Wikipedia
Apatosaurinae
Apatosaurinae is the name of a subfamily of diplodocid sauropods that existed between 157 and 150 million years ago in North America. The group includes two genera for certain, Apatosaurus and Brontosaurus, with at least five species. Atlantosaurus and Amphicoelias might also belong to this group.
Below is a cladogram of apaptosaurine interrelationships based on Tschopp et al., 2015.