The genus Cymatoceras (Nautilida) in the Lower Cretaceous of the Atacama Basin, northern Chile.

Abstract

Fragmentary remains of nautilids assigned to the genus Cymatoceras Hyatt, found in Barremian strata at the Atacama Basin, northern Chile, are described. The specimens can be divided into two taxa: Cymatoceras sp., from the late Upper Barremian, that has a poor preservation, but at the moment its ornamentation type, with coarse ribs with a marked ventral sinus, is only known from this taxon, and Cymatoceras cf. perstriatum (Steuer), from the Upper Barremian. The Chilean material is mainly compared with Cymatoceras taxa present at the Neuquén and Austral basins, in Argentina.