Laboratory researches on lithic and faunal remains from Gotera

TERRAIN/FIELDWORK

The Horn of Africa during the MIS 3 (59-29 ka)

Gotera Archaeological Site, Southern Ethiopia

Laboratory researches on lithic and faunal remains

By Marianna Fusco and Caterina Aureli

Marianna Fusco, PhD candidate & Caterina Aureli, MA student – Department of Ancient World Studies, ‘La Sapienza’ University of Rome – have been laureates of the CFEE 2021 Grants. The five weeks of laboratory researches carried out by Marianna Fusco on the lithic material and by Caterina Aureli on the faunal remains are part of the wider project entitled “(H)Origin: the East African record and the origin of modern human behaviour” directed by Prof. Enza Elena Spinapolice – ‘La Sapienza’ University of Rome.

 

The Gotera archaeological area lies in the Sagan river basin. It is located 50 km East of Chew Bahir lake, not far from Konso, in SNNPR Region (fig. 1). This area is rich in Pleistocene evidence referable to the MSA, probably suggesting continuity in the occupation dynamics of the area during the Upper Pleistocene (Chavaillon & Chavaillon, 1985).

Fig. 1. Map showing the localisation of Got10 archaeological site © Google map

Gotera is an open-air complex located in a depression in an environment of modern savannah. The area contains several human occupations evidence and is part of a low energy paleo-sedimentary basin, between the Omo-Turkana basin to the West and the southern sector of the Main Ethiopian Rift to the East.

During the (H)ORIGIN project field activities, concentrations of MSA archaeological material were identified. Furthermore, the identification of a new area indicated as GOT10 – with a stratigraphic deposit rich in artefacts and faunas in primary training levels referable to MIS 3 – represents a fundamental advance for the reconstruction of the occupation dynamics of the area (fig. 2).

Fig. 2. View of Got10 Site during 2018 excavation

The general aim of these material studies is the analysis of occupation dynamics, resource exploitation, adaptation to climate change, and interactions between Homo sapiens populations during the Late Middle Stone Age (LMSA), more precisely during Marine Isotope Stage – MIS 3 (59-29 ka). This period is characterised by climatic oscillations associated with technological changes within the archaeological records, whose mode and tempo are still to be clarified. Therefore, the research aims at understanding the dynamics underlying these changes from a regional perspective.

 

LITHIC – Research Objectives and Methodology

The sites in the Horn of Africa dated to MIS 3 are limited (Leplongeon et al. 2020). Some of them are characterised by the gradual appearance of technological traits typical of the Later Stone Age (LSA), such as backed pieces, blades, bladelets, and microliths (Leplongeon, 2014). Moreover, the increasing use of ochre and ornamental objects is attested. Furthermore, the decrease of MSA technological traits such as prepared cores, Levallois method, retouched points are other relevant evidence (Grove & Blinkhorn, 2020; McBrearty & Brooks, 2000; Tryon & Faith, 2013). The huge bio-geographical variability of the continent and the development of general theoretical models about the MSA/LSA transition make complicated the understanding of this phenomenon. Therefore, we need to focus on these dynamics at the regional level (Tryon, 2019). Given that, the main goal of the lithic material study is to analyse archaeological contexts dated to MIS 3 in order to integrate the Horn of Africa into the broader debate about causes and modalities of the MSA/LSA transition. The research thus will be developed on a local and regional scale.

1: A complete analysis of Gotera area material collected during survey and excavation activities, through the study of technological variability of lithic industries to better identify the mode and tempo of technological changes in lithic assemblages (Fusco et al. accepted; Spinapolice et al. 2017).

2: A comparative analysis of sites located in the Horn of Africa and dated to MIS 3. The aim is to identify the presence/absence and frequency of technological trends and their diffusion in time and space, to understand the nature of these changes (Leplongeon et al. 2017).

The methodology is based on the observation and definition of visible technological processes through the analysis of lithic assemblage. The archaeological record is analysed as a sequence of technical actions and stone manipulation strategies, in a techno-economic process that goes from the raw material procurement to the flake and tool production, up to the abandonment of the blank/core. The analysis of the unpublished material from the GOT10 site includes the registration of morpho-technological attributes, which flow into a single database. The attributes collected will be used as a set of quantitative and qualitative variables to fit into multivariate statistical analysis that will allow extracting models of similarities and differences within the assemblages. The further analysis involves comparing the GOT10 assemblages with the surface materials previously collected, with the material during the Chavaillon old excavations from the 1970s, and with those of other archaeological contexts located in the Horn and dated to the MIS 3. Through multivariate statistical analyses, we expect to test the relationship between lithic industries and, in general, the different site functions and the hypothesis of the presence of structured populations, their diffusion and/or interaction between them.

The five weeks laboratory study has been organised as follow:

  • Preliminary organisation of the lithic implements collected during the excavation activities at GOT10 with priority given to the lithic implements recorded within the stratigraphic sequence of the Mound 1, then to the surface collection of the whole GOT10 area, and finally with the Scatter n°3 of the 2018 excavation.
  • The formalisation and fulfilment of the E4 data entry software used to collect all the metric and technological attributes of each. E4 is a flexible data entry program designed to make data entry faster and reduce errors.
  • A first photographic survey of the assemblages has been done, using a NIKON D5100.

Fig. 3. Detail of photo acquisition and alignment using Agisoft Metashape.

The registration of the lithic attributes has been made, together with the analysis of the artefacts and the photographic survey. Furthermore, a sample of lithic objects has been acquired through the photogrammetry technique in order to be processed through Agisoft Metashape in the next future (fig. 3).

 

 

 

FAUNA – Research Objectives and Methodology

The study of the faunal remains from the GOT10 site collected during the previous stratigraphic excavation campaigns aims of highlighting the presence/absence of species in time and space and reconstructing the paleoenvironment of the area during the MIS 3. This information will contribute to reconstructing the environment of the area in which Homo sapiens moved. Moreover, it will help to clarify the configuration of GOT10 site within the mosaic environment that characterised Ethiopia and the Horn. Finally, it will shed light on the human-environment relationship at the site during the MIS 3.

The study of the faunal remains proposed is carried out through the classical zooarchaeological method, based on the use of comparative collection stored at the Authority for Research and Conservation of Cultural Heritage (ARCCH), with the supervision of the palaeontology curator Sahale Melaku and supplemented by the use of manuals, atlases, and microscope.

The bone and dental remains from the stratigraphic excavation of the GOT10 site flowed entirely into a complete and searchable new Excel database, valid for the taphonomic study of the remains.  The database was created to recognise post-mortem processes. These processes highlight the faunal assemblage history from both behavioural and ecological perspectives and contribute to elucidating the subsistence strategies and settlement systems of the human groups during MIS 3 in East Africa.

Fig. 4. Study session at ARCCH Lab

The first step of the documentation process involved the classification of each faunal element into two broad categories of “identifiable elements” (for element and/or size class) and “non-identifiable elements”. Then they were examined for fracture patterns, weathering, and human, natural, or animal traces. The data collected for the fragmentation and fracture study included measurements of length, width, the occurrence of fresh fracture, and the maximum circumference for each long-bone fragment. All non-identifiable bones were assigned to one subcategory (e.g., long-bone fragment, non-identifiable fragment, long-bone fragment, and cranial fragment). All the fragments that can be identified as skeletal elements have been subjected to more thorough documentation. In addition to taxon and size class, other variables, such as side and state of fusion, have been recorded for each fragment. The documentation of this group of fragments has adopted a more comprehensive strategy of recording recognisable elements and marks to incorporate as many bone fragments as possible into the skeletal-element profile. All bone fragments have been subjected to detailed examination for surface-modification marks with the use of a microscope (fig. 4).

The five weeks laboratory study has been organised as follow:

  • In-depth observation activity was performed to verify the surface state of materials and the organisation of the zooarchaeological material from the GOT10 excavation within new bags and new labels.
  • Creation of an Excel database to register all the data.
  • Recording the faunal attributes, among which a sample of indeterminable bone fragments was isolated to be processed in order to perform the zooarchaeology by mass spectrometry (ZooMS) analysis.
  • Photographic survey of the material from the stratigraphic sequence of GOT10 (Mound 1) and study using a digital microscope.

 

PRELIMINARY RESULTS AND FINAL REMARKS

The analysis of lithic assemblage from the GOT10 site is still ongoing, and further research stays at ARCCH will be necessary to complete the study of lithics from scatters and clusters.

The preliminary results of this lithic analysis confirmed the exploitation of the local raw materials, quartz and basalt (Fusco et al. accepted). The MSA nature of the assemblage is confirmed by the presence of the Levallois and discoid technology, both on quartz and basalt. Moreover, the high variability of the assemblage is attested, confirmed by the association of Levallois and discoid technology with the presence of the laminar reduction system, as shows the presence of several blades and bladelets both on quartz and basalt. Furthermore, among the quartz assemblage, is strongly attested the presence of the bipolar technology.

In the current debate about the tempo and mode of the MSA/LSA transition in East Africa, the analysis of the archaeological record from the Horn of Africa has relevant importance. Considering the possible presence of structured populations, it is necessary to understand their movements within the continent and the related behavioural implications that such phenomenon generated. Thanks to the presence of an in situ stratigraphy and the abundance of the archaeological record, it will be possible to conduct a detailed study of the Gotera area to measure and test the technological variability of the lithic industries as a proxy to define changes within human groups in time and space. Furthermore, through a comparative analysis at the regional scale, it will be possible to highlight technological trends to test the occurrence of cultural transmission phenomenon between populations or an independent emergency, as convergent evolution.

The analysis of fauna remains from the Gotera area is of fundamental importance for expanding the knowledge about paleoenvironmental data, which can certainly contribute to the understanding of severe climate crisis periods, specifically MIS 3 in East Africa.

The faunal material from the stratigraphic sequence of GOT10 (Mound 1) analysed in this study season showed a high fragmentation, with a good percentage of fragments less than one centimetre in maximum length. Many teeth have been found and analysed, especially from various species’ herbivores. Traces of human modification, especially traces of burns in association with fireplaces, are present in the faunal record but are yet to be clarified. Moreover, much faunal material remains to be organised, studied, and processed. An in-depth analysis of the whole faunal remains will clarify these preliminary results.

 

 

References

Chavaillon N. & Chavaillon J., 1985. Gotera, un site paléolithique récent d’Éthiopie. Paris, Éditions Recherche sur les Civilisations, Mémoire 59.

Fusco, M., Carletti, E., Zerboni, A., Gallinaro, M. and Spinapolice, E.E. accepted. “Lithic Variability and Raw Material Exploitation at the Middle Stone Age (MSA) site of Gotera, Southern Ethiopia: a combined technological and quantitative approach”. Journal of Lithic Studies.

Grove, M., & Blinkhorn, J. 2020. “Neural networks differentiate between Middle and Later Stone Age lithic assemblages in eastern Africa”. PloS one15(8): e0237528.

Leplongeon, A. 2014. “Microliths in the Middle and Later Stone Age of eastern Africa: new data from Porc-Épic and Goda Buticha cave sites, Ethiopia”. Quaternary International343: 100-116.

Leplongeon, A., Ménard, C., Douze, K., Habte, B., Bon, F. & Pleurdeau, D. 2020. “The Horn of Africa at the end of the Pleistocene (75-12 ka) in its macroregional context”. In: Not Just A Corridor. Human Occupation of the Nile Valley and Neighbouring Regions between 75,000 and 15,000 years ago. Natures en Sociétés 3, Muséum national d’Histoire naturelle, Paris.

Leplongeon, A., Pleurdeau, D., & Hovers, E. 2017. “Late Pleistocene and Holocene lithic variability at Goda Buticha (southeastern Ethiopia): Implications for the understanding of the Middle and Late stone age of the horn of Africa”. Journal of African Archaeology15(2) : 202-233.

McBrearty, S., Brooks, A.S., 2000. “The revolution that wasn’t: a new interpretation of the origin of modern human behaviour”. Journal of Human Evolution, 39: 453-563.

Spinapolice, E.E., Gallinaro, M. and Zerboni, A., 2017. “New investigations in Southern Ethiopia (Yabelo and Gotera): Pleistocene and Holocene archaeological evidence”, Scienze dell’Antichità, 23: 37-47.

Tryon, C.A. 2019. The Middle/Later Stone Age transition and cultural dynamics of late Pleistocene East Africa. Evolutionary Anthropology: Issues, News, and Reviews28(5), 267-282.

Tryon, C.A. & Faith, J.T., 2013. “Variability in the Middle Stone Age of Eastern Africa”. Current Anthropology, 54: 234-254.

 

 

 

 


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