Wuerhosaurus

Wuerhosaurus is a genus of stegosaurid dinosaur from the Early Cretaceous Period of China. As such, it was one of the last genera of stegosaurians known to have existed, since most others lived in the late Jurassic.

Discovery and species
Wuerhosaurus homheni is the type species, described by Dong Zhiming in 1973 from the Tugulu Group in Xinjiang, western China. The generic name is derived from the city of Wuerho.[2]

The remains consisted of the holotype IVPP V.4006, a skull-less fragmentary skeleton, and the paratype IVPP V4007,[3] three vertebrae from the tail of a second individual.[4]

A smaller species from the Ejinhoro Formation in the Ordos Basin in Inner Mongolia, W. ordosensis, was formalized by the same researcher in 1993. It is based on specimen IVPP V6877, a fragmentary skeleton lacking the skull. It was found in 1988.[5]

Susannah Maidment and colleagues proposed in 2008 that Wuerhosaurus should be considered a junior synonym of Stegosaurus, with type species W. homheni as Stegosaurus homheni and second species W. ordosensis regarded as dubious.[6] This opinion has been contested, however.

Description
Wuerhosaurus homheni was probably a broad bodied animal. Gregory S. Paul in 2010 estimated the length at 7 metres (23 ft) and the weight at four tonnes.[8] Only a few scattered bones have been found, making a full restoration difficult.[1] Its dorsal plates were at first thought to have been much rounder or flatter than other stegosaurids,[4] but Maidment established this was an illusion caused by breakage: their actual form is unknown. W. homheni had a pelvis of which the front of the ilia strongly flared outwards indicating a very broad belly. The neural spines on the tail base were exceptionally tall.

W. ordosensis was estimated by Paul to have been 5 metres (16.5 feet) long and weigh 1.2 tonnes. It too has a broad pelvis but the neural spines are shorter. The neck seems to have been relatively long.