Echinoderms, such as starfish, sea urchins and sea lilies, use small, flexible, tubular projections called "tube feet" for locomotion, feeding, respiration and sensory perception. Crinoids, a subgroup of echinoderms, are known to have a long fossil record, but these fossils usually preserve only har d skeletal parts, since soft tissues like tube feet are far more difficult to preserve. But researchers recently made a surprising and rare discovery of preserved crinoid tube feet. Their new study, published in the journal Royal Society Open Science, reports that these tube feet are the oldest known specimens, preserved for around 452 million years. ...read more read less