Apatosaurus was a large herbivore from late jurassic USA.it ate plants.Apatosaurus had a long neck which it didn't lift above its shoulder.This sauropod had a long tale which it used as a defense against allosaurus,ceratosaurus,and other predators like saurophoganax.Apatosaurus used to be called Brontosaurus.
Apatosaurus vs ceratosaurus
Brontosaurus turned out to be an Apatosaurus with a Camarasaurus skull.