Micropecten, Dijkstra & Maestrati, 2012

Dijkstra, Henk H. & Maestrati, Philippe, 2012, Pectinoidea (Mollusca, Bivalvia, Propeamussiidae, Cyclochlamydidae n. fam., Entoliidae and Pectinidae) from the Vanuatu Archipelago, Zoosystema 34 (2), pp. 389-408 : 396

Micropecten n. gen.

TYPE SPECIES. — Cyclochlamys plectofilum Oliver & Holmes, 2004 . Recent, Rodrigues Island, Indian Ocean, shallow water.

INCLUDED SPECIES. — Micropecten plectofilum (Oliver & Holmes, 2004) n. comb. and M. excuratus n. sp.

DIAGNOSIS. — Cyclochlamydidae n. fam. with an irregularly lattice-sculptured prodissoconch, conical on left valve and flattened on right valve; antimarginally sculptured valves, at least in late ontogeny, left valve also weakly commarginally sculptured or lacking; preradial stage of right valve with a simple outer layer of longitudinal and hexagonal microstructure. Byssal notch well developed; ctenolium lacking; internal disc riblets absent; hinge teeth and ridges lacking.

ETYMOLOGY. — A small pectinoid. Gender masculine.

REMARKS

Micropecten n. gen. is different from Cyclochlamys by the following morphological characters:

– a rounded prodissoconch angle (obtuse in Cyclochlamys );

– a lattice-sculptured prodissoconch on both valves (left valve antimarginal, right valve almost smooth in Cyclochlamys );

– a simple outer layer of longitudinally hexagonal microstructure in preradial stage on the right valve (throughout right valve in Cyclochlamys );

– and an antimarginal sculpture on the right valve (lacking in Cyclochlamys ).

Micropecten n.gen. also differs from Chlamydella by: – having a circular shape (more posteriorly oblique in Chlamydella ), an antimarginal sculpture on both valves (smooth or commarginally sculptured on the left valve in Chlamydella );

– a latticed sculptured conical left valve prodissoconch (weakly inflated and radially sculptured in Chlamydella );

– a simple outer layer of longitudinally hexagonal microstructure in preradial stage on the right valve (throughout right valve in Chlamydella );

– an antimarginal sculpture on the right valve (lacking in Cyclochlamys ).