A new hadrosaurine dinosaur from the Late Cretaceous of Far Eastern Russia

ABSTRACT

Kerberosaurus manakini, gen. et sp. nov. (Dinosauria, Hadrosauridae) is described on the basis of disarticulated skull elements from the Maastrichtian Tsagayan Formation of Blagoveschensk, Far Eastern Russia. This flat-headed hadrosaur is characterized by a unique morphology of the lateral wall of the braincase, a particularly narrow frontal, a depressed rostral margin of the parietal, a strong, wide and flattened crest around the circumnarial depression, and a very prominent hook-like palatine process on the maxilla. A phylogenetic analysis, based on 21 cranial characters, indicates that, among hadrosaurines, Kerberosaurus is the sister taxon of a monophyletic group formed by Prosaurolophus and Saurolophus. Several independent hadrosaurid lineages migrated from western North America to eastern Asia, probably by late Campanian to early Maastrichtian time. At the end of the Maastrichtian, completely different dinosaur faunas developed in both regions, indicating some kind of geographical or paleoecological barrier.