Gigantohetrus

Gigantohetrus was one of the largest and the last of the Heterodontosaurids, living in what is now Argentina from the Early Cretaceous 105 million years ago to the Late Cretaceous 66 million years ago, being alive as a species for 39 million years. They were about the size of an Edmontosaurus of Late Cretaceous North America. Gigantohetrus was most likely completely herbivorous as their teeth suggests, and since their fossils were found close to other Gigantohetrus skeletons, it is likely that they were herd animals that lived in large herds.