Olorotitan

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Olorotitan
Temporal range:
Ma
Mounted skeleton, Royal Belgian Institute of Natural Sciences
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Clade: Ornithopoda
Family: Hadrosauridae
Subfamily: Lambeosaurinae
Tribe: Lambeosaurini
Genus: Olorotitan
Godefroit et al., 2003
Type species
Olorotitan arharensis
Godefroit et al., 2003

Olorotitan was a

Amur River
.

Discovery and naming

Fossils of the holotype specimen in situ

The

lambeosaurine skeleton discovered anywhere outside of western North America.[1]

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

Amur River, have yielded similarly high numbers of lambeosaurine fossils.[1]

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.[1]

Description

Skull reconstruction.

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,[1] and may have grown up to 12 metres (39 ft) in length, up to 3.5 metres (11 ft) in height and within the range of 2.6–3.4 metric tons (2.9–3.7 short tons) in body mass.[2][3]

Life restoration

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

neural spines, making that caudal area particularly rigid; the regularity of these connections suggests that they are not due to a pathology, although more specimens are needed to be certain. Godefroit and his coauthors found through a phylogenetic analysis that it was closest to Corythosaurus and Hypacrosaurus.[1]

Palaeobiology

Skeletal reconstruction of Olorotitan; on the bottom, preserved bones of the holotype, AEHM 2/845 (left) and referred specimen AEHM 2/846 (right) are shown in white

As a hadrosaurid, Olorotitan would have been a

chewing, and was furnished with hundreds of continually-replaced teeth. Its tall, broad hollow crest, formed out of expanded skull bones containing the nasal passages, probably functioned in identification by sight and sound.[4]

Palaeoecology

Restoration of Olorotitan in environment

O. arharensis shared its time and place with several other types of animal, including two other lambeosaurines: the

hadrosaurine Kerberosaurus is also known from roughly contemporaneous rocks in the area.[5] Unlike the situation in North America, where lambeosaurines are virtually absent from Late Maastrichtian rocks, Asian lambeosaurines are diverse and common at the end of the Mesozoic, suggesting climatic or ecological differences.[1]

See also

References