The subclass Euechinoidea includes almost all living species of
sea urchin, and fossil forms going back as far as the
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...
.
Taxonomy
List of orders according to
World Register of Marine Species
The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms.
Content
The content of the registry is edited and maintained by scientific specialist ...
:
* Infra-classis ''
Acroechinoidea''
** Order ''
Aspidodiadematoida''
** Order ''
Diadematoida''
** Order ''
Micropygoida''
** Order ''
Pedinoida
Pedinoida is an order of sea urchins, containing the single living genus '' Caenopedina''. The group was much more diverse during the Mesozoic, and represents the oldest surviving order of euechinoid sea urchins.
They are distinguished from ...
''
* Infra-classis ''
Carinacea
The infraclassis Carinacea includes most living species of regular sea urchin, and fossil forms going back as far as the Triassic.
Taxonomy
List of orders according to World Register of Marine Species :
* Super-order Calycina
** Order Phym ...
''
** Super-order ''
Calycina''
*** Order ''
Phymosomatoida'' †
*** Order ''
Salenioida
The Salenioida are an order of sea urchins.
Description and characteristics
They are distinguished from other sea urchins by the presence of a large plate on the upper surface, with the anus to one side. They have very large tubercles between ...
''
** Super-order ''
Echinacea
''Echinacea'' is a genus of herbaceous flowering plants in the daisy family. It has ten species, which are commonly called coneflowers. They are found only in eastern and central North America, where they grow in moist to dry prairies and open ...
''
*** Order ''
Arbacioida
Arbacioida are an order (biology), order of sea urchins, consisting of a single 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 Salen ...
''
*** Order ''
Camarodonta''
*** Order ''
Stomopneustoida''
* Order ''
Echinothurioida
The Echinothurioida are an order of sea urchins in the class Echinoidea. Echinothurioids are distinguished from other sea urchins by the combination of a flexible test and hollow spines. The membrane around the mouth contains only simple plat ...
''
* Infra-classis ''
Irregularia
Irregularia is an extant infraclass of sea urchins that first appeared in the Lower Jurassic.
Description and characteristics
These particular sea urchins are distinguished from other sea urchins by their irregular shape: the anus and often ...
''
** Super-order ''
Atelostomata
The Atelostomata are a type of sea urchins. They are distinguished from other sea urchins by their irregular shape and the absence of a feeding lantern. The group includes the well known heart urchins, as well as some less familiar and extinct ...
''
*** Order ''
Holasteroida
Holasteroida is an order of irregular sea urchins.
Characteristics
These irregular sea urchins are characterized by a particularly marked bilateral symmetry, including for the apical system, which is highly elongated. In some contemporary ab ...
''
*** Order ''
Spatangoida
The heart urchins or Spatangoida are an order of sea urchins.
Their body is a somewhat elongated oval in form, and is distinguished by the mouth being placed towards one end of the animal, and the anus towards the other. As a result, heart urc ...
''
** Order ''
Echinoneoida''
** Order ''
Holectypoida
The Holectypoida are an order of sea urchins related to the sand dollars. The order consists of just two living genera, but was once more diverse.
Description and characteristics
In appearance, the living holectypoids are similar to sand dolla ...
'' †
** Super-order ''
Neognathostomata
The Neognathostomata are a superorder of sea urchins.
Description and characteristics
They are distinguished from other sea urchins by their irregular shape and a highly modified feeding lantern. The group includes the well known sand dollars ...
''
*** Order ''
Cassiduloida
Cassiduloida is an order (biology), order of sea urchins. The group was extremely diverse with many families and species during the Mesozoic, but today, only seven extant species remain.
A 2019 phylogenetic systematics study by Souto et al. pres ...
''
*** Order ''
Clypeasteroida
Sand dollars (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) are species of flat, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are k ...
''
*** Order ''
Echinolampadoida''
*** Order ''
Nucleolitidae'' †
File:Spatangus purpureus rob.jpg , '' Spatangus purpureus''
File:Astropyga radiata2.jpg, '' Astropyga radiata''
Image:Paracentrotus lividus profil.JPG, ''Paracentrotus lividus
''Paracentrotus lividus'' is a species of sea urchin in the family Parechinidae commonly known as the purple sea urchin. It is the type species of the genus and occurs in the Mediterranean Sea and eastern Atlantic Ocean.
Description
''Paracent ...
''
File:Echinocyamus pusillus.jpg, ''Echinocyamus pusillus
''Echinocyamus pusillus'', commonly known as the pea urchin or green urchin, is a species of sand dollar, a sea urchin in the family Fibulariidae, native to the northeastern Atlantic Ocean and the Mediterranean Sea. It buries itself in gravel or ...
''
File:Fire Urchin Asthenosoma varium.jpg, '' Asthenosoma varium''.
Echinoidea
Extant Late Triassic first appearances
Taxa named by Heinrich Georg Bronn
{{echinoidea-stub