Like sea stars, ancient echinoderms nibbled with tiny tube feet | Science News

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Like sea stars, ancient echinoderms nibbled with tiny tube feet

Rare 430-million-year-old fossils preserve signs of these tentacle-like limbs

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7:05pm, September 12, 2017
sea star tube feet

MULTI-PURPOSE FEET  Tiny tube feet extend from this sea star’s arm. Uncommonly well-preserved fossils of an ancient relative of this echinoderm show it also had an array of these tentacle-like appendages.

Sea stars and their relatives eat, breathe and scuttle around the seafloor with tiny tube feet. Now researchers have gotten their first-ever look at similar tentacle-like structures in an extinct group of these echinoderms.

It was suspected that the ancient marine invertebrates, called edrioasteroids, had tube feet. But a set of unusually well-preserved fossils from around 430 million years ago, described September 13 in Proceedings of the Royal Society B, provides proof.

Usually, when an echinoderm dies, “the tube feet are the first things that go,” says Colin Sumrall, a paleobiologist at the University of Tennessee, Knoxville who wasn’t part of the study. “The thing that’s so stunning is that they didn’t rot away.”

An abundance of soft-bodied creatures from the Silurian Period, which lasted from 444 million to 419 million years

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