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| Wadisuchus kassabi Saber, Salem, Ouda, Gohar, El-Sayed, O’Connor & Sallam, 2025 Paleoart by Nathan Dehaut. |
Abstract
Dyrosauridae are a clade of crocodyliforms characterized by diverse cranial morphologies and a broad palaeogeographic distribution from the Late Cretaceous to the Palaeogene. However, their early evolutionary history remains poorly understood due to a significant fossil gap during the Campanian. Here, we describe Wadisuchus kassabi gen. et sp. nov., an early-diverging dyrosaurid from the middle Campanian Quseir Formation of Egypt, based on two partial skulls and three partial mandibles. This new taxon displays transitional cranial features—including reduced premaxillary alveoli, modified occlusion patterns, and dorsally positioned external nares—that clarify aspects of cranial evolution related to longirostry in early dyrosaurids. Phylogenetic analyses consistently recover Wadisuchus as the earliest-diverging dyrosaurid, closely related to Chenanisuchus and distinct from Elosuchus, supporting a transition from dyrosauroids to dyrosaurids. Its Campanian age extends the temporal range of the clade and suggests that transatlantic dispersal from Africa to South America occurred earlier than previously recognized. Alongside Brachiosuchus kababishensis from Sudan, the new Egyptian taxon also implies that reverse dispersal into Africa preceded the Maastrichtian. Wadisuchus provides critical insights into the early diversification, palaeobiogeography, and cranial evolution of Dyrosauridae, confirming longirostry as an early-acquired trait and highlighting North Africa as a key region in their origin.
Campanian, Quseir Formation, Egypt, North Africa, Dyrosauridae, phylogeny
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| Life reconstruction of Wadisuchus kassabi from the Late Cretaceous of Egypt, showing an adult capturing a lungfish in a wetland, with a juvenile nearby. The scene highlights the ancient ecosystem, including turtles and lush vegetation, based on fossil evidence from the Quseir Formation. Paleoart by Nathan Dehaut. / MUVP—Scientific supervision |
Wadisuchus kassabi gen. et sp. nov.
Sara Saber, Belal S Salem, Khaled Ouda, Abdullah S Gohar, Sanaa El-Sayed, Patrick M O’Connor and Hesham M Sallam. 2025. An early dyrosaurid (Wadisuchus kassabi gen. et sp. nov.) from the Campanian of Egypt sheds light on the Origin and Biogeography of Dyrosauridae. Zoological Journal of the Linnean Society. 205(2) zlaf134. DOI: doi.org/10.1093/zoolinnean/zlaf134 [27 October 2025]
