What’s the purpose of tails in modern mammals? When did the tail originate?

Question

What’s the purpose of tails in modern mammals? When did the tail originate?

In: 2

Answer 1

Tails originate before the evolution of mammals. They are ancestral to all vertebrates, which is why lizards, amphibians, and fish have them too.

They have several purposes in mammals, including balance, signaling, swatting insects, underwater locomotion, and grasping in the case of animals with prehensile tails. Of course in some lineages, namely the apes, the tail is reduced to the point of being lost.