Asked by: TG Dollin, Dundee
Bats have very thin delicate skeletons that do not fossilise well. The oldest known fossils date from around 52 million years ago and are already very similar to modern bats. Bat wings have evolved from progressively elongated fingers, so bats are effectively flapping their hands. There is still a lot of debate surrounding the relationship between the various bat groups and it is possible that flight evolved separately more than once.