The Echinoid Directory

• Test medium-sized (ca. 35 mm diameter).
• Apical disc small; plate arrangement unknown.
• Ambulacra trigeminate with pore-pairs in rather strongly offset triads at the ambitus; not expanded adorally and becoming linear close to peristome. Plating style unknown.
• Single small primary tubercle to each compound plate. Plates strongly ornamented at ambitus with wedge-shaped pits along to perradius and narrow ridges radiating from the primary tubercle.
• Interambulacral plates above ambitus with single small primary tubercle, centrally placed. At ambitus and adorally with multiple small, subequal tubercles arranged in central band.
• Sutural pits extensive at ambitus and adorally on interambulacral plates (may be taphjonomic artefact of weathering!). Upper and lower sutures deeply excavated, as are the adradial and interradial sutures. Small sutural pits aborally at triple junstions.
• Perisrtome slightly sunken; about one-third of test diameter; feeble buccal notches present.
• Spines and lantern unknown.

Pliocene or Quaternary, Timor.

Martinechinus molengraaffi Jeannet, in Jeannet & Martin, 1937, p. 233, by original designation.

• Only the type species.

Euechinoidea; Camarodonta, Temnopleuroida, Temnopleuridae.

Monotypic; subjective junior synonym of Microcyphus.

The presence of a single primary tubercle on aboral plates suggests this belongs to the subgenus Printechinus.

Jeannet, A. & Martin, R. 1937. Uber Neozoische Echinoidea aus dem Neiderlandisch-Indischen Archipel. Leidsche Geologische mededeelingen 8, 215-308.