Ornithischia Ornithopoda Heterodontosauridae [Herbivore]

Named by Romer (1966) to acknowledge shared characteristics between the small ornithopods Heterodontosaurus (Crompton & Charig, 1962) and Lycorhynus (Haughton, 1924). Small (1-2 ml) bidepal herbivorous ornithischians. According to Weishampel and Witmer (1990), the Heterodontosauridae can be diagnosed on the basis of high-crowned cheek teeth with chisel-shaped crowns, denticles on the uppermost third of the crown, and the presence of large, canine-like teeth in both the premaxilla and the dentary. The cheeck teeth denticles are restricted to the apical third of the tooth crowns. This ans the presence of the large, caniniform teeth characterize the Heterodontosauridae as a monophyletic group.

Triassic Late

Lesotho

Abrictosaurus

Abrictosaurus consors - Upper Eliot Formation

Lycorhinus consors - Upper Eliot Formation

South Africa

Abrictosaurus

Abrictosaurus consors - Upper Eliot Formation

Lycorhinus consors - Upper Eliot Formation

Jurassic Early

Lesotho

Abrictosaurus

Abrictosaurus consors - Upper Eliot Formation

Lycorhinus consors - Upper Eliot Formation

Orange Free State

Lycorhinus angustidens - Upper Elliot Formation

Lanasaurus scalpridens - Upper Elliot Formation

South Africa

Abrictosaurus

Abrictosaurus consors - Upper Eliot Formation

Lycorhinus consors - Upper Eliot Formation

Geranosaurus atavus - Clarence Formation

Heterodontosaurus tucki - Upper Elliot Formation, Clarence Formation

Lycorhinus angustidens - Upper Elliot Formation

Lanasaurus scalpridens - Upper Elliot Formation

Pegomastax africana - Upper Elliot Formation

Jurassic Middle

Manidens condorensis - Canodon Asfalto Formation

Jurassic Late

England

Echinodon becklessi - Middle Purbeck Beds

Sauraechmodon - Middle Purbeck Beds

Sauraechinodon

US

Fruitadens haagarorum - Morrison Formation, Colorado

Cretaceous Early

China

Tianyulong confuciusi - Jehol Group Liaoning Province