The defining feature of the aven group is feathers, not flight. This definition excludes anyother flying animal, such as the Pterosaurs a second archosaurs flying type.
Left: Pterosaurs .
.Bats
are another species that is not apart of the this group. Both the Bats
and the Pterosaurs have no feathers, for flight they both have membranous
wings. Their are also other structural and evolutionary reason why these
two groups are not apart of the aven group.
Left: Bat..
