Pterasteridae is a
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
of
sea stars
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...
in the order
Velatida
The Velatida are an order of sea stars containing about 200 species in five families. These sea stars normally have thick bodies with large discs.
Description and characteristics
This order contains mostly deep or cold seas sea stars, often w ...
, consisting of eight
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
.
Description and characteristics
Pterasterids are primarily deep-water, and have an inflated aboral surface. Like many other members of the ordo
Velatida
The Velatida are an order of sea stars containing about 200 species in five families. These sea stars normally have thick bodies with large discs.
Description and characteristics
This order contains mostly deep or cold seas sea stars, often w ...
, they have a hole in the middle of the central disc called "osculum", from which they can expel mucus for defending against predators.
Many species brood their young in an internal chamber flushed with seawater.
Fossil pterasterids have been found as early as the upper
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...
of the
Cretaceous period
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of t ...
.
Genera
According to the
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 ...
:
* ''
Amembranaster''
Golotsvan, 1998 -- 1 species
* ''
Benthaster''
Sladen, 1882 -- 3 species
* ''
Calyptraster''
Sladen, 1882 -- 5 species
* ''
Diplopteraster''
Verrill, 1880 -- 7 species
* ''
Euretaster''
Fisher, 1940 -- 3 species
* ''
Hymenaster''
Thomson, 1873 -- 51 species
* ''
Hymenasterides''
Fisher, 1911 -- 2 species
* ''
Pteraster''
Müller & Troschel, 1842 -- 46 species
Image:Euretaster insignis.jpg, '' Euretaster insignis''
Image:Bio barnstar4.png, '' Hymenaster echinulatus'' (both faces)
Image:Translucent sea star.jpg, '' Hymenaster sp.''
Image:Bio barnstar3.png, '' Pteraster stellifer'' (both faces)
Image:Expl1068 - Flickr - NOAA Photo Library.jpg, '' Pteraster sp.''
References
External links
*
*
{{Taxonbar, from=Q3469990
Echinoderm families
Extant Campanian first appearances
Taxa named by Edmond Perrier