Analogy of bat & bird wings

Bat wings and bird wings are analogous as flight structures: their structure and function have evolved by different routes from a flightless reptilian ancestor. Note for example that a good portion of the flight surface in bats consists of a membrane stretched between the extended digits (chiropatagium), whereas the digits of the bird are relatively small and do not support the flight surface.

Note also that bat and birds wings are homologous as forelimbs.

Text © 2002 by Steven M. Carr