Thescelosaurus was discovered in 1891. However, this dinosaur did not receive a name until 1913. Why did it take so long?
After being discovered, the fossils were hidden away in a crate in the basement of the Smithsonian Institution until studied many years later by Charles Gilmore.
In 1993, a remarkable Thescelosaurus fossil was found in South Dakota. This complete skeleton had in its chest what many scientists believe was a fossilized heart. Using tomography to scan the heart, it was revealed that it had four chambers. If this is true, it is likely that Thescelosaurus was warm-blooded.
However, some scientists insist that the formation is not a heart, but rather a natural rock formation.
Thescelosaurus had powerful hind legs which allowed it to run quickly while using its long heavy tail as a counter-weight.