PRESENCE OF MAORITRIGONIA FLEMING, 1962 ( BIVALVIA, MINETRIGONIIDAE) IN THE UPPER TRIASSIC OF SOUTH-AMERICA - DESCRIPTIONS OF 2 NEW SPECIES

The genus Maoritrigonia Fleming, 1962, characteristic of the Upper Tri assic of New Zealand and New Caledonia, has been recognized only at a generic level in South America (Chile and Peru?). The taxonomic study of collections from Quebrada San Juan, Atacama Region, and Corral Barr ancas, Coquimbo Region, northern Chile, allowed to recognize two new s pecies which confirm the presence of this genus in the east Pacific ar ea during the Late Triassic. Maoritrigonia sparsico stata nov. sp. has narrow flank and area fibs, all finely tuberculate; interspaces wider than costae; antecarinal depression ca, 35% of the flank length, whic h includes one narrow median costae and 2-4 small tuberculate costella . Maoritrigonia mollesensis nov. sp, is ornamented with broad costae o n the flank, and fine on the area, all tuberculate; interspaces as wid e as the costae; antecarinal depression ca. 30% of the flank length, i ncluding a narrow median riblet and one small tuberculate costule. The species diversity of Maoritrigonia in New Zealand-New Caledonia durin g the Late Triassic, makes it possible to postulate this region as a d ispersion center toward South America.