- Asian sloth bear, Melursus ursinus
- Not Applicable ()
Bears are famous for only having extremely short tails. The species with the longest tail, on average, is the Asian sloth bear Melursus ursinus, whose tail measures 15–18 centimetres (5.9–7 inches). Early species of bear possessed longer, more developed tails, but during evolution the tail gradually diminished in size. Evolutionists believe that this decrease in size occurred because the tail served no useful purpose. In their close relatives, the dogs, the tail plays a very important role in communication, and so has remained long and prominent, whereas during display behaviour bears tend to confront or pose face on, so that even if they possessed a longer tail, it would not be visible, and therefore would serve no useful purpose in communication.