Thescelosaurus Rib Section - 5" Long

This is a mostly complete rib of the small ornithopid dinosaur Thescelosaurus. It's just missing the very tip and a small portion of the head. There have been a few repairs and some minor restoration around the cracks. It was collected on private land in the Hell Creek Formation of South Dakota.

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.

Thescelosaurus was a heavily built bipedal animal, probably herbivorous, but possibly omnivorous. It would have browsed in the first meter or so from the ground, feeding selectively, with food held in the mouth by cheeks while chewing.

The genus attracted media attention in 2000, when a specimen unearthed in 1993 in South Dakota, United States, was interpreted as including a fossilized heart. There was much discussion over whether the remains were of a heart. Many scientists now doubt the identification of the object and the implications of such an identification.