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• Evolutionary Essentials
 Skeletons
In the Cambrian seas, many new types of hard parts evolved, such as shells, plates, and outer coverings. These hard parts are all types of skeletons.
Hard skeletons have solid benefits.
As both predators and prey grew more diverse, hard skeletons—internal or external—were important for several reasons. For prey, skeletons provided protection from predators. For predators, skeletons provided “equipment” for capturing prey.
For both, hard skeletons provided support and a rigid framework for muscle attachment. This allowed bodies to grow bigger than they had before. And skeletons made of minerals were a way of storing chemicals animals needed for basic cell functions.
Skeletons also help us understand evolution.
Animals with hard skeletons are more likely to fossilize. Fossils are the remains or traces of things that were once alive. Scientists study them so we can understand evolution: how life on Earth has changed over time.
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To learn more about how skeletons become fossils, please view the Fossilization video. To access this feature, you will need the Window Media Player plug in for your browser. |
Or, continue to The Evolution of Vertebrates. >>
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