ABSTRACT
Toumaï (Sahelanthropus tchadensis) is, to date, the oldest known hominine. Approximately 7 million years ago, it lived close to the northern shoreline of the paleo Lake Chad, which extended at that time 500 km north of its present location. Here, we describe a new xerine squirrel, Sabara oralacus, gen. et sp. nov., discovered near the site where Toumaï was unearthed. Study of associated fauna is essential to evaluate correctly the precise paleoenvironmental affinities of the first African hominines. The new squirrel displays a mosaic of dental and skull characters characterizing either the tribe Xerini or Protoxerini, which makes its taxonomic assignment at the tribe level difficult. From craniodental characters, we hypothesize that S. oralacus was a ground-dweller, digging burrows, probably with an ecological preference for forest to savannah environments associated with hard fruit-bearing trees.
ACKNOWLEDGMENTS
We are extremely grateful to Jacques Cuisin of the MNHN of Paris for the loan of squirrel specimens and for his help during our study of the collections. Thanks also to Paula Jenkins of the NHM of London and to Josefina Barreiro of the MNCN of Madrid for access to comparative material of modern Xerinae. We thank Chadian authorities (Ministère de l’Education nationale, de l’Enseignement supérieur et de la Recherche, Université de N’Djamena, CNAR), French authorities (MESR, Faculté des Sciences, Université de Poitiers, CNRS, Programme Eclipse, ANR-05-BLAN-0235, ANR-09-BLAN-0238, and MAE, DCSUR Paris, Projet FSP 2005-54 de la Coopération franco-tchadienne et Ambassade de France à N’Djamena), as well as the Région Poitou-Charentes and the French army. We are grateful to all of the MPFT participants for field, technical, and/or administrative work. Thanks to Larry Flynn, Pierre Mein, and another anonymous reviewer for their critical and meticulous review of the manuscript. Financial support for studying collections in the above cited Museums has been provided by the NSF/RHOI “Small Mammals” (Award No. BCS-0321893), MEC (CGL2004-02094/BTE), and MICINN (CGL2008-04200).
‡Laurent Viriot and Pablo Pelaez-Campomanes have equally contributed to this work.
Handling editor: Thomas Martin