Period: Late Cretaceous

Order, Suborder, Family: Ornithischia, Marginocephalia, Protoceratopsidae

Location: North America (Canada, United States)

Length: 8 feet (2.4 meters)

Leptoceratops, the first known protoceratopsid, was found along the Red Deer River of Alberta, Canada, in 1910. This partial skull and skeleton was named Leptoceratops gracilis. It was the latest protoceratopsid, living through the end of the Cretaceous Period along with the large ceratopsid dinosaurs Triceratops and Torosaurus.

Leptoceratops was a lightly built protoceratopsid (its name means "slender-horned face") with long back limbs and short front limbs. The feet had tapered claws. Leptoceratops may have run bipedally (on two legs) or stood on its back legs to feed on tall vegetation. The large skull of Leptoceratops sloped down to a small, pointed, toothless beak. It did not have nasal or brow horns. The neck frill was only slightly developed and solid, and it had a high, raised ridge down its midline.

More partial and complete skeletons were discovered since the first was found. A partial skeleton found in the St. Mary River Formation of Montana in 1916 was first thought to be a new species of Leptoceratops; but it is a new genus, so it was renamed Montanaceratops cerorhynchus. Leptoceratops and Montanaceratops are the only two known North American protoceratopsid dinosaurs.