Home > Diorama > Dinosaur Explorer > Trachodon The Trachodon (which literally means "rough tooth") lived during the Cretaceous period, about 77 - 73 million years ago. This dinosaur is known only from a hand full of teeth and jaw fossils that were discovered in 1856 by Joseph Leidy in Montana. However, from the teeth fossils, it is speculated that Trachodon was more than likely a duck-billed dinosaur, or lambeosaurine hadrosaur. The bill itself contained no teeth, but its many cheek teeth were used to chew and grind rough plant foliage. It is assumed that this species had a bulky body, a stiff tail and was four legged, however, their actual size is still unknown. Three Trachodons can be found in the diorama at Universe of Energy and are located next to the waterfall just beyond the "marsh scene" to the left of the vehicles.