Anchitherium aurelianense (Mammalia, Equidae) (Cuvier, 1825) dans l'Orléanien (Miocène) de France

The characters of the horse Anchitherium Meyer, 1844 are very conservative. While its dental morphology is quite constant, its postcranial morphology is more variable. Fossil remains from the Orleanian (early to middle Miocene, MN3-MN5) localities of Baigneaux-en-Beauce, Pontlevoy and Thenay, Faluns d'Anjou, Chevilly, Neuville-aux-Bois, Chilleurs-aux-Bois, Chitenay, and Montabuzard (Loire basin) and La Romieu (Aquitaine basin) were studied. Based on their tooth and limb morphology, these fossil remains were assigned to Anchitherium aurelianense aurelianense (Cuvier, 1825). The type specimen of the subspecies comes from Montabuzard. We also studied new fossil remains from the following localities within the Sables de l'Orléanais region (France) : Tavers-les-Pavés, and Bois de Maigreville (= Graviers de l'Orléanais). Dental material from Tavers-les-Pavés was attributed to A. a. hippoides Lartet, 1851. Remains from the other localities were characterized by mid- to small-sized skeletons and smallish teeth (smaller than the A. a. hippoides teeth from the more recent localities of Sansan and Simorre [France]). Thematerial from the Buñol (Spain) horse was very similar to that of horses of Baigneaux-en-Beauce and other French localities, and was therefore assigned to A. a. aurelianense. This study showed a strong correlation between tooth and postcranial morphologies and size among all the remains. We consider that all the remains from the Sables de l'Orléanais belong to the same species. From a palaeoecological point of view, the characters of A. a. aurelianense suggest a more closed environment than do those of the more recent subspecies from the middle Miocene.