Crocodylus sudani
- 演化之聲
- Mar 20
- 2 min read
Updated: Apr 9
Age
Quaternary（Pleistocene）
0.09 Ma
Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Family: Crocodylidae
Genus: Crocodylus
Species: Crocodylus sudani
Morphological description
Crocodylus sudani exhibits an overall morphology similar to that of the Nile crocodile (Crocodylus niloticus) and the West African crocodile (Crocodylus suchus). The holotype skull measures 57 cm in length and 34 cm in quadrate width, from which the total body length is estimated to be approximately 4 to 4.3 meters.
The external naris is teardrop-shaped and positioned at the anterior tip of the snout, opening in an anterodorsal direction, differing from the dorsally oriented nostrils of modern crocodiles. The premaxilla bears a small opening anterior to the naris, which accommodates the first dentary tooth when the jaws are closed. At the junction between the premaxilla and maxilla, a distinct notch is present for receiving the enlarged fourth dentary tooth.
The lateral margins of the snout are primarily formed by the maxillae and display an undulating contour. A constriction occurs between the eighth and ninth maxillary alveoli, forming an edentulous notch that allows interlocking with the lower jaw teeth.
Etymology
The species name refers to the Republic of Sudan, where the fossil material was discovered.
Biological description
Fossils of Crocodylus sudani were recovered from the middle reaches of the Atbara River in Sudan. The holotype specimen, Atbara 22–172, consists of an almost complete skull and represents the only known extinct member of the genus Crocodylus from the Late Pleistocene of Africa.
Phylogenetic analyses indicate that Crocodylus sudani is more distantly related to the extant African species C. niloticus and C. suchus, and instead shows closer affinity to extinct African taxa such as Crocodylus anthropophagus and Crocodylus thorbjarnarsoni. In one analysis, C. sudani and C. anthropophagus form a sister group, although the statistical support for this relationship is low.
During the time when Crocodylus sudani lived, the climate was more humid and crocodiles were more widely distributed across Africa. As aridification progressed, the ranges of species such as C. niloticus and C. suchus became more restricted. Because of the strong morphological similarity between C. sudani and modern African crocodiles, combined with limited sampling of crocodile populations in Africa, it has been proposed that C. sudani may not be extinct but could persist as a cryptic species within the Nile Basin, coexisting with C. niloticus. This hypothesis, however, requires further investigation.
(Author: Bai Leng)
Reference
Salih, K., Müller, J., Eisawi, A., Bibi, F. (2025). A new late Pleistocene fossil crocodile from Sudan reveals hidden diversity of Crocodylus in Africa. Scientific Reports.
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