A fragmentary skeleton of Stenonychosaurus inequalis indicates that this small theropod dinosaur is very closely related to Saurornithoides mongoliensis from the Cretaceous of central Asia. Both forms possessed relatively well developed cerebral hemispheres and large eyes, and were probably fleet bipeds with supple raptorial forelimbs. Their extreme rarity as fossils is attributed to their preference for environments not usually preserved in the stratigraphic record.