The Echinoid Directory

• Test depressed with weakly domed upper surface.
• Apical disc relatively small; plates firmly bound to corona. Dicyclic but with periproct slightly offset towards the posterior. Ocular plates small and projecting a little. Genital plate 2 much larger than other genital plates. Periproct subovate.
• Ambulacra trigeminate with pore-pairs in weakly offset triads at the ambitus, expanded adorally to form distinct phyllodes. Primary tubercles irregularly developed on plates above the ambitus; on approximately every second compound plate and placed adjacent to the pore zone. The perradial zone moderately wide with dense granules plus secondary tubercles. Plate compounding diadematid to arbaciid (middle element largest, upper and lower elements smaller and not always reaching the perradius).
• Interambulacral plates much wider than tall at ambitus. Small central primary tubercle plus much smaller flanking tubercles and dense granules above and on either side. Two or three subequal tubercles on each plate below the ambitus.
• Primary tubercles small, imperforate and non-crenulate.
• Horizontal interambulacral sutures incised and granules strongly projecting giving a sculpted appearance.
• Peristome relatively large (more than half test diameter), hardly depressed and with small but distinct buccal notches.
• Spines and lantern unknown.

Cretaceous (Aptian), Switzerland.

Glyptechinus rochati de Loriol, 1873, p. 169, by original designation.

• Only the type species.

Euechinoidea, Echinacea, Stomechinidae.

Monotypic. Subjective junior synonym of Stomechinus Desor, 1856

The presence of strong phyllodes separate this from temnopleuroids, as does its diadematid- rather than echinid-style plate compounding. Distinguished from Stomechinus only in having slightly incised horizontal interambulacral sutures at the ambitus.

de Loriol, P. 1873. Echinologie helvetique. Descriptions des oursins fossiles de la Suisse 2. Echinides de la period Cretacee. H. Georg, Bale.