First record of a chelonioid sea turtle (Testudines, Pan-Cheloniidae) from the late Miocene of Argentina

Abstract

The fossil history of Neogene chelonioid sea turtles from South America is very incomplete. To date, only the isolated remains of dermochelyids and stem-cheloniids have been reported from the Miocene Pacific coast, and a single indeterminate dermochelyid is known from the early Miocene of Patagonia. Here, we describe a partial lower jaw of a fossil chelonioid from the late Miocene of Paraná city, in the Entre Ríos Province of Argentina. This new specimen displays a character state combination consistent with attribution to stem-Cheloniidae, and thus represents the first record of a late Miocene chelonioid from the southwestern Atlantic margin of South America. Agustín Falbo [agustinf_25@hotmail.com], Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo 470 (C1405DJR), Buenos Aires, Argentina; Federico Agnolin [fedeagnolin@yahoo.com.ar], Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo 470 (C1405DJR), Buenos Aires, Argentina. Fundación de Historia Natural ‘Félix de Azara’, Universidad Maimónides, Hidalgo 775 (C1405BDB), Buenos Aires, Argentina.