Echinothurioida

views updated

Echinothurioida (subclass Euechinoidea, superorder Diadematacea) An order of regular echinoids that have flexible tests and compound ambulacral plates bearing three pairs of pores. The tubercles are non-crenulate. At the present day there are many abyssal forms. They first appeared in the Upper Jurassic.

About this article

Echinothurioida

Updated About encyclopedia.com content Print Article Share Article