While other dromaeosaurids filled a variety of specialized ecological niches, mainly those of small predators or larger fish-eating forms, eudromaeosaurs functioned as large-bodied predators of often medium to large-sized prey.
The second distinguishing characteristic of eudromaeosaurs is an expanded and enlarged "heel" on the last bone in the second toe (phalange), which bore the enlarged, sickle-like toe claw.