• (n. pl.) An extinct order of reptiles which stood erect on the hind legs, and resembled birds in the structure of the feet, pelvis, and other parts.
Or·thop'o·da noun plural [ New Latin See Ortho- , and -poda .] (Zoology) An extinct order of reptiles which stood erect on the hind legs, and resembled birds in the structure of the feet, pelvis, and other parts.