1. Huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic
   "The apatosaur, formerly known as brontosaurus, had an extremely long neck"; "The thunder lizard, formerly known as brontosaurus, had an extremely long neck"; "The Apatosaurus excelsus, formerly known as brontosaurus, had an extremely long neck";
   - apatosaur, apatosaurus, brontosaur, thunder lizard, Apatosaurus excelsus

Derived forms: brontosauruses

Type of: sauropod, sauropod dinosaur

Part of: genus Apatosaurus, genus Brontosaurus

Encyclopedia: Brontosaurus