Olorotitan

Skeleton of Olorotitan at the Museum of Natural Sciences in Brussels.

• Eastern Russia, in Kundur ( Udurchukan Formation)

• Olorotitan arharensis

Olorotitan is a genus ornithopoder dinosaurs that is counted among the Lambeosaurinae, a subfamily of Hadrosauridae. So far, a nearly complete skeleton is known, which dates from strata of Late Cretaceous (late Maastrichtian ) from the Amur region in the Russian Far East.

Like its relatives also contributed Olorotitan a bony outgrowth on the head. It was a herbivore that probably both bipedal ( biped ) and four-legged ( quadruped ) could walk.

The only known species of this genus is Olorotitan arharensis, which was described in 2003 by Godefroit, Bolotsky and Alifanov. The name Olorotitan means as much as " giant swan " while the Artepitheth arharensis to the locality in Arhara country applies.

Description

Olorotitan based on an almost complete, around nine to ten meters long, skeleton - the best preserved skeleton Lambeosaurinen outside North America. Although some skull bones ( the neurocranium and the skull roof) are missing, the rear-facing beilförmige skull crest is very well preserved. This is unusual and the most prominent feature also Lambeosaurinen.

Another important autapomorphy is the extended neck, which consists of 18 vertebrae - in contrast to the maximum of 15 cervical vertebrae of all other Hadrosauriden. Even the sacrum ( sacrum) has 15 or 16 vertebrae at least three vertebrae over the other Hadrosauriden. The proximal ( which opens onto the body ) thirds of the tail has connections between the tips of the spinous processes, which reinforce this tail section. A pathological ( caused by disease ) cause of this feature is, however, not be excluded, clarity can only bring further discoveries.

Classification, origin and paleoecology

Within the Lambeosaurinae there are two sub-groups, and the Parasaurolophini Lambeosaurini. Olorotitan is classified in the latter and is considered a sister taxon to the North American species Hypacrosaurus and Corythosaurus.

The Udurchukan to the lineup (the lower part of the Tsagayan - Group) belongs site was discovered in 1991 at Kundur and was by the Olorotitan skeleton also remains of turtles, crocodiles, theropods and Nodosauriden free. At other sites the Amur region, especially in Jiayin and Blagoveshchensk, more Hadrosauriden species were detected, with which shared Olorotitan the habitat. Among the Lambeosaurinen Amurosaurus and Charonosaurus and Hadrosaurine are Kerberosaurus. Unlike in North America where the Lambeosaurinae at the end of the Maastrichtian was rare, it was at the same time in Asia still frequently, which is attributed to climatic or ecological differences.