A PRELIMINARY ANALYSIS OF BOVID MESOWEAR DATA FROM EAST TURKANA (NORTHERN KENYA) FROM 2.0 - 1.4 MILLION YEARS AGO: IMPLICATIONS FOR PLEISTOCENE HOMININ ENVIRONMENTS

Eastern African paleoecosystems have been a vital component of understanding the adaptive landscape inhabited by our earliest ancestors. Paleoenvironmental proxies indicate that these environments were highly dynamic during many of the most important periods in our evolutionary history. Mesowear analyses characterize herbivore tooth wear in relation to ingested foodstuffs across the life span and have provided valuable insights into the spatiotemporal nature of changing environments in eastern Africa. In this study, we use a large compilation (N = 322) of mesowear data from the family Bovidae to gather insights into the vegetation community at East Turkana, northern Kenya between 2.0 – 1.4 Ma – a period that documents the evolutionary transition between early Homo and H. erectus as well as the ecology of Paranthropus boisei (our close fossil relative). In addition, we compare two established methodologies in relation to their implications for environmental reconstruction. First, generally, we find that mesowear scores are consistent with established isotopic reconstructions of the grazer – browser spectrum and indicate that East Turkana environments were dominated by open grasslands throughout this period. However, mesowear data from the tribe Reduncini (e.g., waterbucks) indicate a more browsing diet, a pattern contra to isotopic data that indicate a complete C4 diet. We hypothesize that this is likely related to the ingestion of fresh grass (rather than arid adapted grasses) with little abrasive material, thereby minimizing tooth wear (a pattern typically related to a browsing diet). Finally, we find that both methodologies result in approximately the same environmental interpretation, however one of them provided more resolution. This preliminary analysis will be expanded upon over the next year and will undoubtedly provide novel insights into East Turkana ecosystems