Proceratosauridae

Artistic live reconstruction of the skull of guanlong wucaii

The Proceratosauridae is a family of Tyrannosauroidea with the type genus Proceratosaurus. They were by Oliver Rauhut et al. as all theropods, which are more closely related than Proceratosaurus with Tyrannosaurus, Allosaurus, Compsognathus, Coelurus, Ornithomimus or Deinonychus defined. This study supports the idea that Proceratosaurus is a Tyrannosauroidee and the closest relatives of the Chinese guanlong. Later studies arrange the genera Kileskus and Sinotyrannus.

Features

The skulls of Proceratosauriden were long, built low and light and are thus similar to those of other Coelurosaurier. The premaxillary bone ( premaxilla ) was very high, which had a blunt snout result - a feature that has developed convergent even when the Abelisauriden. The paired nasal bone was fused, slightly arched top and on the top usually very rough, often bark-like structure. Between the teeth of the jaw bone in the front part of the upper jaw were smaller and shaped differently than the remaining teeth, and had a "D" -shaped cross -section. The lower jaw of all Tyrannosauroideen except guanlong had a pronounced crest on the Surangulare which extended laterally just below the jaw joint. The Proceratosauriden head ornaments were detected. In Proceratosaurus a horn is suspected ( Proceratosaurus means as much as "pre- horn lizard" ) and guanlong a comb is demonstrated.

The Proceratosauriden had like most other theropods "S" - shaped bent necks and long tails. The genera had three -fingered, long arms, the 60 percent of the length of the hind legs reached at guanlong. Characteristic features in the pelvic bones include a notch at the bottom of the ilium ( ilium ), extended significantly limited vertical ridge on the ilium, extending from the hip joint socket ( acetabulum ) upwards, and the enlarged end of the pubis ( pubic bone ) with a, the extended "T" -shaped on both sides, more than half as long as was the actual shaft of the pubic bone. These features are found in all known Tyrannosauroideen.

The hind legs of all Proceratosauriden had like most theropods four toes, although the first toe ( hallux ) did not touch the ground. The hind legs were in proportion to body size longer than in almost all other theropods and show proportions that are characteristic of fast moving animals; so the shinbone ( tibia bone ) and the metatarsal bones were extended.

System

The Proceratosauridae is counted among the Tyrannosauroideen, a group which counts among other Tyrannosaurus. The cladogram shows the phylogenetic relationships:

Kileskus

Guanlong

Proceratosaurus

Sinotyrannus

Dilong

Eotyrannus

Stokesosaurus

Xiongguanlong

Dryptosaurus

Raptorex

Appalachiosaurus

Bistahieversor

Tyrannosauridae

Gallery

Comparison of Kileskus with a woman

Fossils of guanlong

Head reconstruction of Proceratosaurus bradleyi

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