Scientists have found fossils of animals with tails dating back hundreds of millions of years. Back then, early fish used their fanlike tails as fins to swim through oceans and escape predators ...

The Conversation is asking kids to send in questions they'd like an expert to answer. Kristin, age 11, wants to know why animals have tails. An expert explains.

Image caption, The chorister design on the tails side s usually seen on 1989-dated coins. The £4,500 sale price makes this 50p more valuable than the 2009 Kew Gardens 50p.