apatosaur
noun(apato-sau-rus)
any of a genus (Apatosaurus of the family Diplodocidae) of very large, herbivorous, sauropod dinosaurs that lived during the Late Jurassic period and reached a length of over 65 feet (20 meters) and a height of 12 feet (3.7 meters) and are thought to have attained a weight of up to 30 tons (27 metric tons)