Hesperosaurus

Skeleton of Hesperosaurus mjosi in the North American Museum of Ancient Life

• United States (Wyoming)

• Hesperosaurus mjosi Carpenter, Miles & Cloward, 2001

Hesperosaurus was a dinosaur genus from the group of Stegosauria. It was discovered in 2001 in North America.

Features

Hesperosaurus reached an estimated length of 5 to 6 meters - but the only specimen found was a subadult animal. As he had all Stegosaurus on a double row of bony plates ( osteoderms ) along the back. These bone plates were - compared with those of Stegosaurus - elongated and oval. At the tip of the tail he wore two pairs of long, pointed spines. The limbs of this dinosaur are not known, the skull was slightly shorter and wider than the other Stegosaurus. Like all Stegosaurus had Hesperosaurus small, adapted to a plant food teeth.

Discovery and designation

Fossils of Hesperosaurus were found in the Morrison Formation in the U.S. state of Wyoming, and in 2001 by Kenneth Carpenter et al. described. There is a nearly complete skeleton of a subadult animal, only the limbs and shoulder blades are missing. The name Hesperosaurus means " Western lizard" (from the ancient Greek ἑσπερο-/hespero- " evening, west " and σαῦρος / sauros "lizard "). The authors named the genus after its location in the western U.S.. The only way, and thus the type species is H. mjosi. The finds are in the early Upper Jurassic ( Oxfordian ) and thus dated to an age of about 163-157 million years.

Hesperosaurus after Stegosaurus only the second known from North America Stegosauriergattung.

System

Hesperosaurus is considered more primitive representatives of Stegosauria. Phylogenetically, it is used as a basal representative of the Stegosaurinae, the more developed Stegosauria, classified (see Nomenclature of Stegosauria ).