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

Derived forms: thunder lizards

Type of: sauropod, sauropod dinosaur

Part of: genus Apatosaurus, genus Brontosaurus

Encyclopedia: Thunder lizard