The Echinoid Directory

• Test depressed in profile with rounded ambitus, slightly domed above.
• Apical disc small, hemicyclic with ocular plate I insert; genital plates with a few scattered tubercles forming an irregular perianal ring. Periproct large, subcircular, with smooth outline; plating unknown.
• Ambulacra straight; plating trigeminate, ambulacra plates compounded in acrosaleniid style (two elements) and bearing the primary tubercle, alternating with a simple element with secondaries only. In some species the upper element of each compound plate is occluded. Pore-pairs undifferentiated; uniserially arranged; no phyllode adorally.
• A single primary tubercle to each compound plate plus a smaller perradial secondary on ambital and adapical plates.
• Interambulacral plates wider than tall; with a single primary tubercle, positioned centrally plus much smaller secondary tubercles flanking; flanking tubercles diminish in size adorally and adapically. No well developed naked interradial zone present aborally.
• Tubercles imperforate and crenulate.
• Peristome small, circular, a little sunken, with rather deep and sharp buccal notches.
• Spines unknown.
• Lantern unknown.

Upper Oligocene, Pakistan.

Micropsis venustula Duncan & Sladen, 1884, p. 119, by monotypy.

• G. venustula (Duncan & Sladen, 1884); Eocene, India.
• G. vilanovae (Cotteau, 1882); Eocene, Spain [includes M. tremadesi Cotteau, 1890].
• G. atacica Cotteau, 1892; Middle Eocene, France.
• other species not checked

Euechinoidea, ?Camarodonta, unnamed family (triplacidiids)

Possibly based on a juvenile Triplacidia lorioli?

Duncan, P. M. 1889. A revision of the genera and great groups of the Echinoidea. Zoological Journal of the Linnean Society, 23, 1-311.

Duncan, P. M. & Sladen, W. P. 1884. The fossil Echinoidea from the Kirthar Series of Nummulitic strata in western Sind. Memoirs of the Geological Survey of India, Palaeontologia Indica. Tertiary and Upper Cretaceous fossils from Western Sind, Series XIV, Vol. 1.3.