Lythronax

Reconstructed skeletons of (A) Lythronax Argestes ( UMNH VP 20200 ) and (B ) Teratophoneus curriei ( UMNH VP 16690 )

• United States (Utah ), Wahweap Formation

• Lythronax Argestes

Lythronax was a genus of dinosaur from the Campanian tyrannosaurider of North America. This is the stratigraphically oldest species Tyrannosauridae family. The only way is Lythronax Argestes.

Description

Lythronax Argestes is known by a partially preserved skeleton, which was associated with a single, immature specimen. The material surrounds the major part of the skull, the pelvis, the left rear leg parts, a rib and a Chevronknochen. Diagnostic features provide, inter alia, in comparison to other tyrannosaurids low number of tooth sockets in the upper jaw (11 ), an inwardly curved, lateral border of the mandible, a high spinous process of the cervical vertebrae and a wider rear portion of the skull dar.

The Rostrum accounts for less than two -thirds of the length of the skull and is thus relatively short. The skull is about 0.4 times as wide as long. The rugged upper jaw had a heterodontes bite, because the first five teeth are significantly larger than the remaining six. The skull as a whole is morphologically similar to that of Tyrannosaurus and Tarbosaurus.

The postcranial morphology similar to that of other tyrannosaurids.

Locality

Fossil material of the holotype of L. Argestes was found in the Wahweap Formation, which is located in Utah (USA). The material located at the Natural History Museum of Utah in Salt Lake City under the catalog number ( UMNH VP 20200 ). The age of the formation is dated at 80.6 to 79.9 million years Lythronax what makes the oldest representative of the tyrannosaurids.

The formation in which it was found, was once part of the island continent Laramidia (now western North America). The discovery of L. Argestes can be concluded that there was the origin of Tyrannosauridae.

System

Lythronax Argestes belonged to the family Tyrannosauridae, a family of great Coelurosaurier that from North America and Asia is mainly known. A detailed phylogenetic analysis of the 2013, based on postcranial 198 and 303 cranial features, Lythronax and Teratophoneus classified as members of the subfamily Tyrannosaurinae. In addition, they are listed as be sister of the genera Tyrannosaurus, Bistahieversor, and Tarbosaurus.