Amphiura is a large genus of brittle star

Brittle star

Brittle stars or ophiuroids are echinoderms in the class Ophiuroidea closely related to starfish. They crawl across the seafloor using their flexible arms for locomotion. The ophiuroids generally have five long slender, whip-like arms which may reach up to in length on the largest specimens...

s (Ophiuroidea) found in oceans worldwide from tropics to Arctic and Antarctic regions.

Systematics and phylogeny

Amphiura is a large genus that is currently divided into the following six subgenera: Amphioplus, Amphiura, Fellaria, Ophionema, Ophiopelte and Ophiopeltis. The once used subgenus Acrocnida has been elevated to a genus rank. Fossil record of the genus of dates back to Turonian

Turonian

The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...

 (Amphiura plana).
Extant species include:

Amphiura acacia Amphiura accedens Amphiura acrisia Amphiura adjecta Amphiura aestuarii Amphiura affinis Amphiura africana Amphiura agitata Amphiura alba Amphiura albella Amphiura algida Amphiura ambigua Amphiura amokurae Amphiura angularis Amphiura annulifera Amphiura anomala Amphiura anster Amphiura antarctica Amphiura arcystata Amphiura argentea Amphiura aster Amphiura atlantica Amphiura atlantidea Amphiura belgicae Amphiura bellis Amphiura benthica Amphiura beringiana Amphiura bidentata Amphiura bihamula Amphiura borealis Amphiura bountyia Amphiura brachyactis Amphiura brevipes Amphiura brevispina Amphiura callida Amphiura callida Amphiura callida is a species of brittle star belonging to the family Amphiuridae. It is only known from the continental shelf off the coast of Cabo Frio, southeastern Brazil .... Amphiura canadensis Amphiura candida Amphiura caparti Amphiura capensis Amphiura carchara Amphiura carnea Amphiura catephes Amphiura celata Amphiura ceramis Amphiura cherbonnieri Amphiura chiajei Amphiura clausadae Amphiura coacta Amphiura commutata Amphiura complanata Amphiura concinna Amphiura concolor Amphiura confinis Amphiura consors Amphiura constricta Amphiura corona Amphiura crassipes Amphiura crispa Amphiura crossota Amphiura crypta

Amphiura dacunhae Amphiura debilis Amphiura deficiens Amphiura deichmanni Amphiura dejecta Amphiura dejectoides Amphiura delamarei Amphiura demissa Amphiura diacritica Amphiura diastata Amphiura diducta Amphiura digitula Amphiura dino Amphiura diomedeae Amphiura dispar Amphiura divaricata Amphiura dolia Amphiura duncani Amphiura ecnomiotata Amphiura elandiformis Amphiura eugeniae Amphiura eugenioides Amphiura exigua Verrill Amphiura fasciata Amphiura fibulata Amphiura ficta Amphiura filiformis Amphiura flexuosa Amphiura florifera Amphiura fragilis Amphiura frigida Amphiura gastracantha Amphiura glabra Amphiura goniodes Amphiura griegi Amphiura gymnogastra Amphiura gymnopora Amphiura heptacantha Amphiura heraldica Amphiura hilaris Amphiura immira Amphiura incana Amphiura inepta Amphiura ingolfiana Amphiura inhacensis Amphiura instans Amphiura iridoides Amphiura joubini Amphiura kalki Amphiura kandai Amphiura kinbergi Amphiura koreae Amphiura lanceolata Amphiura latispina Amphiura leptodoma Amphiura leptotata Amphiura leucaspis Amphiura levidevaspis

Amphiura linearis Amphiura lorioli Amphiura luetkeni Amphiura lunaris Amphiura lymani Amphiura macrostyalia Amphiura maculata Amphiura madecassae Amphiura magellanica Amphiura magnisquama Amphiura maxima Amphiura mediterranea Amphiura megalaspi Amphiura micra Amphiura micraspis Amphiura microplax Amphiura microsoma Amphiura modesta Amphiura monorima Amphiura morosa Amphiura muelleri Amphiura multiremula Amphiura multispina Amphiura murex Amphiura nannodes Amphiura nociva Amphiura norae Amphiura notacantha Amphiura octacantha Amphiura otteri Amphiura pachybactra Amphiura papillata Amphiura parviscutata Amphiura perita Amphiura plantei Amphiura poecila Amphiura polita Amphiura polyacantha Amphiura praefecta Amphiura princeps Amphiura proposita Amphiura protecta Amphiura psilopora Amphiura ptena Amphiura pusilla Amphiura pycnostoma Amphiura rathbuni Amphiura reloncavii Amphiura repens Amphiura retusa Amphiura richardi Amphiura sarsi Amphiura scabiuscula Amphiura scabriuscula Amphiura sculpta Amphiura securigera Amphiura semiermis Amphiura seminuda Amphiura senegalensis

Amphiura septa Amphiura septemspinosa Amphiura serpentina Amphiura sexradiata Amphiura simonsi Amphiura sinicola Amphiura spinipes Amphiura stepanovi Amphiura stictacantha Amphiura stimpsoni Amphiura subtilis Amphiura sundevalli Amphiura syntaracha Amphiura tenuis Amphiura tessellata Amphiura trachydisca Amphiura triaina Amphiura trisacantha Amphiura tumulosa Amphiura tutanekai Amphiura uncinata Amphiura ungulata Amphiura unicinata Amphiura ushakovi Amphiura vadicola Amphiura velox Amphiura verrilli Amphiura verticillata