This point represents the development of antorbital openings -- a pair of openings in front of the eye on the muzzle -- in the common ancestor of archosaurs. Archosaurs, which include crocodylotarsians, pterosaurs, and dinosaurs (including birds), share many advanced features besides the antorbital openings, such as teeth that lie in sockets, and a highly modified jaw joint. Many of the advanced features of archosaurs are related to their capture and ingestion of large vertebrate prey. The function of antorbital openings is unclear.

Anhanguera