While the modern whale is the master of the oceans, perfectly designed for its marine environment, the whale began its evolutionary journey as a much smaller, land-dwelling carnivore.
In a twist of evolutionary fate, the ferocious velociraptor - immortalised in Jurassic Park - has given way to a rather docile descendent: the turkey.
Bears weren't always on top of the predator pecking order. The size of a small dog, the first bears found refuge in trees from larger carnivores until climate changes forced them back to the ground.