Bivalvos límnicos de la Formación La Puerta (Carbonífero Superior), Cordillera Frontal, San Jua n, República Argentina

Acta geológica lilloana 21 (2): 2009

Abstract

A limnic bivalve fauna consisting of three species of the genus Anthraconaia Trueman and Weir is described. The fauna comes from Upper Carboniferous deposits that outcrop in the surrounding area of the river Manrique in the Cordillera Frontal of San Juan province. This paper describes the species: Anthraconaia furquei sp. nov., nthraconaia caballei sp. nov. and Anthraconaia gonzalezi sp. nov. These forms are smaller than usual in these bivalves, presenting a probable case of dwarfism due to the limited availability of organic matter. These facts, combined with the poorness of the fauna studied suggest a very restricted lagoon near the coast, affected by changing environmental conditions under a warm humid climate.