Semantor macrurus Orlov, 1931 (Carnivora, Mustelidae): Morphology of the Hind Limb and a New View on Its Paleobiology
Based on the analysis of joints morphology in the hind limb of Semantor macrurus, it is established that the amplitude of flexion–extension mobility in the hip, knee (stifle), and talocrural (ankle) joints could have reached 90°; the adduction–abduction mobility in the hip joint was up to 60° and, in the talocrural joint, up to 65°. The talocrural joint is hinged and multiaxial, providing a wide range of movements of the autopodium in the course of aquatic locomotion. The hind limb is of the free type. The exterior of Semantor resembles that of otter. The increased length of the crus suggests that the limb was adapted for stroke function (rowing).
Keywords:Mustelidae morphology aquatic adaptations Late Miocene Gusinyi Perelet Kazakhstan
We are grateful to S.V. Kruskop, S.V. Volkov, V.S. Lebedev, V.E. Litvin, and A.A. Lisovsky (ZM MGU) for help during our work; to A.O. Averia-nov, A.N. Tikhonov, and M.V. Sablin (ZIN) for an opportunity to examine the collection and fruitful discussions.
This study was supported in part by the Program of Basic Research of the Department of Biological Sciences of the Russian Academy of Science “Biodiversity of Natural Systems: Biological Resources of Russia: Estimation of the Present State and Fundamental Bases of Monitoring” and the Program of the Presidium of the Russian Academy of Science “Evolution of the Organic World: Role and Effect of Planetary Processes.”
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