A New Tortoise from the Pleistocene of Argentina with Comments on the Extinction of Late Pleistocene Tortoises and Plant Communities

The fossil record of terrestrial tortoises in Argentina is patchy. The aim of the present contribution is to describe a new species of the genus Chelonoidis coming from the Middle Pleistocene of Buenos Aires province. This new species shows a unique combination of apomorphic and plesiomorphic characters unnoticed in other South American taxa. By Pleistocene times, South America was inhabited by diverse giant and small terrestrial chelonians that became extinct at the Pleistocene/Holocene boundary. This should have a deep impact on different plant communities, because tortoises probably constituted important seed dispersors. In this sense, several extant plant species that show a patchy distribution and deficient germination and dispersal, may have been negatively affected by the extinction of Pleistocene tortoises.