & WIEDMANN, 1970): E - AVRAM, P. 23, PL. 1, FIG. 8, 9, 12 (cum syn.). external lobe, L - lateral lobe, U - umbilical lobe, I - internal lobe. DESCRIPTION - Evolute shells with whorls which are wider than their height is. Flanks of whorls are at first ORDER Phylloceratida ARKELL, 1950 low, later somewhat higher and rounded. The ventral SUPER FAMILY Phyllocerataceae ZLTTEL, 1884 side is slightly convex, not very wide. The sculpture of FAMILY Phylloceratidae ZITTEL, 1884 the early whorls, which may be seen at the diameter of approximately 3 mm, consists of relatively sparse GENUS Phylloceras SUESS, 1865 tubercles situated exactly at the middle part of low, TYPE SPECIES: Ammonites heterophyllus SOWERBY, strong rounded whorls. From each tubercle undistinct 1820 ribs are running to the umbilicus. The ventral side is smooth. Once the shell reaches the diameter of 7 mm, its SUBGENUS Hypophylloceras SALFELD, 1924 outer part is covered with densely spaced thin ribs, while TYPE SPECIES: Philloceras ononense STANTON, 1895 the tubercles typical of the juvenile shell, have disappeared. The sculpture of further whorls consists of Phylloceras (Hypophylloceras) cypris cypris (FALLOT & densely spaced, thin, prorsiradiate ribs, while the simple TERMIER, 1923) and bifurcated ribs alternate regularly. The ribs are Pl. 1, fig. 1-2; Fig. 2 bifurcated at flanks. There are 2-3 constrictions per whorl; they are slightly developed at the inner whorls. 1964 Phylloceras (Hypophylloceras) cypris cypris FALLOT & The outer part of not complete suture-line is strongly TERMIER; WIEDMANN, P. 215, PI. 12, FIG. 8; PI. 13, FIG. 3; diverging, as in Costidiscus tenuistriatus (REPELIN) - PI. 14, FIG. 1, TEXT-FIG. 50 (cum syn.) Fig. 3a. MATERIAL - Three shells of various stages of growth DESCRIPTION - Internal whorls with bloom-out lacking the hook (spec. GUDS 1537-9) and one sections. The height of the whorls increases with the fragment of a whorl (spec. GUDS 1540). The outer part increase of the diameter. The last preserved whorl bears of the suture-line is preserved on this fragment. convex, relatively high flanks passing continuously into MEASUREMENTS - The best preserved, however partly rather narrow, strongly convex ventral side. The deformed specimens have the following dimensions: umbilicus is narrow. Densely spaced fine and convex SPEC D H W O H/W ribs, which are separated by narrow and shallow grooves 1538 10.5 3.4(0.32) 5.8(0.55) 4.7 (0.44) 0.58 into partial beams, are seen on the mold. The whorl 1539 23.5 6.5 (0.28) =.11 (0.48) = 11.5 - fragment corresponds to the shell diameter of (0.49) approximately 18 mm (H/W = 1.4). Suture-line (Fig. 2) with diphylloid saddles. REMARKS - Macroscaphites striatisulcatus, closely MATERIAL - Unique fragment of phragmocone with related to M. yvani (Puzos), is characterized by its sections of younger whorls (spec. GUDS 1536). smaller size. The diameter of the coiled part of the REMARKS - Because of the subtrigonal cross-section former species exceeds only exceptionally 30 mm, while of the last whorl, we identify our specimen as a typical in the case of the latter species, it exceeds 40 mm. subspecies and not as P. (H.) cypris cytherae Comparing the similar Costidiscus tenuistriatus WIEDMANN, 1964, which differs in bearing subparallel (REPELIN), which occurs together with M. whorl flanks, i.e. a different whorl section. Because of striatisulcatus, the last one differs in the more the juvenile age of the shell, the suture-line lacks at this outstanding width of whorls. 176 VASICEKZ. - RAKUSM.
OCCURRENCE - According to AVRAM (1976), M. regularly. The biggest fragment of the adult whorl, which striatisulcatus is reported from the Lower Aptian in still belongs to the phragmocone, is more sparsely ribbed France, Rumania, Crimea and Caucasus. with blunt and wider ribs than in the previous stages. SUTURE - LINE - On the spec: GUDS 1543 not only the GENUS Costidiscus UHLIG, 1882 outer part of suture-line but also the inner suture-line arc TYPE SPECIES: Ammonites recticostatus D'ORBIGNY, preserved. The whole suture-line is strongly divided 1841 (Fig. 3a,b). On the broad ventral side broad lobes E and L are situated as well as two lateral saddles. The outer Costidiscus tenuistriatus (REPELIN, 1899) lobe consists of a relatively low secondary oblong saddle. Pl. 1, fig. 8-16; Fig. 3a,b The umbilical lobes (UI, U2) near the coiling line are only imperfectly preserved. The lobe I is relatively 1899 Lyioceras tenuistriatum n. sp., REPELIN, p. 362, pi. 7, fig. 5. narrow and deep. Its basal restriction is not visible. MATERIAL - One well preserved limonitized juvenile external mold (spec. GUDS 1541) and two fragments of DESCRIPTION - Evolute shell with thick whorls with a adult whorls, both with suture-lines (spec. GUDS 1542- coronate cross-section. The flanks of the juvenile whorls are 3). reduced to a narrow zone of maximal convexity of the MEASUREMENTS - Only on one well preserved whorl. Umbilicus is deep, funnel-like; ventral side is wide, juvenile specimen (GUDS 1541) of maximal diameter flatly convex. The sculpture of juvenile whorls consists of 8.5 mm all parameters are measurable. simple, strongly prorsiradiate ribs initiating nearby umbilicus. The ribs end in the middle part of low whorls Spec D H W O H/W with tubercles. The ventral area is smooth. At the diameter 1541 8.5 2.9 (0.34) 5.4(0.64) 3.2 (0.38) 0.54 of about 5 mm the ribs are getting weaker and the tubercles 1542 - 4.7 7.5 - 0.63 are gradually disappearing. From each tubercle two thin ribs 1543 - 8.2 12.6 0.65 bifurcate in the direction to ventral side and then disappear very quickly so that the central part of venter remains REMARKS - The above given species determined by smooth. At the diameter of 7 mm, the first shallow REPELIN at the end of the last century remained rather constriction appears. Behind it the coronate whorl-section unknown. It is typical for its thick whorls which have becomes weak, the ribs are generally thinner and run the same aspect also in the adult stage. We can exclude through the whole whorl. Between the bifurcated ribs, some that the shell becomes uncoiled and develops a hook simple ribs begin to occur. Before passing the quarter- (which is typical for genus Macroscaphites). Thus we whorl, another weak constriction occurs. On the fragment of refer the material described here to the genus the more adult whorl the thin-ribbed sculpture continues, Costidiscus. As C. tenuistriatus occurs together with M. while bifurcated and simple ribs alternate more or less striatisulcatus, we suppose that they form a dimorphic l'ig. 3 - Suture-lines of Costidiscus tenuistriatus (REFEUN). a): outer suture at H - 8.3 mm; b): inner suture at H = 8.3 mm (spec. GUDS 1543). - Linee di sutura di Costidiscus tenuistriatus (REPEUN). a): sutura esterna ad H = 8.3 mm; b): sutura interna ad H = 8.3 mm (spec. GUDS 1543). 178 VASlCEKZ. - RAKUSM. pair, according to the AVRAM'S (1984) data about the Deshayesites sp. ind. dimorphismus of the other species of Costidiscus and Pl. 1, fig. 17-18; Fig. 4 Macroscaphites. The mentioned dimorphic combination does not coincide with the previous older AVRAM'S DESCRIPTION - Semiinvolute to semievolute shell opinion (1976, p. 23). In fact this author considered C. with relatively low whorl. Slightly convex whorl flanks recticostatus n. ssp. and M. striatisulcatus _ as a which converge to the ventral side. The venter is dimorphic pair. relatively narrow and rounded. The fragment has The adult whorls of Costidiscus tenuistriatus are distinct round ribs with interspaces corresponding to the similar to the sculpture of C. grebenianus (TIETZE, 1872, rib thickness. The ribs are slightly sigmoidal, on the pi. 8, fig. 8). However, the whorl-sectiòn of the TIETZE'S venter prorsiradiate. Both simple and bifurcated ribs arc species is opposite because the whorls are evidently distinctly observed, the bifurcation appearing at about higher than their width. KILIAN & REBOUL (1915) the half height of the whorl. At the ventrolateral margin suppose that C. grebenianus could be a dimorphic pair the ribs are slightly thickened. However, behind them with M. striatisulcatus. However, because of the the ribs are feeble (but without any interruption) and different whorl-section this docs not seem to be pass into the venter forming a distinct bow. probable. SUTURE - UNE - Incomplete outer suture-line (Fig. 4) Because of the ribbing style of our biggest fragment, with lobes E and L of approximately the same depths. ANDRUSOV (1931) probably identified the specimens of The outer lobe carries a relatively high secondary saddle, C. tenuistriatus as Macroscaphites yvani afra (SAYN). the lateral lobe is wide, only relatively slightly divided However, this subspecies is characterized by a different and distinctly asymmetric. whorl-section (see SAYN, 1891, pi. 1, fig. 9 b). MATERIAL - One fragment of 1/8 whorl of a DISTRIBUTION - For the holotype of C. tenuistriatus limonitized internal mold with undistinctly preserved REPELIN (1899) gives the Aptian deposits with suture-lines (spec. GUDS 1544). Aconeceras nisum and Dufrenoya furcata near MEASUREMENTS - On the specimen figured in pl. 1, Marseille. fig. 17: H = 8.5 mm, W = 6.2 (W/H = 0.73). REMARKS - In spite of the fact that the fragment is considerably incomplete, on the basis of the sculpture SUBORDER Ancyloceratina WIEDMANN. 1966 and the characteristic of the suture-linc, we may SUPERFAMILY Douvilleicerataceae PARONA & consider that it belongs to the genus Deshayesites. BONARELLI. 1897 However, it is impossible to identify the species. FAMILY Deshayesitidae STOYANOW, 1949 DISTRIBUTION - The genus Deshayesites occurs in the Lower Aptian. GENUS Deshayesites KASANSKY. 1914 TYPE SPECIES: Ammonites deshayesi LEYMERIE in ORDER Ammonitida HYATT, 1889 D'ORBIGNY, 1841 SUPERFAMILY Desmoccrataceae ZITTEL, 1895
Fig. 4 - Fragmentary suture-line of Deshayesites sp. at H = 8.5 mm. - Linea di sutura incompleta di Deshayesites sp. ad H = 8.5 mm. LOWER APTIAN AMMONITES FROM SLOVAKIA 179
FAMILY Desmoceratidae ZITTEL, 1895 as L. E carries median saddle reaching about 1/3 of its SUBFAMILY Puzosiinae SPATH, 1922 height, L is trifid, rather asymmetric. is of a half depth if compared with L and is distinctly asymmetric, GENUS Melchìorites SPATH, 1923 slightly trifid. Axis U3 is obliquely sloped. This lobe is TYPE SPECIES: Ammonites melchioris TlETZE, 1872 trifid and only slightly divided. The first lateral saddle is bipartit, asymmetric, the outer branch being stronger, Melchìorites cf. emerici (RASPAIL. 1831) the second one is similar but with a stronger inner PI. 1, fig. 19-20; Fig. 5 branch. The third saddle is the smallest one, bipartit and nearly symmetrical. 1841 Ammonites Emerici RASPAIL; D'ORBIGNY, p. 160, pi. 51, fig. MATERIAL - Two whorl fragments. The first is badly 1-3 1968 Melchìorites emerici (RASPAIL); WIEDMANN & DIENI, p. preserved as internal mold with partially preserved 109, pi. 10, fig. 5 {cum syn.) suture-lines (spec. GUDS 1545) and the second as external mold. DESCRIPTION - Semiinvolute shells with relatively MEASUREMENTS - The diameter of the spec. GUDS wide whorls of medium height. The flanks are rounded, 1945 may be estimated to 20 mm. By H = 7.5, W = 6.5 their maximum width being approximately at the lower (W/H = 0.86). third of the whorl height. The umbilical area is not REMARKS - According to the whorl-section and preserved. Towards the venter, which is relatively constrictions as well as the suture-lines, we may suppose narrow and rounded, the whorl gradually becomes that the specimens belong to Melchìorites. As the shells narrow. The whorls have relatively sparse S-shaped ribs are incomplete, the species cannot be unambiguously accompanying shallow constrictions making the ribs determined. However, because of the relatively wide more prominent. Both ribs and constrictions are sloped whorls, it is much more probable they belong to M. forward on the ventral side; they cross it forming a bow. enterici as M. melchioris (TlETZE). There are 3-4 constrictions on a quarter of whorl. DISTRIBUTION - Typical representatives of M. emerici SUTURE - UNE - The nearly complete outer suture-line are mainly reported from the Lower Aptian in France. (Fig. 5) has the lobe E of approximately the same depth Spain, Sardinia and Balearic Islands.
Fig. 5 - Outer suture-line olMelchiorites cf. emerici (RASPAIL). a): suture at H = 7.2 mm; b): al H = 6.7 mm (spec. GUDS 1545). - Linea di sutura esterna di Melchioriles cf. emerici (RAS'AIL): a): ad H = 7.2 mm; b): ad H = 6.7. mm (spec. GUDS 1545). 180 VASÌCEKZ. - RAKÙSM.
3. - CONCLUSIONS collaboration, to K. MEZIHORÂKOVÂ (Ostrava) and D. KORN (Tubingen) for the good quality of the In a relatively small collection containing photographs and B. VAVRUSÂKOVÂ (Ostrava) for the predominantly only fragments of ammonite shells, but drawings. The authors are indebted to Dr. F. CECCA for often with preserved suture-lines, we were able to the critical reading of the manuscript and for his determine the following ammonites: Phylloceras comments. (Hypophylloceras) cypris cypris FALLOT & TERMIER, Macroscaphiies striatisulcatus (D'ORBIGNY), Costidiscus tenuistriatus (REPELIN), Melchìorites cf. emerici (RASPAIL), Deshayesites sp. ind. Also a tiny and REFERENCES precisely undeterminable fragment of heteromorph shell belong to this collection; it may be regarded as a ANDRU30V D. (1931) - Sur la subdivision stratigraphique du Crétacé representative of the group Toxoceratoides SPATH, 1924. inférieur de la nappe subtatrique inférieure de la Slovaquie According to ANDRUSOV'S data (1931), also centrale. Vest. St. geol. Ûst. Cs. Republ. 7: 152-160, Praha [in Czech Cheloniceras (C.) cornuelianum (D'ORBIGNY) is grouped with French summary]. to his ammonite collection. From the given ammonite assemblage Deshayesites ANDRUSOV D. (1959) - Geology of the Czechoslovak Carpathians, II. sp. and C. cornuelianum have the highest stratigraphie pp. 375 SAV, Bratislava [in Slovak]. value (however, in case of C. cornuelianum we must suppose that Andrusov's determination was correct). AVRAM E. (1976) - Les fossiles du fly sch éocrétacé et des Considering the general characteristic of the Lower calcaires tithoniques des hautes vallées de la Doftana et du Tirlung (Carpathes Orientales). Mém. Inst. géol. géoph. 24: 5- Cretaceous in the Mediterranean area (NIKOLOV, 1987) 73, Bucuresti. and respecting the zonal scheme proposed for the Aptian in the Mediterranean region (HOEDEMAEKER & BULOT, AVRAM E. (1984) - Correspondent species of the genera 1990; Company, HOEDEMAEKER et alii, 1993), the Macroscaphiies MEEK and Costidiscus UHUG. Spec. Vol. "75 years limonitized (originally pyrilized) ammonites from the lab. paleont.": 67-80, Bucuresti. Medziholie belong unambiguously to the Lower Aptian.
To the proposal for the Lower Aptian ammonite CASEY R. (1961) - A monograph of the Ammonoidea of the Lower zones (from top to bottom): Greensand, III. Palaeontogr. Soc. 115: 119-216, London. Dufrenoya furcata Deshayesites deshayesi HAsKO J. & POLÀK M. (1979) - Explanations to the geological map of Deshayesites weissi Kysucké vrchy Mts. and Krivân Mala Fatra Mts.: pp. 145 GÙDS, Bratislava [in Slovak], Deshayesites tuarkyricus it is suitable to note that the first occurrences of genera HOEDEMAEKER P. J. & BULOT L. (1990) - Preliminary ammonite Prodeshayesites CASEY and Procheloniceras SPATH zonation for the Lower Cretaceous of the mediterranean region. characterize much better the base of the Middle and Géol. alpine 66: 109-112, Grenoble. West European Aptian than the occurrence of Deshayesites tuarkyricus Tovbina proposed as a zonal HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. index which is only imperfectly known in Europe. As to B., AVRAM E., BOODANOVAT. N„ BUTrOR L., BULOT L., CECCA F., DELANOY G., ETTACHFTNI M., MEMMI L., OWEN H. G., RAWSON P. our opinion this suggestion should be replaced by F., SANDOVAL J., TA VERA J. M., THIEULOY J.-P., TOVHNA S. Z. & another more suitable zonal species, preferably of the VAsÌCEK Z. (1993) - Ammonite zonation for the Lower Cretaceous genus Prodeshayesites (as Procheloniceras seems to be of the Mediterranean region; basis for the stratigraphie less frequent). correlations within IGCP-Project 262. Rev. Espanda Paleont., 8 (1): 117-120, 1 tabi, Madrid. With respect to our data, because representantives of genus Dufrenoya BURCKHARDT are absent and especially HAUER F. ( 1872) - Geologische Obersichtskarte der Òsterreichischen- because of the Cheloniceras cornuelianum occurrence in Ungarischen Monarchie, Blatt IX. XI. XII. Jahrb. geol. Reichsanst. the Deshayesites deshayesi and Tropaeum bowerbanki 22: 149-228, Wien. Zones- according to CASEY (1961, p. 208), the fossiliferous deposits on the Medziholie locality probably KILIAN W. & REBOUL P. (1915) - La faune de l'Aptien inférieur des correspond to the range around the D. deshayesi Zone. environs de Montélimar (Drome). Mém. Expl. Carte géol. France: This is, in fact, the only Lower Aptian ammonite locality pp. 221, Paris. in the whole Slovak Central Western Carpathians.
KULLMANN J. & WIEDMANN J. (1970) - Significance of sutures in phytogeny of Ammonoides. Univ. Kansas, paleont. Contr. 47: 1-32, ACKNOWLEDGEMENTS. I^awrence.
Both authors are indebted to the Alexander VON NIKOLOV T.G. (1987) - The mediterranean Lower Cretaceous. HUMBOLDT Foundation for support and facilitating our Geologica balcan., Ser. op. sing. 2: pp. 261, Sofia. LOWER APTIAN AMMONITES FROM SLOVAKIA 181
ORBIGNY A. D' (1840-1842) - Paléontologie française. Terrain Crétacés TIETZE E. (1872) - Geologische und palâontologische Mittheilungen I. Céphalopodes, pp. 662, 148 pis. Masson, Paris. aus dem siidlichen Theile des Banater Gebirgstockes. Jb. Geol. Reichsanst. 20: 35-142, Wien. REPELIN J. (1899) - Note sur I 'Aptien supérieur des environs de Marseille. Bull. Soc. géol. France, III, 27: 363-373, Paris. VAsICEK Z. (1991) - Cephalopod biostratigraphy of the Lower Cretaceous deposits in the Czechoslovak Western Carpathians. Thesis: 1-138. Ostrava - Bratislava [in Czech]. SAYN G. (1891) - Description des Ammonitides du Barrémien du Djebel-Ouach près Constantine. Ann. Soc. Agric. Hist. Nat. et Arts WIEDMANN J.(1964) - Unterkreide-Ammoniten von Mallorca. II. utiles. (1890): 1-78, Lyon. Phylloceratina. Abh. Akad. Wiss. Lit., math.-naturwiss. Kl. (Mainz) 4: 160-264, Wiesbaden. SCHEIBNEROVÀ V. (1962) - Aptian microfauna from the Medziholie Pass below Mt Rozsutec in the Mala Fatra Mts. Geol. Sbor. Slov. WIEDMANN J. & DENI I. (1968) - Die Kreide Sardiniens und ihre Akad. Vied 13: 129-134, Bratislava [in Slovak]. Cephalopoden. Paleontogr. italica 114: 1-171, Pisa. 182 VASlCEKZ. - RAKIJSM.
PLATE 1
Fig. 1,2- Phylloceras (Hypophylloceras) cypris cypris (FALLOT & TERMIER), x 2. 1, lateral view; 2, whorl-section (spec. GUDS 1536). Fig. 3-7 - Macroscaphites striatisulcatus (D'ORBIGNY). 3-5, lateral view, whorl-section, view of the ventral area - all x 4 (spec. GUDS 1537); 6, lateral view, x 2 (spec. GUDS 1538); 7, lateral view, x 1 (spec. GUDS 1539). Fig. 8-16 - Costidiscus tenuistriatus (REPELIN). 8-9, lateral view (fig. 8x3- fig. 9 x 4); 10, whorl-section, x 4; 11, view of the ventral area, x 4 (spec. GUDS 1541); 12-13, lateral view and view of the ventral area, x 3 (SCEC. GUDS 1542); 14, lateral view, x 2; 15, whorl-section, x 2; 16, view of the ventral area, x 2 (spec. GUDS 1543). Fig. 17-18 - Deshayesites sp., x 2. 17, lateral view; 18, whorl-section (spec. GUDS 1544). Fig. 19-20 - Melchiorites cf. emerici (RASPAIL), x 2. 19, lateral view; 20, whorl-section (spec. GUDS 1545). All specimens were bleched with ammonium chlorides and photographed by K. MEZIHORÂKOVÂ (University of Ostrava) and D. KORN - Fig. 3-5 and 9-11 (University of Tubingen). The specimens are deposited at the D. STÛR Institute of Geology in Bratislava under the given numbers.
TAVOLA 1
Fig. 1-2 - Phylloceras (Hypophylloceras) cypris cypris (FALLOT & TERMIER), X 2. 1, norma laterale; 2, sezione della spira (spec. GUDS 1536). Fig. 3-7 - Macroscaphites striatisulcatus (D'ORBIGNY). 3-5, norma laterale, sezione della spira, norma ventrale - tutto x 4 (spec. GUDS 1537); 6, norma laterale, x 2 (spec. GUDS 1538); 7, norma laterale, x 1 (spec. GUDS 1539). Fig. 8-16 - Costidiscus tenuistriatus (REPELIN). 8-9, norma laterale (fig. 8 x3 - fig. 9 x 4); 10, sezione della spira, x 4, 11, norma ventrale, x 4 (spec. GUDS 1541); 12-13, norma laterale e norma ventrale, x 3 (spec. GUDS 1542); 14, norma laterale, x 2; 15, sezione della spira, x 2; 16, norma ventrale, x 2 {spec. GUDS 1543). Fig. 17-18 - Deshayesites sp., x 2. 17, norma laterale; 18, sezione della spira (spec. GUDS 1544). Fig. 19-20 - Melchiorites cf. emerici (RASPAIL), X2. 19, norma laterale, 20, sezione della spira (spec. GUDS 1545). Tutti gli esemplari sono stati cosparsi con sublimato di cloruro d'ammonio e fotografati da K. MEZIHORÂKOVÂ (Università di Ostrava), e D. KORN - Fig. 3-5 e 9.11 (Univesrità di Tubingen). Gli esemplari sono depositati all'Istituto D. STÛR di Geologia a Bratislava con i numeri di inventario indicati.
APPENDIX Mem. Descr. Carta Geol. dit. 1.1 (1995), pp. 187-211
Field-trip across the representative sections for the Upper Hauterivian - Barremian ammonite biostratigraphy in the Maiolica exposed at Monte Nerone, Monte Petrano and Monte Catria (Umbria-Marche Apennines)
Escursione attraverso le sezioni rappresentative per la biostratigrafia ad ammoniti dell'Hauteriviano superiore-Barremiano della Maiolica affiorante a Monte Nerone, Monte Petrano e Monte Catria (Appennino umbro-marchigiano)
FABRIZIO CECCA (*). PAOLO FARAONI (**), AGOSTINO MARINI (***) & GIOVANNI PALLINI (****)
IGCP Projects 343 : Stratigraphie Correlations Basins of Peritelhyan 362: Tethyan and Boreal Cretaceous
ABSTRACT - In this paper we present a part of the geological RIASSUNTO - Si propone in questa nota una parte dell'itinerario delle excursions which were carried out during the 3rd Workshop of the escursioni effettuate nel corso del 3° Workshop del Gruppo di Lavoro International Working Group on Lower Cretaceous Cephalopods. In Intemazionale sui Cefalopodi del Cretaceo inferiore. In particolare si particular are here reported data on recently studied sections in the riportano i dati relativi a quelle sezioni, recentemente studiate nella Maiolica formation of Umbria-Marche Apennines providing significant formazione della Maiolica dell'Appennino Umbro-Marchigiano, rivelatesi information for the ammonite biostratigraphy of the Upper Hauterivian - utili per la biostratigrafia ad ammoniti dell'intervallo Hauteriviano Barremian interval. superiore-Barremiano.
KEY WORDS: Ammonites, Biostratigraphy, Lower Cretaceous, PAROLH CHIAVE: Ammoniti, Biostratigrafia, Cretaceo inferiore, Hauterivian, Barremian, Umbria-Marche Apennines. Hauteriviano, Barremiano, Appennino Umbro-Marchigiano.
(*) Servizio Geologico Nazionale Largo S. Susanna 13,1-00187 Roma, ITALY (**) via Secchiano 16,1-61043 Cagli, ITALY (***) via Venezia 42.1-61043 Cagli ITALY
(****) Università "La Sapienza". Dip. Scienze della Terra, piazzale Aldo Moro 5, 1-00185 Roma ITALY
F. C. is responsible for the palaeontologic identifications and the biostratigraphic interpretation. 188 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
1. - INTRODUCTION Maiolica of the basin succession. The ammonites are here very rare and scattered in the sequence. In this work we present a condensed version of the Nevertheless, they allow some interesting correlations "Excursion guide-book" which was distributed to the between different stratigraphie scales. Calpionellids are participants of the 3rd Workshop of the Lower represented in both types of Maiolica. Cretaceous Cephalopods Team. The data on the In some PCP sections is possible to recognize a Hauterivian-Barremian outcrops are presented here hiatus (see 4.2.3.) between the Upper Berriasian and the whilst information on the Valanginian ammonite-rich Lower Hauterivian p. p. (MICARELLI et alii, 1977) outcrops and the Mame a Fucoidi sections, which were within the Maiolica. In the basin successions of Maiolica visited during the excursions, have been already exposed numerous slumpings are intercalated in levels whose by CECCA (this volume) and by ERBA et alii (1989) ages are not represented on PCP because of this hiatus. respectively. This allows us to demonstrate that the existence of The sections presented here were discovered during palaeotopographic gradients in the sea bottom persisted recent researches, whose results have been already in the Early Cretaceous (LOWRIE & ALVAREZ, 1984), published partly. Therefore we give here new although they were less pronounced than in the Jurassic. unpublished information and a summary of the most Recently CECCA et alii (1994a) have discovered an important results as well. anoxic level which can be recognized at the regional scale. Because of its stratigraphie isochrony, as well as its peculiar lithologie and palaeontologic characteristics this level was formally defined and named Faraoni Level 2. - PREVIOUS WORKS and it is the older anoxic level recognized so far from this region (among the other levels the most important Apart a Barremian pulchellid cited by ZITTEL (1869) are the Selli and the Bonarelli Levels). Its age is clearly and a Hauterivian Pseudothurmannia figured by established by means of ammonites: latest Hauterivian, RAMACCIONI (1939), only the occurrence of aptychi was P. angulicostata zone, P. catulloi subzone. It usually cited in the literature from the Maiolica of Umbria- occurs 65-70 metres below the top of the Maiolica. Marche Apennines. Berriasian and Valanginian However this distance is greater (85 m) in the southern ammonites were figured for the first time by CECCA outcrops. Due to the thickness of this level, ranging from (1985). Recently, numerous Upper Hauterivian - 25 to 40 cm, its identification and consequently its Barremian ammonite levels have been discovered detailed stratigraphie analysis strongly depends on the (BARTOLOCCI et alii, 1993; CECCA et alii, 1994a,b; exposure in the field. CECCA & PALLINI, in press) and also the occurrence of Because of the gradual lithologie transition from the bivalves and gastropods is now demonstrated (CECCA & Maiolica to the overlying Marne a Fucoidi, the boundary PALLINI, in press). between these two formations has been conventionally established in coincidence with the last black chert level (COCCIONI et alii, 1987). 3. - THE MAIOLICA FORMATION (LATE TITHON1AN - EARLY APTIAN p. p.) 4. - THE HAUTERIVIAN - BARREMIAN OUTCROPS
This formation consists mainly of medium bedded The visit of the outcrops is organised following five white micrites with thin interbedded dark pelites, whose different directions (Tab. 1): frequency and thickness increase markedly towards the contact with the overlying Marne a Fucoidi, and nodules 1) Gorgo a Cerbara - Sette Vene, along the road ss and layers of dark chert. These are the characteristics of 257 from Acqualagna to Città di Castello with two stops the Maiolica deposited in the basins surrounding the at Gorgo a Cerbara (km 41.8) and Sette Vene (km 33.7) Jurassic structural highs, or pelagic carbonate platforms localities (8 km); (PCP) sensu SANTANTONIO (1993; 1994). White to light 2) Piobbico - Monte Nerone-Pieia, with four stops at brown nodular limestones and yellowish brown Ranchi, Campo al Bello, Fosso Bugarone and Pieia (25 saccharoidal dolomitized limestones characterize the km); first portion of the Maiolica deposited on the Jurassic PCP. Its thickness varies from 40-80 metres on PCP up 3) Pianello - Secchiano, with two stops, at the Bosso to 450 metres in basin areas. section, along the road lo Cagli, and at Stirpeto (12 km), There are marked differences in the fossil 4) Cagli - Monte Petrano, with two stops, along the associations of the basin and PCP types of Maiolica. In northernn flank of the mountain and along the road (9 the lower part of the latter there are ammonites that are km); locally abundant (CECCA, 1985; CECCA et alii, 1990), 5) Cagli - Chiaserna, with two stops along the road brachiopods, gastropods and echinoid fragments. These to Monte Acuto and another one on the road from there macrofossils are absent or rare in the equivalent to Chiaserna (30 km). ce Tab. 1 - Itinerary of the field-trip on representative sections for Upper Hauterivian - Barremian ammonite biostratigraphy. - Itinerario dell'escursione attraverso le sezioni significative per la biostratigrafia ad arnmoniti dell'Hauteriviano superiore - Barremiano. •0 o
oo Tab. 1 - Itinerary of the field-trip on representative sections for Upper Hauterivian - Barremian ammonite biostratigraphy. Itinerario dell'escursione attraverso le sezioni significative per la biostratigrafia ad ammoniti dell'Hauteriviano superiore - Barremiano dis. V. Pennuti HAIJTERIVIAN-BARIIEMIAN AMMONITE BIOSTRATIGRAPHY 191 ] 92 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
4.1.- GORGO A CKRBARA - SETTI; VENE The Lower Cretaceous biostratigraphy based on calcare ous nannofossil succession of this section has been studied by BRAIjOWER (1987) who correlated it with the magnetic 4.1.1 - The Gorgo a Cerbara section: Upper stratigraphy already realized by LOWRIE & ALVAREZ (1984). Hauterivian -Lower Aptian Maiolica COCCIONI et alii (1992) have studied here the uppermost levels of the Maiolica, near the Barremian-Aptian stage The studied section is located 4 km east of the town boundary, correlating calcareous nannofossils, forams and of Piobbico in the bed of the Candigliano river and east magnetozones. CECCA & PALLINI (in print) have studied the of the Monte Nerone. Here the typical Jurassic - Tertiary ammonite distribution and CECCA et alii (1994b) defined Umbria-Marche succession of basin type crops out. In the correlations with the different scales. COCCIONI et alii fact the Maiolica succession at Gorgo a Cerbara is (1994) have analyzed the palynologie content of the Upper characterized by the occurrence of radiolarites as well as Barremian marly interbeds in the upper portion of the numerous levels with gravity deposits (slumps, debris Maiolica. flows etc.).
4.1.1.1. - Ammonites and biostratigra p h y - Figure 1 presents the detailed stratigraphie log with the indication of the fossiliferous beds. Figure 3 summarizes the ammonite occurrences, the ammonite zonation and its correlation with the magnetic chrons recognized by LOWRIE & ALVAREZ. Hauterivian-Barremian boundary - The oldest ammonite was found in bed 277: it has been identified as Subsaynella sp. (pl. 1, fig. 9). In the beds 264-266 at 817.5 m, Crioceratites sp. gr. duvalii LÉVFAU.v/villiersianus (D'ORBIGNY) and Plesiospi tidiscus sp. (pl. 1, fig. 8, 11 respectively) indicate a Late Hauterivian age, earlier than the P. angulicostata auct. zone and this level can be ascribed to the B. balearis or to the P. ligatus zones. The P. angulicostata zone, and particularly the P. catulloi subzone, is very well represented in bed 246 which corresponds to the guide- bed of the Faraoni Level (CECCA el alii, 1994a). The Hauterivian-Barremian boundary falls surely above bed 246, which contains latest Hauterivian faunas, and below beds 198-200 where we collected a typical Barremian Spitidiscus, i. e. an interval between metres 822 and 833 of LOWRIE & ALVAREZ (1984). In the absence of faunas in the latter interval, the boundary is Fig. 2 - The Gorgo a Cerbara section exposed in the bed of the drawn between metres 824 and 828 on the basis of data Candigliano river. M: Maiolica; F: Mame a Fucoidi. Dashed line: last from other sections (Mount Petrano). Then this stage bed of Maiolica. boundary falls in chron CM4 (Fig. 3). - LA SEZIONE DI GORGO A CERBARA ESPOSTA NEL LETTO DEL FIUME CANDIGLIANO. M: MAIOLICA; F: MARNE A FUCOIDI. IL TRATTEGGIO INDICA Lower Barremian - Typical Barremian Spitidiscus I ULTIMO STRATO DELLA MAIOLICA. occur between beds 200-178 but this docs not correspond to the actual Spitidiscus FO (pl. 1, fig.10) . The section has been bed-by-bed numbered starting This interval is assigned to the hugii zone, although no from the base of the Marne a Fucoidi formation (Fig. 1). other significant Ammonitina have been found. At beds The lithologie boundary between the Marne a Fucoidi 151-153 occur specimens of the genus Holcodiscus (pi. and the Maiolica formations is gradational and it has 2, fig. 21), including the zonal index //. caillaudi been placed with the uppermost occurrence of black (D'ORBIGNY). The fauna of beds 142-143 is also chert in the Maiolica limestones (Fig. 2) according to included in the //. caillaudi zone because of the COCCIONI et alii (1987). presence of Subpulchellia cf. changarnieri (SAYN) (pi. The beds have been correlated with the metre 2, fig. 12), which is limited to the Early Barremian numbers used by LOWRIE & ALVAREZ, (1984), which are (VERMEULEN, 1980). No significant faunas have been still visible. Some slumps disturb the normal found in the interval between beds 177 and 154. The sedimentation, thus the ammonites have been collected sediments inbetween could belong partly to the .V. hugii only in the autochthonous sediments. The ammonites arc and H. caillaudi zones and partly to the S. nicklesi zone. usually rare in the Maiolica formation. However, some The Lower Barremian sediments of the Gorgo a Cerbara biostratigraphic units can be recognized. section are included in chron CM3. HAUTERIVIAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 193
Upper Barremian - The Lower/Upper Barremian (which is better visible from km 10.3) of the Jurassic - boundary has been tentatively drawn around bed 130. Lower Cretaceous succession of the PCP type. This Above the faunas of the H. caillaudi zone no ammonites consists of nodular limestones, intensively dolomitized unambiguously typical of the A. vandenheckii zone have in the Middle and Upper Jurassic units, without any been found. Typical Late Barremian ammonites occur at evidences of gravity deposits. There is a thin beds 121-119: Heinzia gr. provincialis (D'ORBIGNY), H. intercalation of "Calcari Diasprigni" (radiolarites), aff. lindigi (KARSTEN in UHLIG) (pi. 2, fig. 8) and which corresponds to an onlap of basin facies (CECCA et Costidiscus sp. cf. recticostatus (D'ORBIGNY) (pi. 3, fig. alii, 1990) between Lower Bajocian (Humphriesianum 14). In beds 84-85 occurs Coroni tes aff. coronatoides Zone) and Upper Kimmeridgian (Cavouri Zone) nodular (SAYN) and in bed 81 we have found Barremites limestones. Lower Kimmeridgian ammonites have been (Cassidoiceras) cf. cassidoides (UHLIG), H. gr. collected in a calcareous level of the radiolarite provincialis, C. aff. hoplitiformis (SAYN) (pi. 2, fig. 5- intercalation. This hiatus is better visible in the 7). The faunas of the beds between beds 130 and 81 are Bugarone quarry (see 4.2.3). then included in the A. vandenheckei zone. The The Maiolica begins with the dolomitized facies (the occurrence of //. sartousi (D'ORBIGNY) in bed 48 clearly so called "Maiolica dolomitica" or "Maiolica nodulare"), indicate the H. sartousi zone; this species is rather which is typical of the PCP's successions. The abundant in bed 43 where it is associated with H. cf. calpionellid succession has been studied (CECCA et alii. ouachensis (SAYN) (pi. 2, fig. 9-11, 17). Above bed 43 1990) around the Tithonian - Berriasian boundary. The ammonites become extremely rare and mainly ammonites are very rare and only Fauriella represented by the Silesites seranonis (D'ORBIGNY) (Strambergella) cf. carpathica (ZlTTEL) and Spiticeras group, which is poorly significant for biostratigraphic gr. groteanum (OPPEL) have been identified. purposes. Above bed 28, i. e. above metre 882, the beds are barren or do not contain significant fossils for Compared to the basin sections as Gorgo a Cerbara, biostratigraphic purposes. A single specimen, identified the thickness of the Maiolica Formation is here reduced as '/'Prodeshayesites sp. was found in bed 5 (pi. 2, fig. to 50 metres. In fact, there is a hiatus in the Lower 25), thus indicating the Lower Aptian. Cretaceous succession of the Monte Nerone PCP sector. This is well exposed in the next stop. In the upper portion of the Maiolica formation black An Upper Barremian section crops out along the marly interbeds occur. Their frequence increases road, just below the base of the Marne a Fucoidi upwards. Formation. The ammonites, mainly lyloceratids and "barremitids" arc rare. The black marly interbeds 4.1.2 - The Apecchiese road: the latest Hauterivian already seen in an equivalent stratigraphie position al Faraoni Level Gorgo a Cerbara section are well exposed and can be easily sampled. Along the road there is a good exposure of the Faraoni Level (Fig. 4). Compared to Gorgo a Cerbara, the succession of white limestones and thin black shales 4.2.3 - The Fosso Bugarone quarry: 25 Ma hiatus in the is clearly visible here. The TOC content reaches 25% in Jurassic section; the hiatus in the Maiolica Formation some interbeds.
From Campo al Bello we reach the locality "Casalino della Fontanella" (at km 12.1 from Acquanera) and we 4.2 - PIOBBICO - MONTE NERONE-PIEIA turn left. The Maiolica formation crops out at the left side of the road to Pianello, whilst the overlying Marne a 4.2.1 - The Faraoni Level at the Ranchi outcrop Fucoidi formation is covered by vegetation. Above the quarry (Fig. 5), Upper Barremian beds with Silesites From Piobbico, and in particular at km 4.8 of the seranonis (D'ORBIGNY) crop out along the road at km road from Acquanera to the top of Monte Nerone in the 12.9 and the Faraoni Level is exposed at km 13.3 locality named "i Ranchi", at the hairpin bend indicated although it is difficult to recognize because the black in Tabi. 1, there is a good exposure of the Faraoni Level. shales lack. The black shales are clearly visible, encompassing the At 13.7 km turn right off the road to Pianello: the ammonite-rich "guide-bed". two quarries of Fig. 6 are open near the "Fosso del Bugarone". Both show the typical PCP Jurassic-Lower 4.2.2 - The Campo al Bello section: the Berriasian- Cretaceous succession. The second quarry is the type Barremian Maiolica resting on to the Jurassic section of the Bugarone Formation (Early Pliensbachian succession of the Monte Nerone Pelagic Carbonate - Tithonian) which includes the pelagic sediments of the Platform (PCP). PCP areas of the Umbria-Marche region. It consists of bioturbated, more or less dolomitized, and at times Below the lop of Monte Nerone, at km 9.5 of the nodular limestones and marly limestones. No radiolarite road from Acquanera there is a spectacular exposure intercalations exist here. Its thickness is 16 metres in the 194 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
GORGO A CERBARA • MARCHE APENNINES
AMMONITE Magnetic ZONES Anomalies Metres Beds
Nannoconid Marne a Fucoidi 895 — "crisis" Maiolica CMO *~ 5 ?Prodeshayesites sp 890 — R. irregularis
885
•28-31 Silesites cf. seranonis Z ? CMln 880 — G. blowi < • 37 Silesites sp. 875 — ' 43 Heinzia sartousi, H. cf. ouachensis, S. seranonis S ' 48 Heinzia sartousi ^ Sartousi 06 870 70 Barremites mueriensis at CMlr G. duboisi Coronites aff. hoplitiformis, Barremites sp. cf. strettostoma < 81 B. (Cassidoiceras) cf. cassidoides 865 — M 84-85 C. cf.coronatoides, Heinzia provincialis AS W CM 2 860 — ^ Vandenheckei 0m 118 Costidiscus cf. nodosostriatus 855 — Il 19 Heinzia sp. aff. lindigi in UHLIG -121 Costidiscus cf. recticostatus, Heinzia sp. gr. provincialis 850 — -130 Barremites gr. diffïcilis, Dissimilites cf. trinodosum -142-143 Subpulchellia cf. changamieri, Karsteniceras subtile, Leptoceratoides pumilus, Astieridiscus sp. 845 — '149-153 Holcodiscus sp.cf. caillaudi, H. cf. fallax, An aff prychocer. -166 Silesites cf. vulpes, Barremites cf. psilotatus <• A A j CM 3 840 — "178 Spitidiscus aff. intermedius G. gottisi 835 — —198-200 Spitidiscus cf. vandenheckii 830 — C oblongata Globigerinelloides 825 — Catulloi Pseudothurmannia mortilleti catulloi, Ps. belimelensis, CM 4 ^ Angulicostata auct. -246 Ps. angulicostata in LAPEYRE. Psilotissotia favrei 820 — -264-266 Plesiospitidiscus sp. \\ TBalearis- Crioceratites sp. gr. duvalii/villiersianus g Ligatus CM 5 815 —
. 277 Subsaynella sp. Sayni CM 6 810 PC I L. bollii W Calcareous Nannofossil events CU Planktonic Foraminiferal occurrences m normal slumps I I reversed I— Ammonite occurrences
Fig. 3 - Ammonite occurrences and correlation with magnetic anomalies, calcareous nannofossils and planktonic foraminifera events in the Upper Hauterivian - Barremian interval of Oie Gorgo a Cerbara section (from CECCA et alii, 1994b, modified and updated). The metre numbers arc those already used by LOWRIE & ALVAREZ (1984) and BRALOWER (1987). - Punti di ritrovamento delle ammoniti e correlazione con le anomalie magnetiche e gli eventi a nannofossili calcarei e foraminiferi planctonici nell 'intervallo Hauteriviano superiore - Barremiano della sezione di Gorgo a Cerbara. (da CECCA el alii, 1994b, modificato e aggiornato). La numerazione in metri è quella di LOWRIE & ALVAREZ (1984) e BRALOWER (1987). I IAL RNIRMAN-BARRIÏMIAN AMMONITFI BIOSTRATIGRAPI 1Y 195
l:ig. 4 - The dashed lines indicate the uppermost Hauterivian Faraoni Level along the Apccchicse road, km. 33.7. - LE UNEE tratteggiate indicano il Livello haraoni, dell'Iìaulenviano sommitale, esposto lungo la strada Apecchiese. km 33,
Fig. 5 - View ofthe quarries opened in the southern flank of Monte Nerone. M: Maiolica; F: Marne a Fucoidi. 1) Bugarone quarry; 2) Silesites bearing beds; 3) Faraoni Level. - Vista delle cave aperte nel versante meridionale di Monte Nerone. M: Maiolica; F; Marne a Fucoidi. I) cava del Bugarone; 2) strati con Silesites; 3) Livello Faraoni. 196 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
lypc section. On the basis of the ammonite faunal The ammonites are rare but they occur in the Faraoni assemblages, a 25 Ma stratigraphie hiatus has been Level and also in some beds above it. The preservation identified by CECCA et alii (1990). Onto the last Lower of the fossils is very bad and we could not distinguish Bajocian bed conformably rests a succession of beds the different ammonite zones. Heinzia and Silesites starting from the Lower Kimmeridgian Divisum Zone. occur in bed 131. This important hiatus has been reco gnized in all the PCP areas of Umbria-Marche Apennines. The upper boundary of the Bugarone Formation is difficult to define because of the transitional lithologie characters with theb 4.3 - PIANELLO - SECCHIANO ase of the Maiolica (CECCA et alii, 1990; CECCA, 1993). MiCARELLi et alii (1977) recognized a hiatus within 4.3.1 - The Maiolica of the Bosso river section: the type the Maiolica. In fact an unconformity is exposed on the section of the Faraoni Level top of the quarry (see also CECCA, 1993, fig. 20). We interpreted it as a slump scar. However, upper Berriasian The section is a natural outcrop created by the to Valanginian sediments lacks. The sediments above erosion of the river. Here, along the road from Pianello the hiatus have been dated to the Hauterivian p. p. by to Cagli the Jurassic-Tertiary succession is exposed from MiCARELLi et alii (1977). We discovered the Faraoni the younger to the older formations. The Jurassic Level (uppermost Hauterivian) 30 m above the Lower formations display the basin characters. Thus, facies, Tilhonian beds in the natural cut of the Fosso Bugarone, thicknesses and faunas differ from the coeval PCP at the left side of the quarry. Between the Faraoni Level sequence which we have seen in the Monte Nerone area. and the base of the Marne a Fucoidi there are more or The hiatus between Bajocian and Kimmeridgian did not less 35 m of Maiolica. exist here. This interval is represented by silica-rich sediments. 4.2.4 - Pieia: Upper Hauterivian-Upper Barremian The study of the younger portion, Hauterivian- Maiolica Barremian. is still in progress. Sampling for magnetostratigraphy has been realized by J. CHANNELL; The Maiolica which overlies the Pieia succession is the results will be published in a subsequent paper. The exposed along the road but faults and vegetation do not ammonites are rare but they are abundant in the Faraoni allow the study of the complete series. Nevertheless, Level, whose stratotype has been selected in this section close to the village of Pianello, at 22.5 km from (Fig. 6). For the detailed description of the Faraoni Acquanera, the Upper Hauterivian - Upper Barremian Level we refer the reader to the paper by CECCA et alii part of the Maiolica Formation has been studied. (1994a).
Fig. 6 - Reference section of the uppermost Hauterivian Faraoni Level, along the Cagli-Pianello road, km 9.8, Rosso section. - SEZIONE DI RIFERIMENTO DEL LIVELLO FARAONI, HAUTERIVIANO SOMMITALE, AL KM -9.8 DELLA STRADA CAGLI-PIANELLO. SEZIONE DEL BOSSO. HAUTEPJVIAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 197
Concerning the Lower Cretaceous, two portions of from top (boundary with the Marne a Fucoidi). At metre the Maiolica Formation, which are separated by faulting, 70, in bed 144b we have found the guide-bed of the have been studied. The older portion corresponds to the Faraoni level. The first Barremian level has been found uppermost Tithonian - Late Valanginian interval. at metre 62; in bed 132 occur specimens of heteromorph Biostratigraphy based on calpionellids and calcareous ammonites which can be compared with nannofossils has been defined (MICARELLI et alii, 1977; "Paraspinoceras" evolutum (FALLOT & TERMIER). This BRALOWER et alii, 1989). The magnetostratigraphy was species characterizes a level which is also exposed in published by LOWRIE & ALVAREZ (1984), who correlated different outcrops at Monte Petrano (see 4.4.) and it with the Calpionellid events and again by CHANNELL indicates the basal Barremian (VERMEULEN, 1972). & GRANDESSO (1987). At metre 41.5, in bed 114, we have found Holcodiscus fallax (MATHERON) (pi. 2, fig. 22). This 4.3.2 - The Stirpe to section (Poggio le Guaine - species also occurs in the Gorgo a Cerbara section at southern flank of Mount Nerone) metre 847. The Late Barremian Heinzia provincialis This section is a natural exposure located in the (D'ORBIGNY) occurs at metre 24 in bed 79. Specimens of South-East part of Mount Nerone, on the left side of the genera Melchiorites and Anahamulina are relatively Bosso river valley below Poggio le Guaine (Fig. 7). The frequent in beds 79, 80 and 81. Heinzia still occurs in Marne a Fucoidi formation cropping out in this locality bed 52 at metre 14 and just above, in bed 51, Silesites has been described by COCCIONI et alii (1987; 1990) but seranonis (D'ORBIGNY) appears. the Maiolica formation has not been studied so far. The If we do not take into account Phylloceratina, good exposure of the whole Maiolica, from its upper Lytoceratina, which are rare in this part of the section, boundary down to its lower boundary with the Upper and a single Toxoceratoides specimen found in bed 32 at Jurassic Calcari Diasprigni formation will allow us to metre 9, S. seranonis is the only species (pi. 2, fig. 13- study the complete Neocomian succession. Nevertheless, 16, 18, 19) occurring in the upper part of the Maiolica this natural outcrop is exposed on a quite steep slope and formation after the last occurrence of Pulchellids. In fact the worker cannot observe the stratification from the it occurs in four beds again, up to metre 7. A similar necessary distance allowing him to recognize possible distribution has been observed in the Gorgo a Cerbara slumped beds. These are quite frequent in the Maiolica section. outcrops of the surrounding localities. Above metre 7, no significant ammonites have been found so far. 4.3.2.1. - Ammonite distribution (Fig. 8) - Some 300 metres East of the section we studied an We measured the section and numbered the beds starting auxiliary section where we found the Guide-Bed of the
Fig. 7 - View of the Stirpeto section. M: Maiolica; F: Marne a Fucoidi. The Faraoni Level is indicated with dots. The Maiolica - Marne a Fucoidi boundary is indicated with dashes. - Vista della sezione di Stirpeto. M: Maiolica; F: Marne a Fucoidi. Il puntinolo indica il Livello Faraoni. Il tratteggio indica il limite Maiolica - Marne a Fucoidi. 198 CECCA F. - FARAONI P. - MARINI A. - PALLINI O.
STIRPETO (M. NERONE)
SUigcs Zones MARNK A FUCOIDI FORMATION mO
MAIOLICA FORMATION 5 . 23 Silesilcs cf. seranonis .32 S. seranonis, Toxoceratoides sp. 10 Z . 45 S. seranonis < 15 : 49-52 Heinzia sp., S. seranonis, Melchioriles sp.. ? Sartousi
20 < . 76 Heinzia pallimi 03 25 -79-81 Heinzia provincialis, Melchìorites sp. Anahamulina sp. Vandenheckii
30
35
40 114 Holcodiscus fai lax ? Caillaudi Z < 45
50 STIRPETO - Section East < QQ 55 15 • 7 A. aff subcincla 13 Anahamulina sp. 1 60 10 • I'I' I ' I *T O I I I I . 132 "Paraspinoceras" evolulum 1 ' 1 ' 1 ' 1 I lugli 65 5 • - 55 A. cf. boulini Catulloi 70 144 b Guide-bed 0 • .71 Guide-bed z Faraoni Level Faraoni Level Angulicostata auct.
not yet studied D
a.
Fig. 8 - Ammonite occurrences in the Stirpeto sections. - Punti di ritrovamento delle ammoniti nelle sezioni di Stirpeto.
Faraoni Level (CECCA et alii, 1994a). This bed is here (PARONA) (pl. 1, fig. 3, 4), P. sarasini SARKAR (pl. 1, particularly fossiliferous and we take the opportunity to fig. 1), Psilotissotia sp. n., P. bertrandi (NICKLÈS), P. mention the identified species collected in the different reigi (NICKLÈS), P. (Buergliceras) /avrei (OOSTER), sections: Phyllopachyceras infundibulum (D'ORBIGNY), Valdedorsella sp. n. microconch / Valdedorsella Hypophylloceras tethys (D'ORBIGNY), (Puezalpella) cf. haugi (BRESKOVSKI) Macroconch, Eulytoceras anisoptychum (UHLIG), Neolissoceras "Valdedorsella" compsense (KILIAN) Macroconch / grasi (D'ORBIGNY), Hamulinites aff. munieri (NICKLÈS), "Valdedorsella" crassidorsata (KARAKASCH) Acrioceras cf. tabarelli (ASTIER), Emericiceras imlayi microconch, Paraspiticeras sp. However, The most SARKAR, Emericiceras sp., Pseudothurmannia abundant forms are two major groups belonging to the angulicostata (D'ORBIGNY) in LAPEYRE, 1974 (pl. 1, fig. genus Barremites. 2), which corresponds to P. ohmi (WINCKLER) according Above the guide-bed of the Faraoni Level we have to HOEDEMAI;KER (in press), P. mortilleti (PICTET & DE found in this second outcrop a succession of LORIOL) s. str. (pl. 1, fig. 5, 6) and morphotype catulloi Anahamulina species (Fig. 8). An interesting form, HAUTERIVIAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 199
already figured by SIMIONESCU (1898, pl. 1, fig. 11) as "Hamites cf. subcinctus" UHLIG, is characterized by a Road Cagli-Outcrop B large angle between the hook and the. It has been M'Petrano ZONES/ STAGES SUBZONES identified in this work as Anahamulina sp. 1 (pi. 3, fig. BED NUMBERS MÛR 2) and also occurs at Monte Tenetra (see 4.5.1.; pi. 3, fig. 3).
4.4 - CAGLI - MONTE PETRANO CU (3,^" Paraspinoceras" CET < 4.4.1 - The section along the Monte Petrano road: evolutum m Upper Hauterivian-Lower Barremian ammonite b iostratigraphy
The road leads from the town of Cagli up to the top of the mountain. Numerous outcrops of the Maiolica formation are exposed. They are isolated from each other because of faulting. The complete succession is exposed on the northern flank of the mountain (see 4.4.2). Nevertheless some of these outcrops along the road are fossiliferous. In the Outcrop A, indicated 4.1a in < Tabi. 1 are exposed some beds with typical Holcodiscus E3* > caillaudi (D'ORBIGNY) (pi. 2, fig. as well as a pulchellid
corresponding to Nicklesia pulchella (D'ORBIGNY) sensu ZD KILIAN (1888) (pi.2, fig. 1) but probably belonging to < ZL Subpulchellia compressissima (D'ORBIGNY). This has been confirmed by COMPANY et alii (1993) and this level can be ascribed to the caillaudi horizon of their S. CO O compressissima zone, which corresponds to the lower Faraoni level (Si it part of the H. caillaudi zone sensu HOEDEMAEKER & n O COMPANY (1993). One of the best sections of the Faraoni Level as well as the Hauterivian-Barremian boundary is exposed in the Outcrop B (Tab. 1) where we draw this boundary on the basis of the FO of a characteristic heteromorph 6 27 ammonite species corresponding to "Paraspinoceras" evolutum (FALLOT & TERMIER). Different specimens were collected in this bed, thus allowing to define the intraspecific variability (pi. 3, fig. 13-16). Two (S AMMONITES morphotypes are distinguished: one is characterized by •k HARPAGODES-LIKEGASTROPODS simple ribs while the other by the presence of buckled ribs. Some specimens bear buckled ribs in the young Fig. 9 - I.og of a the Outcrop B, exposed along the road Cagli-Monte stage and simple ribs in the adult. Petrano. Bed 32 is the Guide bed of the Faraoni Level. - Colonnina stratigrafica dell 'affiroamento B, esposto lungo la strada Pseudothurmannia specimens have been found also in Cagli-Monte Petrano. the overlying calcareous beds 33 and 34. As Fig. 9 shows, ammonites are absent between beds 35 and 49 and some gastropod specimens occur. These gastropods, TAVERA (pers. comm., jury 1994) who found this form which are characterized by very long, fine, hook-shaped slightly above the base of the Barremian. However, their spines show some morphologic affinities with the genus detailed paleontological study must be done in order to Harpagodes. They are quite common in the studied clarify the taxonomic relationships between the different outcrops from Gorgo a Cerbara to Mount Tenetra. morphotypes (tuberculated with looped ribs associated In bed 49 we have found a fauna only composed by with specimens bearing simple ribs only) as well as their specimens belonging to a "Paraspinoceras" evolutum relations with other uncoiled forms. Forms similar to (FAI .LOT & TERMIER). They occur above the 'TV' evolutum have been found in Cuba and described as Pseudothurmannia beds and according lo VERMEULEN Crioceratites sp. cf. stubelensis DIMITROVA and C. cf. C. (1972) this species indicate the base of the Barremian. sp. A by MYCZYNSKI & TRIFF (1986, pl. 1, fig. 9 and 11 This has been confirmed by COMPANY, SANDOVAL & respectively). 200 CECCA F. - FARAONI P. - MARINI A. - PALLINI G
Fig. 10 - The northern slope of Monte Petrano, section N: view of the Hauterivian Maiolica. The arrow indicates the Faraoni Level - Il versante settentrionale dei Monte Petrano. sezione N: vista della Maiolica della 'Hauteriviano. La freccia indica il Livello Faraoni.
4.4.2 - The northern slope of Monte Petrano: Upper 4.5. - CAGLI - CHIASERNA Hauterivian-Barremian Maiolica (Fig. 10). 4.5.1 - Monte Penetra road: Barremian ammonites The Upper Hauterivian - Lower Barremian portion of the Maiolica Formation is exposed along Four sections, named T, Tc (the portion called Tb is the northern slope of Monte Petrano. Different stratigraphically below Te), VR and VT. have been sections have been logged. All the sections show the logged (Fig. 12, 1.1. 14 and 15 respectively) along the Hauterivian - Barremian transition. Sections M and road from the locality la Fornace, SE of Cagli, up to the N have been logged from Upper Hauterivian levels top of Monte Tenelra. below the Faraoni Level, although ammonites are The first Barremian faunas of Umbria-Marche rare in these levels (Fig. 11). In section D, 15 metres Apennines have been discovered in the beds exposed below the Faraoni Level a Pseudomoutoniceras cf. along this road. Like at Mount Petrano, Maiolica annulare (D'ORBIGNY) has been found (pl. 1, fig. 12); formation irregularly crops out on the road because it is it might indicate the .S'. sayni zone. often covered by vegetation and disturbed by faults. It is The level with the heteromorph ammonite identified impossible to observe the upper boundary of the as "Paraspinoceras" evolutum (FALLOT & THRMIKR), formation. The different studied sections do not give corresponding to bed 49 in outcrop B, exposed along the major informations on biostratigraphy because they arc road, is represented in almost all sections. Levels poorly exposed. However, the Maiolica outcrops of characterized by Holcodiscus gr. caillaudi (D'ORBIGNY) Monte Tenetra area are the most fossiliferous in this are also frequent in all sections (pi. 2, fig. 24), though sector of Umbria-Marche Apennines. the most representative is bed 47 of section D. Sections T and Tc show Lower Barremian levels In bed 62 of section M, below the level with with ammonites. Section VR (Fig. 16) shows the "Paraspinoceras" evolutum (FALLOT & TERMIER) a transition to Upper Barremian levels. The A. Spitidiscus sp. was found. It should indicate the base of vandenheckii zone is well represented: "Ancyloceras" the Barremian although the bad presevation of the gr. vandenheckii (ASTIER) has been found in bed 8 (pi. specimen does not allow us to be sure. If new findings 3, fig. 1) whilst Heinzia gr. provincialis (D'ORBIGNY). confirm this datum, the conventional Haulerivian- Heinzia pallimi CECCA and Subpulchellia hrevicostata Barremian boundary which we used so far in this region, KOTETICIIVILI (pi.2, fig. 3) are common in levels 15 and e. g. the FO of "P. " evolutum, must be lowered. 16 (Fig. 15). HAUTERIVIAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 201
sw STM NK MfPetra.no mO
1 STN 2 MfPetrano
3
4
5
6 cm cm 7 < Dû 8 STL MlPetrano 9
10
11
Road Cagli STH 12 MfPetrano M'Petrano 13
14 "Paraspinoceras"
15 evolutum 16 - - 17 Faraoni Level 18 guide -bed z 19 < 20 > 21 LEGENDA 22
23 covered <
24 sty lolithe 25 chert nodules chert level cm 26 shaly interbed LU Ci 27 slump u
28
29
30
di s V Pannuti
Fig. 11 - Correlation between some of the sections logged on the northern slope of Monte Petrano with the log of the Outcrop B. - Correlazione fra alcune delle sezioni rilevate sul versante settentrionale del Monte Petrano con la colonnina dell 'affioramento B. 202 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
Close lo the top of the mountain, we were able to (Southern slope of Monte Acuto). Maiolica overlies the sample a 4.5 metres thick section (Fig. 15), named VT. Calcari a Saccocoma ed Aptici Formation and the Upper The ammonite faunas show the transition between Tithonian-Upper Hauterivian interval is exposed, the Lower and Upper Barremian. The beds have been rest being covered by detritus. numbered from the base of the outcrop, bed 0 lying just Rare Valanginian ammonites were found by CECCA above the road level. (1985) but the most interesting levels have been recently It is worth noting that in all the studied sections of discovered in the Upper Valanginian - Upper the Monte Tenetra road gastropods (Harpagodes - like Hauterivian interval (Fig. 17). In fact the section has forms as mentioned in Outcrop B along the Monte been sampled for magnetostratigraphy by J. E. T. Petrano road) and bivalves are quite abundant. CHANNELL. The magnetic signal is reliable and the Because of the dipping of the beds from section VT up results will be published soon, together with the lo Monte Alto Hauterivian to Valanginian levels crop out. correlation with ammonites and calcareous nannofossils The succession is not completely visible because of the (studied by E. ERBA). vegetation, furthermore the - erosion of the Maiolica Upper Valanginian ammonites have been found in 10 limestone produces an abundant detritus of calcareous chips metres at the base of the section sampled with CHANNELL which hardly cover the outcrops. Only some small portions (see CECCA, this volume). Crioceratites gr. duvali LÉVEILLÉ of the succession can be logged. A rich Valanginian (pl. 1, fig. 7) and Subsaynella sp have been found at metres ammonite fauna has been collected below Monte Alto; some 22 and 23, thus indicating the S. sayni zone. specimens are figured by CECCA (this volume). However, it is impossible to define here the succession of the beds, then the ammonite biostratigraphy. 5. - CONCLUSIONS
4.5.2 - Southern slope of Monte Acuto: Upper Due to the lithologie character of the Maiolica Valanginian-Hauterivìan Maiolica formation, in the Umbria-Marche Apennines the Lower Cretaceous ammonites are rare and more difficult to The complete Jurassic basin-type succession is collect than the Jurassic ones. Nevertheless, the exposed along the road from M. Catria to Chiaserna ammonite zones defined by HOEDEMAEKER & COMPANY mOr
M.' Tenetra Section T M.' Tenetra beds beds
remitestBlclpsilotatus -Barremites sp. - Phytlopachyceras inlundibulum - Melchiorites melchioris
Phyllopachyceras sp .Barremites sp
Subpulchellia cl castellanensis9
Holcodiscus cl sophonisba? Subpulchellia cl. brevicostata Eulytoceras sp Anahamulina cl. ptychoceroides9 - Haplobrancoceras all.subquadratum Heinzia cl.lindigi - Holcodiscus cl sophonisba9 Hypophylloceras tethys.Eulytoceras pheslu
. Subpulchellia sp Pulchellia sp
- Subpulchellia brevicostata
- Emericiceras sp
_ Karsteniceras cl subtile Nicklesia sp - Holcodiscus cl caillaudi Karsteniceras sp - Leptoceratoides sp. - Subpulchellia cl compressissima''
- Phylloceras sp.. Barremites sp. - Silesites vulpes
^Karsteniceras 10 Phyllopachyceras cl intundibulum 'Anahamulina sp
11 Fig. 12 - Log and ammonite occurrences in section T, Monte Tenetra. See Fig. 13 - Log and ammonite occurrences in section T c/b, Monte Tenetra. Fig. 11 for symbols. See Fig. 11 for symbols. - Colonnina stratigrafica ed ammoniti nella sezione T, Monte Tenetra. - Colonnina stratigrafica ed ammoniti nella sezione T c/b. Monte Si veda la legenda di Fig. lì. Tenetra. Si veda la legenda di Fig. 11. HAUmRTvlAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 203 m0 (1993) can be recognized, at least for some stages or substages. Concerning the Hauterivian-Barremian interval, it is
M.* Tenetra impossible to recognize so far the Lower Hauterivian Section VR and in the Upper Hauterivian it is difficult to recognize beds the P. ligatus and B. balearis zones. The S. sayni zone has been recognized in three sections (Gorgo a Cerbara, 16 -Heinzia gr provincialis.Heinzia pallimi Northern slope of Monte Petrano and Southern slope of - Subpulchellia brevicostata Monte Acuto) on the basis of rare ammonite findings, 15 _ Anahamulina cl. glemmbachensis BarremiteslCassidoiceraslcl.Cassidoides whilst the P. angulicostata zone is well represented by Melchìorites cl.melchioris, Heinzia pallini! Silesites clvulpes its upper subzone, the P. catulloi subzone, in the Faraoni - Karsteniceras sp. Level. The Barremian ammonite zones have been recognized in the Gorgo a Cerbara section whilst only -o some zones are represented in the other localities. c 10 _ Barremites(8 )vocontius,?Subpulchellia sp The base of the Barremian in this region is not - Silesites cl.seranonis. Karsteniceras subtile
-Holcodiscuscl sophonisba.Leptoceratoides sp. defined by the occurrence of Spitidiscus hugii, because "Ancyloceras"gr. vandenheckii Lytoceras sp the first Spitidiscus appear later then their actual FO.
=3 5 Melchìorites sp. We locally use the FO of "Paraspinoceras" evolutum 3 (FALLOT & TERMIER), which is quite frequent in our - Eulytoceras phestun - Silesites cl vulpes outcrops. This species probably occurs slightly higher than the FO of S. hugii (COMPANY, SANDOVAL & TA VERA, pers. comm.) in fact in the Northern slope of Monte Petrano (section M) a fragment of Spitidiscus was found between the Faraoni Level and the level with. "P. " Fig. 14 - Log and ammonite occurrences in section VR, Monte 'Penetra. evolutum (see 4.4.2.). See Fig. 11 for symbols. Colonnina stratigrafica ed ammoniti nella sezione VR, Monte The S. nicklesi zone has not been recognized so far, Tenetra. Si veda la legenda di Fig. 11. whilst the //. caillaudi zone is easily recognized in all sections. The zonal succession defined for the Lower Barremian by COMPANY et alii (1993) in the Subbetic area is not recognizable in Umbria-Marche. Above the levels with H. caillaudi we usually found Heinzia provincialis and H. pallina which are used in our area to draw the boundary between Lower and Upper Barremian. However, in a section at Monte Tenetra M! Tenetra (VR), Ancyloceras gr. vandenheckii, the marker species Section VT of the first ammonite zone of the Upper Barremian, was beds mO, found below the first //. provincialis. The H. sartousi 12 zone is well represented in the Gorgo a Cerbara section o Heinzia cf pallimi and it starts above the beds with Coronites. c v The Upper Barremian H. feraudi, I. giraudi and M c sarasini zones cannot be recognized in our study area Hypophylloceras tethys because of the lack of age diagnostic ammonites. In fact, Anahamulina alt.distans apart the Lower Aptian Prodeshayesites sp. found above Phyllopachyceras cf.inlundibulum
Rei- inlundibulum the last levels with Heinzia at gorgo a Cerbara, Silesites seranonis associated with Phylloceratina and Anahamulina sp.1,Pulchellia ali. orbignyi Lytoceratina are the only ammonites which occur in the H.tethys H.cf.tethys, Leptoceratoides sp. upper portion of the Maiolica formation. -o Anahamulina sp.2 3 Leptoceratoides sp. cf. pumilus Holcodiscusgr caillaudi H.tethys P inlundibulum, Leptoceratoides sp. ACKNOWLEDGEMENTS Eulytoceras phestum We would like to thank G. MAGLI and G. MARTIRE
dis.V. Pannuti for help in the field, as well as A. BUSSOLETTI, F. ABBALLE and M. BALINI for the ammonite photographs. V. PANNUTI realized the drawings. Fig. 15 - Log and ammonite occurrences in section VT, Monte Tenetra. This work was carried out within the program CTB- See Fig. 11 for symbols. • Colonnina stratigrafica ed ammoniti nella sezione VT, Monte Tenetra. CNR "Biostratigrafia ad Ammoniti delle facies Si veda la legenda di Fig. 11. mesozoiche dell'Appennino Centrale". 204 CUCCA I'". - FARA( INI P. - MARINI A. - PAIJJNIO.
Fig. 17 - Southern slope of Monte Acuto. View ofthe Lower Hauterivian Maiolica. - Versante meridionale di Monte Acuto. Vista della Maiolica dell'I! auteriviano inferiore. HAUTERIVIAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 205
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COCCIONI R., ERBA E. & PREMOLI SILVA I. (1992) - Barremian-Aptian SANTANTONIO M. (1994) - Pelagic Carbonate Platforms in the geologic calcareous nannoplankton biostratigraphy from the Gorgo record: their classification, and sedimentary and paleotectonic Cerbara section (Marche, central Italy) and implications for evolution. AAPG Bull., 78 (1): 122-141, Tulsa. plankton evolution. Cretaceous Research, 13: 517-537, London. SIMIONESCU I. (1898) - Studii geologice si paleontologhe din Carpata Sudici. II. Studiul faunei neocomiene din basenul Dimboviciorei. COCCIONI R., FRANCHI R., NESCI O., PERLLLI N., WEZEL CF. & Academia Romana, Pubi, fondului V. Adamachi II: 45-111, BA1T1ST1NI F. (1990) - Stratigrafia, micropaleontologia e miner Bucuresti. alogia delle Marne a Fucoidi (Aptiano inferiore - Albiano superi ore) delle sezioni di Poggio le Guaine e del Fiume Bosso VERMEULEN, J. (1972) - Considerations sur la Psilotissotia malladae (Appennino Umbro-Marchigiano). In: G. PALLINI, F. CECCA, S. (NICKLÈS) et l'origine du genre Nicklesia HYATT. C. R. Somm. Soc. CRESTA & M. SANTANTONIO (Eds.): Atti 11° Convegno Intemazion géol. France, 7, 23, Paris. ale "Fossili, Evoluzione, Ambiente", Pergola,1987: 163-201. VERMEULEN J. (1980) - Etude de la famille des Pulchelliidae. Thèse Univ. Nice, 92 pp., unpublished. COCCIONI R., GALEOTTI S. & SANTARELLI A. (1994) - Preliminary palynological analysis of the Maiolica-Scisti a Fucoidi transition ZITTEL K. A (1869) - Geologische Beobachtungen aus den Central- (Barremian-Aptian) in the Gorgo a Cerbara section (central Italy). Apenninen. In: E. W. BENECKE Geognostisch-Palaeontologischen Paleopelagos (1993), 4, 195-201, Roma. Beitr., 2 (2): 91-178, Mûnchen. CECCA F. - FARAONI P. - MARINI A. - PALLINI G. 206
PLATE 1
Fig. 1 - Pseudothurmannia sarasini SARKAR. Outcrop B, Monte Petrano road, bed 32 ("guide-bed" of the Faraoni Level). Uppermost Hauterivian, P. angulicostata auct. zone, P. catulloi subzone; specimen A 1, coll. FARAONI. Fig. 2 - Pseudothurmannia angulicostata (D'ORBIGNY) in LAPEYRE, 1974. Same section and same bed; specimen A 2, coll. FARAONI. Fig. 3,4- Pseudothurmannia mortilleti catulloi (PARONA). Same section and same bed; 3, specimen A 47; 4, specimen A 6, coll. FARAONI. Fig. 5 - Pseudothurmannia belimelensis DIMITROVA. Stirpeto - section East, bed 71 ("guide-bed" of the Faraoni Level). Uppermost Hauterivian, P. angulicostata auct. zone, P. catulloi subzone; specimen RS 3, coll. FARAONI. Fig. 6 - Pseudothurmannia mortilleti mortilleti (PiCTET & DE LORIOL). Same section and same bed; specimen RS 14, coll. FARAONI. Fig. 7 - Crioceratites gr. duvali LÉVEILLÉ. Southern slope of Monte Acuto, metre 22. Upper Hauterivian, S. sayni zone; specimen MA 613. Fig. 8 - Crioceratites gr. duvalii LÉVFALLÉ/villiersianus (D'ORBIGNY). Gorgo a Cerbara, bed 266. Upper Hauterivian, B. balearis or P. ligatus zones; specimen F 178. Fig. 9 - Subsaynella sp. Gorgo a Cerbara, bed 277. Upper Hauterivian, S. sayni zone; specimen F 626. Fig. 10 - Spitidiscus cf. vandenhecki (D'ORBIGNY). Gorgo a Cerbara, bed 199. Lower Barremian, S. hugii zone; specimen F 152. Fig. 11 - Plesiospitidiscus sp. Gorgo a Cerbara, bed 264. Upper Hauterivian, B. balearis or P. ligatus zones; spec. F 606. Fig. 12 - Pseudomoutoniceras cf. annulare (D'ORBIGNY). Southern slope of Monte Petrano, section D, 15 metres below the Faraoni Level. Upper Hauterivian, S. sayni zone; spec. P-D 455. Fig. 13-16 - "Paraspinoceras" evolutum (FALLOT & TERMTER). Outcrop B, Monte Petrano road, bed 49. Lower Barremian, S. hugii zone. 13, spec. P 470 and 15, spec. P 471 correspond to the morphotype A, with simple ribs while 14, spec. P 469, develops buckled ribs in the young stage; 16, spec. P 472, corresponds to the morphotype B, with buckled ribs. Coll. FARAONI. All figures natural size. The arrows indicate the beginning of the body chamber when visible. Photos 1-6, 8 and 10 by F. ABBALLE (Servizio Geologico Nazionale); 7, 9, 11-13 by A. BUSSOLETTI.
TAVOLA 1
Fig. 1 - Pseudothurmannia sarasini SARKAR. Affioramento B, strada di Monte Petrano, strato 32 ("guide-bed" del Livello Faraoni). Hauteriviano sommitale, zona a P. angulicostata auct., sottozona a P. catulloi; es. A 1, coli. FARAONI. Fig. 2 - Pseudothurmannia angulicostata (D'ORBIGNY) in LAPEYRE, 1974. Stessa provenienza; es. A 2, coli. FARAONI. Fig. 3, 4 - Pseudothurmannia mortilleti catulloi (PARONA). Stessa provenienza; 3, es. A 47; 4, es. A 6, coli. FARAONI. Fig. 5 - Pseudothurmannia belimelensis DIMITROVA. Stirpeto - sezione Est, strato 71 ("guide-bed" del Livello Faraoni). Hauteriviano sommitale, zona a P. angulicostata auct., sottozona a P. catulloi; esemplare RS 3, coli. FARAONI. Fig. 6 - Pseudothurmannia mortilleti mortilleti (PICTET & DE LORIOL). Stessa provenienza; es. RS 14, coli. FARAONI. Fig. 7 - Crioceratites gr. duvali LÉVEILLÉ. Versante Sud di Monte Acuto, metro 22. Hauteriviano superiore, zona a S. sayni; esemplare MA 613. Fig. 8 - Crioceratites gr. duvali Li'WT/LLÉ/villiersianus (D'ORBIGNY). Gorgo a Cerbara, strato 266. Hauteriviano superiore, zona a B. balearis o P. ligatus; esemplare F178. Fig. 9 - Subsaynella sp. Gorgo a Cerbara, strato 277., Hauteriviano superiore, zona a S. sayni; esemplare F 626. Fig. 10 - Spitidiscus cf. vandenhecki (D'ORBIGNY). Gorgo a Cerbara, strato 199. Barremiano inferiore, zona a S. hugii; esemplare F152. Fig. 11 - Plesiospitidiscus sp. Gorgo a Cerbara, strato 264. Hauteriviano superiore, zona a B. balearis o P. ligatus; esemplare F 606. Fig. 12 - Pseudomoutoniceras cf. annulare (D'ORBIGNY). Versante Sud di Monte Petrano, sezione D, 15 metri sotto il Livello Faraoni. Hauteriviano superiore, zona a S. sayni; esemplare P-D 455. Fig. 13-16 - "Paraspinoceras" evolutum (FALLOT & TERMIER). Affioramento B, strada di Monte Petrano, strato 49. Barremiano inferiore, zona a S. hugii. 13, es. P 470 e 15, es. P 471 corrispondono al morfotipo A, con coste semplici mentre 14, es. P 469, sviluppa coste fibulate nello stadio giovanile; 16, es. P 472, corrisponde al morfotipo B, con coste fibulate. Coli. FARAONI. Gli esemplari sono riprodotti a granezza naturale. Quando visibile, le frecce indicano l'inizio della camera d'abitazione. Foto 1-6, 8 e 10 di F. ABBALLE (Servizio Geologico Nazionale); 7, 9, 11-13 di A. BUSSOLETTI. HAUTEPJVIAN-BARREMIAN AMMONITE BIOSTRATIGRAPHY 207 208 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
PLATE 2
Fig. 1 - Pulchellia (Nicklesia) pulchella D'ORBIGNY sensu KILIAN 1888 (or Subpulchellia compressissima (D'ORBIGNY)). Monte Petrano road, Outcrop A, bed 9. Lower Barremian, H. caillaudi zone; specimen AH 467. Fig. 2 - Pulchellia aff. orbignyi BÙRGL. Monte Tenetra, section VT, bed 11. Lower Barremian, H. caillaudi zone; specimen VT 120. Fig. 3 - Subpulchellia brevicostata KOTETISHVILI. Mt. Tenetra, section VR, bed 15 lop. Upper Barremian, A. vandenheckii zone; specimen VR 625. Fig. 4 - Pulchellia (Heinzia) cf. pallina CECCA. Monte Tenetra, section VT, bed 25. Upper Barremian, A. vandenheckii zone; specimen VT 208. Fig. 5 - Coronites aff. hoplitiformis (SAYN). Gorgo a Cerbara, bed 81. Upper Barremian, A. vandenheckii zone; specimen F 171. Fig. 6 - Coronites cf. coronatoides (SAYN). Same section, bed 84; specimen F 399. Fig. 7 - Coronites aff. coronatoides (SAYN). Same section, same bed; specimen F 177. Note in the internal whorl the small bullae between the umbilical edge and the middle of the whorl height. Fig. 8 - Pulchellia (Heinzia) aff. lindigii (KARSTEN in UHLIG, 1887). Same section, bed 119. Upper Barremian, A. vandenheckii zone; spec. F 176. Fig. 9 - Pulchellia (Heinzia) sartousi (D'ORBIGNY). Same section, bed 43. Upper Barremian, H. sartousi zone; specimen F 406. Fig. 10 - Pulchellia (Heinzia) cf. sartousi (D'ORBIGNY) - Same section, same bed; specimen F418. Fig. 11 - Pulchellia (Heinzia) cf.ouachensis (SAYN) - Same section, same bed; specimen F419. Fig. 12 - Subpulchellia cf. changarnieri (SAYN) - Same section, level 142-143. Lower Barremian,//. caillaudi. zone; specimen F161. Fig. 13 - Silesites seranonis (D'ORBIGNY). Stirpeto, bed 32. Upper Barremian, ?//. sartousi zone; specimen S 360. Macroconch. Fig. 14 - Idem. Same section and same bed; specimen S 368. Microconch. Fig. 15 - Idem. Same section, bed 29 a. Same age; specimen S 367. Microconch. Fig. 16 - Idem. Same section, bed 49. Same age; specimen S 366. Microconch. Fig. 17 - Idem. Gorgo a Cerbara, bed 43. Upper Barremian, H. sartousi zone; specimen F 414. Fig. 18 - Idem. Stirpeto, bed 23a. Upper Barremian, ? H. sartousi zone; specimen S 362. Microconch. Fig. 19 - Idem. Same section, bed 29a. Same age; specimen S 365. Microconch. Fig. 20 - Silesites vulpes (COQUAND). Monte Tenetra, section T, bed 4a. Lower Barremian, H. caillaudi zone; specimen T 343. Fig. 21 - Holcodiscus cf. fallax (D'ORBIGNY). Gorgo a Cerbara, level 151-153. Lower Barremian, H. caillaudi zone; specimen F 329. Fig. 22 - Idem. Stirpeto, bed 114b. Lower Barremian, H. caillaudi zone; specimen S 359. Fig. 23 - Holcodiscus caillaudi (D'ORBIGNY). Monte Petrano road, Outcrop A, bed 9. Lower Barremian, H. caillaudi zone; specimen AH 468. Typical specimen. Fig. 24 - Idem. Southern slope of Monte Petrano, section D, bed 47. Lower Barremian, H. caillaudi zone; specimen P-D 571. Fig. 25 - Prodeshayesites sp. Gorgo a Cerbara, bed 5. Lower Aptian; specimen F 463. Fig. 26 - Barremites cf. mueriensis BRESKOVSKI. Gorgo a Cerbara, bed 70. Upper Barremian,/!. vandenheckii zone; specimen F173. Fig. 27 - Barremites vocontius (LORY& SAYN). Monte Tenetra, section VR, bed 10. Upper Barremian, A. vandenheckii zone; specimen VR 317. All figures natural size. The arrows indicate the beginning of the body chamber when visible.
Photos 5-8, 13, 17 by F. ABBALLE; 2, 9 by M. BAUNT(Dip. Scienze della Terra, Milan University); 1, 3, 4, 10-12, 14-16, 18-27 by A. BLBSOLETTI.
TAVOLA 2 Fig. 1 - Pulchellia (Nicklesia) pulchella D'ORBIGNY sensu KILIAN 1888 (or Subpulchellia compressissima (D'ORBIGNY)). Strada di Monte Petrano, Affioramento A, strato 9. Barremiano inferiore, zona a H. caillaudi; esemplare AH 467. Fig. 2 - Pulchellia aff. orbignyi BÛRGL. Monte Tenetra, sezione VT, strato 11. Barremiano inferiore, zona a H. caillaudi; esemplare VT 120. Fig. 3 - Subpulchellia brevicostata KOTETISHVRJ. Stessa provenienza, strato 15 top. Barremiano superiore, zona a A. vandenheckii; es. VR 625. Fig. 4 - Pulchellia (Heinzia) cf. pallimi CECCA. Monte Tenetra, sezione VT, strato 25. Barremiano superiore, zona a A. vandenheckii; es. VT 208. Fig. 5 - Coronites aff. hoplitiformis (SAYN). Gorgo a Cerbara, strato 81. Barremiano superiore, zona a A. vandenheckii; esemplare F 171. Fig. 6 - Coronites cf. coronatoides (SAYN). Stessa provenienza, strato 84; esemplare F 399. Fig. 7 - Coronites aff. coronatoides (SAYN). Stessa provenienza; esemplare F177. Si notino nei giri interni le piccole bullae situate fra il margine ombelicale e la metà del fianco. Fig. 8 - Pulchellia (Heinzia) aff. lindigii (KARSTEN in UHLIG, 1887). Stessa provenienza, strato 119. Barremiano superiore, zona a A. vandenheckii; esemplare. F176. Fig. 9 - Pulchellia (Heinzia) sartousi (D'ORBIGNY). Stessa provenienza, strato 43. Barremiano superiore, zona a H. sartousi; esemplare F 406. Fig. 10 - Pulchellia (Heinzia) cf. sartousi (D'ORBIGNY) - Stessa provenienza; esemplare F418. Fig. 11 - Pulchellia (Heinzia) c/ouachensis (SAYN) - Stessa provenienza; esemplare F419. Fig. 12 - Subpulchellia cf. changarnieri (SAYN) - Stessa provenienza; livello 142-143. Barremiano inferiore, zona a H. caillaudi; esemplare FI 61. Fig. 13 - Silesites seranonis (D'ORBIGNY). Stirpeto, strato 32. Barremiano superiore, zona a ? H. sartousi; esemplare S 360. Macroconco. Fig. 14 - Idem. Stessa provenienza; esemplare S 368. Microconco. Fig. 15 - Idem. Stessa provenienza, strato 29 a; esemplare S 367. Microconco. Fig. 16 - Idem Stessa provenienza, strato 49; esemplare S 366. Microconco. Fig. 17 - Idem. Gorgo a Cerbara, strato 43. Barremiano superiore, zona a H. sartousi; esemplare F 414. Fig. 18 - Idem. Stirpeto, strato 23a. Barremiano superiore, zona a ? H. sartousi; esemplare S 362. Microconco. Fig. 19 - Idem. Stessa provenienza, strato 29a; esemplare S 365. Microconco. Fig. 20 - Silesites vulpes (COQUAND). Monte Tenetra, sezione T. strato 4a. Barremiano inferiore, zona a H. caillaudi; esemplare T 343. Fig. 21 - Holcodiscus cf. fallax (D'ORBIGNY). Gorgo a Cerbara, livello 151-153. Barremiano inferiore, zona a H. caillaudi; esemplare F 329. Fig. 22 - Idem Stirpeto, strato 114b. Barremiano inferiore, zona a H. caillaudi; esemplare S 359. Fig. 23 - Holcodiscus caillaudi (D'ORBIGNY). Strada di M. Petrano, Affioramento A, strato 9. Barremiano inferiore, zona a H. caillaudi; esemplare, AH 468. Forma tipica. Fig. 24 - ldem.Versante Sud di Monte Petrano, sezione D, strato 47. Barremiano inferiore, zona a H. caillaudi; esemplare P-D 571. Fig. 25 - Prodeshayesites sp. Gorgo a Cerbara, strato 5. Aptiano inferiore; esemplare F 463. Fig. 26 - Barremites cf. mueriensis BRESKOVSKI. Gorgo a Cerbara, strato 70. Barremiano superiore, zona a A. vandenheckii; esemplare FI 73. Fig. 27 - Barremites vocontius (LORY &SAYN). Monte Tenetra, sezione VR, strato 10. Barremiano superiore, zona a A. vandenheckii; esemplare VR 317. Gli esemplari sono riprodotti a granezza naturale. Quando visibile, le frecce indicano l'inizio della camera d'abitazione. Foto 5-8, 13, 17 di F. ABBALLE; 2, 9 di M. BAIMI (Dip. Scienze della Terra, Univ. Milano); 1, 3, 4, 10-12, 14-16, 18-27 di A. BUSSOLETT1. IIALmïRIVlAN-BARREMIAN AMMONITE BIOSTRATIORAPIIY 209 210 CECCA F. - FARAONI P. - MARINI A. - PALLINI G.
PLATE 3
Fig. 1 - "Ancyloceras" vandenheckii (ASTIER). Monte Tenetra, section VR, bed 8. Upper Barremian, A. vandenheckii zone; specimen VR 659. Fig. 2 - Anahamulina sp. 1 = "Hamites cf. suhcinctus" LIHLIG in SIMIONESCU, 1898, pl. 1, fig. IL Stirpeto section East, bed 13, Lower Barremian, specimen RS 97. Fig. 3 - Idem. Monte Tenetra, section VT, bed 11. Lower Barremian, H. caillaudi zone; specimen VT 116. Fig. 4 - Anahamulina sp 2. Monte Tenetra, section VT, bed 7. Lower Barremian, H. caillaudi zone; specimen VT 115. Specimen showing affinities with the ammonites of fig. 2 and 3. Fig. 5 - Anahamulina aff. ptychoceroides (UHLIG). Gorgo a Cerbara, bed 153. Lower Barremian, H. caillaudi zone; specimen F 421. Fig. 6 - Idem. Monte Tenetra, section VR, bed 10. Upper Barremian, A. vandenheckii zone; specimen VR 316. Fig. 7 - Anahamulina boutini (MATHERON). Stirpeto section East, bed 55. Upper Hauterivian - Lower Barremian transition; specimen RS 8. Fig. 8 - Anahamulina cf. glemmbachensis IMMEL. Monte Tenetra, section VR, bed 15 top, Upper Barremian, A. vandenheckii zone, specimen VR 629. Fig. 9 - Anahamulina aff. fumisuginum (UHLIG). Monte Petrano road, Outcrop A, bed 6. Lower Barremian, H. caillaudi zone; specimen AH 466. Fig. 10 - Idem. Gorgo a Cerbara, bed 129. Lower Barremian - Upper Barremian transition; specimen F 457. Fig. 11 - Anahamulina cf. subcincta (UHLIG). Southern slope of Monte Petrano, section D, bed 47. Lower Barremian, H. caillaudi zone; specimen P-D 572. Fig. 12 - Anahamulina aff subcincta (UHLIG). Stirpeto section East, bed 7. Lower Barremian; specimen RS 151 Fig. 13 - Transitional form between Acrioceras and Toxoceratoides of the karsteni/silesiacum group. Southern slope of Monte Petrano, section DW, bed 50. Lower Barremian, 3 m below the H. caillaudi zone; specimen P-D 573. Fig. 14 - Costidiscus recticostatus (D'ORBIGNY). Gorgo a Cerbara, bed 121. Upper Barremian. A. vandenheckii. zone; specimen F 155. Fig. 15 - Costidiscus cf. nodostriatus (UHLIG). Gorgo a Cerbara, bed 118. Upper Barremian, A. vandenheckii. zone; specimen F 405. Fig. 16 - Phyllopachyceras infundibulum (D'ORBIGNY) - Gorgo a Cerbara, bed 121. specimen F158. Upper Barremian, A. vandenheckii. zone. All figures natural size. The arrows indicate the beginning of the body chamber when visible. Photo 1 by G. PALLINI; 2-4 by M. BALLNI; 5-16 by A. BUSSOLETn.
TAVOLA 3
P'ig. I - "Ancyloceras" vandenheckii (ASTIER). Monte Tenetra. sezione VR, strato 8. Barremiano superiore, zona a A. vandenheckii; esemplare VR 659. Pig. 2 - Anahamulina sp. I. = 'Hamites cf. subcinclus" UHUG in SIMIONESCU, 1898, tav. 1. fig. 11. Stirpeto, sezione Est. strato 13, Barremiano inferiore, esemplare RS 97. Fig. 3 - Idem. Monte Tenetra, sezione VT, strato 11. Barremiano inferiore, zona a H. caillaudi; esemplare VT 116. P'ig. 4 - Anahamulina sp 2. Monte Tenetra, sezione VT, strata 7. Barremiano inferiore, zona a H. caillaudi; esemplare VT 115. Esemplare affine alle forme di fig. 2 e 3. Fig. 5 - Anahamulina aff. ptychoceroides (UHLIG). Gorgo a Cerbara, strata 153. Barremiano inferiore, zona a II. caillaudi; esemplare F 421. Pig. 6 - Idem. J. Monte Tenetra, sezione VR, strata 10. Barremiano superiore, zona a A. vandenheckii; esemplare VR 316. Fig. 7 - Anahamulina boutini (MATHERON). Stirpeto sezione Est, strata 55. Passaggio Hauteriviano superiore - Barremiano inferiore; esemplare RS 8. Fig. 8 - Anahamulina cf. glemmbachensis IMMEL. Monte Tenetra, sezione VR, strata 15 top. Barremiano superiore, zona a A. vandenheckii; esemplare VR 629. F'ig. 9 - Anahamulina aff. fumisuginum (UHUG). Strada di Monte Petrano, Affioramento A, strata 6. Barremiano inferiore, zona a H. caillaudi; esemplare All 466. Fig. 10 - Idem. Gorgo a Cerbara, strata 129. Passaggio Barremiano inferiore - Barremiano superiore; esemplare F457. Fig. Il - Anahamulina cf. subcincta (UHLIG). Versante meridionale di Monte Petrano, sezione D, strato 47. Barremiano inferiore, zona a H. caillaudi; esemplare P-D 572. F'ig. 12 - Anahamulina aff. subcincta (UHLIG). Stirpeto sezione Est, strato 7. Barremiano inferiore; esemplare RS 151. P'ig. 13 - Forma di transizione tra Acrioceras e Toxoceratoides del gruppo karsteni/silesiacum. Versante meridionale di Monte Petrano. sezione DW, strato 50. Barremiano inferiore, 3 metri sotto alla zona a H. caillaudi; esemplare P-D 573. Fig. 14 - Costidiscus recticostatus (D'ORBIGNY). Gorgo a Cerbara, strato 121. Barremiano superiore, zona a A. vandenheckii; esemplare F155. Fig. 15 - Costidiscus cf. nodostriatus (UHLIG). Gorgo a Cerbara, strato 118. Barremiano superiore, zona a A. vandenheckii; esemplare F 405. P'ig. 16- Phyllopachyceras infundibulum (D'ORBIGNY) - Gorgo a Cerbara, strato 121. Barremiano superiore, zona a A. vandenheckii; esemplare FI58. Gli esemplari sono riprodotti a granezza naturale. Quando visibile, le frecce indicano l'inizio della camera d'abitazione. Foto 1 di G. PALLINI; 2-4 di M. BAUNI; 5-16 di A. BUSSOLETTI. I IAlJlERTvTAN-rjARREMIAN AMMONITE BIOSTOATIGRAPHY 211 Mem. Descr. Carta Geol. d 'It. LI (1995), pp. 213-215
Report on the 3rd international Workshop on the standard Lower Cretaceous ammonite zonation of the Mediterranean region
Rapporto sul 3° Workshop internazionale sulla zonazione standard ad ammoniti del Cretaceo inferiore della regione Mediterranea
PHILIP J. HOEDEMAEKER(l), FABRIZIO CECCA (2) (Reporters) and EMIL AVRAM (3), MIGUEL COMPANY (4), GÉRARD DELANOY (5), ELISABETTA ERBA (6), MoHSSiNE ETTACHFINI (7), PAOLO FARAONI (8), MIKHAIL V. KAKABADZE (9), GIOVANNI LANDRA (6), AGOSTINO MARINI (10), LUCIA MEMMI (11), GIOVANNI PALLINI (12), PETER F. RAWSON (13), PIERRE ROPOLO (14), JOSÉ SANDOVAL (4), JOSÉ M. TAVERA (4) & Zdenek VASICEK (15)
IGCP Projects 343: Stratigraphie Correlations Basins of Peritethyan 362: Tethyan and Boreal Cretaceous
The third international Workshop on the standard Boreal Cretaceous" and 343 "Stratigraphie correlations Lower Cretaceous ammonite zonation of the of Peri-Tethyan basins". Because the first two Mediterranean region was held in Piobbico (Italy) from workshops were held in the framework of IGCP Project 5 to 8 july 1994. It was organized by F. CECCA and G. 262 "Tethyan Cretaceous correlation", a change of PALLINI in cooperation with the Town of Piobbico. Chairman was necessary. Dr. Philip J. HOEDEMAEKER The intemationality of the workshop was good; was reelected as Chairman for this international participants of 10 countries attended the meeting: Working Group and Dr. Peter F. RAWSON was elected as Morocco, Tunisia, Spain, Italy, France, England, The vice-chairman. The connection between Tethyan and Netherlands, Czech Republic, Rumania and Georgia. Boreal ammonite zonations is thus assured. Of course, This 3rd international Workshop was organized in correlations with austral Lower Cretaceous ammonite the framework of IGCP Projects 362 "Tethyan and zones will not be excluded from the discussions.
(1) Nationaal Natuurhistorisch Museum, Leiden, The Netherlands (2) Servizio Geologico Nazionale Largo S. Susanna 13,1-00187 Roma, Italy (3) Institute of Geology and Geophysics, str. Caransebes 1, 78 344 Bucuresti, Rumania (4) Dpt. Estratigrafta y Paleontologia Facultad de Ciencias-Universidad de Granada, Poligono Universitario Fuentenueva, 18002 Granada Spain (5) Muséum d'Histoire Naturelle, 60 Bd. Risso, 06300 Nice, France (6) Università di Milano, Dip. Scienze della Terra, via Mangiagalli 34,1-20133 Milano, Italy (7) Département de Géologie Faculté de Sciences, Université Caddi Ayyad, Bd. Prince Moulay Abdellah, B. P. : S. 15 - Marrakech, Morocco (8) via Secchiano 16,1-61043 Cagli, Italy (9) A. Djanélidze Geological Institute, Academy of Sciences of Georgian Republic, Z. Rukhadze str. 1/9, 380093 Tbilisi, Georgia ( 10) via Venezia 42,1-61043 Cagli, Italy (11) Ministère de l'Economie NationaleDirection Generale des Mines 17, Av. Khereddine Pacha, 1002 Tunis, Tunisia ( 12) Università "La Sapienza", Dip. Scienze della Terra, piazzale Aldo Moro 5,1-00185 Roma, Italy (13) Dept. of Geological Sciences, University College, Gower Street, London WC1E 6BT, United Kingdom (14) Centre d'Etudes Méditerranéennes, 60 Bd. Risso, 06300 Nice, France (15) Katedra geologie a mineralogie VSB, tr. 17 listopadu, CZ-708 93 Ostrava-Poruba, Czech Republic 214 HOEDEMAEKER P. J. - CECCA F. el alii
Tab 1 - Ammonite zonation for the Mediterranean Lower Cretaceous as defined during the Mula Workshop (HOEDEMAEKER & COMPANY, 1993). - Zonazione ad ammoniti per il Cretaceo inferiore mediterraneo definita nel Workshop di Mula (HOEDEMAEKER & COMPANY, 1993).
STAGES ZONES SUBZONES HORIZONS S. (S.) DISPAR S. (S.) DISPAR UPPER S. (F.) BLANCHELI M. INFLATUM E. LAUTUS E. LORICATUS
LB 1 MIDDLE < II. DENTATUS II. SPATHI L. LYELLI LOWER D. MAMMILLATUM L. LARDCFURCATA II. JACOBI UPPER A. NOLANI Z D. NODOSOCOSTATUM MIDDLE P. MELCHIORIS E. SUBNODOSOCOSTATUM < D. FURCATA D. DESHAYESI LOWER D. WEISSI D. TUARKYRICUS H. RIDZCWSKYI M. SARASINI I.GIRAUDI UPPER II. FERAUDIANUS IIA N H. SARTOUSIANA A. VANDENHECKII H. CAILLAUDIANUS ARR ] 05 N. PULCHELLA LOWER S. NICKLESI S. HUGII P. ANGULICOSTATA auct. P. CATULLOI P. ANGULICOSTATA auct. UPPER B. BALEARIS [A N "P. LIGATUS" S. SAYNI u C. CRUASENSC H L. NODOSOPLICATUM ta O. (J.) JEANNOTI LOWER C. LORYI C. LORYI A. RADIATUS
N. (T.) PACHYDICRANUS N. (T.) CALLIDISCUS A N Z UPPER H. TRINODOSUM C. LURCILLATA O O. (O.) NICKLESI S. VERRUCOSUM B. CAMPYLOTOXUS .LA N LOWER T. PERTRANSIENS T. OLOPELA T. ALPILLCNSIS UPPER F. BOISSIERI B. PICTETI M. PARAMIMOUNUM D. DALMASI MIDDLE T. OCCITANICA B. PRIVASENSIS RRIAS 1 T. SUBALPINA BE ' LOWER 13. JACOBI graphics by G.M.B. LOWER CRETA! 1:01 JS AMMONITE ZONATION 215
The main result of the scientific discussions is that (down to 100.000 years). If we stop with this well-tested the attendants did not change the zonal scheme adopted and more than a century old tradition, the comparison during the 2nd Workshop in Mula (Spain) in 1992 with older literature becomes almost impossible. (HOEDEMAEKER & COMPANY, 1993). This scheme is Worldwide correlation can best be done with reproduced here in Table 1. This means that a certain magnetostratigraphy, or with an "integrated stability in standard ammonite zonation has been stratigraphy" approach. reached. This is a good sign because the zonation would The next workshop is planned for 1997 in England loose credibility if it is changed every two years. The where the ammonite zonation of the boreal and possibly zonation adopted by the Workshop will be used on the austral Lower Cretaceous will be discussed and new sequence-stratigraphic Mesozoic-Cenozoic cycle correlated with the slightly corrected Mediterranean chart, which is now in press in a Special Publication of standard. the Society of Economic Paleontologista and Mineralogists (SEPM). Slight corrections are necessary in the Lower Barremian and Lower Valanginian, but the REFERENCES studies in which these corrections are proposed should HOEDEMAEKER J., COMPANY M. (Reporters) and AGUIRRE-URETA M. B.. be published first. AVRAM E., BOGDANOVA T. N., BUJTOR L., BULOT l... CECCA E., During the Workshop P. RAWSON presented his DELANOY G., ETTACHFINl M., MEMMI L., OWEN II. G., RAWSON P. correlation between the pre-Aptian Mediterranean and F., SANDOVAL J., TAVERA J. M., THIEULOY J.-P., TOVBINA S. Z. & Boreal zonation. We refer the reader to his paper VASICEK Z. (1993) - Ammonite zonation for the Lower Cretaceous of the Mediterranean region; basis for the stratigraphie (RAWSON, this volume). correlations within IGCP-Project 262. Revista Espanola de The majority of the attendants agreed that the Paleontologia, 8 (1): 117-120, 1 lab., Madrid. ammonite biochronozones should be used to define RAWSON P. F. (this volume) - The "Boreal" Early Cretaceous (Pre-Aptian) Lower Cretaceous stages; ammonites still provide the ammonite sequences of Nw Europe and their correlation with the finest stratigraphie resolution in the Mesozoic erathem Western Mediterranean faunas. INDEX
CECCA F., PALLINI G. - Preface - Prefazione
HOEDEMAEKER Ph. J. - Introduction - Introduzione
AVRAM E. - Representatives of the Family Holcodiscidae SPATH, 1924 (Ammonitina) in Rumania. Rappresentanti della Famiglia Holcodiscidae SPATH, 1924 (Ammonitina) in Romania
CECCA F. - Late Valanginian ammonites from Monte Catria (Umbria-Marche Apennines, Italy). Ammoniti del Valanginiano superiore del Monte Catria (Appennino Umbro-Marchigiano, Italia) . .
CECCA F. - Pulchellia (Heinzia) pallina sp. n. e Pulchellia (Heinzia) provincialis (D'ORBIGNY): ammoniti del Barremiano superiore dell'Appennino Umbro-Marchigiano. Pulchellia (Heinzia) pallina sp. n. and Pulchellia (Heinzia) provincialis (D'ORBIGNY): Upper Barremian Ammonites of Umbria-Marche Apennines
DELANOY G. - About some significant ammonites from the Lower Aptian (Bedoulian) of the Angles - Barrême area (South-East France). Su alcune ammoniti significative dell' Aptiano inferiore (Beduliano) nell 'area di Angles-Barrême (Sud-Est della Francia)
KAKABADZE M. V., KOTETISHVILI E. - New data on the Upper Barremian biostratigraphy of the Georgian region (Caucasus). Nuovi dati sulla biostratigrafia del Barremiano superiore della regione georgiana (Caucaso)
MEMMI L. - Biostratigrafia dell'Aptiano in Tunisia nord-orientale. Considerazioni stratigrafiche sull'Aptiano e l'Albiano in Tunisia. Aptian biostratigraphy of northeastern Tunisia. A stratigraphical approach of Aptian and Albian of Tunisia
RAWSON P. F. - The "Boreal" Early Cretaceous (Pre-Aptian) ammonite sequences of Nw Europe and their correlation with the western Mediterranean faunas. Le successioni ad ammoniti "Boreali " del Cretaceo inferiore (Pre-Aptiano) dell'Europa Nord Occidentale e loro correlazione con le faune mediterranee occidentali.
RAWSON P. F. - Biogeographical affinities of NW European Barremian ammonite faunas and their palaeogeographical implications. Affinità biogeografiche delle faune ad ammoniti del Barremiano dell'Europa nord occidentale e loro implicazioni paleogeografiche
ROPOLO P. - Implications of variation in coiling in some Hauterivian (Lower Cretaceous) heteromorph ammonites from the Vocontian basin, France. Implicazioni della variabilità dell'avvolgimento in alcune ammoniti eteromorfe dell'Hauteriviano (Cretaceo inferiore) del bacino voconziano, Francia. .
VASÌCEK Z. - Aptian and Albian ammonites in the Western Carpathians (the Czech and Slovak Republics). Ammoniti aptiane ed albione nei Carpazi occidentali (Repubbliche Ceca e Slovacca)
VASÌCEK Z., RAKUS M. - Lower Aptian Ammonites from the Medziholie locality (the Mala Fatra Mountains, Slovakia). Ammoniti dell'Aptiano inferiore della località di Medziholie (Monti Mala Fatra, Slovacchia) 218 INDEX
APPENDIX
CECCA F., FARAONI P., MARINI A., PALLINI G. - Field-trip across the representative sections for the Upper Hauterivian - Barremian ammonite biostratigraphy in the Maiolica exposed at Monte Nerone, Monte Petrano and Monte Catria (Umbria-Marche Apennines). Escursione attraverso le sezioni rappresentative per la biostratigrafia ad ammoniti dell'Hauteriviano superiore- Barremiano della Maiolica affiorante a Monte Nerone, Monte Petrano e Monte Catria (Appennino umbro-marchigiano)
HOEDEMAEKER Ph. J. , CECCA F., (Reporters) and AVRAM E., COMPANY M., DELANOY G., ERBA E., ETTACIIFINI M., FARAONI P., KAKABADZE M. V., LANDRA G., MARINI A., MEMMI L., PALLINI G., RAWSON P. F., ROPOLO P., SANDOVAL J., TAVERA J. M. & VASÌCEKZ. - Report on the 3rd international Workshop on the standard Lower Cretaceous ammonite zonation of the Mediterranean region. Rapporto sul 3° Workshop internazionale sulla zonazione standard ad ammoniti del Cretaceo inferiore della regione Mediterranea
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