Elsevier

Quaternary International

Volume 526, 20 August 2019, Pages 4-14
Quaternary International

Constraining time and ecology on the Zinj paleolandscape: Microwear and mesowear analyses of the archaeofaunal remains of FLK Zinj and DS (Bed I), compared to FLK North (Bed I) and BK (Bed II) at Olduvai Gorge (Tanzania)

https://doi.org/10.1016/j.quaint.2019.05.041Get rights and content

Abstract

Defining the time that any given archaeofaunal assemblage took to be accumulated is challenging. Understanding the time variable is crucial to interpret how early sites were formed and what these sites represent in terms of hominin behavior. Two complementary dental analysis techniques (microwear and mesowear) have been used to understand dietary niches of ungulates. Microwear has also specifically been used to detect the character of occupations at archaeological sites. Here, we apply these techniques to a selection of Olduvai sites. Microwear and mesowear analyses on bovid teeth from a set of anthropogenic sites (FLK Zinj, DS, BK) and a carnivore palimpsest (FLK North) yielded different results. Microwear data from the three anthropogenic sites are similar, reflecting short, seasonal occupations, in contrast with the carnivore assemblage, which suggests a more prolonged period of deposition. The similar microwear signal in the two pene-contemporaneous sites of FLK Zinj and DS is encouraging, but caution in its interpretation is applied because of limited tooth enamel preservation and the resulting small sample size. The results shown here must be considered as a baseline for future and more extensive studies. Both microwear and mesowear analyses show that the most common bovid taxa in the Bed I sites exhibit mixed feeding signals. This reinforces the caution about interpretations of dietary niches of extinct ungulates based on their modern counterparts and emphasizes that for some taxa, the adoption of a browsing or grazing diet is context (time and locus) specific.

Introduction

Although interpreting agency at the earliest archaeological sites has been controversial for several decades, understanding the timing and duration of specifically anthropogenic depositional processes at these sites has been even more challenging (Domínguez-Rodrigo et al., 2007). Regardless of which side of the hunting-scavenging debate one favors, current evidence suggests that a) hominin input was marginal in the accumulation of faunas at some sites, b) anthropogenic accumulations, in contrast, exist at other sites and, c) in the latter case, all or most of the fauna accumulated was transported by hominins targeting bulk defleshing and long bone marrow exploitation of small and medium-sized carcasses (Domínguez-Rodrigo and Barba, 2007; Domínguez-Rodrigo et al., 2007; Pobiner et al., 2008; Ferraro et al., 2013; Parkinson, 2013, 2018; Domínguez-Rodrigo, 2015; Domínguez-Rodrigo and Pickering, 2017). These anthropogenic loci remain the source of speculation regarding how much occupation time they represent and the type of depositional processes (single continuous or multiple discontinuous) that created them. Potts (1988) initially suggested that the extensively weathered assemblages from Olduvai Bed I sites indicated that deposition occurred intermittently over a time span involving many years. Domínguez-Rodrigo et al. (2007), in contrast, argued that bone weathering at these sites was mostly chemical and not subaerial, representing diagenetic modifications that were unrelated to depositional time spans. Most bones at the anthropogenic site of FLK Zinj unaffected by chemical weathering show no traces of subaerial weathering, indicating a relatively fast accumulation over one or two years (Bunn et al., 1986; Binford et al., 1988; Domínguez-Rodrigo et al., 2007).

Olduvai Gorge has played a prominent role in all these debates since it contains the best-preserved anthropogenic sites for the early Pleistocene. Some of these are vertically discrete concentrations of stone artifacts and fossil bones from a diversity of animals, where time-averaging can be better understood than in vertically-dispersed archaeological deposits. A thin (<20 cm) clay stratum situated under Tuff IC in Bed I contains a diverse set of pene-contemporaneous archaeological and paleontological sites over the same paleolandscape surface: FLK NN, FLK Zinj, AMK, PTK, DS and AGS (Uribelarrea et al., 2014; Aramendi et al., 2017; Domínguez-Rodrigo and Cobo-Sánchez, 2017; Domínguez-Rodrigo et al., 2017). This is a unique opportunity for understanding Oldowan hominin behavioral variability over a diverse set of habitats situated in lacustrine-alluvial ecotones.

FLK Zinj (Bed I, Olduvai Gorge, Tanzania) is famous for being the most widely debated early Pleistocene anthropogenic site. It is the second largest window onto an early Pleistocene paleo-surface occupied by hominins after DS (David's Site), which is situated on the same 1.84 Ma paleolandscape (Domínguez-Rodrigo et al., 2017). PTK (Philip Tobias Korongo) is also situated in the same paleosurface as FLK Zinj and DS (Fig. 1). At no other early Pleistocene site is there as much taphonomic evidence as at FLK Zinj and DS (work in progress) that the bulk of the faunal accumulation was carried out by hominins (see summary in Domínguez-Rodrigo, 2015; Domínguez-Rodrigo and Pickering, 2017). Interestingly, the amounts of bones and macrommamal animals unearthed at FLK Zinj and DS are more abundant than those documented in many modern hunter-gathererścamps (Bunn, 1983a, Bunn, 1983b; Bunn et al., 1988; Bartram et al., 1991; Lupo, 2001). This could imply more prolonged time span(s) of occupation at these sites and/or bigger group sizes. Recent modeling of the spatial dispersal of food refuse at FLK Zinj and the amount of animal food represented by the animal parts excavated at the site suggest -using ethnoarchaeological referential frameworks-that the amount of time represented by the assemblage may have been large and so may the number of potential hominins who occupied that space (Domínguez-Rodrigo et al., 2019). An estimate of a minimum of four months and between 16 and 28 individuals was produced using Yellen (1977) data on Kalahari foraging camps and updated regression formulas (Domínguez-Rodrigo et al., 2019). The time estimate was conservative, since it was based on just the preserved amount of food and not the carcass parts potentially deleted by post-depositional agents. This could imply an even longer length of occupation by hominins at the site. This would also indicate that occupations at FLK Zinj were either few and prolonged or short and multiple over a short time scale, as suggested by the taphonomic preservation of bone surfaces.

The application of the same regression formulas to the spatial analysis of PTK yielded similar estimates of occupants (average = 13; maximum = 20) and length of occupation ranging between one and five months (Cobo-Sánchez et al., 2018). Data from both sites suggest that group sizes were bigger than traditionally assumed for Oldowan hominins and that the occupation of the sites was not ephemeral. This similarity between both sites for the two types of estimates can also be applied to the similar spatial configuration of both assemblages, indicating a common behavioral pattern (Domínguez-Rodrigo and Cobo-Sánchez, 2017)

The Olduvai sites have been used to model seasonal foraging by hominins within lacustrine habitats, mostly during the dry season (Peters and Blumenschine, 1995; Blumenschine and Peters, 1998). If hominins were behaving as these models suggest, it would be expected that the occupation of sites by the paleo-lake would have been seasonal (i.e., short and possibly redundant). In contrast, if hominins were exploiting resources on the lacustrine basin all year round, it would be expected that the occupation of the Bed I sites would have been more prolonged and multi-seasonal. Evidence against the formation of FLK Zinj and DS1 during the dry season could be inferred from the taxonomic composition of both faunal assemblages, dominated by Kobus, Parmularius and Antidorcas, all of them potentially classifiable as local fauna. The virtual lack or underrepresentation of migratory taxa (i.e., wildebeest) argues against an intensive occupation during the dry season, unless these taxa were already migrating like they do today in the Serengeti, returning to the region during the short wet season.

Tooth enamel microwear analyses have been used to interpret diets from fossil ungulates (Solounias and Semprebon, 2002; Rivals and Deniaux, 2003; Rivals et al., 2007b; Solounias et al., 2010, 2013; Rivals and Semprebon, 2011; Uno et al., 2018). This technique has also been used to study seasonality and types of occupations by hominins during site formation (Rivals and Deniaux, 2005; Rivals et al., 2009, 2015a; 2015b; Sánchez-Hernández et al., 2014; Rodríguez-Hidalgo et al., 2016). A substantial amount of microwear research has been done via two-dimensional imaging under high or low magnification and identification and quantification of relevant enamel alteration features (namely, pits and scratches). This has been considered by some to involve a high degree of subjectivity (Scott et al., 2006). An alternative 3D method called microwear texture analysis (MTA) has been built with the intention of not involving any subjective assessment of enamel alteration features and has been applied in order to identify the diets of a wide array of faunal taxa (Scott et al., 2005; Ungar et al., 2007; Scott, 2012; Merceron et al., 2014; Williams, 2014; Souron et al., 2015; Calandra and Merceron, 2016; Ragni et al., 2017). However, the focus of MTA has been mostly on diet breadth and dietary niche reconstruction rather than on seasonality and length of occupation at anthropogenic sites. Importantly, microwear texture analyses have been applied to the artiodactyl faunas of some of the Olduvai Bed I sites, with results suggesting a prolonged year-round deposition of faunal materials at these sites (Gurtov, 2016).

Constraining the temporal framework during which site formation took place is of utmost relevance to interpret what these early Oldowan sites represent in terms of the behavior of those early humans. Rivals et al., 2015a, Rivals et al., 2015b, using alternative methods of microwear scoring and quantification of feature variability, elaborated a type of microwear analysis aimed at determining the duration of faunal depositional events in archaeological assemblages. We believe this approach is currently more adequate for assessing time and number of occupations in any given archaeofaunal assemblage than available techniques of MTA, since it has successfully been tested for this purpose with controlled samples.2 This is why we will adopt this technique here for testing alternative scenarios of site formation (single or multiple occupations involving short or prolonged time spans) in the anthropogenic sites of the Zinj paleolandscape; namely at FLK Zinj and DS. Although not pertaining to the Zinj paleolandscape, comparisons will also be made with fauna from the FLK N faunal assemblage (Upper Bed I), mostly created by carnivores (Domínguez-Rodrigo et al., 2007), to contrast hominin and non-hominin agency in site formation and use. Comparisons will be also extended to BK5, which corresponds to Leakey's (1971) excavation of this upper Bed II site where a “herd” of 24 Pelorovis was found. This large bovid assemblage was recently interpreted as a time-averaged deposit, therefore purportedly spanning carcass deposition at different intervals during a long time span (Organista et al., 2016).

A second target in the present work is to present new dietary inferences for the taxa most widely represented in these Bed I assemblages: Antidorcas recki, Kobus sigmoidalis, and Parmularius altidens. Additional taxa from Bed I (e.g., Connochaetes) and Bed II (Pelorovis)oldowayensis were also included for comparative reasons. For this purpose, we will combine microwear and mesowear techniques. Microwear analysis uses the proportion of abrasive features (i.e., pits and scratches) to differentiate between grazing, browsing, and mixed diets on short-term temporal frameworks (Grine, 1986; Solounias and Moelleken, 1992; Solounias and Hayek, 1993; Solounias and Semprebon, 2002; Rivals and Deniaux, 2003; Rivals et al., 2007b; Solounias et al., 2010, 2013; Rivals and Semprebon, 2011; Uno et al., 2018). Mesowear analysis focuses on the attritional and abrasive wear of teeth, which is reflected on the particular topography of their occlusal surfaces (Kaiser and Solounias, 2003; Fortelius and Solounias, 2000; Franz-Odendaal and Kaiser, 2003; Clauss et al., 2007; Louys et al., 2011; Kaiser et al., 2013). The springbok (Antidorcas marsupialis) is the closest living relative of the prehistoric Antidorcas recki. Antidorcas marsupialis is mainly a browser, feeding on leaves, shrubs, and succulents. It lives in dry areas occupying grasslands, bushlands, and shrublands. Modern waterbucks (i.e.,Kobus ellipsiprymnus) are the closest modern phenetic relatives to Olduvai's Kobus sigmoidalis. Kobus ellipsiprymnus is highly dependent on water and leaves in riverine and lacustrine settings, although it feeds mainly on grasses. Parmularius altidens is an extinct Pleistocene alcelaphini genus/species, which has been compared to modern topi (Damaliscus), hartebeest (Alcelaphus), and hirola (Beatragus hunteri). These three alcelaphines are mainly grazers adapted to open habitats, but they resort to browsing substantially during the dry season. Here, we will test if these fossil taxa fed like their modern counterparts and were adapted differently to the savannah biome. This has important repercussions for our understanding of the environments where hominins lived at Olduvai Gorge and also for the timing of interaction between hominins and these ungulates.

Section snippets

Microwear analysis and type of site occupation

Standard analytical approaches to the study of tooth enamel microwear were initially based on the use of only the upper and/or lower second molar for quantifying microwear features (Solounias and Moelleken, 1992, Solounias and Semprebon, 2002; Rivals and Deniaux, 2003; Semprebon et al., 2004b; Rivals and Semprebon, 2011; Rivals, 2012; Sánchez-Hernández et al., 2014). Subsequently, it has also been applied to other molars (e.g., Rivals and Deniaux, 2005; Rivals et al., 2009, 2015a; 2015b;

Microwear analysis and duration of site occupation

Data on the microwear features of the selected Olduvai sample are shown in Table 1. The FLK Zinj Antidorcas microwear scratch pattern with high CV and SD occurs within the error zone of Area C, suggesting a probable redundant deposition in different times of the year. The FLK Zinj Kobus sample falls within the error zone of area A, indicating a potential (but insecure) single depositional moment, spanning no more than one season. Alternatively, it could represent several visits at the same time

Microwear analysis and type of site occupation

MTA studies have had very limited success in determining season of death and even differentiating generalist diets from mixed diets among ungulates (Scott, 2012). MTA also has not built a proper referential analogical framework to interpret length of occupation and seasonality efficiently. For this reason, Gurtov (2016) argued that such an analogical framework was necessary and she elaborated one using impala (Aepyceros melampus) from Lake Eyasi (Tanzania) as a proxy to assess potential

Conclusions

Hominins responsible for the anthropogenic sites of FLK Zinj and DS were not determined by vegetation in their selection of loci to process animal carcasses and make stone artifacts in the lacustrine ecosystem. Most of the fauna that they exploited was local and probably underwent very little transportation. This is supported by an analysis of skeletal abundances of elements most likely to resist attritional processes (i.e., high-survival skeletal set) (Marean and Cleghorn, 2003; Cleghorn and

Conflict of interest

Authors have no conflict of interest.

Acknowledgements

This work was carried out with support from a Research Salvador Madariaga grant to MDR (Ministry of Education, Culture and Sport, Spain. Ref PRX16/00010). 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

References (110)

  • J.T. Faith et al.

    Long-distance carcass transport at Olduvai Gorge? A quantitative examination of Bed I skeletal element abundances

    J. Hum. Evol.

    (2009)
  • A.O. Gidna et al.

    An ecological neo-taphonomic study of carcass consumption by lions in Tarangire National Park (Tanzania) and its relevance for human evolutionary biology

    Quat. Int.

    (2014)
  • F.E. Grine

    Dental evidence for dietary differences in Australopithecus and Paranthropus: a quantitative analysis of permanent molar microwear

    J. Hum. Evol.

    (1986)
  • L.F. Loffredo et al.

    Cautionary lessons from assessing dental mesowear observer variability and integrating paleoecological proxies of an extreme generalist Cormohipparion emsliei

    Palaeogeogr. Palaeoclimatol. Palaeoecol.

    (2014)
  • J. Louys et al.

    Mesowear as a means of determining diets in African antelopes

    J. Archaeol. Sci.

    (2011)
  • K.D. Lupo

    Archaeological skeletal part profiles and differential transport: an ethnoarchaeological example from Hadza bone assemblages

    J. Anthropol. Archaeol.

    (2001)
  • G. Merceron et al.

    3D dental microwear texture analysis of feeding habits of sympatric ruminants in the Białowieża Primeval Forest, Poland

    For. Ecol. Manag.

    (2014)
  • E. Organista et al.

    Biotic and abiotic processes affecting the formation of BK Level 4c (Bed II, Olduvai Gorge) and their bearing on hominin behavior at the site

    Palaeogeogr. Palaeoclimatol. Palaeoecol

    (2017)
  • M.C. Pante et al.

    A new high-resolution 3-D quantitative method for identifying bone surface modifications with implications for the Early Stone Age archaeological record

    J. Hum. Evol.

    (2017)
  • J.A. Parkinson

    Revisiting the hunting-versus-scavenging debate at FLK Zinj: a GIS spatial analysis of bone surface modifications produced by hominins and carnivores in the FLK 22 assemblage, Olduvai Gorge, Tanzania

    Palaeogeogr. Palaeoclimatol. Palaeoecol.

    (2018)
  • J.A. Parkinson et al.

    Characterizing felid tooth marking and gross bone damage patterns using GIS image analysis: an experimental feeding study with large felids

    J. Hum. Evol.

    (2015)
  • C.R. Peters et al.

    Landscape perspectives on possible land use patterns for Early Pleistocene hominids in the Olduvai Basin, Tanzania

    J. Hum. Evol.

    (1995)
  • T.W. Plummer et al.

    Hominid paleoecology at Olduvai Gorge, Tanzania as indicated by antelope remains

    J. Hum. Evol.

    (1994)
  • B.L. Pobiner et al.

    New evidence for hominin carcass processing strategies at 1.5 Ma, Koobi Fora, Kenya

    J. Hum. Evol.

    (2008)
  • F. Rivals

    Ungulate feeding ecology and middle Pleistocene paleoenvironments at Hundsheim and Deutsch-Altenburg 1 (eastern Austria)

    Palaeogeogr. Palaeoclimatol. Palaeoecol.

    (2012)
  • F. Rivals et al.

    Dental microwear analysis for investigating the diet of an argali population (Ovis ammon antiqua) of mid-Pleistocene age, Caune de l'Arago cave, eastern Pyrenees, France

    Palaeogeogr. Palaeoclimatol. Palaeoecol.

    (2003)
  • F. Rivals et al.

    Investigation of human hunting seasonality through dental microwear analysis of two Caprinae in late Pleistocene localities in Southern France

    J. Archaeol. Sci.

    (2005)
  • F. Rivals et al.

    Investigation of equid paleodiet from Schöningen 13 II-4 through dental wear and isotopic analyses: archaeological implications

    J. Hum. Evol.

    (2015)
  • F. Rivals et al.

    A new application of dental wear analyses: estimation of duration of hominid occupations in archaeological localities

    J. Hum. Evol.

    (2009)
  • F. Rivals et al.

    Dietary plasticity in ungulates: insight from tooth microwear analysis

    Quat. Int.

    (2011)
  • F. Rivals et al.

    Evidence for geographic variation in the diets of late Pleistocene and early Holocene Bison in North America, and differences from the diets of recent Bison

    Quat. Res.

    (2007)
  • F. Rivals et al.

    Dietary traits of the ungulates from the HWK EE site at Olduvai Gorge (Tanzania): diachronic changes and seasonality

    J. Hum. Evol.

    (2018)
  • A. Rodríguez-Hidalgo et al.

    Season of bison mortality in TD10.2 bone bed at Gran Dolina site (Atapuerca): integrating tooth eruption, wear, and microwear methods

    J. Archaeol. Sci.: Report

    (2016)
  • C. Sánchez-Hernández et al.

    Short, but repeated Neanderthal visits to Teixoneres Cave (MIS 3, Barcelona, Spain): a combined analysis of tooth microwear patterns and seasonality

    J. Archaeol. Sci.

    (2014)
  • R.S. Scott et al.

    Dental microwear texture analysis: technical considerations

    J. Hum. Evol.

    (2006)
  • G.M. Semprebon et al.

    Can low-magnification stereomicroscopy reveal diet?

    J. Hum. Evol.

    (2004)
  • N. Solounias et al.

    Dietary adaptations of two goat ancestors and evolutionary considerations

    Geobios

    (1992)
  • L.E. Bartram et al.

    Variability in camp structure and bone food refuse patterning at kua san hunter-gatherer camps

  • L.R. Binford et al.

    Fact and fiction about the Zinjanthropus floor: data, arguments, and interpretations

    Curr. Anthropol.

    (1988)
  • L.C. Bishop et al.

    Palaeoecology of Kolpochoerus heseloni (= K. limnetes): a multiproxy approach

    Trans. Roy. Soc. S. Afr.

    (2006)
  • R.J. Blumenschine

    Early Hominid Scavaging Opportunities. Implications of Carcass Availability in the Serengeti and Ngorongoro Ecosystems

    (1986)
  • R.J. Blumenschine et al.

    Archaeological predictions for hominid land use in the paleo-Olduvai Basin, Tanzania, during lowermost Bed II times

    J. Hum. Evol.

    (1998)
  • R.J. Blumenschine et al.

    Late Pliocene homo and hominid land use from western Olduvai Gorge, Tanzania

    Science

    (2003)
  • H.T. Bunn

    Comparative analysis of modern bone assemblages from a San hunter-gatherer camp in the Kalahari Desert, Botsuwana, and from a spotted hyena den near Nairobi, Kenya. Animal and Archaeology, 1. Hunters and Their Prey

    BAR Int. Ser.

    (1983)
  • H.T. Bunn

    Comparative analysis of modern bone assemblages from a San hunter-gatherer camp in the Kalahari Desert, Botswana, and from a spotted hyena den near Nairobi, Kenya

    Anim. Archaeol.

    (1983)
  • H.T. Bunn et al.

    Systematic butchery by Plio/Pleistocene hominids at Olduvai Gorge, Tanzania [and comments and reply]

    Curr. Anthropol.

    (1986)
  • I. Calandra et al.

    Dental microwear texture analysis in mammalian ecology

    Mamm Rev.

    (2016)
  • E. Camarós et al.

    Make it clear: molds, transparent casts and lightning techniques for stereomicroscopic analysis of taphonomic modifications on bone surfaces

    J. Anthropol. Sci.

    (2016)
  • M. Clauss et al.

    Tooth wear in captive giraffes (Giraffa camelopardalis): mesowear analysis classifies free-ranging specimens as browsers but captive ones as grazers

    J. Zoo Wildl. Med.

    (2007)
  • N.E. Cleghorn et al.

    Distinguishing selective transport and in situ attrition : a critical review of analytical approaches

    J. Taphonomy

    (2004)
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