[1] A 507 million years old species, Totiglobus spencensis, is actually the first known echinoderm adapted to live on a hard surface after the soft microbial mats that covered the seafloor were destroyed in the Cambrian substrate revolution.

Some authors propose that an enigmatic Ediacaran (about 600 Ma) organism Arkarua is also an edrioasteroid, but this interpretation did not gain wide acceptance.

The main feature consisted of five arms, or ambulacra, in the body wall radiating outwards from the central mouth.

The anus was under the mouth region and was made of small triangular plates to form a cone-shaped area.

The mode of life was sessile; they were often attached via a stalk made of small plates to a hard object such as a carbonate hardground or shell.