Kelmayisaurus

Jawbone of Kelmayisaurus

• Karamay, Xinjiang Province China

• Kelmayisaurus petrolicus

Kelmayisaurus is a genus of dinosaur theropder Carcharodontosauridae family from the Lower Cretaceous of China. Dong Zhiming published in 1978 the first scientific description of the genus with the type species K. petrolicus. 2012 described Stephen L. Brusatte, Roger Benson and Xu Xin him again.

Description

In Kelmayisaurus there was a large carnivorous dinosaur. An exact size specification is due to the sparse fossil material hardly possible Brusatte et al. but inferred from the length of the mandible that its size was comparable to that of Allosaurus. Accordingly Kelmayisaurus reached an estimated length of ten to eleven feet and a weight of about 1600kg.

The holotype consists of a left lower jaw, and also parts of the left maxilla. Of the latter only a small fragment is preserved, but shows similarities with the Allosauroiden Allosaurus, Neovenator and Monolophosaurus. The rough surface of the bone as it is found in more advanced Carchadodontosauriden and Abelisauriden missing. The lower jaw is, however, well preserved and nearly complete. The bone is of a length of 525mm, and has on the side of a concave groove on which Brusatte et al. regarded as an autapomorphy.

System

The exact assignment of the genus was long uncertain. Dong classified Kelmayisaurus in its first description as Megalosauriden, Carroll ( 1988) saw a member of the Carnosauria, Molnar et al in it. (1990 ) and Dong Tetanuren a classified him in 1992 as Allosauriden. Rauhut and Xu (2005) eventually call him due to lack of findings as a nomen dubium.

Brusatte et al. (2011 ), however, consider Kelmayisaurus after a cladistic analysis as a valid species and as a representative of the basal Carcharodontosauridae, the opposite is the branch of Acrocanthosaurus and other advanced Carcharodontosauriden together with Eocarcharia.

Eocarcharia

Kelmayisaurus

Acrocanthosaurus

Advanced Carcharodontosauriden (including Giganotosaurus, Carcharodontosaurus, Tyrannotitan )

Thus Kelmayisaurus would Shaochilong after the second known Carcharodontosauride from Asia and thus supports the idea that this family was widespread throughout the lower and middle Cretaceous.

However, the authors also acknowledge that a different classification of Kelmayisaurus can not be entirely excluded. So there is also the possibility of a relationship to, among other Megalosaurus or guanlong. However, a close examination of the fossils and a comparison with other types of support to continue the membership of the Carcharodontosauridae.