FIRST RECORD OF HYPOSAURUS (DYROSAURIDAE, CROCODYLIFORMES) FROM THE UPPER CRETACEOUS SHENDI FORMATION OF SUDAN

We describe a new record of the dyrosaurid crocodyliform genus Hyposaurus, from the ? Campanian-Maastrichtian Shendi Formation of Sudan, based on a partial mandibular symphysis, two posterior portions of the upper jaw, and a fused frontal bone, all belonging to a single individual. The material can be assigned to Hyposaurus on the basis of the elliptical shape of the mandibular symphysis (wider than high) and the overall flat shape of the mandible. At the same time, the fossil material differs from other species of Hyposaurus in having (1) an enlarged eighth alveolus of the dentary relative to the other alveoli; (2) a reduced interalveolar space between the ninth and tenth alveoli; and (3) a prominent ridge and groove sculpturing on the dorsal side of the mandible along the symphyseal region. However, due to the fragmentary nature of the material, we refrain from drawing any higher-resolution taxonomic conclusions. The occurrence of Hyposaurus within the Shendi Formation represents the first record of this genus from the Late Cretaceous of Africa and potentially extends its temporal range to the Campanian. Whereas this occurrence in the Late Cretaceous of Sudan supports previous hypotheses of an African origin for Hyposaurus, more complete material is needed for evaluating these hypotheses in a phylogenetic framework. We also wish to stress that the genus Hyposaurus requires detailed revision.