Edrioasteroidea(redirected from Edrioasteroid)
a class of extinct marine Paleozoic animals of the phylum Echinodermata. The theca resembled a pouch or disk and lacked a stalk, arms, and brachioles. Most Edrioasteroidea attached themselves to a substrate, although some lay freely on the bottom. Particles of food entered the oral field along the ambulacral grooves, through the pores of which the tube feet of the abulacral system emerged.
The Edrioasteroidea lived from the Cambrian to the Carboniferous, flourishing in the Middle Ordovician and Late Devonian. Remains are seldom found. About 30 genera with 100 species are known, almost all from Europe and North America. In the USSR they have been found in Ordovician deposits in Estonia and in Devonian deposits in Leningrad and Voronezh oblasts of the RSFSR.
REFERENCESOsnovy paleontologa: Iglokozhie, gemikhordovye, pogonofory i shchetinkocheliustnye. Moscow, 1964.
Treatise on Invertebrate Paleontology, vol. 1. Kansas, 1966.