When did whales become sea creatures? Print E-mail

Whales are mammals, just like us, and more than 50 million years ago, their ancestors walked on land as we do. It's not clear what these animals were like, but some paleontologists believe they may have been hoofed mammals, something like modern cows. Other paleontologists believe that whales were more like modern wolves. Over the course of millions of years, the ancient creatures spent more and more time in the water, living partly on land and partly in the sea, like modern sea lions or otters. Eventually, the creatures stopped climbing onto land altogether, and they slowly lost their now-useless legs and fur. The evidence for this hypothesis is fairly compelling: Paleontologists have even found fossilized whale-like creatures with legs so small that they couldn't possibly support the animal's weight.

You are probably thinking that the path of these creatures from land to sea is an odd turn of events. Why would a land mammal, specifically adapted for life on solid ground, evolve into a sea creature, spending much of its time away from air and sunlight? The best guess is that the whale's ancestors simply went where the food was. The ocean is filled with a wide variety of fish and crustaceans, while food along the coast can be scarce. Most likely, whale ancestors first ventured into the water to take advantage of this bounty.

To make this transition, whales had to overcome a number of obstacles. First of all, they had to contend with reduced access to breathable air. This led to a number of remarkable adaptations. The whale's "nose" moved from the face to the top of the head. This blowhole makes it easy for whales to breathe in air without fully surfacing. Instead, a whale swims near the surface, arches its body so its back briefly emerges and then flexes its tail, propelling it quickly to lower depths.

Whales Bermuda, Powered by Joomla! and designed by SiteGround web hosting