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