Echinoderms Temporal range: Late Ediacaran-Recent | |
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Sea urchin | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | |
Subkingdom: | |
Superphylum: | |
Phylum: | Echinodermata |
Echinoderms are a successful phylum of marine animals. They include sea stars, brittle stars, sea urchins, sea cucumbers and their relatives.
Echinoderms have these features:
Echinoderms live in all parts of the ocean, but mostly on the sea floor. Some are filter feeders, and others (starfish) are important predators of molluscs and other shell-fish. They are extremely common near the shore, and on reefs.
They have a long and abundant fossil record. This phylum appeared in the early Cambrian period; it contains about 7,000 living and 13,000 extinct species. The four or five main groups are called sub-phyla by some authorities, and classes by others.