Bistahieversor

The skull of Bistahieversor during preparation

• Kirtland Formation, New Mexico

Bistahieversor is a dinosaur, which belonged to the Tyrannosauroidea and was first described in 2010. The only way is Bistahieversor sealeyi.

The genus was named after the Bisti Wilderness Area, New Mexico, where their fossils were found, and the Latin word for destroyer ( Eversor ). The Style epithet honors sealeyi Paul Sealey, who found the holotype specimen. Bistahieversor lived in the Upper Cretaceous (late Campanian ).

The holotype specimen is a preserved in the anatomical context skull with skeleton. In addition, a fragmentary preserved skull, the skeleton of a young animal, and part of a leg of a right tears third copy was found. For the first description, only the skulls were examined. Its total length is estimated to be 8 m.

Features

The skull of the holotype specimen is 107 inches long and above the orbit ( eye socket) 31 inches high. Had Bistahieversor in contrast to other tyrannosaurs an additional craniotomy above the eyes, a keel along the lower jaw and teeth longer than Tyrannosaurus rex. In his upper jaw, he showed a distinct tooth gap ( dichotomy ).

Probably the basal tyrannosaur flachschädeligen of the Jurassic and Lower Cretaceous began their prey mainly with the front limbs, a feature that was later adopted in more advanced tyrannosaurs of the late Cretaceous of the powerful jaws. The scientists believe that the also hochschädelige Bistahieversor only had small, reduced forelimbs. They are, however, not yet exposed.

Bistahieversor is regarded as evidence for the proposition that the hochschädeligen, equipped with very strong jaws tyrannosaurs developed only in western North America, which was separated from the eastern part of the continent by the Western Interior Seaway, a shallow sea. Ostnordamerikanische tyrannosaurs like Appalachiosaurus stayed with the original feature of a low muzzle.