Dos nuevas especies del genero Paulckella Cooper et al. 1989 (bivalvia; trigoniidae), del cretacico inferior, norte de Chile

Abstract

RESUMEN. Se proponen dos nuevas especies del genero Paulckella Cooper et al. 1989, P. covacevichi y P. taverai, sobre la base de ejemplares recolectados en Molle Alto, Region de Atacama y en Quebrada El Way, Region de Antofagasta, respectivamente. P. covacevichi se distingue por tener un angulo umbonal obtuso y costas subumbonales bifurcadas, gruesas. P. taverai, en cambio, posee un angulo umbonal agudo y costas subumbonales bifurcadas, con ramas mas finas. P. covacevichi se asigna al Aptiano superior, por su asociacion con Parahoplites gr. nutfieldiensis (J. Sowerby) y P. taverai, tentativamente, al Hauteriviano-Aptiano. Se comentan, ademas, aspectos taxonomicos, cronoestratigraficos, paleogeograficos y filogeneticos del genero Paulckella. ABSTRACT. Two new species of the genus Paulckella Cooper et al. 1989, P. covacevichi and P. taverai, are here proposed based on specimens collected in Molle Alto, Atacama Region and in Quebrada El Way, Antofagasta Region, respectively. P. covacevichi is distinguished by its obtuse umbonal angle and coarse bifurcating subumbonal costae. P. taverai is characterized by its acute umbonal angle and subumbonal costae with finer branches. P. covacevichi is assigned to the late Aptian based on its association with Parahoplites gr. nutfieldiensis (J. Sowerby) and P. taverai, tentatively, to the Hauterivian-Aptian. Finally, taxonomic, chronostratigraphic, paleogeographic and phylogenetic features of Paulckella are commented.