Name means: Slender Horned Face
Range: Late Cretaceous (Campanian-Maastrichtian, 80-65 MYA) from Montana, Wyoming, Alberta (Canada)
Size estimate: 6-7 ft length, 150-400 lbs
Discovery: Barnum Brown, 1914
Classification: dinosauria, ornithischia, ceratopsia, coronasauria, leptoceratopsidae
A distant cousin of Triceratops, this little horned dinosaur belonged to a branch of the group that changed less than their giant cousins. Unlike the giant horned dinosaurs, Leptoceratops kept its two-legged gait, smaller head, and grasping forearms. Though it may have been able to move on all fours, it could not turn its hands to face its feet. The palms of its hands always faced inward, toward its chest or each other. These features resemble older, ancestral ceratopsians, but Leptoceratops lived at the same time and place as Triceratops. Scientists do not know exactly why it changed less. One theory says these animals ate different kinds of plants than the giant North American lineage. These plants remained in Asia for a long time but invaded North America later. The ancestors of Leptoceratops followed, and ended up living alongside their stranger cousins.
Leptoceratops’ jaws could process food very effectively. Curved scratches on their teeth show that they moved their jaws in a circular motion as they chewed. Reptiles don’t normally do this, but plant-eating mammals often do. Complex chewing motion forces food to come in contact with more of the tooth. This makes it possible for animals to chew tougher plant material than if their jaws just went up and down.