Kileskus

Diagram of the skeleton, known parts are located.

• Western Siberia, Russia ( Itat Formation)

• Kileskus aristotocus

Kileskus is a genus theropod dinosaur from the group of Tyrannosauroidea. So far, only fragmentary jaw bone and bones of the fingers and the foot are known to have been found in western Siberia in Russia and the Middle Jurassic ( Bathonian ) originate. This is one of the oldest known representative of the Tyrannosauroidea and the parent group Coelurosauria.

Kileskus was first scientifically described in 2010 by Averianov and colleagues with the only kind, Kileskus aristotocus. These researchers assign Kileskus the Proceratosauridae, a group within the Tyrannosauroidea, which further comprises the genera guanlong and Proceratosaurus.

Features

The Proceratosauridae characterized by an abnormal skull crest, whose presence at Kileskus but - due to the very fragmentary remains - can not be confirmed. However, since the other two representatives of Proceratosauridae showed a comb, the researchers suggest such even when Kileskus (principle of phylogenetic grip ).

In the paired premaxillary bone ( premaxilla ), one sitting in front of the upper jaw bone, each were four teeth; at about 29 cm long upper jaw were each 17 teeth. Kileskus This differs from Proceratosaurus which had each 22 teeth in the upper jaw. Unique among related genera was of course an oriented upwards bone crest on the upper jaw.

Fund and naming

The fossils include a fragmentary right maxilla ( holotype, specimen number ZIN PH 5/117 ), a left Zwischenkieferbein, a fragment of a left Surangulare ( a bone of the lower jaw ), a metacarpal, a phalanx, two metatarsals, a toe bone and a toe-nail with a.

These fossils - discovered in Berezovsk quarry in the district Sharypovo in the Krasnoyarsk region in western Siberia - were found distributed over an area 1-2 square meters. They come from the gray clays of the upper Itat lineup, including their diverse vertebrate fauna, among other dinosaurs, pterosaurs, crocodiles, turtles, lizards and various mammals.

The name comes from the Kileskus Khakassian language, meaning " lizard ". The second part of the species name, aristotocus, ( ancient Greek άριστότοκος, - " of sublime origin " ) has the systematic position within the advanced theropod group Coelurosauria.

System

Kileskus is counted as basal Porceratosauridae. Other genera of this family are Proceratosaurus, guanlong and Sinotyrannus. The Proceratosauriden are a group of Tyrannosauroidea, the sister taxon are derived Tyrannosauroidea, which include, among other things, Dilong and Tyrannosaurus.

Kileskus

Guanlong

Proceratosaurus

Sinotyrannus

Derived Tyrannosauroidea (such as Dilong, Tyrannosaurus )