2.3" Ornithischian Dinosaur Caudal Vertebrae - Montana

This is a well preserved, caudal (tail) vertebrae from either the dinosaur Thescelosaurus or Pachycephalosaurus. Isolated verts from these two Ornithischian dinosaurs would be basically indistinguishable. It comes from the Hell Creek Formation in Powder River County, Montana. There is some repair and minor gap filling of the repaired cracks.

Thescelosaurus was a small ornithopod dinosaur that appeared at the very end of the Late Cretaceous period in North America. The preservation and completeness of many of its specimens indicate that it may have preferred to live near streams. This bipedal ornithopod is known from several partial skeletons and skulls that indicate it grew to between 2.5 and 4.0 meters (8.2 to 13.1 ft) in length on average. It had sturdy hind limbs, small wide hands, and a head with an elongate pointed snout. The form of the teeth and jaws suggest a primarily herbivorous animal.

Pachycephalosaurus was a bipedal dinosaur that lived during the Late Cretaceous period and probably was about 15 feet in length. It had a distinctive, large, bony, dome on top of it's skull up to 10 inches thick to cushion it's brain from impacts.