The Avisauridae are a family of extinct Enantiornithine birds known from Cretaceous North and South America.. They are represented by four genera. Avisauridae was erected by Brett-Surman and Paul in 1985. They included in this Family a few fossils that they believed belonged to small non — avian dinosaurs. Chiappe and Calvo (1994) found that the Avisauridae shared adaptations of the foot — including a fully reversed and distally placed hallux with a large claw — that indicated the ability to perch in trees. They argued that an arboreal habit was most likely for all of the Avisauridae.