Category: Asterozoa

Belongs within: Valvatacea.Contains: Astropectininae. The Paxillosida are a group of starfish associated with sandy or muddy habitats. They mostly lack a number of features found in other starfish, such as an anus, extra-oral feeding, suckered tube feet, or a brachiolaria larval stage (Matsubara et al. 2005). Historically, the genus Luidia was thought to represent a early-diverging relict… Continue reading Paxillosida

Belongs within: Ambuloasteroidea.Contains: Solasteridae, Pterasteridae. The Spinulosacea are a lineage of asteroids potentially supported by the absence of a mouth and a rudimentary gut in the larva, more or less asymmetrical coelomic sac formation in early development, and terminals that originate from the fusion of many calcification centres (Blake 1987). Adult forms have large, spade-… Continue reading Spinulosacea

Belongs within: Ophiodermatidae. The Ophiocomidae are a group of brittle stars bearing stout arms with long spines (Spencer & Wright 1966). Characters (Spencer & Wright 1966): Arms stout, widest at some distance from base. Arm spines long, at angle to arm. Oral frame with well-developed lateral wings. Teeth stout, quadrangular. Oral papillae border each jaw. Dental papillae… Continue reading Ophiocomidae

Belongs within: Asterozoa.Contains: Lysophiurina, Zeugophiurina, Ophiurida. The Ophiuroidea include the brittle stars, a group of starfish-like echinoderms with slender arms distinctly divided from the central disc. In the Ordovician to Devonian Stenurida, the structure of the arm joints more or less allowed for only simple movements, but in other groups the arm plates are progressively… Continue reading Ophiuroidea

Belongs within: Gnathophiuridea. The Ophiotrichidae are a family of stout-toothed brittle stars with quadrangular, spiniform tooth papillae clustered at the apex of each jaw, and no oral papillae. Their fossil record is limited with questionable exemplars from the Lower Jurassic (Spencer & Wright 1966). <==Ophiotrichidae |–Ophiomaza Lyman 1871 [incl. Luetkenia Brock 1888 nec Claus 1864… Continue reading Ophiotrichidae

Belongs within: Ophiuroidea.Contains: Ophiurinae, Ophiolepididae, Ophiochitonidae, Gnathophiuridea, Ophioleucinae, Ophiacanthidae, Ophiodermatidae, Ophiomyxinae. The Ophiurida include the modern brittle stars, distinguished from stem-group fossils by their fused vertebrae (Thuy & Stohr 2016). Historically, the Phrynophiurida have been recognised as a distinct order from the Ophiurida with arm plates reduced and covered by a thick soft skin (Spencer… Continue reading Ophiurida

Belongs within: Forcipulatida.Contains: Leptasterias, Asterias. The Asteriidae are a family of starfish with a swollen body and both straight and crossed pedicellariae. Of the three subfamilies listed below, the Pycnopodiinae have the aboral skeleton obsolescent whereas Neomorphaster has the primary aboral plates conspicuously enlarged. Pycnopodiinae have inferomarginals with two spines, heavily wreathed with pedicellariae, and… Continue reading Asteriidae

Belongs within: Asteriidae. Asterias is a cosmopolitan genus of sea stars with a large disc and relatively broad arms. Characters (from Spencer & Wright 1966): Disc fairly large, arms 5 or 6, rather broad and short; aboral skeleton an open network with spines in nearly regular series along midline and margin of arms but elsewhere… Continue reading Asterias

Belongs within: Asteroidea.Contains: Forcipulatida, Valvatacea, Spinulosacea. The Neoasteroidea represents the starfish crown group, including all living starfish and all known Asteroidea from the Mesozoic and Cenozoic eras (Blake & Hagdorn 2003). <==Ambuloasteroidea |–CalliasterellidaeBH03 | |–Protarthraster Spencer 1918 [Protarthrasterinae]SW66 | | `–*P. longimanus (Whidborne 1896) [=Palaeaster longimanus]SW66 | `–CalliasterellinaeBH03 | | i. s.: ‘Calyptactis’ confragosus Miller… Continue reading Ambuloasteroidea