Early ancestors of the ocean's biggest animals once walked on land. Follow their extraordinary journey from shore to sea. Although whales are expert swimmers and perfectly adapted to life underwater, ...

Animals can be divided into groups ... They have claws or nails on their toes and lay eggs on land. Some reptiles have four legs, while others have no legs, like snakes. Reptiles can live in ...

And they decide dragons have four legs and wyverns only have two legs ... and got, 'yes, there are no six-limbed animals on the face of the Earth.' So I went for the more realistic thing.

Many of the most telling fossils have been dug up in Greenland ... From these finds, it now appears that the four legs common to land animals today really evolved for another purpose: navigating ...