Taphonomic analysis of the level 3b fauna at BK, Olduvai Gorge

Abstract

The association of stone tools and modified bones at archaeological African Plio-Pleistocene sites is essential to understanding the socio-economics of early hominin behavior. Previous research at BK suggests the site was repeatedly visited by hominins for short time periods. During these occupations, the hominins had a primary role in the exploitation of small, medium, and large size carcasses. The present study analyzes the faunal material recovered from level 3b at BK (BK3b). The results indicate that BK3b operated as a place consciously selected by hominins to carry out specific activities, which resulted in a large accumulation of lithic materials and bone remains. The high frequency of cut-marked specimens, even more than is documented at FLK Zinj, supports the idea that hominins at BK3b butchered and demarrowed the bones from animals of all sizes.

Introduction

The African Plio-Pleistocene witnessed the first stone tool assemblages associated with bones from several animals. Sites such as Ain Boucherit, dated to 2.4 million years ago (Ma) (Sahnouni et al., 2018), Gona dated to 2.5–2.1 Ma (Domínguez-Rodrigo et al., 2005), and Lokalalei 2C (2.34 Ma) (Roche et al., 1999) all show evidence of butchery marks on bones belonging mainly to medium and small carcasses. Nevertheless, all these assemblages are not in primary context or the samples are too small to fully ascertain the socio-economic behavior of early hominins. From 2 Ma onwards several archaeological sites that preserve stone artifacts and cut-marked fossil bones belonging to different taxa from the same level are documented. These sites are referred to as “Type C″ sites (Isaac, 1978, 1984) and are found at several localities, including Koobi Fora (1.95 Ma) (Bunn, 1994), FLK Zinj (1.84 Ma) (Leakey, 1971), El-Kherba (1.78 Ma) (Sahnouni et al., 2013), FLK W (1.7 Ma) (Yravedra et al., 2017b), the ST site complex at Peninj (1.5–1.3 Ma) (Domínguez-Rodrigo et al., 2002), SHK (∼1.5 Ma) (Domínguez-Rodrigo et al., 2014a), and BK (1.35 Ma) (Domínguez-Rodrigo et al., 2009a, 2014b; Organista et al., 2015, 2017). The growing sample of Type C sites now allows us to better characterize their relationship with the behavior of early Homo. At the Bell's Korongo (BK) site in particular there is strong evidence for repeated carcass butchery throughout a deep stratigraphic sequence that spans a significant amount of time, which offers us the opportunity to understand in some detail the socio-economic behavior and evolution of early Homo.

Early access (implying bulk defleshing) by hominins to large carcasses has now been demonstrated at several Early Pleistocene sites such as Kanjera South (e.g., Ferraro et al., 2013), Koobi Fora: FxJj50 (Bunn, 1994) and FwJj20 (Braun et al., 2010), El-Kherba (Sahnouni et al., 2013), Buia (Fiore et al., 2004), and the ST Site Complex (Domínguez-Rodrigo et al., 2002). To date, at Olduvai Gorge, the archaeological record preserves only limited taphonomic evidence for the manipulation by hominins of megafauna during Bed I times at FLK North (Domínguez-Rodrigo et al., 2010) and during lower Bed II times at SHK (Domínguez-Rodrigo et al., 2014a) and FLK West (Yravedra et al., 2017b). This situation changes during middle and upper Bed II times, where hominins' systematic exploitation of megafauna is thoroughly documented throughout the stratigraphic sequence of BK (Domínguez-Rodrigo et al., 2014b; Organista et al., 2015, 2017; Yravedra et al., 2019 accepted). In the current study, we present the taphonomic results of a new archaeological level with evidence for anthropogenic activity, level 3b at BK, which was initially excavated by M. Leakey (1971) and reopened by The Olduvai Paleoanthropology and Paleoecology Project (TOPPP) in 2006.