Noun
An extinct order of herbivorous dinosaurs having the feet of a saurian type, instead of birdlike, as they are in many dinosaurs. It includes the largest known land animals, belonging to Brontosaurus, Camarasaurus, and allied genera. See Illustration in Appendix.
Source: Webster's dictionaryThe femora of Apatosaurus are very stout; some of the most robust femora of any member of Sauropoda. Source: Internet
He classified this group within Sauropoda, a group he erected in the same study. Source: Internet