The Echinoid Directory

• Test ovate with shallow but distinct anterior sulcus; posterior face truncate. Test subquadrate in outline, longer than wide. Depressed in profile.
• Apical disc ethmophract with four gonopores; posterior genital plates abutting; slightly posterior of centre.
• Anterior ambulacrum sunken from apex to peristome; pore-pairs heterogeneous, formed of a mixture of elongate \'petal-type\' pores and smaller circumflexed pore-pairs.
• Other ambulacra petaloid and flush. Anterior petals flexed forwards, with pore-pairs in posterior column much better developed than those in anterior column. Posterior petals much shorter and straighter.
• In anterior petals there are up to two plates in the posterior column to every one plate in the anterior column.
• Peristome subcircular and facing downwards.
• Labral plate relatively large and triangular; longer than wide. Sternal plates subequal; median suture more or less vertical. Subsequent plating biserial.
• Periproct towards top of posterior truncate face; subcircular.
• No fascioles, although a band of denser and more aligned granules occurs between the ambitus and a zone level with the ends of the petals.
• Aboral tubercles small and scattered; set in a groundmass of fine granules.

Cretaceous (Barremian to Cenomanian), Europe, North Africa, North and South America.

Spatangus oblongus Brongniart, 1821, p. 555, by original designation.

• H. oblongus (d'Orbigny, 1853); Valanginian, Hauterivian, western Europe.
• H. delgadoi (de Loriol, 1888); Berrriasian-Aptian, Spain and Portugal
• H. renevieri (Desor, 1858); Late Barremian and Aptian, western Europe.
• H. transiens Devries (1956); Algeria.
• H. tissoti Coquand; Albian, North Africa.
• H. peroni Ficheur; Albian.
• many others not checked...

Spatangoida, stem group (toxasterids).

Paraphyletic (by exclusion of Washitaster).

Differs from Toxaster in having pores in the frontal ambulacrum a mixture of wide and narrow forms. Also the anterior petals have fewer plates in the anterior column than the posterior column. This last character it shares with Washitaster, which differs in having multiple fasciole bands running laterally around the sides of the test.

d'Orbigny, A. 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).

Villier, L., David, B. & Neraudeau, D. 2001. Ontogenetic and morphological evolution of the ambulacral pores in Heteraster (early spatangoids). Pp. 563-567 in M. Barker (ed.) Echinoderms 2000. Swets & Zeitlinger, Lisse.