Nuevo Percichthyidae (Teleostei, Percoidei) del Plioceno temprano de la provincia de Buenos Aires (Argentina) y sus implicancias biogeográficas

Abstract

New Percichthyidae (Teleostei, Percoidei) from the early Pliocene of the Buenos Aires province (Argentina) and its biogeographical implications. The paleoichthyological record from the early Pliocene of Farola Monte Hermoso locality, southern Buenos Aires province (Argentina) is still patchy and biased. During such time span, this locality may be related to the Río Colorado paleobasin, and consequently may have been related to the Austral Ichthyogeographical Region. In the present contribution we describe a new genus and species of a very large Percichthyidae, coming from fluvial deposits of the Monte Hermoso Formation. The new taxon constitutes the sister group of the genera Percichthys and Santosius. This finding, together with other pre­vious paleoichthyological records, as well as phylogenetic and phylogeographic molecular analyses of living taxa, suggest the existence of an ichthyofaunistic turnover for the late Neogene in the Patagonian region. In this way, the current composition of the Patagonian ichthyofauna would be of recent age, possibly from the Pleistocene.