annelids

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What are segmented worms? Annelids, evolution, and biology

By |2018-04-13T14:37:43+00:00May 27th, 2017|Biology|

An annelid, or segmented worm Roundworms probably evolved into segmented worms, or annelids, about 545 million years ago. The earliest annelids all lived in the ocean, as most kinds of annelid still do today. Some annelids live inside of sponges. Their long bodies were shaped like a hollow tube, with a long tunnel running [...]

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What are intestines? Evolution and Digestion

By |2017-09-17T09:06:21+00:00May 26th, 2017|Biology|

Whale intestines (from Medicine Chest) The first animals to have anything like an intestine evolved around 548 million years ago. These were roundworms, just a few millimeters long, and they had just a simple tube running from their mouth to their anus - no stomach in the middle. But already these roundworm guts [...]

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