1Archaeology, University of Cape Town, 2Education, American Museum of Natural History
April 17, 2020 , Diamond 6
The Okote, KBS and Upper Burgi members of East Turkana cover an important time in hominin evolution ranging between 1.4 and 2 million years ago. The Omo-Turkana basin has seen various environmental shifts during this time (Bobe 2011, Cerling et al. 2015) and environmental variation has been suggested to correlate with behavioural and anatomical changes within the hominin lineage. Palaeoenvironmental reconstruction in this area is imperative to provide a framework for understanding how climate and environmental change has influenced hominin evolution.The current study uses three-dimensional geometric morphometrics (3D GM) to quantify morphological shape variations in bovid metapodials (n=29). Fossils were compared with data previously published on extant African bovids with known habitat preferences and locomotor patterns (n=370). Ecomorphological analysis was conducted to determine fossil bovid locomotor behaviour, and by extension habitat preference and the palaeo-vegetation of three subregions in the Koobi Fora Formation. Twenty landmarks were collected from the distal metapodial epiphyses. Landmark data were subjected to generalized Procrustes, principal components and discriminant function analyses (DFA). DFA jackknife (cross-validation) analysis resulted in classification success rates of 81% and 78% for metacarpals and metatarsals respectively. The majority of Upper Burgi fossils (66.7%) classified with modern open-habitat dwelling species. All KBS samples were classified into either heavy cover or closed habitats. The Okote samples were classified across categories, but with the majority (65%) in closed or heavy cover habitats. Results are mostly consistent with previous habitat reconstructions at East Turkana, suggesting a particular mix of habitats across the Omo-Turkana basin.
PAST, National Science Foundation (BCS-1624398, REU supplement1930719) and the National Museums of Kenya.