First sea turtle remains (Pan-Chelonioidea) from the Eocene of Algarrobo, central Chile

Abstract

Abstract: Two isolated bones of sea turtles from Algarrobo, in central Chile, are here described. A fragment of a flat element of Ypresian age is here identified as part of a right hypoplastron, referable to an indeterminate Pan-Chelonioidea. A second, large fragment from Middle-to-upper Eocene levels belonging to the second or fourth left pleural of a carapace, preserves distinctive features such as a considerable uniform thickness (5-7 mm), and a prominent ventral rib ridge, plus scute sulci remarkably similar to extant Cheloniidae such as Chelonia mydas or Lepidochelys spp. Based on these features, it is here identified as an indeterminate Pan-Cheloniidae. The studied material represents the first occurrences of sea turtles in the Eocene of central Chile. The different ages of the specimens show the persistence of Pan-Chelonioidea related taxa throughout the Eocene in the southeastern Pacific, helping to fill in the austral geographic gap of the group during the Paleogene.