Ray-finned fishes (Actinopterygii) from the lower Maastrichtian of Algarrobo, central Chile

Abstract

This research presents new material of ray-finned fishes recovered from Upper Cretaceous strata exposed in the city of Algarrobo, central Chile. The material includes specimens here referred to the genus Enchodus, which are the first local records of early Maastrichtian age. Three coeval, isolated teeth are here referred to the genus Pachyrhizodus, and six distinctive, barracuda-like teeth are here referred to as indeterminate pachycormids. These finds represent the first record of Pachyrhizodus and the second record of a pachycormid in the Upper Cretaceous of southern South America. In addition, it is provided a critical review of the historic ray-finned fishes from the Upper Cretaceous Quiriquina Formation of central Chile and equivalent units within the Arauco Basin. The updated information suggests that latest Cretaceous actinopterygian diversity along the southeastern Pacific was much discrete than previously thought, and unusually scarce in terms of abundance. Locally, this scarcity was already present during the lower Maastrichtian and persisted throughout the end of the Cretaceous.