Trilobiten aus dem Unter-Devon des sªAnti-Atlas, Sª Mit 10 Abbildungen, 11 Tabellen und 16 Tafeln GUNNAR SCHRAUT Kurzfassung in der vorliegenden Arbeit werden Trilobiten aus dem Unter-Devon (Pragium -Ober-Emsium) des sª Anti-Atlas (Sª abgebildet und beschrieben. Es handelt sich dabei haupts~ichlich um Rheinische Formen, welche dem obersten Pragium und dem Ober-Emsium angeh6ren. Altere Taxa aus der Herzynisch-b6hmischen Fazies liegen ausschliel31ich aus dem Pragium vor. 19 Arten und Unterarten konnten von insgesamt 8 verschiedenen Lokalitfiten (Fundpunkte und Profile) aufgefunden werden. Neu sind die folgenden f'ª Taxa: Paralejurus elayounensis n. sp., Phacops (Phacops) saberensis torkozensis n. ssp., Phacops (Phacops) vogeli n. sp., Reedops intermedius chlupaci n. ssp. und Treveropyge marokkensis n. sp. Arduennella maillieuxi (ASSELBERGHS 1923) und Parahomalonotus planus planus (KOCH 1883) werden erstmals aus dem Unter-Devon (oberstes Pragium) von Marokko beschrieben. Die schon bekannten Formen besitzen Vertreter im Rheinischen Schiefergebirge (Deutschland), in der Bretagne (Frankreich), in B6hmen (Tschechische Republik) und in Spanien. Konsequenterweise bedeutet dies, daB die genannten geographischen Bereiche im mittleren und oberen Unter-Devon durch einen flachen Schelf ohne deutlich ausgel~r~igte pal~iobiogeographische Schranken miteinander verbunden waren und/oder geographisch nicht weit auseinander lagen. Abstract[Trilobites from the Lower Devonian of the south-eastern Anti-Atlas System, South Morocco.] --This paper deals with trilobites from the Lower Devonian (Pragian -Upper Emsian) from the south-eastern part of the Anti-Atlas System (South Morocco). Nineteen species and subspecies were determined from 8 different Lower Devonian localities, and these are described, figured and compared to similar forms.The following species and subspecies are new: Paralejurus elayounensis n. sp., Phacops (Phacops) saberensis torkozensis n. ssp., Phacops (Phacops) vogeli n. sp., Reedops intermedius chlupaci n. ssp. and Treveropyge marokkensis n. sp. Most of them represent rhenish forms from the uppermost Pragian and the Upper Emsian. Hercynian-bohemian forms are only present in the Pragian Stage. Arduennella maillieuxi (ASSELBERGHS 1923) and Parahomalonotus planus planus are recorded for the first time in the Devonian of Morocco. Since most of the species are well known forms from the Rheinisches Schiefergebirge (Germany), Brittany (France), Bohemia (Czech Republic) and from Spain there must have been very close paleobiogeographic relations. Therefore a shallow marine shelf with no paleobiogeographical boundaries probably existed between this regions and/or they were located very close together.

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Eine neue Unterart von Phacops (Phacops) sparsinodosus STRUVE 1970 aus dem Mittel-Devon von Marokko Mit 8 Abbildungen GUNNAR SCHRAUT Kurzfassung Aus dem tiefen Mittel-Devon (tiefes Eifelium) des Profils Zguid III ira sª Antiatlas (Marokko) wird die neue Unterart Phacops (Phacopa9 sparsinodosus struvei n. ssp. aufgestellt und stratigraphisch mit Hilfe ron Ammonoideen und Trilobiten eingehfingt. Der Fund eines vollst~indigen Schalenexemplars von Phacops (Phacops) sparsinodosus gallicus (STRuVE 1982) aus den Grauwacken-Schiefern der Assise de Bure, Couvinien Col, Grenz-Bereich Unter-Devon/Mittel-Devon, erfordert eine Neudarstellung dieses Taxons und erm6glicht einen guten Vergleich mit den bisher bekannten Unterarten. Durch das Vorkommen von Fidelites sp. und Thysanopeltis speciosa in Marokko und von Pinacitesjugleri in Belgien ist die stratigraphische Einstufung beider Unterarten in das untere Mittel-Devon (tiefes Eifelium) gesichert. Abstract [A new subspecies of Phacops (Phacops) sparsinodosus STRUVE 1970 from the Middle Devonian of Morocco.] The new subspecies Phacops (Phacops) sparsinodosus struvei n. ssp. is based on material from the Zguid fil section (southern part of the Antiatlas, Morocco). Age correlations were made using ammonoids and trilobites. A nearly complete specimen of Phacops (Phacops) sparsinodosus gallicus (STRuVE 1982) with exce[lent shell preservation is described. Ir was found in the ,,Grauwacken-Schiefern" of the Assise de Bure in Belgium (Couvinien Col), type-locality of the taxon.It is now possible to compare all subspecies of Ph. (Ph.) sparsinodosus with the same level of preservation. The trilobite records together with the occurrences ofFidelites sp., Thysanopeltis speciosa (Morocco) and Pinacites jugleri (Belgium) indicate ah approximate stratigraphic position within the lower part of the Eifelian (Middle Devonian).

The Carboniferous is characterized by drastic climatic and environmental fluctuations, which include multiple phases of glaciation resulting in an icehouse climate. Additionally, dynamic continental reconfigurations forced the contraction of the Rheic Ocean resulting in the closure of the Rheic-Tethyan Gateway, which precluded further faunal exchanges between the North American and Eurasian marine realms. Interestingly, cartilaginous fishes seem to be relatively immune to these drastic climatic and environmental changes. The Eurasian fossil record of Paleozoic sharks is strongly biased towards intensively sampled localities from England, Ireland, Scotland, and the Russian Platform. Here we present rare dental material from the Serpukhovian (early Carboniferous) of Austria, adding new information to the paleogeographic distribution of ctenacanthiform sharks. The new material revealed the first record of the genus Saivodus in Central Europe and allowed us to recognize a new species, Cladodus gailensis sp. nov., and a remnant of fossilized cartilage. In an attempt to identify possible linkages between climatic or environmental fluctuations on shark diversity throughout the Carboniferous, we provide a synopsis of the distribution and diversity of elasmobranchs based on primary literature. This preliminary assessment at genus level indicates two pronounced events of extinction, with the first one occurring during the latest Mississippian and the second one towards the end of the Pennsylvanian. The first extinction event distinctly correlates with the known diversity decline of other marine inhabitants and the second occurred during an unstable period of multiple phases of glaciation.