Olorotitan

Phylogeny: Dinosauria > Ornithischia > Genasauria > Neornithischia > Cerapoda > Ornithopoda > Iguanodontia > Ankylopollexia > Styracosterna > Hadrosauriformes > Hadrosauroidea > Hadrosauridae > Lambeosaurinae > Lambeosaurini

Overview: There are two major subfamilies in the family Hadrosauridae – the Saurolophinae and the Lambeosaurinae. Saurolophines, which included dinosaurs like Maiasaura and Edmontosaurus, usually had long and wide-billed snouts, while the snouts of lambeosaurines were shorter and more narrow. Bony head crests appeared among members of both subfamilies, but it those of the Lambeosaurinae were often far larger and more extravagant. We can see this with Olorotitan – the “giant swan”. Its crest, formed out of part of its nasal bones, took the form of a large, backward-pointing hatchet blade-like structure. The crest was hollow and linked to the respiratory system, so some believe Olorotitan, and other lambeosaurines with similar crests, could use their crests as resonating chambers to make loud calls. They also would’ve been used for courtship purposes.

Olorotitan was a decently large hadrosaurid, growing to be about eight or nine meters long, so in the same size range as related genera like Parasaurolophus or Lambeosaurus. These dinosaurs all evolved from bipedal ancestors. While they could walk up on their hind legs, most of their time would’ve been spent down on all fours, with low-level vegetation making up a fair bit of their diet. Olorotitan, like all hadrosaurids, had highly efficient jaws and teeth for dealing with even tougher plant material. Fossils attributed to Olorotitan are known from the Amur region of Russia, in the far eastern part of the country, along the Amur River, which forms a border with the northeast of China. Much of its skeleton has been recovered, with all bones being found within the rock layers of the Udurchukan Formation, meaning Olorotitan lived towards the end of the Cretaceous.