Permian Deep-Water Ostracods from Sicily (Italy). Part 2: Biofacial Evaluation and Remarks to the Silurian to Triassic Paleopsychrospheric Ostracods

Geol. Paläont. Mitt. Innsbruck, ISSN 0378-6870, Sonderbd. 3, S. 25-38, 1991

PERMIAN DEEP-WATER OSTRACODS FROM SICILY (ITALY). PART 2: BIOFACIAL EVALUATION AND REMARKS TO THE SILURIAN TO TRIASSIC PALEOPSYCHROSPHERIC OSTRACODS

Heinz Kozur

Abstract: The Permian sequence of the Sicanian paleogeographic domain in Western Sicily was deposited under continuous pelagic deep-water conditions with unrestricted connection to the Permian Pacific (Panthalassa). The ostracod faunas of these pelagic deposits indicate an ecotype that is common and characteristic for open pelagic conditions and water-depths below 200-500 m in Silurian to Triassic géosynclinal areas. Because of the very low evolutionary rates these cosmopolitic faunas contain during the Late Paleozoic and Triassic increasing percentages of archaic elements that disappeared suddenly during the Upper Liassic, when thermospheric conditions were established in the world oceans. The term Thuringian for this ecotype cannot be used, because this term is preoccupied by the Thuringian stage (= Zech- stein) of Upper Permian. The term paleopsychrospheric ostracod faunas is introduced here for these above mentioned Si- lurian to Triassic (Lower Liassic) ostracod faunas. General morphologic characters and distribution patterns of these paleopsychrospheric ostracod faunas show similarities to the Tertiary - Recent psychrospheric ostracod faunas (e.g. total lack of eye tubercles in such groups that have contemporaneous representatives with eye tubercles in shallow-water seas, dominance of smooth and spined forms by absence of the sculpture type with heavy broad ribs, very homogenous faunas over large distances, very high percentage of cosmopolitic species).

Zusammenfassung: Die permischen Schichtenfolgen der Sicanischen paläogeographischen Einheit Westsiziliens wurden unter kontinuierli- chen pelagischen Tiefwasserbedingungen bei uneingeschränkter Verbindung zum permischen Pazifik (Panthalassa) sedimentiert. Die Ostracodenfaunen dieser pelagischen Ablagerungen zeigen einen Ökotyp an, der in silurischen bis triassischen Geosynklinalgebieten weit verbreitet ist und offene pelagische Bedingungen bei Wassertiefen unter 200-500 m charakterisiert. Wegen der sehr geringen Evolutionsraten enthalten diese kosmopolitischen Faunen während des Jungpaläozoikums und der Trias wachsende Anteile von archaischen Elementen, die während des Oberlias plötzlich verschwanden, als sich thermospherische Bedingungen in den Weltozeanen einstellten. Die Bezeichnung "Thuringian" für diesen Ökotyp kann nicht verwendet werden, weil diese Bezeichnung für die Thu- ringian-Stufe (= Zechstein) des Oberperm präokkupiert ist. Die Bezeichnung paläopsychrosphärische Ostracodenfaunen wird hier für diese oben genannten silurischen bis triassischen (unterliassischen) Ostracodenfaunen eingeführt. Allge- meine morphologische Merkmale und Verbreitungsmuster dieser paläopsychrosphärischen Ostracodenfaunen zeigen Ähnlichkeiten mit den tertiären bis rezenten psychrosphärischen Ostracodenfaunen (z.B. totales Fehlen von Augenkno- ten in solchen Gruppen, die altersgleiche Vertreter mit Augenknoten in Flachmeeren besitzen, Dominanz von glatten und bestachelten Formen bei Abwesenheit des durch grobe, breite Rippen gekennzeichneten Skulpturtypus, sehr homogene Faunen über große Entfernungen, hoher Prozentsatz kosmopolitischer Arten).

1. INTRODUCTION ostracod faunas have been found, the composed strati- graphic column of pelagic Permian and Triassic in West- In part I of this paper (this volume) Permian deep- ern Sicily, and the ostracod plates have been presented in water ostracod faunas from pelagic sequences of the Sosio part 1 (text-figs. 1-3, pis. 1, 2). Valley area and the Lercara-Roccapalumba area (both In the present part 2 the paleoecologic importance of Western Sicily) were described. The map of the investigat- the rich deep-water ostracod faunas from the higher Mid- ed areas, the geological sketch of the Torrente San Caloge- dle Permian to basal Upper Permian and of similar faunas ro section WSW of Pietra die Salomone, where the richest in the Paleozoic and in the Triassic is discussed.

25 2. REMARKS TO THE PERMIAN BASI- Quite characteristic for the limy sandstones and NAL SEQUENCE IN WESTERN SICILY sandy limestones of the flysch unit are enigmatic, spine- like microproblematica. Like echinoderms, they consist of CATALANO; DI STEFANO & KOZUR (1988b) high-magnesium calcite, but all are tetraradiate with pores recognized for the first time a Permian pelagic deep-water between the 4 ridges. Their paleoecologic significance is sequence in the Sicanian paleogeographic domain of unknown, but because they are quite missing in the accom- Western Sicily. According to these authors, it consists of panying shales and siltstones with deep-water fossils, they Kungurian (Jachtashian) flysch, a Kubergandinian Olis- are rather components transported into the basin together tostrome Unit and a Wordian to Dzhulfian Claystone Unit. with the algae, bryozoans etc. On the other hand, these mi- The Kungurian flysch is the oldest well exposed croproblematica are also unknown from typical shallow- stratigraphie unit in the Sicanian paleogeographic domain. water carbonates of Lower Permian age. Perhaps they indi- Several 100 m of this unit are exposed, but its thickness cate, as N. pequopensis and S. behnkeni, outer shelf con- may be considerably larger, because its base is never ex- ditions. posed. The flysch consists of reddish or gray sandstones, As a whole, the typical Kungurian flysch sequence is siltstones and shales. Graded bedding, flut casts and other a deep-water deposit with strong influx of clastic material sedimentary marks are common in these rocks. Resedi- and partly also with resedimented shallow-water fossils. mented limy sandstones to sandy limestones occur subor- Strong terrigenous influx and layers with fine plant detritus dinately in the reddish or reddish and gray part of the indicate the vicinity of a land or island arc. The flysch may flysch, whereas in the gray part only few banks of carbo- indicate last Hercynian compressive movements. The co- natic sandstones have been found. nodonts are slightly altered (CAI = 2), unlike the Chihsian Trace fossils of the Nereites ichnofacies are com- to Rhaetian conodonts of the Sicanian paleogeographic do- mon. Especially frequent are Paleodictyon and feeding main that are quite unaltered (CAI = 1 ), if they are not ther- traces with meander patterns, but Paleodictyon seems to mally alterd along young faults. be restricted to the red flysch. This ichnofacies, especially The flysch sequence is overlain by the Olistostrome the common occurrence of Paleodictyon (first evidence of Unit (see part 1, Unit A in text-fig. 2) of several tens to this Silurian - Tertiary ichnogenus in the Permian) is more than 100 m thickness. Its matrix is a dark-gray, soft, known only from deep-water deposits, according to FREY often pyritic clay with sand grains, among it rose quartz. It & SEILACHER ( 1980) from the lower bathyal and abyssal contains only very few, but partly stratigraphically impor- zones in water-depths well below 1000 m. tant fossils. The conodont association with Mesogondo- Except of trace fossils only Ammodiscus sp. is fre- lella phosphoriensis (YOUNQUIST; HAWLEY & quent in the shales and siltstones, but neither ostracods nor MILLER) and Sweetognathus subsymmetricus WANG; other fossils with calcareous shells occur. Only in the gray RITTER & CLARK indicates basal Middle Permian (Ku- flysch occasionally prints of very small (juvenile ?) bi- bergandinian) age. Like in the flysch, also these condonts valves and very few ostracods can be found. Conodonts are from the matrix of the Olistostrome Unit are typical Cir- rare and represented by the pelagic Mesogondolella inter- cum-Pacific species. Except of conodonts, only a few pyri- media (IGO) and M. idahoensis (YOUNGQUIST; tized radiolarians (mainly Albaillellacea) and very few of HAWLEY & MILLER) indicating a Jachtashian (Kungu- the above mentioned microproblematica are present that rian) age of the flysch. Plant detritus occurs in some layers may be reworked from the underlying flysch sequence. of the gray flysch. Therefore the coast of a continental area Spormorphs are common, but plant detritus cannot be ob- or island arc was not far during the deposition of the flysch. served. The few limy sandstones or sandy limestones are The olistoliths consist largely of gray flysch sedi- rich in resedimented shallow-water fossils (algae, bryo- ments from the underlying sequence. Rocks unknown zoans, few ostracods and fusulinids). They are often cor- from sequences are also present among the olistoliths. roded or show other signs of resedimentations. Except of They consist of dark-gray, hard radiolarian marls, some- these fossils transported from adjacent shallow-water what siliceous, radiolarian-rich calcilutites, resedimented areals, some well preserved conodonts are present. Like in calcarenites, biogenic limestones and dark-gray, marly the shales and siltstones the pelagic M. intermedia and M. brachiopod-ammonoid limestones with light-grày lime- idahoensis occur, but additionally Neostreptognathodus stone interclasts. pequopensis BEHNKEN and Sweetognathus behnkeni All these limestones and marls contain very rich pe- KOZUR are present indicating more marginal and shal- lagic Circum-Pacific faunas. The radiolarian-bearing olis- lower environments. toliths (marls, calcilutites, see above) contain typical Cir-

26 cum-Pacific Lower Permian Pseudoalbaillella associa- contain more than 1,000 conodonts per kg material. Except tions, e.g. with Pseudoalbaillella scalprata scalprata of conodonts these calcarenites contain sponge spicules HOLDS WORTH & JONES, P. scalprata post scalprata and ostracods, but often also debris of phosphatic fossil re- ISHIGA, P. (Kitoconus) elongata ISHIGA & IMOTO. mains (redeposited fish remains), partly with bonebed These radiolarians indicate Jachtashian (Kungurian) age. character. For some faunas latest Artinskian age cannot be excluded. Pelagic sedimentation continued during the Triassic These rocks are therefore lateral equivalents of the flysch (see part 1, text-figs. 2,3). In the Lower Ladinian (Unit C in deposited in more distal parts of the basin without terrigen- text-fig. 2) gray, greenish-gray and red radiolarites, green- ous influx. ish tuffites, siliceous, partly cherty limestones prevail, The calcarenites and biogenic limestones contain whereas the Upper Ladinian is built up by greenish-gray to very rich Chihsian pelagic conodont faunas with Meso- pink nodular cherty limestones, somewhat marly shales gondolella zsuzsannae KOZUR, rare M. slovenica RA- and quite subordinately red radiolarites (Unit D in text- MOVS and some Hindeodus sp. In the biogenic limesto- fig. 2). In the Middle Carnian dark-gray, marly, often cher- nes additionally reef-debris occur (reef-slope sediments). ty limestones and marly shales prevail and from the Upper The brachiopod- and ammonoid-bearing limestones Carnian to Rhaetian a monotonous sequence of bedded, contain few conodonts, M. idahoensis (YOUNGQUIST; light-gray cherty limestones is present. HAWLEY & MILLER) and Sweetognathus guizhouensl BANDO et al. that indicate latest Jachtashian (latest Kun- gurian) to Chihsian age. Scolecodonts are common, indicating that these rocks were not deposited in water depth 3. PALEOECOLOGIC EVALUATION OF below 100 m, where scolecodonts are rare. THE DEEP-WATER OSTRACOD FAU- As a whole, the Chihsian olistoliths indicate a shal- NAS FROM THE MIDDLE-UPPER PER- lowing of the basin after the deposition of the flysch and MIAN CLAYSTONE UNIT OF THE SOSIO contemporaneous radiolarian marls and radiolarian-bear- VALLEY AREA AND OF PALEOZOIC TO ing calcilutites during the Jachtashian (Kungurian). Seem- TRIASSIC OSTRACOD FAUNAS FROM ingly carbonatic sedimentation prevailed during the Chih- SIMILAR ENVIRONMENTS sian. Pelagic limestones prevail, but reefs were present adjacent to the basin. The ostracod faunas of the Middle-Upper Permian The Olistostrome Unit indicates the onset of a new Claystone Unit, both from the red clays and from the cal- sedimentation cycle. During this time a deepening of the carenites, are quite different from the well known and rich basin and a transgression on the foreland began. In the next contemporaneous shallow-water ostracod faunas from the higher unit, the Claystone Unit (see part 1, Unit B in text- adjacent Western Tethyan shelf. In the red clays, even the fig. 2), predominantly red, in the lower part also light-gray genera are different except of some ubiquitous forms, like clays without any sand content have been deposited. Partly Haworthina, Roundyella and doubtful Bashkirina. In they contain only siliceous microfossils (radiolarians, the calcarenites (reworked subordinately also in the red spicules of Silicospongea), partly also ostracods and fo- clays) several genera of kirkbyids are identical with the raminifers are present. These clays represent a strongly shallow-water ostracod faunas. Bairdia and Cryptobair- condensed sequence. In a few meter of these clays Wordi- dia are here common and Parabythocythere is present. an, Capitanian, Abadehian and Dzhulfian fossils can be But even in these faunas neither among the kirkbyids nor found. The radiolarian fauna consists of Circum-Pacific among Bairidia, Cryptobaridia and Parabythocy there species, dominated by highly evolved Follicucullidae, e.g. identical species with the shallow-water faunas can be Pseudoalbailella eurasiatica KOZUR; KRAHL & found. Whereas the shallow-water faunas from adjacent MOSTLER, Follicucullus monacanthus ISHIGA & areas are quite different, similar ostracod faunas can be IMOTO, F. cf. charveti CARIDROIT & DE WEVER, found in Lower Permian beds of Timor Island. Both these Ishigaconus scholasticus (ORMISTON & BABCOCK). similarities and the difference against contemporaneous In some samples mass occurrences of radiolarians with shallow-water faunas from the adjacent shelf are facies- several 100,000 specimens per kg material can be ob- controlled (see below). served. The richest ostracod faunas have been found in sam- Conodonts are nearly absent in the clays, but ex- ple 655 (1 kg red clay) of Upper Capitanian to Abadehian tremely frequent in broken, thin beds of calcarenites that age. The clay disintegrated in cold water and was washed

27 with a 0.063 mm sieve. The residues (72 g) consist exclu- turn, are here more frequent, especially Kellettina reticu- sively of fossils. Except of some 100 ostracods, some fora- lata is common. miniferes and few siliceous sponge spicules, only radiolar- The kirkbyids of the calcarenites (and of the red ians are present. They are quite identical with species from clays) are all very small forms (mostly 200-300 (im long), the highest Middle Permian to basal Upper Permian red in contrary to contemporaneous species (often of the same deep-sea cherts from Japan and from Oman. They indicate genera) from adjacent shallow-water seas that are in gener- pelagic conditions and a broad, open deep-water connec- al 600-1,000 ¡im long. Part of these forms, especially from tion to the Permian Pacific (Panthalassa). The same is indi- the red clays, are seemingly juvenile forms, but also the cated by the pelagic conodont faunas from the calcarenites adults of the most species are very small. There is a possi- that consists likewise exclusively of Circum-Pacific spe- bility that these small forms lived interstitially, like the re- cies. cent Punciidae. The calcarenites consist of biogenic calcareous Even the calcarenites have not yielded any real shal- sands without any terrigenous components. They are dia- low-water fossil. Seemingly this fauna was transported genetically not much changed and have still many open from shallower, but not shallow seas adjacent to reefs into pores (poorly cemented). Between the biogenous calcare- the deep water basin. From the geological situation can be ous sand grains many fossils, especially ostracods, sponge concluded that the faunas of these calcarenites are mixed spicules and conodonts can be observed on the surface of and they should contain faunal elements that lived origi- these rocks. These calcarenites may have been the distal nally in different water depth. But ostracods with eye tu- parts of fans of transported material from adjacent reefs. bercles and sculpturated bairdiids, frequent in contempo- Only few such calcarenites are present. With exception of a raneous shallow-water sediments of the Western Tethys more than 10 cm thick bank from the lower part of the se- shelf, are quite missing. The accompanying other faunal quence, they are only some mm thick. All these calcaren- elements are pelagic. Therefore also this ostracod fauna is ites are broken and randomly distributed in the strongly not a shallow-water fauna, but has lived in water depth be- disturbed red clays. low 300 m (missing eye tubercles !). No macrofossils can be found in these calcarenites The red clays are real deep-water sediments, indicat- (and in the red clays). So, seemingly the reefs were not im- ed by all, mainly siliceous faunal elements (CATALNO; mediately adjacent to the deposition area of the red clays DI STEFANO & KOZUR, 1988 a, b and in press). This is with some calcarenites. Reef limestones are only known also indicated by the geological development of this area. from tectonic blocks in the Sosio Valley. Already the Kungurian flysch contains very rich deep-sea The ostracods of the calcarenites are white and have trace fossil associations with numerous Paleodictyon. In white calcareous matrix. Some of so preserved ostracods the Middle Permian in the whole southern and central part can be found also quite subordinately in the red clays most- of the Western Tethys sinking tendencies and wide trans- ly adjacent to the calcarenites. They seemingly derived gressions on the foreland can be observed (e.g. with more from these calcarenites, in which they can be easily moved than 4,000 m Wordian and Capitanian shallow-water sedi- from their surface. Amphissites ? sosioensis, Kellerina ments in Tunisia). The time-equivalents of this thick se- reticulata, Kirkbya ? n. sp., Nodoparaparchites reticu- quence are few meters of red shales in the Sicanian paleo- lonodosa and Parabythocythere siciliensis could be geographic realm of Western Sicily. The sedimentation found only in this preservation and have therefore original- rate was therefore very low. Input of terrigenous material, ly not lived in the red clays, but they are all known from the like in the Lower Permian cannot be observed anymore. calcarenites. Some of the red clays contain only siliceous faunal The ostracod fauna of the calcarenites consists of elements (radiolarians, sponge spicules, agglutinated fo- Bairdia/Cryptobairdia (only 2 species, but many speci- raminifers), in others also calcareous microfossils (ostra- mens) and of some species that can be also found in the red cods, calcareous foraminifers, but not fusulinids) occur. clay. Sinocoelonella densistriata is frequent in both rocks The red clays with some calcareous microfaunas beside and also Spinomicrocheilinella dargenioi, Microcheili- dominating siliceous microfossils have been surely de- nella sp., Paraberounella laterospina and the Bashkir i - posited above the CCD. Those red clay that contain only na, Haworthina and Roundyella species can be found in fossils with siliceous skeleton may indicate deposition be- both facies. On the other hand, Pseudospinella ruggierii low the. CCD. and Spinososioella catalanoi, both frequent in the red The evaluation of all geological and faunistical data clays, could not be found in the calcarenites. Kirkbyids, in shows that the ostracod-bearing red clays has been deposit-

28 ed above, but near the CCD. Their deposition depth was After this faunal event in the deep-water associa- surely considerably deeper than 1000 m water-depth. The tions, not related to a comparably strong event in the shal- deep-water connection to the Permian Pacific was broad low-water faunas, quite transitional changes from the shal- and unrestricted, because the radiolarian and conodont low-water into deep-water ostracod assemblages can be faunas are even in specific level identical with the Circum- observed. Mostly the same groups occur in the shallow- Pacific faunas. and deep-water, only with other species or partly genera. The climate during the Middle and Late Permian was The morphologic differences between the shallow- and in the Western Tethys area subtropical/tropical (reefs in deep-water ostracod faunas are from this time the same as shallow-water blocks in Sicily, fusulinid-algal limestones indicated by BENSON (1984) for thermospheric Creta- on the Western Tethys shallow-water shelves). But in ceous deep-water ostracods against contemporaneous Gondwana and in the Angaride Province cold-water fau- shallow-water ostracods. This situation continued from nas are known throughout the Permian and in the deeper the Toarcian up to the Late Cretaceous or even Paleocene. Lower Permian glacial sediments are widespread in Gond- In this time the world oceans were really thermo- wana and some glaciomarine sediments were reported spheric. Because of the missing thermocline, the differenc- from the higher Permian of northern Siberia. Therefore we es between the shallow-water and deep-water ostracods can await psychrospheric conditions in the world oceans were not so great and the changes were gradual over a long- during the Permian. er depth interval. Moreover, the Jurassic and Cretaceous The extreme differences between the shallow-water deep water ostracods were not so cosmopolitic than the Eo- and deep water ostracods in the Western Tethys confirms cene to recent psychrospheric ostracods and the Silurian to this opinion. Seemingly a distinct thermocline between the basal Jurassic paleopsychrospheric (term explained later) warm surface water and the colder deeper water was ostracods. present that acted as faunal barrier. Quite the same strong Except of the archaic paleopsychrospheric deep-wa- differences between shallow-and deep-water faunas were ter ostracods from pelagic sediments with unrestricted present during the Triassic. Deeper water faunas from pe- broad connection to the world ocean we find in the Triassic lagic sediments of areas with free connection to the world (and before) also deep-water ostracod faunas that are not ocean contain an archaic ostracod fauna with Acantho- archaic and therefore not so different from the shallow- scapha, Tricorninacea, strongly spined primitve Bytho- water associations. In contrary to the shallow-water faunas cytheracea, Healdiacea and other Paleozoic elements. they do not contain any taxa with eye tubercles, and species This fauna has a distinct Paleozoic aspect. Contemporane- with more delicate sculpture and broad ventral wings are ous shallow-water ostracod faunas have, in turn, typical more frequent than in shallow-water associations. Almost Meso-/Cenozoic character with many sculpturated bair- all typical Paleozoic elements, like Acanthoscapha, Tri- diids, heavily sculpturated Cytherocopina etc. Also here corninacea, are absent. Only Healdiacea are frequent, but no common species can be found between the shallow-wa- they are not restricted to deep-water environments and ter and the open-sea deep-water ostracod faunas and the common also in shallow-water sediments below the wave- transition between these faunas is rather fast. In an estimat- base. ed depth interval from about 100 m to about 500 m the os- These ostracod faunas occur in restricted basins in- tracod fauna changed nearly totally. side or behind carbonate platforms, which have no open This situation continued until the lowermost Juras- deep-water connection with the world ocean. These are os- sic. In the Toarcian a drastic world-wide change occur. In tracod faunas of low energy environments in water-depths deep water sediments, without any change of facies, sud- of more than 200 m indicated by microfacial investiga- denly all Paleozoic elements (Acanthoscapha, Tricornini- tions. From the geological situation and the subtropi- dae, Healdiacea), still dominant before, disappeared. In the cal/tropical warm climate during the Triassic can be con- same time a drastic change in the radiolarian faunas can cluded that these basins were thermospheric deeper water be observed, where nearly all Triassic elements suddenly areas. There are some evidences that at least the western- disappeared and the fauna became dominated by very most part of the southern branch of Triassic Tethys had al- small forms, especially williriedellids. From this moment so thermospheric conditions, whereas the northern branch the dominance of Entactinaria and Spumellaria against was two-layered with distinct thermocline. These two the Nassellaria changed into absolute dominance of Nas- branches were separated by the Kreios Plate sensu TOLL- sellaria. Also among the brachiopd faunas in this level MANN (compare TOLLMANN & KRISTAN-TOLL- many archaic elements disappeared. MANN, 1985) which could be a barrier for cooler bottom

29 water. The investigations to this problematic are still in BECKER (in BÄNDEL & BECKER, 1975) named progress. the here discussed deep water ostracod faunas as "Thurin- The archaic character of the Triassic (and Permian) gian Ecotype" following ZAGORA (1968) who discrimi- deep-water ostracods from areas with open deep-water nated a "Thuringian typus" for these faunas. BECKER re- connection to the world ocean indicates that these ostra- garded this fauna in contrary to the "Eifelian Ecotype" cods lived in a very stable biotope that has not significantly (shallow-water ostracods) as fauna of deeper water. Unfor- changed since the latest Ordovician/earliest Silurian. In tunately, both Eifelian and Thuringian are stratigraphie this very long time interval the oceans were surely psych- stages, so both terms can be misinterpreted. Especially in rospheric during the Late Ordovician and the Late Carbon- the Permian, "Thuringian Ecotype" would mean Zechstein iferous/Early Permian glaciations. No changes in the basic ecotype (Thuringian stage = Zechstein). character of the Silurian to Lower Carboniferous open pe- KOZUR (1972) prefered a genetic designation and lagic deep water faunas against Lower Permian or even he regarded these faunas as psychrospheric faunas, be- Late Permian ones can be observed. cause of their outstanding similarities (both in the mode of If in this long time interval several times thermo- distribution, morphology and sharp differences to the shal- spheric and psychrospheric conditions had changed in the low-water faunas) to Tertiary - recent psychrospheric os- world oceans, than the observed constancy of the here dis- tracods. However, because the Jurassic/Cretaceous oceans cussed deep water ostracod faunas.would be unexplaina- were surely thermospheric, it is better to name this fauna ble. As clearly observable in recent psychrospheric and paleopsychrospheric, a term introduced here. thermospheric deep-water ostracod faunas (e.g. from the According to KOZUR ( 1972) this fauna is restricted Atlantic Ocean and from the Mediterranean Sea) the dif- to environments with open deep water connection to the ferences between these faunas are drastical. The changes world ocean and water depth below 200-500 m (upper between psychrospheric and thermospheric ostracod fau- depth boundary of this fauna minimum 150-200 m, maxi- nas in the present day Mediterranean Sea from the Tertiary mum 500 m). As pointed out by KOZUR ( 1972) these data to recent are likewise drastical. The above mentioned are well established not (only) by comparisons with Ter- Toarcian break in the deep water ostracod faunas was like- tiary to recent psychrospheric ostracod faunas, but above wise very¡ strong. all by microfacial data that are quite independent from the This latter event is especially important for the ex- ostracod data. planation of the conditions before this event. The Juras- According to KOZUR (1972) there are no data to sic/Cretacrous oceans were surely thermospheric. The on- recognize, which water depth below the above mentioned ly explanation for the sudden disappearence of all the Pale- upper limit of the paleopsychrospheric fauna can be attrib- ozoic elements (that had survived in deep water environ- uted to these faunas, but, of course, these faunas have lived ments even such global events, like the Permian-Triassic in water depth well above the CCD, because they have boundary) is, that the pre-Toarcian oceans were not ther- been solved from pelagic limestones. Most of the paleo- mospheric. psychrospheric ostracod faunas have lived in water depth Because no stronger climatic changes can be ob- between 200 and 1,000-2,000 m. Faunas from still greater served during the higher Liassic, the change from a two- water depth should be expected from sediments deposited layered psychrospheric world ocean into a thermospheric near the CCD. As mentioned above, the Middle/Late Per- ocean must be caused by changes in the paleogeography mian red deep water clay from Western Sicily with the os- that have changed the oceanic circulation. If, for instance, tracod fauna described in part 1 of the present paper may the transport of warm surface water into polar regions was belong to this type of sediments. interrupted, the outflow of cold bottom water from these Bairdia s.l. (including Cryptobairdia SOHN) is regions into low latitude oceans would end. missing or extremely rare in this fauna. Quite in the con- If we trace back the archaic Permian and Triassic trary, the ostracod faunas from the few intercalated thin deep-water faunas into the Lower Paleozoic then we find calcarenites yielded many bairdiid specimens (but only this fauna exclusively in such pelagic sediments, for which one or two species unlike the shallow-water faunas with facial, faunal and geological data indicate free deep water many specimens and species). This fauna has several spe- connections to the world ocean or the depositional areas of cies in common with the red deep-water clays, others are these sediments werde situated on the margin of oceans, missing (see above) and the frequency of common species e.g. Devonian to Lower Carboniferous Hercynian geosyn- is partly different. Also this fauna has no representatives of cline of Europe, Asia and North Africa, Permian Tethys the contemporaneous shallow-water faunas from the ("Paleotethys") north of Gondwana, Timor Island. Western Tethyan shelfs. If this fauna is composed of ostra-

30 cods from different water depth, transported into the deep (8) Eye tubercles, present among many Triassic shallow- basin, so even the ostracods from the shallowest involved water ostracods, are quite missing. environment have lived below the environment of the (9) The number of species is low. Western Tethyan shallow-water faunas. (10) The hinges are primitive, mostly adont, rarely lopho- The absence or extreme scarcity of Bairdia s.l. in dont. the red clays is surely not caused by different substrates, As already pointed out by KOZUR (1972) these because bairdiids are frequent in shallow-water clays or characters can be only used for recognition of a paleo- micritic limestones. Seemingly paleopsychrospheric os- psychrospheric ostracod fauna, if the whole ostracod fauna tracod faunas rich in Bairdia s.l., represent the upper of rich associations will be evaluated and if all these cha- (depth) fauna of these associations, whereas the fauna racters are regarded together. The characters 4-10 alone without or with quite subordinate Bairdia s.l. represent the can be also found among shallow-water ostracods. For in- deeper (depth) fauna of these associations. In the Devonian stance, strongly spined species can be also found in some the "Cypridine Shales" would represent the latter deeper fresh-water ostracod faunas. The deep-water ostracods are faunas, as already assumed by KOZUR ( 1972). In the Per- in general more thin-shelled, but Cytherellacea are also in mian, the ostracod fauna of the Sicilian red deep-water paleopsychrospheric deep water ostracod faunas thick- clays would belong to the deeper, the fauna of the Lower shelled. On the other hand, fresh-water ostracod faunas are Permian "flysch" of Timor to the shallower paleopsychros- generally more thin-shelled than even deep-water faunas. pheric ostracod faunas. However, also the latter fauna was In the case of eye tubercles, only the total absence of this not a shallow-water fauna, but has lived below 200 m wa- feature in all ostracods of a rich fauna is important, because ter depth. many ostracods, like Platycopina, Cladocopida and Heal- A confirmation of the above considerations yielded diacea have never eye tubercles, neither in deep-water nor Triassic ostracod faunas from sediments deposited near the in shallow-water environments. CCD (cherts/cherty limestones above oceanic pillow la- The number of species is related to all paleopsych- vas). These sediments yielded ostracod faunas very poor in rospheric deep-water associations from different parts of species and specimens that have not yielded so far any bair- the world against all different shallow-water associations. diids. In a single shallow-water association the number of spe- The following characteristics for the Triassic paleo- cies is often lower than in a single paleopsychrospheric as- psychrospheric ostracods can be established (KOZUR, sociation. But because of the high facial differentation in 1972, p. 633): the shallow-water against a rather uniform paleopsychro- ( 1 ) Large part of the fauna is archaic (before only known spheric environment, the shallow-water faunas are by far up to the Lower Carboniferous or even Late Devoni- more differentated and they comprise about 70% of the an), like Tricorninacea, primitive, heavily spined By- known Triassic ostracod species. thocytheracea (Paraberounella, Nemoceratina, Tu- With exception of the points 1, 2 the above men- ber oceratina), Acanthoscapha, Acratia, Healdia, tioned characters of the paleopsychrospheric ostracods are Cavellina, Sulcella, Discoidella. the same as BENSON & SYLVESTER-BRADLEY (2) Compared with Triassic shallow-water faunas, but al- (1971) described for recent psychrospheric ostracods. If so compared with Triassic thermospheric deep-water we include into the considerations also the Tertiary psych- faunas from restricted basins, the phylomorphogenet- rospheric ostracods, than we can also point 2 recognize in ic changes within the Triassic paleopsychrospheric recent psychrospheric ostracods. But even the archaic faunas during the Triassic were only very slow. - character for some recent psychrospheric ostracods can be (3) The faunas were homogenous over huge distances proven. Paleozoic elements are, of course, in general not (very high percentage of cosmopolitic species). more present, because they disappeared with the beginning (4) The most species are thin-shelled. of thermospheric oceans during the Lower Jurassic. (5) Some of the species are larger than Triassic shallow- Inspite of these obvious similarities between the re- water ostracods, e.g. Acanthoscapha with more than cent psychrospheric and the Silurian to basal Liassic paleo- 2 mm length. psychrospheric ostracod faunas, the term paleopsychros- (6) The surface/volume ratio is in general high. pheric refers rather to the existence of a two-layered ocean (7) Many ostracods are smooth or strongly spined. The with distinct thermocline than to the absolute temperature sculpture type of strong broad ribs, quite frequent in of the lower layer. Of course, this lower layer was relative- the contemporaneous shallow-water faunas, is miss- ly considerably cooler than the upper layer, but the temper- ing. ature must not have been so low than in present day psych-

31 rospheric oceans. However, because of the quite different archaic aspect of these faunas is already distinct, because character of the paleopsychrospheric ostracods from the the shallow-water faunas contain in this time already many contemporaneous shallow-water (and also from contem- higher evolved Podocopida, Platycopida and Reticuloco- poraneous thermospheric deep water) ostracods and be- pida. On the other hand, among the Metacopina, Puncioco- cause of the cosmopolitic distribution of the paleopsych- pina, Binodicopina and the few Beyrichiida that can be rospheric ostracods, these differences can be only ex- found in Late Paleozoic paleopsychrospheric ostracod plained by the presence of a distinct thermocline. Moreo- faunas, especially such primitive forms can be observed ver, below this thermocline the temperature of the lower that were not more present in contemporaneous shallow- layer must be both regionally and seasonally constant and water faunas. not regionally and seasonally changing. Inspite of the fact that the paleopsychrospheric ostra- The paleopsychrospheric ostracods from the Siluri- cod faunas have evolved more than 200 my in a very stable an up to the Permian do not show decisive differences environment as discussed above, they cannot be regarded against the Triassic ones, but not all 10 points listed above, as abyssal faunal elements from ancient oceanic plains that can be used for recognition of these faunas. So, the hinge is should have had especially stable environments. Rocks also among the most shallow-water ostracods primitive from these ancient oceans are today mostly not preserved and not only among the paleopsychrospheric ostracods. or they consist of often metamorphic remnants of oceanic Many shallow-water ostracods are in the Paleozoic very crust covered by cherts and deep-sea clays deposited be- big forms, so that we cannot find real general size differ- low the CCD. They do not contain any ostracods, because ences between shallow-water and paleopsychrospheric os- microfossils with calcareous shells cannot be preserved tracods. Rather the paleopsychrospheric ostracods are of- there. ten smaller than the contemporaneous shallow-water os- Preserved non-metamorphic ostracod-bearing deep- tracods. Such small forms are also present among the Tri- water sediments are in general limestones from the contin- assic paleopsychrospheric ostracods, but because here the tental slope or from non-oceanic basins deposited under majority of the shallow-water ostracods is small, the very water-depths of 200 m to 1,000- 2,000 m. In these sedi- large representatives of the paleopsychrospheric ostracod mentation areas the nutrient supply, but also the sedimen- faunas are more striking. Eye tubercles are also in Paleozo- tation rate was surely higher than in oceanic abyssal plains. ic paleopsychrospheric ostracod faunas quite missing, but Therefore the diversity of these ostracod faunas will be with exception of the Permian shallow-water faunas and surely higher than in abyssal plains. the few Silurian/Devonian shallow-water faunas with Compared with the most paleopsychrospheric ostra- many Leperditida also in the shallow-water mostly such cod faunas that derived from epibathyal (subbathyal) sedi- ostracods occur that have no eye tubercles, because only ments, the few known ostracod faunas of real deep-sea sed- such groups are present that have never eye tubercles (also iments are very poor. In the Meliata-Hallstatt rift, the Mid- not in shallow-water environments). dle Triassic suboceanic pillow lavas are overlain by red ra- All these differences show the historical aspects in diolarites, higher up radiolarites and cherty limestones. the development of the paleopsychrospheric faunas. Espe- The first sediments have been deposited below, the latter cially distinct is this aspect regarding the archaic character one a little above the CCD in water depth probably below of the Triassic paleopsychrospheric ostracod faunas. This 2-3,000 m. Here a very poor ostracod fauna was found, feature is caused by the slow evolutionary rates in an envi- consisting of 2 species of healdiids. Neither spined Cythe- ronment that was nearly stable over the long time span of rocopina nor Acanthoscapha, both very typical for Trias- more than 200 my. In the latest Ordovician, where during sic paleopsychorspheric ostracod faunas have been found. the glaciation psychrospheric conditions has been estab- These latter typical paleopsychrospheric faunas are widely lished in the world oceans, the new environment was popu- distributed in distal slope sediments of the Meliata-Hall- lated mainly by the more modern podocopids. Therefore statt rift (e.g. in cherty limestones, Hallstatt Limestones). If the Silurian paleopsychrospheric ostracod faunas are not the scarcity of ostracods in the pillow lava-chert-cherty archaic, but more "modern" (dominated by podocopids) limestone sequence from central parts of the suboceanic than the contemporaneous shallow-water faunas, domi- (about 1,000 km wide) Meliata-Hallstatt rift is not preser- nated by the more primitive Beyrichiida and Leperditiida. vation controlled, than the fossil abyssal ostracod fauna In the Late Paleozoic, where the paleopsychrospheric os- were at least during the Triassic extraordinary poor and not tracod faunas contain the same groups, often the same fam- characterized by the most typical elements of the paleo- ilies and genera than the Silurian and Devonian ones, the psychrospheric ostracod fauna.

32 According to KOZUR (1972) the paleopsychro- References spheric ostracod faunas can be subdivided into 4 groups, recognizable also in the paleopsychrospheric fauna from BÄNDEL, K. & BECKER, G. (1975): Ostracoden aus pa- läozoischen Kalken der Karnischen Alpen (Silurium the Middle/Late Permian of Western Sicily: bis Unterkarbon). - Senckenbergiana lethaea, 56(1), (a) Genera that are known since the Devonian or still ear- 1-83, Frankfurt a.M. lier from paleopsychrospheric ostracod faunas ("Thu- BECKER, G. (1978): Flachwasser-Ostracoden aus dem ringian Ecotype") or near related forms that have not hohen Westfal Asturiens (Kantabrisches Gebirge, N- changed much since this time, e.g. Tricorninidae, Ne- Spanien). 1. Palaeocopida. - Senckenbergiana lethaea, 59(1/3), 37-69; Frankfurt a.M. moceratina, Pamberounella, Acanthoscapha, Boh- BECKER, G. (1981): Ostracoda aus cephalopoden- lenatia etc. In the Permian except of these forms also führendem Oberdevon im Kantabrischen Gebirge (N- the Rectonariidae belong to this group. Spanien). 1. Hollinacea, Primitiopsacea, Kirkbyacea, (b) Genera that lived formerly in shallow-water or in shal- Healdiacea und Bairdiocypridacea. - Paleontographi- low and deep water, later only in paleopsychrospheric ca, A, 173, 1-63, Stuttgart. deeper water, in the Triassic, e.g. Microcheilinella, BECKER, G. (1987): Ostracoda des Thüringer Ökotyps aus dem Grenzbereich Devon/Karbon N-Afrikas Acratina, in the Permian, for instance, Solleikope. (Marokko, Algerien). - Palaeontographica, A, 200 (c) shallow-water faunal elements that immigrated into (1-3), 45-104, Stuttgart. the paleopsychrospheric faunas, if the population BECKER, G. & SANCHEZ DE POSADA, L.C. (1977): pressure in the shallow-water populations was very Ostracoda aus der Moniello-Formation Asturiens high. These elements disappeared, if their frequency (Devon; N-Spanien). - Paleontographica, A, 158 (4/6), 115-203, Stuttgart. in the shallow-water faunas decreased. In the Triassic, BENSON, R.H. (1984): Estimating greater paleodepth for instance, some sculpturated Bairdiidae immigrat- with ostracods, especially in past thermospheric ed into the paleopsychrospheric faunas. They became oceans. — Palaeogeogr., Palaeoclim., Palaeoecol., 48, there strongly spined forms. But with the decline of 107-141, Amsterdam. the sculpturated bairdiids in post-Triassic shallow- BENSON, R.H. & SYLVESTER-BRADLEY, P.C. water sediments, no sculpturated bairdiids can be ob- (1971): Deep-sea ostracods and the transformation of ocean to sea in the Tethys. - Bull. Centre Rech. Pau- served in post-Triassic deep-water sediments. In the SNPA, 5, 63-92, Pau. Paleozoic the likewise subordinate paleopsychro- BLESS, M.J.M. (1987): Lower Permian ostracodes from spheric Beyrichiida (often spined forms) belong to Timor (Indonesia). - Proc. Kon. Nederl. Akad. We- this group. tensch., Ser. B, 90 (1), 1-13, Amsterdam. (d) Genera that are both in shallow-water and in deep-wa- BLUMENSTENGEL, H. ( 1965): Zur Taxionomie und Bi- ostratigrpahie verkieselter Ostracoden aus dem ter sediments present, but mostly represented by dif- Thüringer Oberdevon. - Freiberger Forsch.-H., ferent species, e.g. Cryptobairdia, Covellina, Cythe- C 183, 1-127, Leipzig. rella, Hungarella. The latter genus is in the Triassic' CATALANO, R.; DI STEFANO, P. & KOZUR, H; (1988 not present in water depth above 30-50 m, but below it a): First evidence of Lower Permian Albaillellacea is frequent in all water depths. (Radiolaria) in the Tethyan Eurasia. - Atti 74. Congr. Soc. Geol. It., A, 124-125, Benevento. CATALANO, R.; DI STEFANO, P. & KOZUR, H. (1988b): New results in the Permian and Triassic stratigraphy of western Sicily with special reference to the Acknowledgements section at Torrente San Calogero SW of the Pietra di Salomone(Sosio Valley). -Atti74.Congr. Soc. Geol. The author thanks very much Prof.Dr. R. Catalano, It., A, 126-133, Benevento. CATALANO; R.; DI STEFANO, P. & KOZUR, H. (in Dr. M. Gullo, Dr. P. Di Stefano and Prof. G. Ruggieri, all press): New data on Permian and Triassic stratigraphy Palermo, and Prof.Dr. H. Mostler, Innsbruck, for many sci- of Western Sicily. -N. Jb. Geol. Paläont., Abh.; Stutt- entific, technical and financial help. gart. CHEN, DE-QIONG & BAO, HONG (1986): Lower Per- mian ostracodes from the Chihsia Formation of Jurong and Longtan, Jiangsu province. - Acta Micropalaeont. Sinica, 3 (2), 107-136, Beijing. CHEN, DE-QIONG & SHI, CONG-GUANG (1982): Lat- est Permian Ostracoda from Nantong, Jiangsu and from Mianyang, Hubei. -Bull. Nanjing Inst. Geol. Pa- leont., Acad. Sinica, 4, 105-152, Nanjing.

33 FREY, R.W. & SEILACHER, A. (1980): Uniformity in KOZUR, H. (1981): Einige neue Ostracoden-Arten aus marine invertebrate ichnology. - Lethaia, 13, dem Oberperm des Bükk-Gebirges (Nordungarn). - 183-207, Oslo. Proc. Geoinst., 15, 199-204, Beograd. GRAMM, M.N. ( 1976): The inter-relation between the Pa- KOZUR, H. (1985 a): Neue Ostracoden-Arten aus dem leozoic ostracods Roundyella and Scrobicula. - oberen Mittelkarbon (höheres Moskovian), Mittel- Geol. Foren, Stockholm Förh., 98(3), 217-226, und Oberperm des Bükk-Gebirges (N-Ungarn). - Stockholm. Geol. Paläont. Mitt. Innsbruck, Sonderbd. 2, 1-145, GRAMM, M.N. ( 1977): A new family of Palaeozoic ostra- Innsbruck. cods. - Palaeontology, 20 (2), 475^82, London. KOZUR, H. (1985 b): Biostratigraphic evaluation of the GRAMM, M.N. (1984): Vnutrennie struktury rakovin pa- Upper Paleozoic conodonts, ostracods and holothuri- leozojskich ostrakod. - AN SSSR, Dalnevost. Naucn an sclerites of the Bükk Mts. Part II: Upper Paleozoic Centr Bio.-Pocv. Inst., 71 pp., Leningrad ("NAU- ostracods. - Acta Geol. Hungar., 28 (3-4), 225-256, KA"). Budapest. GRAMM, M.N. & IVANOV, V.K. (1975): The ostracod KOZUR, H. & KRAHL, J. (1987): Erster Nachweis von Paraparchites minax Ivanov, sp. nov. from the Per- Radiolarien im tethyalen Perm Europas. -N. Jb. Geol. mian of U.S.S.R., and its muscle-scarfiled. -Palaeon- Paläont., Abh., 174 (3), 357-372, Stuttgart. tology, 18(3), 551-561, London. KOZUR, H. & MOSTLER, H. (1989): Radiolarien und GRÜNDEL, J. ( 1961 ): Zur Biostratigraphie und Fazies der Schwammskieren aus dem Unterperm des Vorurals. - Gattendorfia-Stufe in Mitteldeutschland unter be- Geol. Paläont. Mitt. Innsbruck, Sonderbd., 2 (2), sonderer Berücksichtigung der Ostracoden. - Frei ber- 146-320, Innsbruck. ger Forsch.-H., Ç 111, 53-173, Leipzig. LOGAN, A. & HILLS, L.V. (eds.): The Permian and Tri- GRÜNDEL, J. (1962): Zur Taxionomie der Ostracoden assic systems and their mutual boundary. - Canadian der Gattendorfia-Stufe Thüringens. - Freiberger Soc. Petrol. Geol., Mem., 2,766 pp., Calgary, Alberta. Forsch.-H., C 151, 51-105, Leipzig. MOORE, R.C. (ed.) ( 1961 ): Treatise on Invertebrate Pale- GRÜNDEL, J. (1966): Zur Entwicklung und Taxionomie ontology, part Q, Arthropoda, 3, Ostracoda, 442 pp., der Tricornidae (Ostracoda) in Mitteleuropa. - Pa- Kansas. läont. Z., 40 (1/2), 89-102, Stuttgart. OLEMPSKA, E. (1979): Middle to Upper Devonian Os- GRÜNDEL, J. (1967): Zur Großgliederung der Ordnung tracoda from the southern Holy Cross Mountains, Po- Podocopida G.W. MÜLLER, 1894 (Ostracoda): - N. land. - Palaeont. Polonica, 40, 57-162, Warszawa, Jb. Geol. Paläont., Mh., 1967 (6), 321-322, Stuttgart. Krakow. GRÜNDEL, J. (1969): Neue taxionomische Einheiten der SCHALLREUTER, R. (1973): Die Ostracodengattungen Unterklasse Ostracoda (Crustacea). -N. Jb. Geol. Pa- Hyperchilarina und das Apa re hit e s-Prob\em. - läont., Mh., 1969 (6), 353-361, Stuttgart. Geol. For. Stockholm Förh., 95 (1), 37-49, Stock- GRÜNDEL, J. (1973): Bythocytheridae (Ostracoda) aus holm. dem Oberdevon/Dinant des Thüringer Schieferge- SHI, CONG-G AUNG & CHEN, DE-QIONG (1987): The birges. -Z. geol. Wiss., 1 (3), 329-340, Berlin. Changxingian ostracods from Meishan, Changxing, GRÜNDEL, J. & KOZUR, H. (1972): ZurTaxonomie der Zheiiang. - Stratigraphy and palaeontology of sys- Bythocytheridae und Tricornindae (Podocopida, Os- tematic boundaries in China. Permian and Triassic tracoda). - Monatsber. Deutsch. Akad. Wiss. Berlin, boundary, 1,23-101. 13(1971) (10/12),.907-937, Berlin. SOHN, I.G. (1954): Ostracoda from the Permian of the GRÜNDEL, J. & KOZUR, H. (1975): Psychrosphärische Glass Mountains, Texas. - U.S. Geol. Surv., Prof. Ostracoden aus dem Perm von Timor. - Freiberger Paper, 264 A, 1-14, Washington. Forsch.-H., C 304, 39^5, Leipzig. SOHN, LG. (1983): Ostracods of the "Winifrede Lime- GUAN, SHAO-ZENG (1978): Arthropoda, Crustacea stone" (Middle Pennsylvanian) in the region of the BRONGNIART et DESMAREST, 1822, Ostracoda proposed Pennsylvanian system stratotype, West Vir- Latreille, 1806. In: Atlas of paleontology in central ginia. -Bull. Amer. Paleont., 84 (316), 1-53, Ithaca. Southern China, 4, Micropaleontology, 115-325. TOLLMANN; A. & KRISTAN-TOLLMANN, E. ( 1985): KOZUR, H. ( 1971 ): Neue Ostracodenarten aus der tethya- Paleogeography of the European Tethys from Paleo- len Trias. In: BUNZA, G. & KOZUR, H.: Beiträge zur zoic to Mesozoic and the Triassic relations of the east- Ostracodenfauna der tethyalen Trias. - Geol. Paläont. ern part of Tethys and Panthalassa. In: N AK AZAW A, Mitt. Ibk, 1 (2), 1-76, Innsbruck. K. & DICKINS, J.M. (eds.): The Tethys, 3-22, Tokyo. KOZUR, H. (1972): Die Bedeutung triassischer Ostraco- ZAGORA, K. (1968): Ostracoden aus dem Unter-/Mittel- den für statrigraphische und paläoökologische Unter- devon von Ostthüringen. - Geologie, 17, Beih., 62, suchungen. - Mitt. Ges. Geol. Bergbaustud., 21, 1-91, Berlin. 623-660, Innsbruck.

34 Appendix To your 3 points the following answers:

The data of part 2 of the present paper were presented (1) Your "Thuringian Ecotype" does not only indi- together with the text-figs, and plates of part 1 in a lecture cate low-energy environments both in shallow-marine and on the 1st European Ostracodologists' Meeting (EOM '89) in deep-water areas. Many ostracod faunas are known from at 4.8.1989 in Frankfurt a.M. low-energy environments in the Triassic and Paleozoic Two comments were made by Prof.Dr.G. BECKER, that have not yield the "Thuringian Ecotype" ostracods. Frankfurt, and Prof.Dr.K.G. McKENZIE, Melbourne. Restricted basins are in general characterized by low-ener- These comments were presented once more after the lec- gy environments, but independent from their water depth, ture in written form to the author for publishing together both the shallower and the deeper restricted basins (the lat- with the replies by the author. Here the comments and the ter below 200 m water-depth) never yielded the ostracod replies are presented. faunas of the "Thuringian Ecotype". These ostracod faunas can be only found, if free unrestricted deep-water connections to the world oceans are present in the time intervals Prof. Dr. Becker: from the Late Ordovician to basal Jurassic and from the Eocene to recent. You and Dr. GRÜNDEL are equating faunas of the I do not know any shallow-water low-energy ostra- Hercynian geosyncline (faunas of the Thuringian Eco- cod assemblage (e.g. back-reef seas) that have yielded dur- type) with modern deep-sea faunas. Allow me to point to ing the Paleozoic and Triassic ostracods of the "Thuringian three backs: Ecotype". For instance, the Pe§ti§ Shale of the Apuseni First, the Thuringian Ecotype (in my delimition) Mountains in Romania, a time- and facies-equivalent of does not mean automatically deep-sea. It indicates gener- the "Grenzbitumenzone" in the Tessin Alps, has yielded a ally low-energy environments. very rich typical shallow-water ostracod fauna with sever- Second, the Devonian Sea was warm ("Klima stel- al species possessing eye tubercles, like in other shallow- lenweise sogar warm", KLULTAE & KRS, 1967). There water faunas. The Pe§ti§ Shale is an extremely low-energy were at this time no connections to the polar regions. There environment, in which even prints of the soft bodies of were no cold bottom currents. The sea was thermospheric. many animals are preserved. There were no psychrospheric (ostracod) faunas in the There is surely a general agreement between the os- Hercynian Geosyncline. tracodologists that the persistance of morphologically Third, modern deep-sea faunas are rather unknown highly specialized forms, like Tricorninidae, Rectonarii- (letter of Prof. WHATLEY), only 65-70% of the species dae, Acanthoscapha and many others from the Devonian have been described. There are, however, at least more dif- or even Silurian up to the Late Permian and partly even into ferences than similarities between the Thuringian Ecotype the Triassic requires an extremely stable environment dur- and modern deep-sea faunas. ing these very long time intervals. Shallow-water low-energy environments are very unstable environments, even with strong seasonal temperature differences, but also in Reply Kozur: time (geologically only shortly existing environments). These unstable environments are quite unsuitable for ex- Your discussion does not refer to my present paper, tremely long persisting faunas with very low evolutionary but to publications by KOZUR (1972) and GRÜNDEL & rate. Moreover, the most important elements of the "Thu- KOZUR (1975). We have not published in these papers ringian Ecotype" have even crossed the P/T boundary, the that the ostracod faunas of the Hercynian geosyncline strongest caesure in shallow-marine biota in the whole (your "Thuringian Ecotype") are deep-sea faunas, but we Phanerozoic time. The "Thuringian Ecotype" persisted have regarded these faunas as psychrospheric faunas. Ac- across the P/T boundary. cording to KOZUR (1972) these faunas indicate a mini- Moreover, in all Paleozoic and Triassic ostracod as- mum water depth of 150-200 m, for the Triassic psychro- sociations of the "Thuringian Ecotype" never a specimen spheric faunas of Felsöörs water depth of more than 500 m with eye tubercles was found. Referring to the discussion were assumed. This has nothing to do with modern deep- of McKenzie, we should therefore await water depth below sea faunas that live on abyssal plains in generally 280 m, what excludes shallow-marine low-energy envi- 4-6,000 m water depth. GRÜNDEL & KOZUR ( 1975) re- ronments. ferred to the data given by KOZUR (1972).

35 (2) There is no evidence for thermospheric Devonian All these discussed data indicate that the Devonian ocean. Warm climate ("Klima stellenweise sogar warm") ocean was not thermally unlayered (thermospheric), but in the Devonian does not exclude a two-layered oceanic thermally two-layered, like during the whole time-inter- model with a cooler lower layer permanently separated by val, in which the "Thuringian Ecotype" existed. This is a thermocline from the upper warmer layer, like in the confirmed by the fact that the "Thuringian Ecotype" sud- present day tropical regions of the world oceans. Accord- denly disappeared with the beginning of the Jurassic/Cre- ing to all paleogeographic reconstructions the Devonian taceous thermospheric ocean. In the Toarcian all archaic oceans had broad connections to the Polar regions (com- elements in open deep water faunas, that have survived pare McKERROW & SCOTESE, 1989). Therefore I do from the Devonian (or even earlier) without significant not know the base for your paleogeographic considera- changes until the basal Jurassic, suddenly disappeared. To tions. these faunal elements belong Acanthoscapha, Tricornina- If the Devonian oceans were thermospheric, then it cea, Healdiacea. This drastic changes in the deep water cannot be explained, why in the surely psychrospheric faunas, not accompanied by likewise drastic changes in the oceans during the Pennsylvanian/Lower Permian Gond- shallow-water faunas, is the normal effect that can be wana glaciation the "Thuringian Ecotype" persisted with- awaited, if the long existing psychrospheric ocean changed out any significant change in its character and even in the into a thermospheric ocean. Because the Jurassic/Creta- main generic composition, whereas in the same time-inter- ceous oceans were surely thermospheric, the pre-Toarcian val the shallow-marine ostracod faunas changed very oceans were surely not thermospheric (down until the lat- much. As we know from the Tertiary, the changes between est Ordovician, where the "Thuringian Ecotype" began). thermospheric and psychrospheric ostracod faunas were (3) If 65-70 % of the species of modern deep-sea fau- drastical. Recent thermopsheric and psychrospheric ostra- nas have been described, than this fauna is by far better cod fauns are different each other, even if a connection be- known than any fossil fauna and compared with the fossil tween both areas exists (e.g. Atlantic - Mediterranean Sea). faunas not "relatively unknown". Therefore we can com- Moreover, the differences between the "Eifelian pare these faunas with fossil assemblages at least so good, Ecotype" (shallow-water ostracods) and the "Thuringian like Devonian, Carboniferous, Permian and Triassic fau- Ecotype" (psychrospheric ostracods) were very big, indi- nas of the "Thuringian Ecotype". cating a faunal barrier in form of a thermocline. In the Ju- It is quite understandable that between the "Thurin- rassic and Cretaceous thermospheric oceans the differenc- gian Ecotype" (Silurian or latest Ordovician to Lower Li- es between the shallow-water and the deep-water faunas assic) and the 200 my later existing recent psychrospheric were not so big. The thermospheric deep water ostracods ostracod faunas more differences than similarities can be were not basically different from time-equivalent shallow- found. During this long time interval two strong changes in water ostracod faunas except that they are always blind (no the oceanic deep water faunas can be observed: Within the eye tubercle) and some morphological differences can be Liassic the thermospheric ocean began and by this all the recognized. But they consist of the same ostracod groups, long existing archaic (Paleozoic) elements of the pre-Ju- partly also the same genera with different species. Com- rassic psychrospheric ostracod faunas ("Thuringian Eco- pared with the shallow-water faunas, they have no archaic type") disappeared. During the Eocene, where psychro- character. Quite on the contrary the Triassic psychrospher- spheric conditions were re-established in the world oceans, ic faunas have distinct Paleozoic character, whereas the distinct changes in the deep water ostracod faunas were contemporaneous shallow-water faunas have distinct caused again. For this reason, the recent psychrospheric Mesozoic character. ostracod fauna cannot be so archaic, like the Triassic one, Finally, the Jurassic and Cretaceous thermospheric because this archaic character depends on the length of the deep water ostracod faunas are not cosmopolitic, like the time-interval, in which psychrospheric conditions existed "Thuringian Ecotype" (e.g. Devonian psychrospheric os- (Silurian to Triassic against Eocene to recent). For this rea- tracods from Europe, North Africa and China have a high son, the Silurian psychrospheric ostracod fauna are not ar- percentage of cosmopolitic common species). The high chaic, but rather modern, compared with contemporane- vertical exchange of water masses in thermospheric oceans ous shallow-water faunas. causes regional differences " in the temperature of the The basic morphological and especially also distri- oceanic deep water. Therefore the thermospheric deep- bution characters between recent psychrospheric ostracod water fauna cannot be cosmopolitic. faunas and the "Thuringian Ecotype" are the same as already pointed out by KOZUR (1972): Cosmopolitic distri-

36 bution, very strong differences against the shallow-water psychrospheric ostracods live in water depth below 500 m faunas that indicate the presence of an effective ecologie in two-layered oceans and their margins. In uplifted areas barrier (thermocline), high percentage of smooth and or- within the oceans and in polar regions psychrospheric os- nate (spined) forms, sculpture more delicate, no forms with tracods begins already well above 500 m, about in broad, heavy ribs or with eye tubercles are present, very 200-300 m water depth, according to BENSON (1988) the slow evolutionary rate indicating a very stable biotope strongest changes are at about 400 m water depth. I do not without seasonal and regional temperature differences etc. see any reason that the upper limit of fossil psychrospheric faunas has been lower than today. The deep water character of the red Middle/Late Per- mian clays of the Sicaniän paleogeographic realm in West- Additional reference for the reply, not quoted ern Sicily lies beyond any doubt, because all faunal ele- in the present paper ments indicate not only deep water, but also unrestricted broad deep water connections to the Permian Pacific, McKERROW; W.S. & SCOTESE, C.R. (eds.) (1989): At- where even the same radiolarian and conodont species oc- las of Paleozoic basemaps. In: Paleozoic paleogeogra- cur. phy and biogeography. - Geol. Soc. London, Spec. Because of cold climates in the boreal and notai seas, Pubi, (pre-print). the Permian oceans were surely two-layered with lower psychrospheric layer that should be spearated from the upper warm layer in subtropical/tropical areas by a distinct Prof. Dr. McKenzie: thermocline. The very sharp differences in the contemporaneous Permian shallow and deep water faunas indicate Although a depth of around 500 m (mesobathyal) the presence of a thermocline. may seem sufficient for a psychrospheric fauna most The Lower Permian ostracod faunas of Timor Island workers understand the word "psychrospheric" to define were regarded by GRÜNDEL & KOZUR ( 1975) as psych- greater than 1,000 m depths and cold temperatures - as in rospheric. Acccording to BLESS (1987), referring to modern oceans. Further, the loss of an eye tubercle in phys- AUDLEY-CHARLES (1965, 1968) these ostracods de- ical terms - cf. recent work by KONTRO VITZ - may only rived from a shallow-marin flysch that contains dominant- require depths greater than 285 m. ly cephalopods, trilobites, conodonts, foraminifers (am- I believe that Dr. KOZUR needs to define his inter- modiscids, attached forms, simple endothyrids). Accord- pretation of the term psychrospheric more precisely in the ing to AUDLEY-CHARLES (1965, 1968) this "shallow- sense in which most workers understand the term (cold not marine flysch" was deposited immediately adjacent to an relatively cool; more than 1000 m deep; like modern deep ocean in the N. If these sediments are really flysch, than oceans). I feel that the onus of proof still rests with Dr. KO- shallow-water deposition can be excluded. Flysch con- ZUR to establish credibly that his Sicilian and Timor fau- tains often shallow-water fossils and even land-plant detri- nas are psychrospheric. tus, but these fossils are transported from adjacent cordille- ras or shallow-water areas. In the faunal list by BLESS (1987) and van den Reply Kozur: BOOGAARD (1987) even such resedimented shallow- water fossils are not mentioned. The conodont fauna con- In 1972 I have defined the Triassic psychrospheric sists almost exclusively of Mesogondolella and Vjalo- ostracods in detail. In this paper I have pointed out that the vognathus, two typical pelagic conodonts of deeper water. upper limit of this fauna was between 200 and 500 m. No indicative shallow-water conodonts, like Stepanovi- These data are confirmed by microfacies data (quite inde- tes, are present. Even Neostreptognathodus, dominant in pendently from the ostracod data) that indicate for sedi- shallow basinal facies of this time, is quite missing, so that ments with Triassic psychrospheric ostracods always de- the conodont fauna indicate pelagic deeper water facies. positional water depth from more than 200 m (upper limit The same is indicated by the foraminifers. Fusuli- 200 m, maybe considerably deeper). Maybe that some nids, dominating in all Permian shallow-water limestones, people have defined psychrospheric^ostracods as living in are quite missing. Also calcareous algae, very frequent in more than 1,000 m water depth, but BENSON & SYL- Permian shallow-water limestones, were not reported. Os- VESTER-BRADLEY (1971) pointed out that recent tracods with eye tubercles, typical for Permian shallow-

37 water sediments, are likewise missing. On the contrary, Additional references for the reply, not quo- Pseudospinella, quite characteristical for the Sicilian ted in the present paper deep water ostracod fauna, is also in the ostracod faunas of Timor Island frequent. AUDLEY-CHARLES, M.G. (1965): Permian palaeogeo- Even, if the sediments would be to a large part shal- graphy of the northern Australia-Timor region. - Pa- laeogeogr., Palaeoclimatol., Palaeoecol., 1, 297-305. low-water sediments (of course, in this case not a flysch), AUDLEY-CH ARLES, M.G. (1968): The geology of Por- than psychrospheric ostracods could occur in all beds de- tuguese Timor.- Mem. Geol. Soc. London, 4, 76 pp. posited below 200 m water depth. Timor Island is situated BENSON, R.H. (1988): Ostracods and Palaeocéanogra- near to the margin of Gondwana, where from the Lower phy. - In: DE DECKKER, P.; COLIN, J.-P. & PEY- Permian cold water shallow-marine faunas are known. Be- POUQUET, J.-P. (eds.): Ostracoda in the Earth Scienc- es, 1-26. cause the depositional area was immediately at the margin KONTROVITZ, M. & MYERS, J.H. (1988): Ostracod of an ocean, under such climatic conditions already at eyes as paleoenvironmental indicators: Physical limits 200 m water depth psychrospheric conditions would be es- of vision in some podocopids. - Geology, 16, tablished. There are no paleontological data that indicate 293-295. water depth of fewer than 200 nrfor the ostracod-bearing VAN DEN BOOGAARD, M. (1987): Lower Permian co- x limestones. nodonts from western Timor (Indonesia). - Proc. Kon. Nederl. Akad. Wetensch., Ser. B, 90(1), 15-39. The data of KONTROVITZ & MYERS (1988) that ostracods can use sunlight only to a maximum depth of about 280 m are very important and they fit very well with my opinion about the upper depth limit of the (paleo)psychrospheric ostracods. But - as you have pointed out - this is a boundary in physical terms and the live does not always exactly follow such terms. According to BEN- SON (1984), ostracods with eye tubercles are present among recent living faunas in some places as low as 600 m water depth, exceptionally even down until 900 m water depth. In any case, ostracod faunas, in which forms with Author's address: eye tubercles are regularly present, should indicate water Dr. sc. Heinz Kozur, Rézsü ut 83, H-1029 Budapest, depth above 200 m. In those geological times, where in the Hungary shallow-water ostracods with eye tubercles are frequent (Permian to recent), rich faunas without representatives with eye tubercles that show also the other character of (paleo)psychrospheric ostracod faunas, indicate water depth below 200 m or even below 300-500 m. submitted: June 18, 1991 accepted: July 20, 1991