The Echinoid Directory

Clypeaster Lamarck, 1801, p. 349

[=Scutum Schumacher 1817, p. 33 (objective); =Echinanthus Gray, 1825, p. 427 (non Leske) (objective); =Nyctimene Gistl, 1848, p. 175 (objective); =Rhaphidoclypus A. Agassiz, 1863, p. 25, type species R. scutiformis A. Agassiz (=Echinus reticulatus Linnaeus 1758, p. 666), by subsequent designation of Lambert & Thiery 1914, p. 301; = Stolonoclypus A. Agassiz, 1863, p. 25, type species S. placunarius A. Agassiz (=Echinanthus humilis Leske 1778, p. 185, by subsequent designation of Lambert & Thiery 1914, p. 301; = Alexandria Pfeffer 1881, p. 63, type species A. magnifica Pfeffer, 1891; = Echinorodorum Pomel, 1883, p. 68 (objective); = Pavaya Pomel, 1883, p. 68, type species Clypeaster corwini Pavay, 1874, p. 98; = Anomalanthus Bell, 1884, p. 43, type species Echinanthus tumidus Woods 1878, p. 169; = Bunactis Pomel, 1887, p. 204, type species Clypeaster scillae Desmoulins, 1837, p. 64, by subsequent designation of Lambert 1912; = Laganidea Pomel, 1887, p. 172, type species Clypeaster scutellaeformis Pomel, 1885, p. 30, by subsequent designation of Lambert 1912; = Myophyma Pomel, 1887, p. 260, type species Clypeaster altus Lamarck, 1816 (=Echinanthus altus Leske, 1778) by subsequent designation of Durham, 1955; = Oxypleura Pomel, 1887, p. 221 (non Amyot & Serville, 1843); = Paratina Pomel, 1887, p. 190 (non Mik, 1874); Platypleura Pomel, 1887, p. 174 (non Amyot & Serville, 1843); = Pliophyma Pomel, 1887, p. 247, type species Clypeaster atlas Pomel, 1887, p. 252, by subsequent designation of Lambert, 1912; Diplothecanthus Duncan 1889, p. 153 (objective); = Plesianthus Duncan 1889, p. 154, type species Echinanthus testudinarius Gray, 1851 (nomen dubium); = Biarrizella Boussac, 1911, p. 30, type species B. marbellensis Boussac, 1911; = Dactylanthus Lambert, 1912, p. 89 (non Carlgren; 1911); = Eurycoila Lambert, 1912, p. 90, type species Clypeaster intermedius Desmoulins, 1837; = Eurypleura Lambert, 1912, p. 90 (non Kaup, 1858); = Paleanthus Lambert, 1912, p. 89, type species Clypeaster breunigi Laube, 1868; = Coronanthus Lambert, 1913, p. 123, type species Clypeaster microstoma Lambert, 1914; =Oxyclypeina Lambert & Thiery, 1913, p. 122 (pro Oxypleura Pomel, 1887), type species Clypeaster doma Pomel, 1887; = Paratinanthus Lambert & Thiery, 1913, p. 122 (pro Paratina Pomel, 1887), type species Clypeaster confusus Pomel, 1887; = Platyclypeina Lambert & Thiery, 1913, p. 122 (pro Platypleura Pomel, 1887), type species Clypeaster marginatus Lamarck, 1816; =Tholeopelta Lambert & Thiery, 1913, p. 122 (pro Eurypleura Lambert, 1912), type species Clypeaster duchassaingi Michelin, 1861; =Alexandraspis Lambert & Thiery, 1914, p. 315 (pro Alexandria Pfeffer, 1881) type species Alexandria magnifica Pfeffer, 1881; =Guebhardanthus Lambert, 1914, p. 17, type species Clypeaster priscus Oppenheim, 1901; =Laubeanthus Lambert, 1914, p. 19, type species Clypeaster breunigi Laube; =Leptoclypeus Koehler, 1922, p. 31, type species Clypeaster annandalei Koehler, 1922; = Rhaphydoclypus Checchia-Rispoli, 1925, p. 63 (nomen vanum); = Orthanthus Mortensen, 1948, p. 34, type species Clypeaster euclastus Clark, 1941; = Zanolettia Sanchez Roig, 1951, type species Z. zanolettii Sanchez Roig, 1951; = Herrerasia Sanchez Roig, 1952, type species Clypeaster profundus Sanchez Roig, 1949, p. 91 (non C. profundus L. Agassiz, 1840); = Rojasaster Sanchez Roig 1952, p. 135, type species Clypeaster hernandezi Sanchez Roig, 1952 ]

Diagnostic Features
  • Test ovate to subpentagonal with rounded margin.
  • Apical disc central; 5 gonopores.
  • Internal buttressing usually well developed around periphery; composed of circumferential partitions in peripheral part and thin pillars towards centre. In the type species an inner circumferential partition creates a double-walled margin.
  • Petals well developed; plating compound with every other plate a demiplate.
  • All interambulacra disjunct on oral surface.
  • Periproct oral, towards posterior margin; positioned between third and fifth pairs of post-basicoronal interambulacral plates.
  • Food grooves a simple strong perradial trunk; unbranched and confined to oral surface.
  • Pores and tubercles not linearly arranged but irregularly scattered.
Distribution
Late Eocene to Recent; very widespread in tropical to temperate regions.
Name gender masculine
Type
Echinus rosaceus Linnaeus 1758, p. 665, by original designation.
Species Included
Classification and/or Status

Clypeasteroida; Clypeasterina; Clypeasteridae.

Monophyletic.

Remarks

One of the commonest fossil echinoids in the Tertiary. Many nominal species have been described, but only two others have the characteristic double-walled structure of the type species, C. rosaceus. Mortensen (1948) and all subsequent workers have left the many species in the single 'umbrella' genus Clypeaster while acknowledging that there is considerable heterogeneity amongst species.

An internal mould of a Clypeaster species is illustrated here, as this form of preservation is not uncommon.

Lamarck, J. B. P. M. d. 1801. Système des animaux sans vertèbres, ou Tableau général des classes, des ordres et des genres des ces animaux, 432 pp. Deterville, Paris.

Mortensen, T. 1948. A Monograph of the Echinoidea IV.2 Clypeasteroida. C. A. Reitzel, Copenhagen.