The Echinoid Directory

Cleistechinus de Loriol 1882, p. 27

Diagnostic Features	Test small (20 mm), ovate, thin-shelled without anterior sulcus; depressed in profile. Apical disc compact, ethmolytic, with two gonopores (no gonopores in anterior genital plates). Positioned strongly towards the anterior All ambulacra flush aborally; pores small and undeveloped (apetaloid) but doubled in paired ambulacra. Ambulacral plates almost as large as interambulacral plates aborally. Anterior ambulacrum with rudimentary pores only Plastron plating unknown. Periproct on posterior truncate face; slightly sunken. Subanal fasciole present and well developed; no other fascioles present
Distribution	Miocene (Serravalian), Italy, Cyprus.
Name gender	masculine
Type	Cleistechinus canaverii de Loriol 1882, p. 27, by original designation.
Species Included	Only the type species.
Classification and/or Status	Spatangoida, Micrasterina, ?Palaeotropidae. Monotypic. A junior synonym of Palaeobrissus Agassiz, 1883.
Remarks	The species was redescribed by Callegari (1931), but the type material is so poor that much remains unknown. Better preserved material has recently been found of this species from coeval beds in Cyprus (Smith & Gale 2009). Callegari, 1931. Su Alcuni Echinidi Miocenici de S. Severino (March). Memorie dell\' Instituto Geologico della Universita di Padova 9, 1-30. De Loriol, P. 1882. Description des échinides des environs de Camerino. Mémoires de la Société de Physique et Histoire Naturelle Genève 28(3), 32 pp., 3 pls. Smith, A. B. & Gale, A. S. 2009. The pre-Messinian deep sea Neogene echinoid fauna of the Mediterranean: Surface productivity controls and biogeographical relationships. Palaeogeography, Palaeoclimatology, Palaeoecology, 281, 115-125.