What adaptations do apatosaurus have?

Apatosaurus was a brilliant dinosaur from the Jrassic, 150 milliion years ago. It was discovered by the famous paleontologist Othneil Charles Marsh and its name means deceptive lizard. It was herbivorous and 70-90 feet long. It is thought that it consumed gastroliths, or stomach stones, to help it digest the tough plant matter it consumed. One of the most remarkable theories in my opinion is the presence of a claw on its front limbs. It seems to me it wouldn't be able to use the claw very well though, seeing as it moved on four legs.