The Echinoid Directory

Claviaster d\'Orbigny, 1856, p. 281

[=?Thomasaster Lambert, 1920, p. 138, type species Archiacia araidahensis Gauthier, 1902; =?Passalaster Pomel, 1883, p. 55, type species Claviaster costat ]

Diagnostic Features	Test of medium size, elongate, adapically very high, drawn-out cylindrical prominence overhanging anterior margin; greatest width posterior of centre; oral surface flat or sunken towards peristome Apical system tetrabasal, very eccentric anteriorly, compact Petals moderately developed, ambulacrum III non-petaloid, often in a groove. Pores conjugate, inner pores circular, outer pores slit-like. Ambulacral plates beyond petals with a double series of double pores, except in non-petaloid ambulacrum III where there is a single series of double pores Periproct inframarginal, longitudinal, in longitudinal groove continuing to apical system Peristome anterior Bourrelets slightly developed Phyllodes reasonably broad, double-pored with many pairs of pores in two series in each half ambulacrum No buccal pores Tubercles slightly larger adorally than adapically Narrow naked zone in interambulacrum 5
Distribution	Cretaceous (Cenomanian-Turonian) North Africa
Name gender	masculine
Type	Archiacia cornuta L. Agassiz, in Agassiz & Desor, 1847 p. 159; by original designation.
Species Included	?C. araidahensis (Gauthier, 1902); Cenomanian, Egypt C. cornuta (L. Agassiz, 1847); Turonian, Egypt ?C. costatus Pomel, 1883; Turonian, Egypt C. libycus Gauthier in Thomas & Gauthier, 1889; Cenomanian, Tunisia
Classification and/or Status	Irregularia; stem group Neognathostomata;Archiaciidae
Remarks	Claviaster is similar to Archiacia, both genera having inflated tests with a high, drawn-out cylindrical prominence overhanging the anterior margin, double pored phyllodes and a non-petaloid ambulacrum III. These genera differ in that ambulacrum III of Archiacia has a double series of double pores, while ambulacrum III in Claviaster has a single series of double pores. D. Zaghbib-Turki. 1981. Claviaster, Echinide Cassiduloide du Cretace Superieur Mediterraneen est un Archiacidae. Annales de Paleontologie (Invertebres), 67, (1), pp. 49-56, 1 pl. Orbigny, A. d' 1854-60. Paléontologie Française. Terrains Crétacés. Tome 6. Echinodermes, Échinoides irréguliers. 596 pp, pls 801-1006. G. Masson, Paris. 1-32 (July 1854); 33-64 (Oct. 1854); 65-96 (Nov. 1854); 97-128 (Jan. 1855); 129-192 (Mar. 1855); 193-208 (May 1855); 209-224 (Aug. 1855); 225-272 (Nov. 1855); 273-320 (Oct. 1856) pp. 273-352 (Oct. 1856), pp. 353-384 (1857), pp. 385-400 (1858), pp. 401-432 (1858), pp. 433-596 (1860).