is a small phylum
of marine sediment
with about a dozen known species. The phylum was discovered in 1983 by marine biologists
. The animals have a head, mouth and digestive system as well as a set of specialized umbrella skeleton like scales at each end that are used to move the animals. There is no circulatory system and no endocrine system. The body cavity is a pseudocoelom with a mouth and an anus. The animals are bisexual and probably oviparous. They have no fossil record.