Mareleptopoma Moolenbeek & Faber, 1984

Renard, Jacques Le & Bouchet, Philippe, 2003, New species and genera of the family Pickworthiidae (Mollusca, Caenogastropoda), Zoosystema 25 (4), pp. 569-591 : 575

Genus Mareleptopoma Moolenbeek & Faber, 1984

TYPE SPECIES. — Mareleptopoma karpatensis Moolenbeek & Faber, 1984 , by original designation.

REMARKS

Mareleptopoma differs from Sansonia by its rissoiform (not trochiform) outline, more convex whorls, a less thickened and less oblique apertural rim, a narrow (if present) umbilicus, and a convex base sculptured with numerous concentric cords not forming a major keel at the periphery.

The type species of Mareleptopoma is rather peculiar, and the original generic diagnosis is too specific. We have therefore modified the original concept of Mareleptopoma in order to accomodate several additional species: the general outline is turbinate or rissoiform, rather than trochiform; the protoconch may be multispiral or paucispiral, depending on the mode of development (the original diagnosis erroneously described the protoconch of M. karpatensis as mammillated, suggesting a lecithotrophic development, but Moolenbeek & Faber’s original figure 48 shows a sinusigera larval shell, with a deep sinus); there is a narrow, but open umbilicus in several species; a microsculpture of spiral rows of granules may or may not be present, depending on the species.

As redefined, Mareleptopoma is pan-tropical in distribution, and is known since the Oligocene (P. Lozouet pers. comm.). Moreover, it includes the most abundant species of Pickworthiidae , M. iredalei (Bavay, 1921) .