Simbakubwa kutokaafrika gen. et sp. nov. (Hyainailourinae, Hyaenodonta, “Creodonta”, Mammalia) a gigantic carnivore from the earliest Miocene of Kenya
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ID: 00000C483
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Hyainailourine hyaenodonts are among the largest terrestrial carnivorous mammals known. Hyainailourinae likely originated in Afro-Arabia in the early Paleogene, then dispersed to Europe, Asia, and North America in the early and middle Paleogene. Understanding the evolution of this widely dispersed clade is crucial for interpreting the ecological transition from Paleogene to Neogene faunas in Afro-Arabia and Eurasia. The fossil record for hyainailourines in Afro-Arabia is primarily composed of fragmentary dental material, with few associations between upper and lower dentitions. The paucity of associated material has made it difficult to unravel the phylogenetic relationships among taxa within Hyainailourinae. In this study we describe associated dental and postcranial material from Simbakubwa kutokaafrika gen. et sp. nov. the most complete hyainailourine known from sub-Saharan Africa. The relatively young adult from the early Miocene locality of Meswa Bridge was between 280 kg and 1550 kg and has only light wear on its dentition, making it important for documenting morphology in a clade where heavy tooth wear often obscures phylogenetically important features. Simbakubwa differs from Hyainailouros in exhibiting distinctive, lingually oriented molar protocones, relatively gracile metastyles, and buccolingually compressed, shearing canines. The upper molars of Simbakubwa exhibit deep carnassial notches and fusion of the tall paracones and shorter metacones into a single piercing cusp. A Bayesian phylogenetic analysis recovers Simbakubwa within a clade of large-bodied Miocene hyainailourines (including Hyainailouros and Megistotherium) that originated in Afro-Arabia and dispersed to Eurasia during the early Miocene.