| Histocidaris | |
|---|---|
 | |
| Histocidaris variabilis seen off Hawaii by NOAA Okeanos Explorer mission | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Echinoidea |
| Order: | Cidaroida |
| Family: | Histocidaridae |
| Genus: | Histocidaris Mortensen, 1903 [1] |
| Species | |
See text | |
| Synonyms | |
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Histocidaris is a genus of sea urchins in the family Histocidaridae. Some species are known from the fossil record.
The Diadematidae are a family of sea urchins. Their tests are either rigid or flexible and their spines are long and hollow.
Arbacioida are an order of sea urchins, consisting of a single extant family, the Arbaciidae. They are distinguished from other sea urchins by the presence of five separate plates around the anus. Unlike their close relatives, the Salenioida, all of the tubercles on their tests are of similar size.
Cidaroida is an order of primitive sea urchins, the only living order of the subclass Perischoechinoidea. All other orders of this subclass, which were even more primitive than the living forms, became extinct during the Mesozoic.
Cidaridae is a family of sea urchins in the order Cidaroida.
Spatangus is a genus of heart urchins in the Spatangidae family. The genus is synonymous with the previously recognised genera Prospatangus Lambert, 1902 and Spatagus. There are nine recognised species. The type species is Spatangus purpureus Müller, 1776 by subsequent designation.
Holasteroida is an order of irregular sea urchins.
Clypeaster, common name "cake urchins" or "sea biscuits", is a genus of echinoderms belonging to the family Clypeasteridae.
Araeosoma is a genus of deep-sea sea urchins in the family Echinothuriidae.
Histocidaris elegans is a species of sea urchin in the family Histocidaridae.
Temnopleuridae is a family of sea urchins in the infraorder Temnopleuridea.
The pourtalesiids (Pourtalesiidae) are a family of irregular sea urchins that live in the deep sea. They are secondarily bilateral-symmetrical and like other representatives of the taxon Holasteroida they lack the lantern of Aristotle, which is typical for many other sea urchins. The genus Pourtalesia was named after Louis-François de Pourtalès who first collected these animals while dredging at a depth of 600 m. The family is known already from the Upper Cretaceous (Maastrichtian) and is distributed worldwide.
Goniocidaris is a genus of sea urchins (Echinoidea) in the family Cidaridae and typical of the subfamily Goniocidarinae. Extant species are mostly found in Indo-Pacific seas, often living at depth.
Schizasteridae is a family of echinoderms belonging to the order Spatangoida.
Stylocidaris is a genus of echinoderms belonging to the family Cidaridae.
Euryalidae is a family of echinoderms belonging to the order Euryalida.
Maretiidae is a family of echinoderms belonging to the order Spatangoida.
Brissopsis is a genus of echinoderms belonging to the family Brissidae.
Echinocyamus is a genus of echinoderms belonging to the family Fibulariidae.
Stereocidaris is a genus of echinoderms belonging to the family Cidaridae.
Echinolampas is a genus of echinoderms belonging to the family Echinolampadidae.
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