Avialae facts for kids

Avialae is a term for birds and their immediate extinct ancestors. It is a clade of dinosaurs containing their only living representatives (birds) and whatever coelurosaurs are regarded as their ancestors. There are two ways it can be defined:

Definition by physical characters

Avialae is defined as a clade based on physical characteristics. Jacques Gauthier named Avialae in 1986 as all dinosaurs that possessed feathered wings used in flapping flight, and the birds that descended from them.

Branch-based definition

Several other authors use a similar, but branch-based, definition: all theropods closer to birds than to Deinonychus.