| Aspidodiadema | |
|---|---|
 | |
| Aspidodiadema arcitum | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Echinoidea |
| Order: | Aspidodiadematoida |
| Family: | Aspidodiadematidae |
| Genus: | Aspidodiadema Agassiz, 1879 |
| Type species | |
| Aspidodiadema tonsum Agassiz, 1878 | |
| Species | |
See text. | |
Aspidodiadema is a genus of echinoderms belonging to the family Aspidodiadematidae. [1] The species of this genus are found in the Indo-Pacific and Caribbean. [2]
The test is small and subglobular with fragile plating which is firmly tessellated. The apical disc is monocyclic. The plates membrane is embedded and does not touch the coronal plates. [2]
The ambulacral plating is pseudocompound with single large primary tubercle on every third plate which is much enlarged compared to the others. The primary tubercles form an alternate series down the perradius. These traits distinguish this genus from Plesiodiadema and Gymnotiara. The primary tubercles are perforated and notched. The secondary tuberculation confined to plate margins. The peristome has shallow, rounded buccal notches. [2]
The spines are slender and arranged in whorls. The lumens are filled with a mesh of horizontal dividers and vertical pillars. [2]
The following species are recognised: [1]
Coelopleurus is an extant genus of echinoids with fossil records dating back to the Eocene, with remains found in Europe and North America.
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.
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.
Toxopneustidae is a family of globular sea urchins in the class Echinoidea.
Echinidae is a family of sea urchins in the order Camarodonta. Members of the family are found in the Atlantic Ocean and the Antarctic.
Sterechinus is a genus of sea urchins in the family Echinidae. All living members of the genus are found in the waters around Antarctica but the first species described in the genus was a fossil and was found in Europe.
Aspidodiadema jacobyi is a small sea urchin in the family Aspidodiadematidae. It lives in tropical seas at great depths. Aspidodiadema jacobyi was first scientifically described in 1880 by Alexander Emanuel Agassiz, an American scientist.
Clypeaster, common name "cake urchins" or "sea biscuits", is a genus of echinoderms belonging to the family Clypeasteridae.
Aspidodiadema sinuosum is a species of sea urchin of the family Aspidodiadematidae. Their armour is covered with spines. It is placed in the genus Aspidodiadema and lives in the sea. Aspidodiadema sinuosum was first scientifically described in 1981 by Mironov.
Aspidodiadema tonsum is a species of sea urchin of the family Aspidodiadematidae. Their armour is covered with spines. It is placed in the genus Aspidodiadema and lives in the sea. Aspidodiadema tonsum was first scientifically described in 1879 by Alexander Emanuel Agassiz.
Eucidaris is a genus of cidaroid sea urchins known as slate pencil urchins. They are characterised by a moderately thick test, a usually monocyclic apical disc, perforate and non-crenulate tubercles and nearly straight ambulacra with horizontal pore pairs. The primary spines are few and widely spaced, stout with blunt flat tips and beaded ornamentation and the secondary spines are short and apressed. They originated in the Miocene and extant members of the genus are found in the tropical Indo-Pacific Ocean, East Pacific, Atlantic Ocean and Caribbean Sea.
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.
Caenopedina is a genus of sea urchins of the family Pedinidae.
Stylocidaris is a genus of echinoderms belonging to the family Cidaridae.
Plexechinus is a genus of echinoderms belonging to the monotypic family Plexechinidae.
Brisaster is a genus of echinoderms belonging to the family Schizasteridae.
Echinocyamus is a genus of echinoderms belonging to the family Fibulariidae.
Stereocidaris is a genus of echinoderm belonging to the family Cidaridae.