A new species of the productid brachiopod Aseptella from the Lower Carboniferous of the Cantabrian Mountains (Spain)

Abstract

A new species of Aseptella, A. beetsi, is described fom Lower Carboniferous, Visean (Arundian-Holkerian) to lower Namurian (Arnsbergian) griotte limestones of the Cantabrian Mountains, variously called Alba or Genicera Formation. The new species, with a weakly developed brachia! median septum, seems to be the ancestor of the type species, A. asturica, from the Bashkirian of Cantabrian Mts, which only develops a median septum in its juvenile specimens. The new species shows a peculiar offshoot of the marginal ridge, possibly for better separation of the ears. The systematic position of the genus Aseptella is briefly discussed as are the implications of the occurrence of this genus in Argentina.