The pourtalesiids (Pourtalesiidae) are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of irregular

sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...

s 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 The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cret ...

(

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

) and is distributed worldwide.

Species and genera

Currently, there are 10 genera with 28 extant and 5 extinct species described. * genus '' Ceratophysa'' Pomel, 1883 ** '' Ceratophysa ceratopyga'' ( A. Agassiz, 1879) ** '' Ceratophysa rosea'' ( A. Agassiz, 1879) * genus '' Cystocrepis'' Mortensen, 1907 **'' Cystocrepis setigera'' ( A. Agassiz, 1898) * genus '' Echinocrepis'' A. Agassiz, 1879 **'' Echinocrepis cuneata'' A. Agassiz, 1879 ** '' Echinocrepis rostrata'' Mironov, 1973 * genus '' Echinosigra'' Mortensen, 1907 **'' Echinosigra (Echinogutta) amphora'' Mironov, 1974 ** '' Echinosigra (Echinogutta) antarctica'' Mironov, 1974 ** '' Echinosigra (Echinogutta) fabrefacta'' Mironov, 1974 ** '' Echinosigra (Echinogutta) valvaedentata'' Mironov, 1974 ** '' Echinosigra (Echinosigra) mortensi'' Mironov, 1974 ** '' Echinosigra (Echinosigra) phiale'' (Thomson, 1873) ** '' Echinosigra (Echinosigra) porrecta'' Mironov, 1974 ** '' Echinosigra (Echinosigra) vityazi'' Mironov, 1997 * genus '' Galeaster'' Seunes, 1889 † **'' Galeaster carinatus'' Ravn, 1927 † ** '' Galeaster dagestanensis'' Poslavskaya & Moskvin, 1960 † ** '' Galeaster minor'' Poslavskaya, in Moskvin & Poslavskaya, 1949 † ** '' Galeaster muntshiensis'' Tzaghareli, 1949 † ** '' Galeaster sumbaricus'' Poslavskaya, in Moskvin & Poslavskaya, 1949 † * genus '' Helgocystis'' Mortensen, 1907 **'' Helgocystis carinata'' ( A. Agassiz, 1879) * genus '' Pourtalesia'' A. Agassiz, 1869 **'' Pourtalesia alcocki'' Koehler, 1914 ** '' Pourtalesia aurorae'' Koehler, 1926 ** '' Pourtalesia debilis'' Koehler, 1926 ** '' Pourtalesia heptneri'' Mironov, 1978 ** '' Pourtalesia hispida'' A. Agassiz, 1897 ** '' Pourtalesia jeffreysi'' Thomson, 1873 ** '' Pourtalesia laguncula'' A. Agassiz, 1879 ** '' Pourtalesia miranda'' A. Agassiz, 1869 ** '' Pourtalesia tanneri'' A. Agassiz, 1898 ** '' Pourtalesia thomsoni'' Mironov, 1976 ** '' Pourtalesia vinogradovae'' Mironov, 1995 * genus '' Rictocystis'' Mironov, 1996 **'' Rictocystis jensenae'' Mironov, 1996 * genus '' Solenocystis'' Mironov, 2008 **'' Solenocystis imitans'' Mironov, 2008 * genus '' Spatagocystis'' A. Agassiz, 1879 **'' Spatagocystis challengeri'' A. Agassiz, 1879

References

{{Authority control Holasteroida Echinoderm families Taxa named by Alexander Agassiz