Polychaete
paraphyletic group of annelids / From Wikipedia, the free encyclopedia
Polychaetes, or bristle worms, are a class of annelid worms.
Quick Facts Polychaetes, Scientific classification ...
Polychaetes | |
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A variety of marine worms from Das Meer, M.J. Schleiden (1804–1881). | |
Scientific classification | |
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Class: | Polychaeta Grube, 1850 |
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They are generally found in a marine environment. There are more than 10,000 known species in this class. They are ancient animals, dating back to 518 million years ago. They are first found in the early Cambrian fossil beds of Sirius Passet in Greenland.[1]
Each of their body segments has some fleshy protrusions that stand out. These 'parapodia' have many bristles, which are made of chitin. This is different from the Oligochaeta, which are similar in form, but only have a few bristles.
Common species are the lugworm, and the clam worm Nereis (which is sometimes also called a 'sandworm').[2]