Moluscos del Plioceno Superior marino de Isla Guamblin, Archipielago de los Chonos, sur de Chile

Abstract

ABSTRACT. Upper Pliocene marine mollusks from Guamblin Island, los Chonos Archipelago, southern Chile. Nineteen species belonging to bivalves (7) and gastropods (12) from Guamblin Island (Los Chonos Archipelago, Chile), are described and figured. Among them, Epitonium biroi, Polinices (Euspira) guamblinensis, Cymatium remotum, Xymenopsis? hero, Cryptogemma senex and Hindsiclava ignorata, are proposed as new species. The comparative analysis of this molluscan assemblage with others of the Chilean Neogene allows to relate it with that of the Tubul Formation (Arauco), recorded as Upper Pliocene and located 850 km northward. In accordance with this fact, a late Pliocene age is here proposed for the fossiliferous beds of Guamblin Island. The occurrence of some turrids and bivalves suggests an offshore depositional environment, with depth conditions of about 50-100 m. The bivalves Nuculana elegans (Hupe), Chlamys tenuicostatus (Hupe), Cardiocardita volckmanni (Philippi) and Eurhomalea araucana (Philippi) are proposed as late Pliocene characteristic fossils.