- A very large sauropod dinosaur of the genus Apatosaurus (or Brontosaurus) of the late Jurassic Period. Apatosaurs had a long neck and tail and a relatively small head. See Note at brontosaurus.
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Examples from the Web for apatosaurus
This was about thirty feet long, and is known as Apatosaurus grandis.Extinct Monsters
H. N. Hutchinson