A geoarchaeological reassessment of the co-occurrence of the oldest Acheulean and Oldowan in a fluvial ecotone from lower middle Bed II (1.7ma) at Olduvai Gorge (Tanzania)

doi:10.1016/j.quaint.2019.09.037

Quaternary International

Volume 526, 20 August 2019, Pages 39-48

https://doi.org/10.1016/j.quaint.2019.09.037 Get rights and content

Abstract

The coexistence of the oldest Acheulean and Oldowan industries means that the appearance of the former cannot be due to an anagenetic development from the latter. At Olduvai Gorge, Tanzania, both industries are found within the same chronostratigraphic unit, the Lower Augitic Sandstone (LAS; 1.7 Ma), at HWK, HWK-E, HWK-EE (Oldowan) and FLK-W and FLK-N (Acheulean). Recently, McHenry and Stanistreet (2018) and Stanistreet et al. (2018) have argued that the Acheulean site of FLK West is actually located within a more recent stratigraphic unit, the Middle Augitic Sandstone (MAS). If so, the Acheulean could potentially have evolved from the Oldowan anagenetically. We test this hypothesis by reviewing the stratigraphy of the LAS from the HWK area to the FLK-W site. Hay's (1976) previous work stresses the continuity of the LAS from HWK-EE to FLK-NN, and stratigraphic and sedimentological evidence indicates that while the MAS has eroded away, the LAS is continuous throughout the study area. According to Hay (1976), Uribelarrea et al. (2017) and this work, the LAS is present at HWK-EE, HWK-E, HWK, HWK-W, FLK-S, FLK-W, FLK-N and FLK-NN. The emergence of the Acheulean at Olduvai Gorge ca. 1.7Ma and its coexistence with the Oldowan thus demonstrates a cladogenetic, rather than an anagenetic, origin for the Acheulean. This has implications for the behavioral and biological interpretations of the origin and co-existence of both types of industries.

Introduction

Two paradigms compete to explain the emergence of the Acheulean stone tool industry. The older, which is inspired by traditional Darwinian gradualism where stone tool industries and hominins co-evolved, presents a linear evolutionary path. This anagenetic conception posits that Homo habilis produced the Oldowan technology, which evolved and was replaced by the Acheulean technology associated with Homo erectus/ergaster (e.g., Leakey, 1951, De la Torre and Mora, 2014; De la Torre, 2016; Sánchez-Yustos et al., 2016). An alternative cladogenetic view maintains that the Acheulean technology emerged and co-existed with the Oldowan during hundreds of thousands of years and that both technologies reflect different adaptive behaviors rather than just different cognitive skills and, therefore, different hominins (e.g., Leakey, 1971; Heinzelin et al., 2000, Díez-Martín and Eren, 2012; Domínguez-Rodrigo et al., 2014, Diez-Martín et al., 2015; Uribelarrea et al., 2017).

The older anagenetic paradigm has been revised by redefining both industries on technological grounds, whereas the cladogenetic paradigm rests on a typological concept of both industries (Leakey, 1971; Baena et al., 2012). This handicaps tests of either approach because they both abide by different conceptual arguments. The anagenetic conceptual framework is cognitive, whereas the cladogenetic approach is functional. The epistemologically-unwarranted cognitive approach has lead lithic experts to identify some assemblages as Acheulean based simply on the single occurrence of a handaxe or a large format artefact among thousands of small flakes and cores (De la Torre and Mora, 2014). However, typological approaches that use arbitrary frequency thresholds of large format tools in any given assemblage to qualify as Acheulean are also heuristically problematic (Leakey, 1971). The fact is that there are assemblages with large numbers of handaxes and other large format tools and others that are dominated by cores and small flakes that most certainly reflect different behaviors. At Olduvai, the former occur in different palaeogeographic settings than the latter (Hay, 1976; Domínguez-Rodrigo et al., 2017; Uribelarrea et al., 2017; Domínguez-Rodrigo, 2018).

Recently, it has been argued that, technologically, the transition of the Oldowan to the Acheulean occurs at Olduvai Gorge (Tanzania) in the middle of middle Bed II in the stratigraphic unit referred to as the Middle Augitic Sandstone (MAS) (McHenry and Stanistreet, 2018; Stanistreet et al., 2018). On the other hand, Diez-Martín et al. (2015) argue that the transition occurs in lower Bed II, in the Lower Augitic Sandstone (LAS), as seen at the FLK West¹ Acheulean site at ca. 1.7 Ma (Diez-Martín et al., 2015). FLK West was inferred to be pene-contemporaneous with HWK, HWK E and, HWK EE (Uribelarrea et al., 2017), all of them classified as Oldowan (Leakey, 1971; De la Torre et al., 2018). This would support a cladogenetic evolution of the Acheulean. However, McHenry and Stanistreet (2018) and Stanistreet et al. (2018) argue that FLK West is located stratigraphically higher due to the erosion of the LAS by the MAS, which, according to these authors, is associated with the overlying Bird Print Tuff (BPT). Should that be true, then the Acheulean industry could potentially have evolved from the Oldowan anagenetically. Here, we test this hypothesis by reviewing the stratigraphy from the HWK area to the FLK West site, especially between the two outcrops where, we will show, the MAS, rather than the LAS, disappears by erosion. This reinforces previous adscription of FLK West to the lower part of the sequence.

Section snippets

Methods

This study uses a standard stratigraphic model, which applies classic stratigraphic techniques: a) strata identification, genesis interpretation, and local stratigraphic succession, b) the movement from a local to a regional scale through correlation of different stratigraphic and tectonosedimentary units, c) a detailed stratigraphic interpretation that includes the reconstruction of depositional environments, lateral extension, stratigraphic relationships with other units, and even the

Geological framework: Lower to Middle Bed II between HWK and FLK-W, 1.7 ma

Bed II is especially interesting since it displays a wide variety of sedimentary environments, including lacustrine, fluvial, Aeolian, and volcanic facies in a very tectonically active setting that was influenced considerably by the geometry of sedimentary units. Lower Bed II is particularly important since it contains the oldest Acheulean industry at Olduvai Gorge (1.7 ma; Diez-Martín et al., 2015). According to Hay (1976), during the beginning of Bed II, the Olduvai basin was dominated by the

LTK section, locality 44

This locality is equivalent to section 11 and HWK-W from Hay (1996) and with HWK-W 16, Loc. 44 from McHenry and Stanistreet (2018). At this locality (Fig. 1), the base of Bed II up to the LD is represented by 3 m of waxy claystone (Hay, 1976). Locally, earthy claystone levels <1 m in thickness can be found since these deposits are in a transitional facies as defined by Hay (1996). Tuff IIA (<50 cm) is embedded in the upper half of this clay unit, 1.5–2.0 m above Tuff IF (Fig. 3).

Unit 1
Lowermost Bed

Stratigraphical correlation

Between LTK and LR, there seem to be no major lithological or facies changes, and the described units are found in the same stratigraphical position in relation to Tuff IF (Fig. 4). The basal deposit of Bed II is a waxy claystone in most places around the junction. According to Hay (1996), in this area, waxy claystones form most of the interval between tuffs IF and IIA in the northern area, whereas they interfinger with earthy claystones in the southern part. The interbedded Lemuta member,

Richard Hay's (1976) stratigraphy

According to Hay (1976), Middle and Lower Bed II has probably the most complex geology at Olduvai, particularly in the central zone, where the “Eastern fluvial-lacustrine deposits” include a wide variety of sedimentary environments (lacustrine, fluvial, and aeolian) with base level changes and tectonic activity. Hay (1976) pays special attention to the interval between the LD and the BPT, describing five evolutionary stages, summarized below (Pages 87–91 and Figs. 26, 27 and 28 in Hay, 1976).

Conclusions

According to Hay (1976), the LAS are present at HWK-EE, HWK-E, HWK, HWK-W, FLK-S, FLK-W, FLK-N, and FLK-NN. Between HWK and FLK-W the palaeosurface prior to the BPT erodes the MAS from Loc. 44 northwards and also partially erodes Tuff IIB at Loc. 45d. The MAS unit and Tuff IIB are not present at FLK-W. The MAS unit is typically lacustrine, whereas the LAS unit is fluvial and fluvial-lacustrine and, therefore, they are distinguishable. LAS overlies the LD practically throughout the gorge, while

Declaration of competing interest

The authors declare having no conflict of interest.

We don't have conflict of interest, we make a scientific critique.

Acknowledgements

We thank the Tanzanian Commission for Science and Technology (COSTECH), the Department of Antiquities, the Ngorongoro Conservation Area Authority in the Ministry of Natural Resources and Tourism and the National Museums of Tanzania for permission to conduct research at Olduvai Gorge and at the National Museum in Dar es Salaam. We also thank the Spanish Ministry of Economy and Competitiveness for funding this research (HAR2017-82463-C4-1-P) and the Ministry of Culture for funding our research

References (22)

F. Bibi et al.
Paleoecology of the Serengeti during the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania: The mammal and fish evidence
J. Hum. Evol.
(2018)
I. De la Torre et al.
From the oldowan to the acheulean at Olduvai gorge
J. Hum. Evol.
(2018)
M. Domínguez-Rodrigo et al.
Paleoecological reconstructions of the Bed I and Bed II lacustrine basins of Olduvai Gorge (Tanzania) and insights into early human behavior
Palaeogeogr. Palaeoclimatol. Palaeoecol.
(2017)
M. Domínguez-Rodrigo et al.
The evolution of hominin behavior during the Oldowan-Acheulean transition: recent evidence from Olduvai Gorge and Peninj (Tanzania)
Quat. Int.
(2014)
L.J. McHenry et al.
Tephrochronology of bed II, Olduvai gorge, Tanzania, and placement of the oldowan–acheulean transition
J. Hum. Evol.
(2018)
P. Sánchez-Yustos et al.
Techno-economic human behavior in a context of recurrent megafaunal exploitation at 1.3 Ma. Evidence from BK4b (Upper Bed II, Olduvai Gorge, Tanzania)
J. Archaeol. Sci.: Reports
(2016)
I.G. Stanistreet
Fine resolution of early hominin time, Beds I and II, Olduvai Gorge, Tanzania
J. Hum. Evol.
(2012)
I.G. Stanistreet et al.
Bed II sequence stratigraphic context of EF-HR and HWK EE archaeological sites, and the oldowan/acheulean succession at Olduvai gorge, Tanzania
J. Hum. Evol.
(2018)
K.T. Uno et al.
Large mammal diets and paleoecology across the Oldowan–Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses
J. Hum. Evol.
(2018)
D. Uribelarrea et al.
A reconstruction of the paleolandscape during the earliest acheulean of FLK west: the co-existence of oldowan and acheulean industries during lowermost bed II (Olduvai gorge, Tanzania)
Palaeogeogr. Palaeoclimatol. Palaeoecol.
(2017)

I. Baena et al.

Testing cognitive skills in Early Pleistocene hominins: an analysis of the concepts of hierarchization and predetermination in the lithic assemblages of Type Section (Peninj, Tanzania)

(2012)

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FLK West (Bed II, Olduvai Gorge) contains the oldest association of Acheulian stone tools and exploitation of fauna (including megafauna) by hominins in the Pleistocene. Recently, the FLK West paleolandscape has been intensively studied, unveiling a spatial association between archaeological materials and hydrothermal resources. A new type of landscape use by hominins has also been documented around the area where the pene-contemporaneous FLK West and HWK site complex were formed, resulting in an array of habitats spanning thousands of square meters covered with large amounts of lithic artefacts. Here, we show how the intensive use of certain environments by hominins resulted in these “megasites”, in which hominins engaged in a variety of activities, complementary to those performed at discrete archaeological clusters like FLK West. Despite using these habitats redundantly as quarries, hominins performed extensive core reduction of several types of raw materials indicating a dexterity and careful planning undocumented in earlier periods. Here, we also show how palaeoecological reconstructions must be based on fine-scale geological analyses, given the palimpsestic nature of both geological and anthropogenic processes. The research reported here also uncovered an additional unknown source of metamorphic rocks for hominins at Olduvai, which questions a large part of previous modeling based on hominin provisioning exclusively at Naibor Soit. We also show that the manufacture of handaxes was slightly older than documented at FLK West and that they occur in isolation on the landscape in addition to being clustered at sites. This implies that at the beginning of the Acheulian, hominins were not only using and discarding handaxes at specific loci, but they also transported these tools for various activities across the landscape as part of their strategized adaptation to those environments. The occurrence of these intensively-used megasites hints at some territorial behaviors by early Acheulian hominins.
Modeling Oldowan tool transport from a primate perspective
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Living nonhuman primates have long served as a referential framework for understanding various aspects of hominin biological and cultural evolution. Comparing the cognitive, social, and ecological contexts of nonhuman primate and hominin tool use has allowed researchers to identify key adaptations relevant to the evolution of hominin behavior. Although the Oldowan is often considered to be a major evolutionary milestone, it has been argued that the Oldowan is rather an extension of behaviors already present in the ape lineage. This is based on the fact that while apes move tools through repeated, unplanned, short-distance transport bouts, they produce material patterning often associated with long-distance transport, planning, and foresight in the Oldowan. Nevertheless, remain fundamental differences in how Oldowan core and flake technology and nonhuman primate tools are used. The goal of the Oldowan hominins is to produce sharp-edged flakes, whereas nonhuman primates use stone tools primarily as percussors. Here, we present an agent-based model that investigates the explanatory power of the ape tool transport model in light of these differences. The model simulates the formation of the Oldowan record under the conditions of an accumulated short-distance transport pattern, as seen in extant chimpanzees. Our results show that while ape tool transport can account for some of the variation observed in the archaeological record, factors related to use-life duration severely limit how far an Oldowan core can be moved through repeated short-distance transport bouts. Thus, the ape tool transport has limitations in its ability to explain patterns in the Oldowan. These results provide a basis for discussing adaptive processes that would have facilitated the development of the Oldowan.
After the emergence of the Acheulean at Melka Kunture (Upper Awash, Ethiopia): From Gombore IB (1.6 Ma) to Gombore Iγ (1.4 Ma), Gombore Iδ (1.3 Ma) and Gombore II OAM Test Pit C (1.2 Ma)
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Citation Excerpt :
Currently, there is some consensus that the technological and typological characteristics differencing the so-called Developed Oldowan from the Acheulean reflect techno-economic and functional variations, rather than biological or cultural factors (Isaac, 1969; Stiles, 1977, 1979; Gowlett, 1988; Domínguez-Rodrigo et al., 2005; Semaw et al., 2009; Díez-Martín and Eren, 2012; Gallotti, 2013; de la Torre and Mora, 2014; Santonja et al., 2014; Rubio-Jara et al., 2017; Gallotti and Mussi, 2018; Sánchez-Yustos et al., 2018). However, Semaw et al. (2020) recently favoured again Leakey's hypothesis while Uribelarrea et al. (2017; 2019) suggest the co-occurrence of Oldowan and Early Acheulean in the same landscape during the initial emerging Acheulean, i.e. during the deposition of lowermost Bed II at Olduvai. The small bifacial tool just pre-dating 1.2 Ma at Gombore II OAM Test Pit C and the shaping flake dated between 1.2 and 0.87 Ma (Fig. 15 a-b) suggest that by then the hominins had refined their skills in shaping handaxes.
While the emergence of the Acheulean is well documented in East Africa at ~1.7 Ma, subsequent developments are less well understood and to some extent controversial. Here, we provide robust evidence regarding the time period between 1.6 Ma and 1.2 Ma, based on an interdisciplinary approach to the stratigraphic sequences exposed in the Gombore gully of Melka Kunture, in the upper Awash Valley of Ethiopia. Throughout the Pleistocene, the environment differed significantly from elsewhere in Africa because of the elevation at 2000 m asl, the cooler and rainy climate, the Afromontane vegetation, the development of endemic animal species, and the recurrent impact of volcanic activity. At Gombore IB, dated ~1.6 Ma, remains of Homo erectus/ergaster have been discovered, associated with a rich early Acheulean assemblage. The techno-typological analysis of the lithic record from Gombore Iγ (~1.4 Ma) and Gombore Iδ (~1.3 Ma), where substantial areas have been excavated, and the contrasting evidence from Gombore OAM Test Pit C (~1.2 Ma), suggest that the scarcity or lack of large flakes and large cutting tools at the two earlier sites is possibly not just the outcome of sampling bias, but rather of the adaptation of H. erectus/ergaster to the local resources, in a relatively isolated environment. The sites of Gombore gully provide new evidence on the complex pattern of human evolution and adaptation in East Africa during the Lower Pleistocene.
The evolution of stone tool technology at Olduvai Gorge (Tanzania): Contributions from the Olduvai Paleoanthropology and Paleoecology Project
2022, Anthropologie (France)
Citation Excerpt :
The LAS fluvial system included a network of braided channels flowing SE-NW towards the central paleo-lake and merging progressively in fewer water courses downstream. FLK West is precisely deposited in one of these downstream channels closer to the lake margin (Uribelarrea et al., 2014, 2019). The FLK West channel is ∼40 m wide and has a maximum depth of 1.2 m and it is infilled with six stratigraphic levels fining upwards (from bottom to top, L6 to L1).
Since 2006, The Olduvai Paleoanthropology and Paleoecology Project (TOPPP) is conducting intensive research in a number of classical and newly discovered sites throughout the sequence of Olduvai Gorge, in Tanzania. Over these fifteen years of intense fieldwork, efforts have mostly focused on the Oldowan and Acheulean evidence located in Bed I and Bed II, but also intended on more recent and less known resources of the archaeological record, such us those located in the Ndutu beds. In this work we present a synthetic and comprehensive view of the most significant scientific contributions produced by our team in the fields of lithic technology and paleo-economic studies, including: the remarkable enlargement of our knowledge on the technological behaviors undertaken during the Oldowan, as recorded in the various sites recently discovered within the Zinj paleosol (Bed I); the characterization of the oldest Acheulean in the Olduvai basin (and one of the earliest evidence of this techno-complex in East Africa) after the discovery by our team of the exceptional site of FLK West (Lower Bed II); new insights into the enduring debate of the techno-functional meaning of the Developed Oldowan/Acheulean interface through the re-excavation of various classical sites located in Middle and Upper Bed II, such as SHK, TK and BK, and the confirmation of the Acheulean ascription of their lithic assemblages; the discovery of a number of MSA sites, such as VCS and DGS, that confirm the significance of the MSA record in the Olduvai basin and nearby.
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Citation Excerpt :
No stratigraphic correlations with Lower/Middle Bed II tuffs were originally made (Díez-Martín et al., 2015), so others (McHenry and Stanistreet, 2018; Stanistreet et al., 2018b) placed this handaxe-rich assemblage in the Middle Augitic Sandstone (MAS), which would position this site stratigraphically above late Oldowan occurrences such as HWK EE (de la Torre et al., 2018c) and MNK Skull (this paper). This interpretation has been vigorously contested (Uribelarrea et al., 2019), who now identify one of their previously uncorrelated tuffs as the BPT, and the artefact-bearing deposits underneath as LAS. Should these correlations be correct, late Oldowan assemblages in LAS such as HWK EE (de la Torre et al., 2018c) and FLK North Sandy Conglomerate (Leakey, 1971) would be coeval with early Acheulean sites like the one at the FLK West Locality (Díez-Martín et al., 2015).
MNK Skull is one of the most significant archaeological sites in Olduvai Gorge, particularly due to the previous discovery of human fossils referred to in the paper where the Homo habilis taxon was originally defined. An important archaeological assemblage is contained in the same horizon as the hominin fossils, constituting the last evidence of both Homo habilis remains and handaxe-free tool kits in the Olduvai Gorge sequence. Our excavations at the site are the first to be conducted since the original work in the 1960s, and sought to refine the archaeological context wherein the Homo habilis remains were discovered. Chronostratigraphic results place the MNK Skull sequence in Middle Bed II prior to deposition of Tuff IIB. The assemblage was deposited near the shoreline, as Palaeolake Olduvai withdrew into the basinal depocentre, and fossils and stone tools were subjected to significant post-depositional processes. The assemblage was affected by mudflow deposits that buried and preserved the assemblage but also entrained surficial bone and lithic elements into the flow. Rather than an occupation site as originally interpreted, the assemblage is better understood as a background deposit, possibly accumulated on an unconformity surface over a long period of time. The stone tool assemblage is typical of the Oldowan, with no technological elements announcing the appearance of the Acheulean, which is well attested to across the Olduvai sequence in post-Tuff IIB times. Our results highlight that, with an approximate age of circa 1.67 Ma, MNK Skull stands as a key site to understand the late Oldowan and the disappearance of Homo habilis in East Africa.
Recent discoveries on the evolution of early human behavior at Olduvai Gorge (Tanzania)
2019, Quaternary International

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A geoarchaeological reassessment of the co-occurrence of the oldest Acheulean and Oldowan in a fluvial ecotone from lower middle Bed II (1.7ma) at Olduvai Gorge (Tanzania)

Abstract

Introduction

Section snippets

Methods

Geological framework: Lower to Middle Bed II between HWK and FLK-W, 1.7 ma

LTK section, locality 44

Stratigraphical correlation

Richard Hay's (1976) stratigraphy

Conclusions

Declaration of competing interest

Acknowledgements

J. Hum. Evol.

J. Hum. Evol.

Palaeogeogr. Palaeoclimatol. Palaeoecol.

Quat. Int.

J. Hum. Evol.

J. Archaeol. Sci.: Reports

J. Hum. Evol.

J. Hum. Evol.

J. Hum. Evol.

Palaeogeogr. Palaeoclimatol. Palaeoecol.

Testing cognitive skills in Early Pleistocene hominins: an analysis of the concepts of hierarchization and predetermination in the lithic assemblages of Type Section (Peninj, Tanzania)