Bollettino della Società Paleontologica Italiana Modena, Novembre 1999

Some upper Silurian - middle Devonian conodonts from the northern part ofWestern Meseta ofMorocco: systematic and palaeogeographical relationships

El Mostafa BENFRIKA Deparrment of Geolosr University Hassan II-Mohammedla, Casablanca

KEYWORDS- Conodonts, Silurian, Devonian, Western Meseta, Morocco.

ABSTRACT- This is the first report on Wenlock-Givetian conodonts ftom the northern parto/Western Meseta ofM orocco. The systematic study of this North Aftican materia! brings complementary data on the palaeogeographic distribution over the world at this period. Fauna! affi.nities are recognised between Western Moroccan Meseta, Centra! Europe and North America, particulary during the Upper Silurian and Lower f5evoman.

RIASSUNTO- [Conodonti del Siluriano superiore- Devoniano medio della parte settentrionale della Meseta occidentale (Marocco): sistematica e relazioni paleogeografìche] -E' questa la prima segnalazione di conodonti di età compresa tra il Wenlock e il Givetiano nella parte settentrionale della Meseta occidentale del Marocco. Lo studio sistematico di queste faune nordajricane porta nuovi dati alle conoscenze sulla paleobiogeografia di quel periodo. Vt>ngono osservate affinità faunistiche, particolarmente strette durante i[Siluriano sup. e il Devoniano inf, tra la Meseta marocchina occidentale, l'Europa centrale e il Nord America.

INTRODUCTION precision about the stratigraphy of the Silurian to Middle Devonian (Benfrika, 1994). The purpose of this paper is to describe some conodonts of Silurian and Devonian age from the northern p art of Western Meseta of M o rocco an d ro RELATIONS present palaeogeographical relationships berween these faunas and those from other parts of the world. UPPER SILURIAN . The North Western Meseta is characterised by a ', continuous sequence of marine sediments (carbonates The Wenlock-Ludlow, identifìed in northern part and shales) from Lower Silurian until Middle ofWestern Meseta (Rabat-Tiflet area), has particulary Devonian. The Silurian strata represent a transgressive yielded condonts, which show similarity with North sequence resulting to a sea level rise, as consequence of Arnerican and centrai European conodonts; for exam- the melting of the Late Ordovician glaciers. This ple, Kockelelfa absidata, Kockelella stauros, Kockelelfa transgression reached its maximum in the Llandoverian. variabilis, Ozarkodina bohemica, Ozarkodina excavata, The most common facies of the Silurian are the Ozarkodina sagitta sagitta, Polygnathoides emarginatus. graptolitic black shales with intercalations oflimestone This conodont fauna occurs mainly in Oued Grou (beds or lenses) in the upper part of the sequence. (SE ofRabat). The lithofacies in this area is represented In the Lower-Middle Devonian, Marocco by condensed successions with a lower part composed continued to be part of the Gondwana passive margin. of graptolitic black limestone and an upper part with The sedimentation from the Silurian to the Devonian crinoidallimestones. The sagitta Zone and the lower was steady without any effects of the late Caleodonian variabilis Zone are identifìed in this sequence by the orogeny. The Lower Devonian lithofacies is formed by presence of the index fossiles, Ozarkodina sagitta sagitta shales with bioclastic carbonate intercalations, whereas, an d Kockelella to Garcia-Lopez et in the Middle Devonian, carbonate sedimentation al. ( 1996), this type of condensed succession occurs in prevailed with extensive development of reefbuildups. the Southern Montagne Noire, Caledonian Coastal In North Western Meseta, the Silurian and the Ranges and Sardinia. In other part, i t seems that North Devonian crop out mainly in Rabat-Tiflet area, Oued Western Mesetean Silurian conodont fauna, and Cherrat, Oulad Abbou, Mechraa Ben Abbou, Ben particulary that from the Rabat-Tiflet area, show a Ahmed (Text-fìgs. l, 2). The more complete study of relatively higher diversity in Gondwana as compared conodonts in this region reported here brings additional with those from Spain, for example. 312 E.M. BENFRIKA

-30N

Anti-Atlas

D Post-Paleozoic D Precambrian and Palaeozoic Jì;>- D Northern part of western Meseta

1. Sahara Domain 2. Western Sahara 3. Anti-Atlas 4. Meseta (a: Western; b: Eastern) o 200 km 5. Atlas 6. Rif

Texr-fìg.l - Main srrucrural domains of Morocco.

LOCHKOVIAN The limestone contains a few conodonts, tentaculites, osrracods, brachiopods and trilobites. The shales During the Lochkovian, a conodont fauna identica! contain graptolites. According to Alberti (1988), the with centrai Europe an d North America has been found Rabat-Tiflet area, during the Silurian and Devonian, in North Western Moroccan Meseta, for example: is very reminiscent of the Barrandian area in facies Caudicriodus woschmidti, Ozarkodina remscheidensis and faunal development. remscheidensis, Ozarkodina steinhornensis repetitor, Ozarkodina wurmi. PRAGIAN The majority of these conodonts occurs from upper Lochkovian of SE of Rabat, where the lithofacies is During the Pragian, the species of North Western represented by black, bituminous, fìne-grained, platy Moroccan Meseta are Caudicriodus celtibericus, limestones with intercalations of thin layers of shales. Caudicriodus curvicauda, Latericriodus steinachensis, Ozarkodina pandora, Ozarkodina steinhornensis miae SILURIAN AND DEVONIAN CONODONTS FROM WESTERN MESETA 313

O 10 Km L--..J Tifiet* AK T

CHAOUIA

Berrechid*

Ben Ahmed* *Setta t

*Khouribga PLATEAU DES PHOSPHATES

CJ Silurian

- Lower and Middle Devonian (+ Silurian from Rabat to Tiflet)

REHAMNA - Upper Devonian-Tournasian

Text-fig. 2 - Schematic geologica! map of the northern part of the Western Moroccan Meseta showing the distriburion of the Silurian - Devonian/Tournaisian and the locality referred to in the text. Map modifìed after Hollard, H. 1967 and Pique, A. 1979. (BA: Oued Bou Regreg right-bank; BH: Bou Regreg left-bank; BD: Bled D fa; G: Oued Grou; AK: Al Khaloua; T: Tiflet; OA: Oulad Abbou; AQ: Ain Qçob; AA: Al Attamna; CB: Carrière Bouchhada; KD: Koudiat Ed Dib).

and, after Alberti (1988), Eognathodus sulcatus. Except EMSIAN ANO MIDDLE DEVONIAN for Caudicriodus celtibericus, ali species are recognised at Centrai Europe (Chlupac et al., 1980; Chlupac, With the Emsian, the conodont faunas ofMoroccan 1993) and North America. The species Ozarkodina Meseta presemed more affinities with Pre-Saharian steinhornensis miae, Caudicriodus celtibericus and (Ami-Atlas) and European Faunas, compared with Caudicriodus curvicauda were also recognised in Spain. those from NorthAmerica: Latericriodus bilatericrescens, These species occur mainly in Rabat-Tiflet area, Latericriodus beckmanni, Icriodus ancestralis, Icriodus where the lithofacies is composed ofbioclastic nodular culicellus, Icriodus fusiformis, Icriodus rectirostratus, limestone of grey colour with numerous tentaculites. Ozarkodina steinhornensis steinhornensis, Pelekysgnathus 314 E.M. BENFRIKA serratus srratus, Polygnathus dehiscens, Polygnathus is not considered here like one characteristic feature. mversus. The other elements are identica! with During the Middle Devonian, the conodonts from corresponding elements of K variabilis. Morocco (Anti-Atlas, Meseta, Centrai Morocco) showed increasing cosmopolitanism: Eognathodus Range and distribution - Wenlock-Ludlow from bipennatus, lcriodus brevis, lcriodus corniger, lcriodus Rabat-Tiflet area (sagittalstauros Zone- Lower variabilis obliquimarginatus, lcriodus struvei, Ozarkodina Zone). bidentata, Ozarkodina brevis, Ozarkodina plana, Ozarkodina raschi, Polygnathus angusticostatus, Materia! and occurrence- 16 Pa elements from Oued Polygnathus angustipennatus, Po'Jtnathus costatus, Grou (SE ofRabat), samples G4, Gl4, Gl5, Gl7; 4 Polygnathus latus, Polygnathus linguiformis, Polygnathus Pa elements, 2 Pb, 2 Sa, l Sb, 5 Se from Oued Tiflet (S pseudofoliatus, Polygnathus rhenanus, Polygnathus ofTiflet), samples T2, T3. timorensis, Polygnathus varcus, Po!ygnathus xylus, Tortodus kockelianus, Tortodus variabilis. KOCKELELLA STAUROS Barrick & Klapper, 1976 Pl. l, fig. 8 CONCLUSIONS Pa element: During the Upper Silurian and Lower Devonian 1976 Kockelella stauros sp. nov.- BARRJCK & KLAPPER, pp. 76-77, pl. 3, figs. 1-11. (Lochkovian an d Pragian), the closest palaeo- geographicai relationships are between North Western Remarks and relations- The Sa an d Sb are identicai Moroccan Meseta, centrai Europe and North America with corresponding elements of K variabilis. compared with Spain. For the Emsian, the communications with North America decreased, while Range and distribution-Wenlock from S.E. ofRabat they increased with Europe and Moroccan Pre-Sahara. (sagittalstauros Zone). With the Middle Devonian, the conodonts of Morocco showed increasing cosmopolitanism, Materia! and occurrence- 3 Pa elements, 2 Sa, l Sb privileged by greater communication between most from Oued Grou (SE ofRabat), sample Gl4. paleogeographical areas. So, most conodonts from Moroccan Meseta are cosmopolitan and illustrate the faunal homogeneity between North Gondwanan KOCKELELLA VARIABILIS Wailiser, 1957 regions and other paieogeographic area. Pl.l,fig.4 Furthermore, the systematic study of these North African fossils brings complementary precisions about Pa element the stratigraphy from Wenlock (sagitta Zone) to 1957 Kockelella variabilis n. sp.- WALLISER, p. 35-36, pl. l , figs . Givetian (varcus Zone) of the North Western Moroccan 3-10. Meseta and corroborates the affinities (at the species 1964 Kockelella variabilis Walliser - W ALLISER, p. 40, p!. 8, fig. level) between Spanish-Central European and North 12, pl. 16, figs. 1-15. 1976 Kockelella variabilis Walliser - BARRJCK & KlAPPER, p. 77, American faunas. p!. 3, figs. 12-1 7.

Remarks and relations - The mesetean specimens with the position of the expanded part of the basai SYSTEMATIC PALAEONTOLOGY cavity and its process compare closely with those illustrateci by Walliser (1957, 1964). The other KocKELELLA ABSIDATA Barrick & Klapper, 1976 elements (Pb, M, Sa, Sb and Se) are similar to those Pl. l, fig.5 illustrateci by Barrick & Klapper (1976). The Pa element of Kockelella variabilis ichnusae Serpagli & Pa element Corradini 1998 differs from that of mesetean specimens 1964 Ozarkodina Jundamuntata (Walliser)- W ALLISER, pp. 56-57, pl.23, figs. 5-16, 18-24. principally by a platform bordered by a rim and by 1976 Kockelella absidata n.sp. - BARRJCK & KLAPPER, p. 73, pl. 2, fused demicles on the anterior biade. figs. 15-16 Range and distribution - Ludlow of Rabat-Tiflet Remarks and relations- Some features of mesetean (Lower variabilis Zone). specimens, like the width of cusp, the o udine of basai cavity, are slighdy different from those illustrateci by Materia! and occurrence- 4 Pa elements, l Pb, l M, Barrick & Klapper (1976). The arched posterior biade 2 Sa, l Sb, l Se from Oued Grou (SE ofRabat), sample SILURIAN AND DEVON/AN CONODONTS FROM WESTERN MESETA 315

G 17; 12 Pa elements from Oued Stour, sampies 0ZARKODINA SAGITTA SA GITTA (Walliser, 1964) Nl, N2 (Rabat-Tiflet area). Pl. l, fig. 3

Pa element 0ZARKODINA BOHEMICA (Walliser, 1964) 1964 Spathognathodus sagitta sagitta n.ssp. W ALLISER, pp. 82-84, pl. 18, figs. 8-11. P l. l, fig.l, 2 1975 Ozarkodina sagitta sagitta (Walliser) - ALDRIDGE, p. 330, p!. 47, fig. 13 (Pa element). Paelemenr 1964 Spathognathodus sagitta bohemicus W ALLISER, p. 83, p!. 18, Remarks and relations - The Pa element of Ozar- fìgs. 23-24. 1975 Ozarkodinasagitta bohemica (Walliser) -ALDRIDGE, p. 327, kodina sagitta rhenana and Ozarkodina sagitta sagitta pl. 47, fig. 21. are simiiar, but in the Pa element of O. sagitta rhenana, 1987 Ozarkodina bohemica (Walliser) - OvER & CHATTERTON, the denticles ares distinctly broader, iess closely spaced p!. 8, figs. 13, 14. and iess numerous. The Pa element of Ozarkodina bohemica (Walliser) has a broad basai cavity and Remarks and relations - Ozarkodina snajdri characteristic fusion of the denticles above the cavity. (Walliser) differs from Ozarkodina bohemica in the Range and distribution - Weniock from Oued Grou width and the extension of its basai cavity. This basai (SE of Rabat). cavity is broad and does not extend to the posterior end. Materia! and occurrence - 15 Pa elements, l Sa, 2 Sb, 5 Se, from Oued Grou (SE ofRabat), sampies G4, Range and distribution - Weniock (sagittalstauros G6. Zone) from Oued Grou (SE ofRabat) and Oued Tiflet (S ofTiflet), 0ZARKODINA EXCAVATA (Branson & Mehi, 1933) Materia! and occurrence- 14 Pa elements from Oued Pl. l, fig. 7 Grou (SE ofRabat), sampies G5, G9, G 10, G 11, G 15; l Pa eiements from Oued Tiflet (S ofTiflet), sampie Remarks and relations- This species has a iarge range T2. from the Siiurian to early Devonian and shows various morphotypes (subspecies?). The different elements the mesetean taxa are closeiey simiiar to those illustrated 0ZARKODINA REMSCHEIDENSIS REMSCHEIDENSIS by numerous authors, for exampie Wiison (1989). (Ziegier, 1960) Pl. l, fig. 6 Range and distribution - Weniock to Late Pragian- Early Emsian from Western Moroccan Meseta. Pa Element 1960 Spathognathodus remscheidensis n.sp. ZIEGLER, pp. 194-196, pl. 13, figs. 1-2, 4-5, 7-8, 10-14. Materia! and occurrence- The different elements of 197 4 Ozarkodina remscheidensis remscheidensis (Ziegler) - l

Materia! and occurrence- 20 Pa elements, 18 Pb, l Remarks and relations - The specimens from the M, l Sa, l O Sb, 19 Se form Oued Grou (SE of Rabat), Moroccan meseta resembies Ozarkodina {andora sampies G22, G23, G24; l Pa elements from oued morphotype aipha from iower Devonian o centrai Tiflet (S ofTiflet), sampie Tl7; 3 specimens Pa from Nevada figured by Murphy et al. (1981) and to a Oued Bou Regreg (SE ofRabat). specimen from New South Waies illustrated by 316 E.M BENFRIKA

Sorentino (1989) and Wilson (1989). They have the 0ZARKODINA STEINHORNENSIS REPETITOR (Car!s & same characteristic features: Oudine of expanded basai Gand!, 1969) cavity, posterior position of the expanded basai cavity, P!. l, fig. 11 the lack of ornament on their platform lobes. Pa elemenr Range and distribution - Late Lochkovian - Early 1969 Spathognathodus steinhornensis repetitor n.ss p. CARLS & GANDL, pp. 198-200, pl. 19, fig. 3. Pragian from Tiflet an d SE of Rabat. 1971 Spathognathodus steinhornensis repetitor Carls & Gand! - BULTYNCK, pp. 18-25, pl. 3, figs. 1-24; pl4, figs. 1-5, textfigs. Materia/ and occurence - 7 Pa elements from Oued 12-14. Bou Regreg (SE ofRabat), samples BG 18, BG20; 2 Pa elements from Oued Tiflet (S ofTiflet), samples T20, Range and distribution- Upper Lochkovian from T23. SE ofRabat.

Materia/ and occurrence- 3 Pa elements from SE of 0ZARKODI NA STEINHORNENSIS MIAE (Bultynck, 1971) Rabat (Bled Dfa, Bou Regreg, Oued Grou), samples P!. l, fig. 19 Dl3, BD24, G 25.

Pa elemenr 1971 Spathognathodus :teinhornensis n.ssp. BuLTYNCK, p. 25, CAUDICRIODUS CURVICAUDA (Carls & Gand!, 1969) pl. 4, figs . 13-14, pl. 5, figs. 1-14, text-figs. 19-21. P!. l, fig. 13 1989 Ozarkodina steinhornensis miae (Bulrynck)- BuLTYNCK, pl. 16, figs. 10-11. Pa elemenr 1969 Icriodus huddlei curvicauda n.ssp. CARLS & GAND L, pp.l80- Remarks and relations - Bu!tynck (1971) has 182, pl. 16, fìgs. 10-1 7 distinguished 3 subspecies (a, y) on the basis of 1976 Caudicriodus curvicauda (Carls & Gand!)- BULTYNCK, pp. differences in the denticles. The mesetean materia! is 28-29, pl.6, fìgs 10-15, text-fìg. 3. similar in the lack of prominent cusp to morphotype 0:. Remarks and relations - This species differs from Caudicriodus celtibericus by the fact that the latera! Range and distribution - Pragian- Emsian (kindlei- process is arched. dehiscens Zone) from Rabat-Tiflet area. Range and occurrence- Pragian (kindlei Zone) from Materia/ and occurrence - 28 Pa elements, 2 Pb, l AIAttamna. Sa, 3 Se from Al Khaloua, samples AK 8, AK 9, AK 12; 2 Pa elements from Oued Bou Regreg (SE Rabat), Materia/ and occurrence - 7 Pa elements from Sidi samples BG 27, BG 28; l Pa element from Oued Tiflet Ahmed El Mdoun (Al Attamna), sampleAA18. (S. ofTiflet), sample T28.

EXPLANATION OF PLATE l

Figs. 1-2 - Ozarkodina bohemica (Wailiser, 1964). l) Pa elemenr; !arerai view (xl30), G-8. 2) Pa elemenr; aborai view (x90), G-11. Fig. 3 - Ozarkodina sagitta sagitta (Wailiser, 1964). Pa elemenr; orai view (x70) , G-4. Fig. 4 - Kockelella variabilis Wailiser, 1957. Pa elemenr; orai view (x70), G-16. Fig. 5 - Kockelella absidata Barrick & Klapper, 1976. Pa elemenr; !arerai view (xl l l), G-14. Fig. 6 - Ozarkodina remscheidensis remscheidensis (Ziegler, 1960). Pa element; !arerai view (x70), G-22. Fig. 7 Ozarkodina excavata (Branson & Mehl, 1933). Pa elemenr; orai view (x70), G-3. Fig. 8 - Kockelella stauros Barrick & Klapper, 1976. Pa elemenr; orai view (x70), G-14. Fig. 9 Polygnathoides emarginatus (Branson & Mehl, 1933). Pa elemenr; !arerai view (x90), S-2. Fig. 10 - Caudicriodus woschmidti (Ziegler, 1960). Pa elemenr; !arerai view (a) and orai view (b) (x90), BH-3. (Processes is broken). Fig. 11 Ozarkodina steinhornensis repetitor (Carls & Gand!, 1969). Pa elemenr; !arerai view (a) and aboral (b) view (xl 50), BH-18. Fig. 12 - Caudicriodus celtibericus (Carls & Gand!, 1969). Pa elemenr; ora! view (x70), AK-6. Fig. 13 - Caudicriodus curvicauda (Carls & Gand!, 1969). Pa element; orai view (x70), AA-18 Fig. 14 - Pelekysgnathus serratus serratus Jentzsch, 1962. Pa element; orai view (xlOO), AK-4. Fig. 15 Latericriodus steinachensis (Al-Rawi, 1977). Pa elemenr; orai view (x44), T-22. Figs. 16-18 - Ozarkodina pandora Murphy, Mani & Wailiser, 1981 . Orai view, !arerai view an d aborai view (x90), BH-20. Fig. 19 Ozarkodina stenhornensis miae (Bulrynck,l971). Pa element; orai view (x90), AK-12. E.M. BENFRIKA, SILURIAN AND DEVONIAN CONODONTS FROM WESTERN MESETA P!. l 318 E.M. BENFRIKA

CAUDICRIODUS CELTIBERICUS (Carls & Gandl, 1969) the transverse rows are regular; the process branches Pl. l, fig. 12 from the posterior end; the basai cavity is less broad. In Latericriodus beckmanni, the platform is more Pa element slender; the number of transverse rows is more 1969 Icriodus huddlei celtibericus n.ssp. CARLS & GANDL, pp. 182- 1mporrant. 183, pl. 16, fìgs. 18-20 1976 Caudicriodus celtibericus (Carls & Gand!)- BULTYNCK, pp. 29-31 , pl. 6, fìgs. 7-19; pl. 7, fìgs. 27-29. Range and distribution - Lower part of Pragian (sulcatus Zone) from S ofTiflet. Remarks and relations - The mesetean materia! is closely similar to spanish materia!. Materia! and occurrence - l Pa element from Oued Tiflet (S ofTiflet), sample T22. Range and distribution- Pragian-Emsian (kindlei- dehiscens Zone) from Rabat-Tiflet area, Oued Cherrat and Mechraa Ben Abbou. PELEKYSGNATHUS SERRATUS SERRATUS Jentzsch, 1962 P l. l, fig. 14 Materia! and occurrence- 335 Pa elements, 13 Pb, 13 M, 17 S from Al Khaloua, samples AKI-AK12; Pa element 1962 Pelekysrathus serrata n.sp. JENTZSCH, p. 970-971 , p!. 2, fìgs. 133 Pa elements, l Pb, 3M, 2 S, from Sidi Ahmed El 7, 8; p . 3, fìgs . 6, 9, 15, 16. Mdoun (Al Attamna), samples AA1-AA14, AT18- 1969 Pelekysgnathus serrata elata n.ssp. CARLS & GANDL, p. 192- AT20; 122 Pa elements, From Oued Bou Regreg (SE 193, pl.l9, fìgs. 10-14. ofRabat ), samples BG26, BG34, Dl9, D 3-D26; 40 1976 Pelekysgnathus aff. P.serratus elatus- BuLTYNCK, p. 60, pl. 5, Pa elements,l Pb, l S from Oued Tiflet (S ofTiflet), fìgs . 6-11. samples TI6, T27; 12 Pa elements, l Pb, 2 M from Ain AL Qçob (Oued Cherrat), samples AQI-AQ4; 4 Remarks and relations - Bultynck (1976) Pa elements from Koudiat Ed Dib (Mechraa Ben distinguished in Spanisch Conodonts, Pelekysgnathus Abbou), sample KD3; 2 Pa elements from Oued Grou aff P. serratus from Pelekysgnathus serratus elatus. The (SE Rabat), sample G31. main distinction is the presence in P. serratus elatus of a cusp not arched posteriorly. The mesetean materia! shows the same difference. P. aff. P. serratus elatus CAUDICRIODUS WOSCHMIDTI (Ziegler, 1960) illustrateci by Bultynck (1976) is here considered as Pl. l, fig. IO conspecific, because of its transitionnal connection.

Pa element Range and distribution - Emsian (dehiscens Zone) 1960 Icriodus woschmidti n.sp. ZIEGLER, p. 195-196, pl. 15, fìgs. from Rabat-Tiflet area. 16-18, 20-22. Materia! and occurrence - 2 Pa elements from Al Range and distribution - Lochkovian from SE of Khaloua, sample AK12; l Pa element from Oued Bou Rabat. Regreg (SE ofRabat), sample BD43

Materia! and occurrence- l Pa element from Oued Bou Reg reg (SE ofRabat), sample BG3. POLYGNATHO!DES EMARGINATUS (Branson &Mehl, 1933) Pl. l, fig. 9 LATERICRIODUS STEINACHENSIS (Al-Rawi, 1977) Pl. l, fig. 15 Pa element 1933 Polygnathellus emarginatus n.sp. BRANSON & MEHL, p. 49, Pa element pl. 3, fìg. 38 1977 Icriodus steinachensis n.sp. AL-R.AWl , pp. 55-56, pl. 5, fìg. 1964 Polygnathoides emarginatus (Branson & Mehl) -WALLI SER, 42. p. 66, pl. 8, fìg. 16; pl. 18, fìgs. 1-6 1980 Icriodus steinachensis Al-Rawi- l

Remarks and relations - In Latericriodus nevadensis Range and distribution - Ludlow from Al Khaloua Klapper and Johnson(l980), the basai cavity is more (Lower variabilis Zone). narrow at the anterior part; in Latericriodus bilatericrescens bilatericrescens: the main denticle is Materia! and occurrence- l specimen Pa from Oued longer; the angle with the main latera! process is greater; Stour (Al Khaloua), sample AS2. SILURIAN AND DEVONIAN CONODONTS FROM WESTERN MESETA 319

ACKNOWLEDGMENTS episodios carbonatados en el Silurico de la Cadena Hercinica Meridiana! y el dominio Sahariano: Revista espanola de P. Bulrynck (Inst. Roy. Belgium) is deeply acknowledged for Paleontologia, no exrraorinario, junio 1996: 33-57. his help and discussion on conodonrs in Leuven. HOLLARD, H., 1967, Le Dévonien du Maroc et du Sahara Nord- Occidental: Internat. Symp. o n the Devonian system, Calgary, 1967, l, pubi. Alberta Soc. Perrol. Geo!.: 203-244. REFERENCES }ENTZSCH, I., 1962, Conodonten aus dem Tentaculiten Knollenkalk (Unterdevon) in Thuringen: Geologie, 11 : 961-985. ALBERTI, G.K.B., 1988, Stratigraphische Unrerliederung einiger MuRPHY, M.A., MATTI, J.C. & WALLISER, O.H., 1981, Biosrra- Lochkovium/Praguium Grenzeprofìle (Unrer-Devon) in NW- tigraphy and evolution of the Ozarkodina remscheidensis- Marokko, Oberfranken und Vicroria (SE-Australien) auf Eognathodus sulcatus lineage (Lower Devonian) in Germany Grund von Dacryoconariden und Conodonten: and Cenerai Nevada: J.Paleont., 55: 774-772. Senckenbergiana Lethaea, 68 (5/6): 479-493. KLAPPER, G. &]OHNSON, ].G. , 1980, Endemism and Dispersal of ALDRIDGE, R.J., 1975, The Silurian Conodont Ozarkodina sagitta Devonian Conodonrs: Journal of Paleontology, 54: 400-455. and its value in correlation: Palaeonrology, 18: 323-332, pl.47. KLAPPER, G. & MURPHY, M.A., 1975, Silurian-Lower Devonian AL-RAWI, D., 1977, Biosrratigraphische Gliederung der Conodont Sequences in the Roberts Mounyains Formation Tenrakuliten-Schichten des Frankenwaldes mit Conodonten of Centrai Nevada: University of California Publication in und Tenraculiten (Unrer- und Mirtel-Devon, Bayer, Geologica! Sciences, 111: 1-62. Deutschland): Senckenbergiana Lethaea, 58: 25-79. OVER, D.]. & CHATTERTON, B.D.E., 1987, Llandoveryro Wenlock BARRICK, J.E. & KLAPPER, G., 1976, Mulri-elemenr Silurian (Late (Silurian) Conodont Fauna from the Arctic and Western Norrh Llandoverian-Wenlockian) Conodonrs from the Clarita America: Geologica et Palaeonrologica, 21: 1-49. Formation, Airbuckle Mounrains, Oklahoma, and phylogeny PIQUE, A., 1979, Evolurion structurale d'un segmenr de la Chalne of Kockelella: Geologica et Palaeonrologica, 10: 59-98. Hercynienne: La Meseta Marocaine Nord-Occidentale: Thèse BENFRIKA, E.M., 1994, Conodonres siluriens et dévoniens de Docrorat en Sciences Naturelles, Strasbourg: 253pp. (Wenlock-Givetien) du Nord Ouest de la Meseta Marocaine: SERENTINO, L., 1989, Conodont Assemblages Spanning the Systématique, srratigraphie et biofaciès: Thèse de Docrorat en Lochkovian-Pragian (Early Devonian) Boundary at Eurimbla, Sciences (Ph.D.), Katholieke Universiteit Leuven (K. U. Centrai New Sourh Wales: Courier Forschungs-Instirut Leuven), Belgium: 260 pp., 20 pls. Senckenberg, 11 7: 81-115. BRANSON, E.B. & MEHL, M.G., 1933, Conodont Srudies n°l: SERPAGLI, E. & CoRRADINI, C., 1998, New taxa of Kockelella Conodonrs from the Harding Sandsrone of Colorado; (Conodonta) from Late Wenlock-Ludlow (Silurian) of Conodonts from the Bainbridge (S ilurian) of Mossouri; Sardinia. In: Serpagli E., (ed.), ECOS VII-Sardinia Guide- Conodonrs from the Jefferson City (Lower Ordovician): book: Giornale di Geologia, s. 3', 60, Spec. Issue: 79-83. University of Missouri Studies, 8 (1): 5-72. WALLISER, O.H., 1957, Conodonten aus dem Oberen Gorlandium BuLTYNCK, P. 1971, Le Silurien Supérieur et le Dévonien Inférieur Deurschlands und der Karnischen Alpen: Notizblatt Hessisches de la Sierra de Guadarrama (Espagne Centrale). Deuxième Landesamt fur Bodenforschung Wiesbaden, 85: 28-52. parrie: Assemblages de Conodonres à Spathognathodus: WALLISER, O.H., 1964: Conodonren des Silurs: Abhandlungen Bullettin de Instirut Royal de Sciences Naturelles de Belgique, Hessisches Landesamt fur Bodenforschung Wiesbaden, 41: 47 (3): 43 pp. 1-106. BuLTYNCK, P. 1976, Le Silurien Supérieur et le Dévonien Inférieur WILSON, G.A., 1989, Documenrarion of Conodonr Assemblages de la Sierra de Guadarrama (Espagne Centrale). Troisième across the Lochkovian-Pragian (Early Devonian) Boundary at partie: Elémenrs Icriodontiformes, Pelekysgnathiformes et Wellingron, Centrai New Sourh Wales, Australia: Courier Polygnathiformes: Bullerrin de Institut Royal de Sciences Forsch.-Inst. Senckenberg, 117:117-171. Narurelles de Belgique, 49 (5): 74 pp. ZIEGLER, W., 1960, Conodonren aus dem Rheinischen Unterdevon BuLTYNCK, P. 1989, Conodonts from the Lagrange Limesrone (Gedinnium) des Remscheider Sattels (Rheinisches (Emsian), Armoricain Massif, No nh-Western France: Courier schiefergebirge): Palaonrologische Zeitschrift, 34: 169-20 l. Forschungs-Institur Senckenberg, 117: 173-203. CARLS, P. & GANDL, ].,)969, Stratigraphie und Conodonren des Unter-Devons der Osrlichen Iberischen Kerren (NE-Spanien): Neues Jahrbook fur Geologie und Palaontologie Abhandlungen, 132: 155-218. (manuscript received December 21, 1998 CHLUPAC, I; KRiz, J & ScHONLAUB, H.P., 1980, Silurian and accepted March 24, 1999) Devonian Conodont localities of the Barrandian: Second European Conodont Symposium (ECOS II), Abhandlungen der Geologischen Bundesanstalt, 35: 147-180. CHLUPAC, I., 1993: Geology of the Barrandian: A fìeld trip guide: El Mostafa BENFRIKA Senckenberg-Buch 69, 163 pp. Frankfurt am Main. Departmenr of Geology, University Hassan II-Mohammedia GARCIA-LOPEZ, S., RoDRIGUEZ-CANERO, R., SANz-LorEz, ]., Faculry of Sciences Ben M'Sik SARMIENTO, G. & VALENZUELA R.Ios, J.I., 1996, Conodonrs y Casablanca CP 20450 Marocco.