Water, gravity, and trophic dynamics in the Misiam palimpsest, Olduvai Gorge

Abstract

Misiam is a modern leopard-generated wildebeest bone accumulation located on the slope of a steep ravine within Olduvai Gorge (Tanzania). We present a taphonomic assessment of how leopard feeding behaviour shaped the bone assemblage, accumulated during the wet season, as well as contextualising the extent of secondary hyaenid scavenging. The spatial formation of this taphonomic palimpsest has resulted from the temporal sequence of interactions with the bone remains. The impact of additional agents and processes—such as fungi, insects, weathering, and, most importantly, gravitational displacement driven by water flows generated during the rainy season—adds to the complexity of this locality. This last factor may have played a decisive role in the density-mediated osteological attrition documented in the bone assemblage, perhaps to an even greater extent than hyaenid activity. Given the critical importance for analogical studies of documenting all relevant taphonomic factors at work in modern assemblages, our perspective allows for a comprehensive interpretive assessment of the site. The Misiam surface assemblage, a leopard-generated bone accumulation palimpsest with multiple taphonomic agents and processes at work within a short time span, has therefore significant implications for nuancing or complementing the interpretation of Early Pleistocene localities, such as FLK-North, FLK-Zinj or TK in Olduvai (Tanzania), Ubeidiya (Israel) or Barranco León in Orce (Spain), among others.