Understanding Evolution

Tools for success: The exoskeleton and the jointed limb

Evolution works with whatever variation happens to exist in a lineage. Lucky for arthropods, they have a lot of raw material to work with. All arthropods inherited characteristics that allowed them to evolve in response to opportunities. Let's look at a couple of very successful groups, trilobites and crustaceans.

The trilobite and crustacean

In this section, we will take a closer look at two groups of arthropods and examine these key questions:
  • How did the exoskeleton contribute to the evolutionary success of trilobites?

  • How did jointed limbs contribute to the evolutionary success of crustaceans?


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Understanding Evolution © 2017 by The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California