Scientists have found fossils of animals with tails since hundreds of millions of years ago. Back then, early fish used their tails as fins（鳍）to swim through oceans, and run away from enemies.
Scientists believe that dinosaurs used their tails to balance their heavy heads and bodies while they walked.
Similarly, kangaroos use their tails for balance. But their tail also works as their third powerful leg, it can help push them forward. In addition, a monkey's tail can also act like a hand, helping it to hold onto tree branches.
But their roles are quite different. Most tailed insects use their tails to lay eggs. Birds use their tails to balance while sitting on trees. They also use tails to control directions. For many birds, a spread and raised tail is part of the lover-finding show. Male ones will spread their colorful tails to attract female ones.
Besides, animal that live in groups, like wolves, use different tail position to show their rank. Scientists believe those tails disappeared around 20 million years ago. Once they started walking upright, we lost them because we had no use for them anymore.
A. Although humans don't have long tails like monkeys, we did have tails! B. As the fish walked onto the land, their tails started to change too. C. This helped them run fast enough to catch and kill other animals. D. Many insects also have tails. E. Take peacocks for example. |
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