A hidden treasure of the Lower Pleistocene at Olduvai Gorge, Tanzania: The Leakey HWK EE assemblage

Abstract

HWK EE is a little-known archaeological site from the top of Lower Bed II and the basal part of Middle Bed II, Olduvai Gorge, Tanzania. The site was originally excavated in the early 1970s by Mary Leakey, but the excavations and resulting lithic and fossil assemblages were never described. Here we report for the first time on the lithic and fossil assemblages that were recovered by Mary Leakey from the site. The lithic assemblage is one of the largest of any Oldowan site and is characterized by a core-and-flake technology with simple flaking techniques and minimal reduction of cores. Retouched flake frequencies and battered tools are higher than those reported for Olduvai Bed I and Lower Bed II assemblages, but flaking schemes are poorly organized. The fossil assemblage is well-preserved, taxonomically-rich, but dominated by bovids, and includes abundant feeding traces of both hominins and carnivores. Hominins are inferred to have broken the majority of limb bones at the site for access to marrow, while both carnivores and hominins likely had access to at least some flesh. HWK EE may represent one of the last Homo habilis sites at Olduvai Gorge, and is important to understanding the behavioral and cultural mechanisms that led to the emergence of the Acheulean and Homo erectus in the region.

Raw material optimization and stone tool engineering in the Early Stone Age of Olduvai Gorge (Tanzania)

“…Lavas, available in river channels across the Olduvai palaeo-basin, were used to produce flakes, cores and large cutting tools (LCTs), including handaxes, and are abundant in Oldowan and Acheulean sites. When smaller lava tools were made there is a notable disparity between the number of cores and flakes present at sites [7,14,16,[19][20][21][22][23]. Quartzite, mostly sourced from the Naibor Soit inselberg approximately 3 km north of the confluence of the Main and Side Gorges, was extensively used at Olduvai, predominantly for the production of small flakes (debitage), which frequently (but not always [24]) outnumber their lava counterparts [1,2,7,14,[16][17][18][19]22,23,25].…”

“…When smaller lava tools were made there is a notable disparity between the number of cores and flakes present at sites [7,14,16,[19][20][21][22][23]. Quartzite, mostly sourced from the Naibor Soit inselberg approximately 3 km north of the confluence of the Main and Side Gorges, was extensively used at Olduvai, predominantly for the production of small flakes (debitage), which frequently (but not always [24]) outnumber their lava counterparts [1,2,7,14,[16][17][18][19]22,23,25]. Quartzite LCTs are also well represented at many Acheulean sites, although notable inter-site variation in LCT raw material composition exists [7,15,18,19,21,[24][25][26].…”

Microhabitat Variability in Human Evolution

“…Although we have longterm records that demonstrate changes in plant landscape composition (Feakins et al, 2005;Feakins et al, 2007;Feakins et al, 2013;Uno K. T. et al, 2016), they do not necessarily show the ecological subtleties and complexity that on-site (i.e., proximal) records can provide. Increasingly, however, phytolith and pollen records (Bonnefille, 1995;Barboni et al, 1999;Albert et al, 2006;Bamford et al, 2006;Bamford et al, 2008;Albert et al, 2009;Barboni et al, 2010;Rossouw and Scott, 2011;Albert and Bamford, 2012;Barboni, 2014;Albert et al, 2018;Itambu, 2019;Mercader et al, 2021;Stollhofen et al, 2021), as well as paleontological and stable isotope analyses (WoldeGabriel et al, 1994;Cerling et al, 1997;Pickford and Senut, 2001;Wynn, 2001;White et al, 2009b;WoldeGabriel et al, 2009;Prassack, 2010;Cerling et al, 2011;Kovarovic et al, 2013;Magill et al, 2013a;Quinn et al, 2013;Bibi and Kiessling, 2015;Bibi et al, 2018;Colcord et al, 2018;Pante and de la Torre, 2018;Prassack et al, 2018;Faith et al, 2019;Roberts et al, 2020;Sanders, 2020), have sought to track changes in landscapes occupied by Pleistocene hominins. The pursuit of more detailed data relating to hominin population resourc...…”

El estudio funcional lítico en la Early Stone Age (ESA) africana. Aplicación analítica, metodológica y experimental en los yacimientos arqueológicos del Lecho II de la Garganta de Olduvai, Tanzania

“…En este sentido, realizaron sondeos aleatorios a lo largo de las paleosuperficies con el objeto de reconstruir los contextos paleoecológicos y las actividades de los homininos a lo largo de la Garganta (Blumenschine y Masao, 1991;Blumenschine y Peters, 1998;Blumenschine y Selvaggio, 1988;Blumenschine et al, 2003;2012a;2012 b McHenry y Pante et al, 2018;Prassack et al, 2018;Proffitt, 2018;Rivals et al, 2018;Stanistreet et al, 2018 (Aramendi et al, 2017;Diez Martín et al, 2009b;Domínguez-Rodrigo et al, 2009b;2009e;2010a;2014c;Domínguez Rodrigo y Cobo Sánchez, 2018;Sánchez Yustos, 2016;Santonja et al, 2014;Organista, 2018;Uribelarrea et al, 2014;Yravedra et al, 2016… entre otros) TOPPP lleva a cabo una serie de estudios multidisciplinares que buscan, por un lado, revisar los yacimientos clásicos excavados con anterioridad y, por otro, descubrir nuevos enclaves. Todas estas investigaciones continúan ampliando nuestro conocimiento de las formas de vida y de las mentes de los primeros ancestros humanos incluyendo, en un primer momento, nuevas reconstrucciones sobre la formación y el paleoambiente de los yacimientos más significativos del Lecho I (Ashley et al, 2010), así como nuevas interpretaciones de los yacimientos excavados con anterioridad por los Leakey (Domínguez Rodrigo, 2009e Domínguez-Rodrigo et al, 2007.…”

“…Sin embargo, aguas abajo, en la zona de los ríos entrelazados, la densidad de materiales aumenta notablemente. Se han localizado hasta tres yacimientos relevantes: HWK, HWK-E y HWK-EE (Leakey, 1971;Pante et al, 2018;Rivals et al, 2018a;Stanistreet et al, 2018; .…”