Ichthyostega clearly spent some time out of water. From these finds, it now appears that the four legs common to land animals today really evolved for another purpose: navigating swampy wetlands ...

The common hippopotamus, Hippopotamus amphibius, is one of the largest land animals on Earth. Adult hippos can weigh between 1.5 to 3 tons (that's like a small car!), and they can grow as long as 16 ...