Our knowledge of the first animals comes from tracks left on the seabed by worms. The first animals had soft bodies, which do not become fossils easily, so it is not easy to know much about them.
The first animal-like organism was probably amoebas or another one-celled organism. Then animals like jellyfish, trilobites and sea anemones evolved.
The first animals were not like any thing we have ever seen. In act, they were so weird-looking that if we saw one, we would doubt that it was an animal at all!
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