Bothriocidaroida

Bothriocidaroida

[‚bä·thrē·ō‚sik·ə′rȯid·ē·ə] (paleontology) An order of extinct echinoderms in the subclass Perischoechinoidea in which the ambulacra consist of two columns of plates, the interambulacra of one column, and the madreporite is placed radially.