A hyaena on stilts: comparison of the limb morphology of Ictitherium ebu (Mammalia: Hyaenidae) from the Late Miocene of Lothagam, Turkana Basin, Kenya with extant Canidae and Hyaenidae

• Published in: PeerJ (San Francisco, CA) CA), 2024-06, Vol.12, p.e17405, Article e17405
• Main Authors: van der Hoek, Julien, Werdelin, Lars
• Format: Article
• Language: English
• Subjects: Analysis; Anatomy and Physiology; Animals; Carnivora; Cursoriality; Diseases; Ecology; Ecosystems and species history; Ekosystem och arthistoria; Environmental aspects; Evolutionary biology; Evolutionary Studies; Femur - anatomy & histology; Forelimb - anatomy & histology; Fossils; Functional morphology; Genetic aspects; Growth; Humerus - anatomy & histology; Hyenas; Kenya; Locomotion; Locomotion - physiology; Morphological variation; Multivariate statistics; Paleontology; Zoology
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.17405

The long, gracile morphology of the limb bones of the Late Miocene hyaenid has led to the hypothesis that this animal was cursorial. The forelimb and femur of the holotype were compared with specimens of extant Hyaenidae and Canidae. Two morphometric methods were used. The first used measurements to calculate indices of different morphological characters. The second method involved capturing photographs of the anterior distal humerus of each specimen, mapping six landmarks on them, and calculating truss distances. These distances represent a schematic reproduction of the elbow. Multivariate statistical analysis primarily separated the data based on taxonomy, yet locomotor and habitat categories were also considered. has an overall morphology similar to that of the maned wolf and a distal humerus reminiscent of that of the aardwolf. The long, gracile limb bones of are suggested to be adaptations for pouncing on prey, for locomotor efficiency, and for looking over the tall grass of the open environments the animal lived in, much like the present-day maned wolf.