The Caudofoveata are a relatively obscure class of mollusc and for a long time they were not even recognised as molluscs at all. They are exclusively marine and are found at depths of more than 20m burrowed in muddy sediments. Relatively little is known about them as little work has been done on live animals. They are generally only picked up in dredge or grab samples which have been preserved. They live in burrows formed by pushing the head down through the sediment by a series of muscular contractions and expansions.