Olorotitan

Olorotitan was a genus of lambeosaurine duckbilled dinosaur from the middle or latest Maastrichtian-age Late Cretaceous, whose remains were found in the Udurchukan Formation beds of Kundur, Amur River Region, Far Eastern Russia. The type, and only species is Olorotitan arharensis. It was one of the last non-avian dinosaurs and it went extinct during the Cretaceous–Paleogene extinction event. The holotype specimen of Olorotitan, consisting of a nearly complete skeleton, was discovered in field work in the Udurchukan Formation of Kundur in the Amur region of Russia between 1999 and 2001. Pascal Godefroit and colleagues described and named it as a new species in 2003. It was the first nearly complete dinosaur specimen to be described from Russia, and is the most complete lambeosaurine skeleton discovered anywhere outside of western North America. Large numbers of fragmentary dinosaur, turtle, and crocodilian specimens were found in the several hundred square metre area around the discovery site. Similarly aged localities in Blagoveschensk, also from the Udurchukan Formation and Jiayin, on the Chinese side of the Amur River, have yielded similarly high numbers of lambeosaurine fossils. The generic name Olorotitan means "titanic swan" because its neck is longer when compared with other hadrosaurs, while the specific descriptor arharensis refers to Arhara County where the fossil was found. Olorotitan arharensis is based on the most complete lambeosaurine skeleton found outside North America to date. It was a large hadrosaurid, comparable with other large lambeosaurines such as Parasaurolophus cyrtocristatus, and may have grown up to in length, up to in height and within the range of in body mass. It is characterized by the large hatchet-like hollow crest adorning its skull, very distinct from the crests of all of its North American relatives. The skull itself was supported by a rather elongated neck, having eighteen vertebrae, exceeding the previous hadrosaurid maximum of fifteen.