Early and Middle Devonian cephalopods from Hamar Laghdad (Tafilalt, Morocco) and remarks on epicoles and cameral deposits

摘要

Devonian condensed sections of the northern Tafilalt Platform (Anti-Atlas, Morocco) are often extremely rich in cephalopod associations. Here, we describe Pragian to late Givetian cephalopods from Hamar Laghdad (Tafilalt). In total, we found 44 species belonging to 32 genera. While no new species of ammonoids or bactritids were recovered, we report two new genera and eight new species of nautiloids, which have been studied much less than the other cephalopod groups in the past despite their great abundance, diversity and morphologic disparity in the eastern Anti-Atlas. The genera Mesonaedyceras and Subtheoceras are newly introduced as well as the new species Aphyctoceras friesenbichlerae, Astoceras floweri, Geidoloceras hebeiseni, Infundibuloceras kroegeri, Mesonaedyceras laterobliquum, Pachtoceras laghdadense, Pseudendoplectoceras angustum and Subtheoceras striatum. In addition, we describe exceptionally preserved three-dimensional cameral deposits of orthoconic cephalopods and several cases of post mortem epicoles on cephalopod conchs.