A new late Pleistocene fossil crocodile from Sudan reveals hidden diversity of Crocodylus in Africa.

While Crocodylus fossils are common in late Cenozoic deposits of Africa, there is a lack of knowledge about species diversity within the genus, especially after the Early Pleistocene. Here we report on a complete skull of a new fossil Crocodylus from the Late Pleistocene of the Middle Atbara River, eastern Sudan. Cranial morphology resembles Plio-Pleistocene species of Crocodylus from Africa in having upturned squamosals, though not as prominently developed as in these species, whereas the skull differs from fossil and extant Crocodylus in having a vaulted sagittal boss on the dorsal surface of the rostrum, and in the absence of a supraoccipital exposure on the dorsal skull table. Phylogenetic analyses indicate the Atbara Crocodylus represents a separate species and is more closely related to the fossil African crocodiles than the extant forms. The new species represents the first fossil Crocodylus to be described from the Late Pleistocene of Africa, providing new information on the occurrences and diversification of the genus Crocodylus during the Late Pleistocene.