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Diagnostic Features
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Test flattened below and domed above; circular to slighly pentagonal in outline; ambulacra inflated and interambulacra depressed adapically.
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Apical disc small, dicyclic. Genital plates large and pentagonal; ocular plates smaller. All plates more or less bare, decorated by epistroma. Periproct subcircular.
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Ambulacra straight, expanding to ambitus; generally rather inflated; aboral pore-pairs uniserial, subconjugate with the two pores rather widely separated and enlarged adapically, but small and oblique adorally, remaining uniserial to peristome edge.
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Plating in arbaciid triads throughout, with upper and lower elements as demiplates and each triad dominated by a large primary tubercle; no perradial granular zone.
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Interambulacra a little wider than ambulacra. Above ambitus plates distinctly differentiated into an interradial sunken and naked zone, without tubercles and with just epistroma, and an outer, adradial band. A vertical ridge marks the boundary between the two zones. Adradially there is usually a small primary tubercle on each plate, except on the most adapical plates.
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At the ambitus interambulacral plates with two subequal primary tubercles; the outer series continuing above the ambitus almost to the apical disc.
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Primordial interambulacral plate present at edge of peristome, with primary tubercle.
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Primary tubercles imperforate and non-crenulate. The areole forms a slightly raised platform on the plate.
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Peristome subcircular or subpentagonal, large (about half test diameter). Buccal notches feeble with long, well developed tags.
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Sphaeridial pits multiple and positioned along perradius.
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Spines long (approaching 2 x test diameter), slender, with distal cortex; becoming trigonal in cross-section distally.
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Distribution
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Eocene and Oligocene, Europe, North Africa, North America, India.
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| Name gender |
masculine |
| Type |
Coelopleurus equis Agassiz, 1840, p. 12 [=Cidaris coronalis Leske, 1778, p. 136, by monotypy.
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| Species Included |
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C. coronalis Agassiz, 1846; Lutetian, Europe, North Africa [=C. delbosi Desor, 1857; Lutetian, France; = C. munieri Cotteau, 1892; Middle Eocene, Europe].
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C. isabellae Cotteau, 1892; Eocene, Spain.
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C. douvillei Cotteau, 1892; Lutetian, France.
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C. forbesi d'Archiac & Haime, 1854; Eocene, Pakistan.
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C. arnaudi Cotteau, 1883, Oligocene (Rupelian), France.
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C. infulatus (Morton, 1833); late Middle Eocene, eastern USA.
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| Classification and/or Status |
Euechinoidea, Echinacea, Arbacioida, Arbaciidae.
Presumed paraphyletic.
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| Remarks |
Distinguished from the subgenus C. (Keraiophorus) by having two equal primary tubercles on ambital and subambital plates and a single(rather than double) pore in its ocular plates. Distinguished from the subgenus C. (Murravechinus) by having interambulacral and ambulacral primary tubercles of similar size. Distinguished from Arbacia by its multiple sphaeridial pits and the demarcation of adradial and interradial zones of the aboral interambulacra.
Agassiz, L. 1840. Catalogus systematicus Ectyporum Echinodermatum fossilium Musei Neocomiensis, secundum ordinem zoologicum dispositus; adjectis synonymis recentioribus, nec non stratis et locis in quibus reperiuntur. Sequuntur characteres diagnostici generum novorum vel minus cognitorum, 20 pp. Oliv. Petitpierre, Neuchâtel.
Mortensen, T. 1935. A monograph of the Echinoidea II. Bothriocidaroida, Melonechinoida, Lepidocentroida and Stirodonta. C. A. Reitzel, Copenhagen.
Reguant, S., Roman, J. & Villatte, J. 1970. Echinides de l\'Eocene moyen de la region de Vic (Barcelona). Bulletin de la Societe geologique de France (7) 12, 894-912.
Carrasco, J. F. & Farres, F. 2001. Excepcional conservacion de fases juveniles de Coelopleurus coronalis (Echinoidea) en el Eocene de Vic, Barcelona. Batalleria 10, 37-48.
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