| Noun | 1. | genus Brontosaurus - large quadrupedal herbivorous dinosaurs with very long neck and tail; late Jurassic reptile genus - a genus of reptiles Sauropoda, suborder Sauropoda - any of the sauropod dinosaurs apatosaur, apatosaurus, Apatosaurus excelsus, brontosaur, brontosaurus, thunder lizard - huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic |