Pinacosaurus

Skeletal reconstruction of Pinacosaurus

• Asia (Mongolia, China)

• Pinacosaurus grangeri Gilmore, 1933
• Pinacosaurus mephistocephalus Godefroit, Pereda - Superbiola, Li & Dong, 1999

Pinacosaurus was a genus of bird Beck dinosaurs from the group of Ankylosauria. She lived in the Upper Cretaceous in East Asia.

Features

Of Pinacosaurus mainly subadulter animals were found which had a length of 1.5 meters. The fossil material of adult animals is scanty, it may have reached a length of 5 meters. Pinacosaurus moving quadruped ( on all fours ) continued and was compared with other Ankylosauridae more easily built. As with all ankylosauruses the hull with an armor of bony plates covered, bony spine cusp offered additional protection. The tail ended like many Ankylosauridae in a bony club, which probably served the enemy defenses.

The skull ( in adult animals 31 inches long ) is mainly characterized by the additional openings in the area of the nostrils, which otherwise can be found in any Ankylar. The first specimen found had a pair of additional openings in animals later found four and five pairs have been described openings. The exact function of these openings is controversial. The snout ended in a round, toothless horny beak. The teeth were adapted as with all ankylosauruses small and a plant food.

Discovery and designation

Pinacosaurus one of the dinosaurs that were discovered in the 1920s by an initiated by the American Museum of Natural History expedition to the Gobi Desert. The first description dates back to 1933, the name Pinacosaurus means " plank lizard". In addition to the original findings in the Mongolian region Ömnö Gobi aimag later finds in the Chinese provinces of Inner Mongolia and Shandong were made. Type species is P. grangeri; in the 1990s was described by P. mephistocephalus a second type that is different among others in the number of located next to the nostrils holes. The finds are dated to the Late Cretaceous (late Santonian to middle Campanian ) at an age of about 85 to 76 million years.

System

Pinacosaurus is expected within the Ankylosauridae in the group of Ankylosaurinae, where it is counted an unnamed clade of Asian species, which also includes still Saichania, Talarurus and Tianzhenosaurus. According to phylogenetic studies of Vickaryous et al. the genus might be paraphyletic with respect to Tianzhenosaurus because P. is related mephistocephalus closer grangeri with this than with Fr.