The earliest fossil record of the poorly known family Condylocardiidae from Argentina

Abstract

The scarcely known family Condylocardiidae (Bivalvia: Archiheterodonta) is poorly represented in the fossil record and their living representatives are also poorly known. This work presents a new representative of the family from the early Pliocene of marine terrace of Cerro Laciar (Santa Cruz Province). Carditella pitufina sp. nov. is described and characterized by a shell large for the genus, 15 radial ribs as wide as interspaces, high hinge plate and broad and large hinge teeth. The poor record of the family may be due to an identification bias, probably because the tiny size of specimens and its similarity with carditids. This new species resembles to the living Carditella tegulata from southern Argentina and Chile and they could be closely related. Carditella pitufina sp. nov. represents the most ancient record of Carditella in South America and the most ancient record of Condylocardiidae in Argentina.