1 The endocranial morphology of the extinct North American lion (Panthera atrox) 2 Andrew R Cuff1,2, Christopher Stockey3, Anjali Goswami1 3 1. GEE, University College London, Darwin Building, Gower Street, London, WC1E 6BT, United 4 Kingdom. 5 2. Structure and Motion Lab, Department of Comparative Biomedical Sciences, The Royal Veterinary 6 College, Hawkshead Lane, North Mymms, Hatfield, Herts, AL9 7TA, United Kingdom. 7 3. Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom. 8 9 Short title: Endocranial anatomy of Panthera atrox. 10 Four figures, two tables. 11 12 13 Corresponding author: Andrew R Cuff - Structure and Motion Lab, Department of Comparative 14 Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, 15 AL9 7TA, United Kingdom. Phone: 01707 666420.
[email protected]. 16 1 17 Abstract 18 The extinct North American lion (Panthera atrox) is one of the largest felids (Mammalia, Carnivora) 19 to have ever lived, and is known from a plethora of incredibly well preserved remains. Despite this 20 abundance of material, there has been little research into its endocranial anatomy. CT scans of a 21 skull of P. atrox from the Pleistocene La Brea Tar pits were used to generate the first virtual 22 endocranium for this species and to elucidate previously unknown details of its brain size and gross 23 structure, cranial nerves, and inner ear morphology. Results show that the gross brain anatomy is 24 broadly similar to that of other pantherines, although P. atrox displays less cephalic flexure than 25 either extant lions or tigers, instead displaying a brain shape that is reminiscent of earlier felids.