Asterostomatidae

Belongs within: Irregularia. The Asterostomatidae are a possibly polyphyletic group of heart urchins characterised by the loss of petals and/or fascioles (Fischer 1966). Moving to the top when shifting to the depths Published 25 November 2023 In 1966, the Treatise on Invertebrate Paleontology volumes dealing with the stem-less echinoderms (sea urchins, sea stars, etc.) reached… Continue reading Asterostomatidae

Echinoida

  Purple sea urchin Strongylocentrotus purpuratus, copyright Kirt L. Onthank.   Belongs within: Echinacea.Contains: Strongylocentrotus, Echinus. The Echinoida are a group of echinoids with a camarodont lantern known from the Palaeocene (possibly the Upper Cretaceous) to the present. Gill slits are shallow in most families but are narrow, distinct and commonly deep in Toxopneustidae (Fell… Continue reading Echinoida

Published
Categorised as Echinozoa

Echinus

Belongs within: Echinoida. Echinus is a genus of sea urchins known from the Pliocene to the present (Fell & Pawson 1966). Characters (from Fell & Pawson 1966): Test widest at circular ambitus; ambulacral plates trigeminate, with primary tubercle on every alternate (or every third) ambulacral plate. Buccal membrane containing scattered plates. Secondary radioles only slightly… Continue reading Echinus

Published
Categorised as Echinozoa

Holothuria

Belongs within: Aspidochirotida. Holothuria is a genus of sea cucumbers found primarily in coastal regions, particularly around coral reefs. Some species such as the edible sea cucumber H. edulis are eaten by humans. Characters (from Rowe 1969): Tentacles 17–30, usually 20, pedicels and papillae variously arranged on the ventral and dorsal sides respectively; anal papillae… Continue reading Holothuria

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Categorised as Echinozoa

Orthopsidae

Belongs within: Euechinoidea. The Orthopsidae are a group of echinoids of uncertain affinities known from the Lower Jurassic to the Upper Cretaceous (Fell & Pawson 1966). Characters (from Fell & Pawson 1966): Test small or large, regularly hemispherical or globular. Lantern camarodont (known only in Orthopsis). Ambulacra simple, without compounded plates, at most with only… Continue reading Orthopsidae

Published
Categorised as Echinozoa

Calycina

Belongs within: Echinacea. The Calycina are a group of echinoids known from the Lower Jurassic (possibly the Upper Triassic) to the present. Members of this group commonly have one or more large suranal plates over the apical system that superficially resemble a calyx. They are first represented in the fossil record by the Acrosaleniidae, which… Continue reading Calycina

Published
Categorised as Echinozoa

Hemicidaroida

Belongs within: Echinacea. The Hemicidaroida are a group of echinoids with a stirodont lantern and perforate primary tubercles known from the Upper Triassic to the Upper Cretaceous (Fell & Pawson 1966). <==Hemicidaroida [Hemicidarina] | i. s.: Allomma Pomel 1883FP66 | `–*A. normanniae (Cotteau 1863) [=Pseudodiadema normanniae]FP66 | Colpotiara Pomel 1883FP66 | `–*C. matheyi (de Loriol… Continue reading Hemicidaroida

Published
Categorised as Echinozoa

Temnopleuroida

Belongs within: Echinacea. The Temnopleuroida are a group of echinoids with a camarodont lantern known from the Lower Jurassic to the present (Fell & Pawson 1966). Characters (from Fell & Pawson 1966): Lantern camarodont (unknown in Glyphocyphidae). Test usually sculptured with ridges (epistroma) or sutural depressions or both, at least in immature stages; if test… Continue reading Temnopleuroida

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Categorised as Echinozoa

Thylechinus

Belongs within: Phymosomatoida. Thylechinus is a genus of echinoids known from the Upper Cretaceous to the Oligocene of Eurasia, northern Africa and South America (Fell & Pawson 1966). Characters (from Fell & Pawson 1966): Test hemispherical, of moderate size. Ambulacral plates trigeminate. Apical system dicyclic, oculars usually widely exsert. Female (of type species) with sunken… Continue reading Thylechinus

Published
Categorised as Echinozoa

Phymosomatoida

Belongs within: Echinacea.Contains: Thylechinus. The Phymosomatoida are a group of echinoids known from the Lower Jurassic to the present, characterised by the possession of a stirodont lantern and imperforate primary tubercles (Fell & Pawson 1966). Characters (from Fell & Pawson 1966): Lantern stirodont. Apical system lacking large polygonal suranal plates, not simulating calyx. Primary tubercles… Continue reading Phymosomatoida

Published
Categorised as Echinozoa