4 Legged Herbivorous Dinosaurs
Herbivorous dinosaurs tended to be quadrapeds (think of the sauropods, the ceratopsians, stegosaurus,...). Carnivorous ones tended to be bipedal (T Rex, Allosaurus, Velociraptor,...). There are exceptions like the duckbills but they may have gone about on all 4s some of the time.