Stephanocrinidae

Belongs within: Crinoidea. The Stephanocrinidae are a group of crinoids known from the Middle Ordovician to the Upper Silurian, characterised by unique sausage-shaped cover plates and biserial arms (Moore et al. 1978). Characters (from Moore et al. 1978): Crinozoans with three circlets of regularly arranged thecal plates, without pores and infolds of any type, with… Continue reading Stephanocrinidae

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Categorised as Crinoidea

Hemistreptocrinida

Belongs within: Crinoidea. The Hemistreptocrinida are an Ordovician group of small crinoids with plate circlets in the cups only slightly offset (Moore et al. 1978). Characters (from Moore et al. 1978, as Paractocrinidae): Small crinoid cups composed of three or more circlets of plates which are only slightly offset rather than alternating; anal plates absent;… Continue reading Hemistreptocrinida

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Categorised as Crinoidea

Homocrinidae

Belongs within: Inadunata. The Homocrinidae are a group of crinoids with small, conical cups known from the Middle Ordovician to the Middle Silurian (Moore et al. 1978). Characters (from Moore et al. 1978): Cup small, conical; B, C, and E radials compound: anal X incorporated in cup between C and D radials. Homocrinidae [Homocrinacea, Homocrinicae,… Continue reading Homocrinidae

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Categorised as Crinoidea

Sycocrinitidae

Belongs within: Cyathocrinida. The Sycocrinitidae are a group of crinoids with a globular theca bearing a single arm, known from the Carboniferous and Permian periods (Moore et al. 1978). Characters (from Moore et al. 1978): Theca with one arm-bearing radial; other radials present or absent, commonly unequal and reduced in size; infrabasals three; anal X… Continue reading Sycocrinitidae

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Categorised as Crinoidea

Streblocrinidae

Belongs within: Cyathocrinida. The Streblocrinidae are a group of armless crinoids known from the Middle Devonian to the Upper Permian (Moore et al. 1978). Characters (from Moore et al. 1978): Theca typically composed of infrabasals, basals, and orals; abrachiate; radials and anal plate absent in all but most primitive genera; posterior oral commonly with hydropore… Continue reading Streblocrinidae

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Categorised as Crinoidea

Pelecocrinidae

Belongs within: Dendrocrinida. The Pelecocrinidae are a group of crinoids with tall, ovoid crowns known from the Carboniferous and Permian periods (Moore et al. 1978). The Pelecocrinidae Published 1 January 2022 The latter part of the Palaeozoic represented a peak in crinoid diversity. More families of crinoid have been recognised from the Carboniferous and Permian… Continue reading Pelecocrinidae

Rutkowskicrinidae

Belongs within: Dendrocrinida. The Rutkowskicrinidae are a group of crinoids with low conical cups and ridged thecal plates known from the late Silurian to the early Carboniferous (McIntosh 2001). Characters (from McIntosh 2001): Cup low conical, width approximately equal to or slightly exceeding height, with thecal plates of medium thickness and most commonly ridged. Infrabasal,… Continue reading Rutkowskicrinidae

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Categorised as Crinoidea

Cromyocrinacea

Belongs within: Dendrocrinida.Contains: Cromyocrinidae. The Cromyocrinacea are a group of crinoids with bowl-shaped cups and sparsely branching arms known from the Carboniferous and Permian periods (Moore et al. 1978). Characters (from Moore et al. 1978): Cup bowl-shaped, with or without basal concavity, radials with plenary articular facets, two or three anals in cup. Anal sac… Continue reading Cromyocrinacea

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Categorised as Crinoidea

Cromyocrinidae

Belongs within: Cromyocrinacea. The Cromyocrinidae are a group of crinoids with globose cups known from the Carboniferous and Permian periods (Moore et al. 1978). Characters (from Moore et al. 1978): Cup more or less globe-shaped, including forms with upflared or subhorizontal infrabasals; mostly three anal plates in cup but exceptionally only two. Anal sac very… Continue reading Cromyocrinidae

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Categorised as Crinoidea

Phanocrinidae

Belongs within: Erisocrinacea. The Phanocrinidae are a group of crinoids with apposed arms known from the Carboniferous period (Moore et al. 1978). Characters (from Moore et al. 1978): Tall, comparatively narrow cylindrical crown with apposed arms. Cup bowl-shaped, medium high or low, base concave or sub-horizontal; radial articular facets plenary; three to one anal plates… Continue reading Phanocrinidae

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Categorised as Crinoidea