Description of a new species of Offneria (Hippuritida, Caprinidae) from the lower Aptian of southeast Spain. Stratigraphic, evolutionary, palaeobiogeographic and palaeoenvironmental implications

Abstract

A new species of Offneria (Caprinidae) Offneria prebetica nov. sp., is described from the Murcia region (Prebetic zone, SE Spain). Its type level is the upper Bedoulian. The key diagnostic character of the new species is the presence on the ventral side of the left valve of an inner row, or double row, of polygonal canals flanked by outer piriform canals with one or two orders of bifurcations. Offneria prebetica nov. sp. is the most advanced species of the genus. Cluster analysis shows the placement of the new species in the monophyletic group of European species, in agreement with its geographic location. Offneria appears to be the most prolific genus of the Caprinidae with species having contrasting ages and palaeobiogeographic distributions. Stratigraphic data from SE Spain indicate that the Offneria lineage was resilient to the environmental perturbations recorded during the late Bedoulian, Offneria prebetica nov. sp. may be used as a time marker for this interval, and its last occurrence was coeval with the “Mid-Aptian extinction event”.