An echinoderm of the class "Echinoidea"; a sea urchin.
- ‘Sponges are preyed upon by gastropods, polychaetes, asteroids, echinoids, turtles, and fishes.’
- ‘We have interpreted it as a synapomorphy for asteroids, ophiuroids, echinoids, and holothuroids, to the exclusion of the crinoids.’
- ‘The coarser fraction of chalk consists mainly of the skeletal debris of foraminifera, calcispheres, bivalve fragments, echinoid plates, and bryozoan, ostracod, and coral debris.’
- ‘Fossils include foraminiferans, brachiopods, echinoids, pelecypods, cephalopods, shark teeth, fish vertebrae, as well as asteroids, gastropods, a pterosaur, a nodosaurid, and decapods.’
- ‘Terebratulid / echinoid reef mounds provided a buffer from the strong waves of the open ocean, which prevented disarticulation of many whole specimens.’
Relating to or denoting echinoids.
- ‘In the echinoid gene order, the tRNA gene cluster follows the putative control region.’
- ‘This implies that the ancestral polarity of the 4.6-kb inversion is the echinoid pattern.’
- ‘Seven horizons of echinoid aggregations, totaling approximately 3 % of the channel thickness, occur in the black shale.’
- ‘The gastropod assemblage suggests an Albian age and the echinoid assemblage reportedly indicates a late Albian age.’
- ‘Despite the astonishing abundance of echinoid spines in the coral reef horizon, echinoid tests were not found here.’