Thescelosaurus

Thescelosaurus or "marvelous lizard" was a mid-size dinosaur from the late Cretaceous that roamed the northwest US. They were bipedal and reached a length of 13 feet. Fossil remains include well preserved teeth, bones, and claws, and are highly valued by collectors. These top quality specimens were all legally collected from private lands in the northwestern US. Late Cretaceous, Hell Creek Fm. (or equivalent), 68-66 MYA.

Thescelosaurus fossils are less abundant than the large theropods and herbiovores in the Hell Creek Fm. A dinosaur census conducted by the Hell Creek Project calculated relative abundance of the Thescelosaurus was 8% of the population. Today, we find fossilized teeth, unguals (claws), spikes, and non-associated bones. Authenticity guaranteed.

Thescelosaurus tooth identification. Thescelosaurus teeth are routinely identified and sold as Pachycephalosaurus teeth since they maxillary teeth have similar shape and size. There has been some good work done presented in the Fossil Forum. The Fossil Forum author concludes that Pachycephalosaurus maxillary teeth can be differentiated from Thescelosaurus teeth since the Pachy teeth exhibit “vertical ridges are more pounced, fewer and a more prominent center ridge may exist. There is also no symmetry with the crowns.” Several good photographic references are provided. Link to the Fossil Forum discussion. A dominant center ridge appears to be consistent and lack of symmetry on the crown appeared in most of the Pachycepholsaur reference teeth.  That said, rooted teeth from both species are scarce and are highly collectable.

Thescelosaurus ungual (claw) identification. Thescelosaurus unguals (claws) are routinely identified and sold as Pachycephalosaurus unguals as they have a similar shape and size. Unfortunately there is little reference data for Pachycephalosaurus unguals with only one Pachy specimen with partial legs found. Per my discussion with the primary Fossil Forum Hell Creek dinosaurs author, he suggested “to differentiate between the two is Thescelosaurus claws are flat and triangular and the ones with a twist are Pachy”. That said, unguals  (claws) from both species are rare and are highly collectable.