Additions to the sauropod dinosaur fauna of the Cenomanian (early Late Cretaceous) Kem Kem beds of Morocco: Palaeobiogeographical implications of the mid-Cretaceous African sauropod fossil record

摘要: Abstract Determining the relationships of mid-Late Cretaceous African taxa is central to understanding timing and resultant palaeobiogeographical patterns Gondwanan fragmentation. The early Late (Cenomanian) Kem beds southeastern Morocco preserve a diverse vertebrate fauna, including sauropod dinosaurs. Sauropod material includes holotype rebbachisaurid diplodocoid Rebbachisaurus garasbae fragmentary remains representing indeterminate titanosauriforms rebbachisaurids. Here, we describe two new specimens from beds. A dorsal neural arch with complex internal pneumaticity tentatively attributed somphospondylan titanosauriform. caudal vertebra possessing several synapomorphies excavated by large pervasive lateral pneumatic foramen, feature undocumented in other However, vertebrae are currently unknown for sympatric R. garasbae, so this element could be referable that taxon or second, previously unknown, species. Interestingly, displays mosaic features otherwise restricted limaysaurine nigersaurine rebbachisaurids, suggesting placement basal these clades, which position usually recovered R. garasbae phylogenetic analyses. review mid-Cretaceous fossil record removes dicraeosaurids Africa, restricting clade single post-Jurassic occurrence Argentina. All diagnostic can Whereas rebbachisaurids were seemingly northwestern Africa disappeared post-Cenomanian, widespread across continent survived until latest Cretaceous. development Trans-Saharan Seaway might have acted as dispersal barrier groups. In contrast, been able cross barrier, but it possible they also unable disperse, not closely related rest continent. New materials better titanosaur interrelationships will crucial teasing scenarios apart.