Trilophosaurus

left|thumb|Front of T. buettneri skeleton, American Museum of Natural History Trilophosaurus (Greek for "lizard with three ridges") is a lizard-like trilophosaurid allokotosaur known from the Late Triassic of North America. It was a herbivore up to 2.5 m long.

== Description == Trilophosaurus had a short, unusually heavily built skull, equipped with massive, broad flattened cheek teeth with sharp shearing surfaces for cutting up tough plant material. Teeth are absent from the premaxilla and front of the lower jaw, which in life were probably equipped with a horny beak. Based on evidence derived from tooth wear patterns, Trilophosaurus was able to masticate labiolingually. thumb|left|T. buettneri compared to a human. The skull is also unusual in that the lower temporal opening is missing, giving the appearance of a euryapsid skull. Because of this, the trilophosaurs were once classified with placodonts within Sauropterygia. Carroll (1988) suggested that the lower opening may have been lost to strengthen the skull.