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• Image Gallery
Arthropods
Arthropods (AR-thruh-pahds) all have jointed appendages, such as legs and pincers, and segmented bodies protected by a hard outer skeleton. Insects, spiders, scorpions, and crabs—all are arthropods.
Within groups, diversity and numbers can rise and fall over time. In the Cambrian Period, there were thousands of different kinds of trilobites, which were arthropods. But by the Ordovician Period, their numbers were diminishing.
Arthropods are the most common animals today, just as they were in the Cambrian: more than 80% of living animal species are arthropods.
Continue to Echinoderm Images. >>
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