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"Studies of Early Hominid Adaptation and Dispersal into North Africa:<br/>Archaeological Investigations at the Plio-Pleistocene Site of Ain Hanech, Algeria"

Final Report Summary - PALEONORTHAFRICA (Studies of Early Hominid Adaptation and Dispersal into North Africa:<br/>Archaeological Investigations at the Plio-Pleistocene Site of Ain Hanech, Algeria)

Funded by the Research Executive Agency of the European Commission (Marie Curie Integration Grant), studies on early hominid adaptation and dispersal into North Africa were undertaken at the paleontologically and archaeologically rich area of Ain Hanech in northeastern Algeria. Ain Hanech preserves the oldest archaeological occurrences in North Africa (ca. 2.3-1.8 million years ago), and consists of a sedimentary basin strata dating from the Pliocene to the Holocene with multiple fossil and artifacts bearing horizons. The studies entail comprehensive multidisciplinary research integrating stratigraphy and dating, geoarchaeology and site formation processes, paleontology, taphonomy, and archaeology. The primary objectives of this research project comprise: 1) determining accurately the timing of when early humans inhabited North Africa using paleomagnetism and Electron Spin Resonance (ESR) dating techniques as well as biochronology of large fossil mammals; 2) investigating the stratigraphic profiles of the deposits containing the Plio-Pleistocene archaeological occurrences and assessing them for site formation processes; 3) identifying new sites with potential of yielding archaeological remains and fossil hominids through extensive survey and mapping of unexplored areas; 4) reconstructing North African early hominid paleoecology and understanding the relationship between the environment and hominid behavior; 5) characterizing the lithic technology used by the hominids for subsistence acquisition and foraging strategies, as well as their overall adaptation to the environment; and 6) documenting early hominid subsistence patterns and discerning their relative role in the accumulation of the remains at the archaeological localities.
Over the duration of the project, fieldwork and laboratory analyses were carried out to achieve the outlined objectives, including: 1) survey and mapping, 2) stratigraphy and dating studies, 3) archaeological excavations, 4) reconstruction of the paleoecology, 5) taphonomic and zooarchaeological studies, and 6) lithic technology studies. The survey and mapping tasks focused on the surrounding of Ain Hanech site and the desiccated northeast part of the sedimentary basin. For effective mapping, quick data collection, and accurate plotting of archaeological finds, we used a Geographic Information System integrating satellite image data (Spot5), aerial photographs, topographic and geological maps, Laser Station and Global Positioning System (GPS), and 3D Laser Scan. The survey and mapping task allowed to document several new archaeological and paleontological localities. In addition, the use of the 3D laser technology has generated pertinent topographic data and 3D models that allowed us to map with a high precision the fossil bearing-deposits and to study effectively their topography.
The stratigraphic study consisted of describing comprehensively the profiles of four main paleolithic sites (Ain Boucherit Units P/Q and R, El-Kherba, and Ain Hanech), positioning them firmly relative to the regional stratigraphy, characterizing their sedimentary context for paleoenvironmental reconstruction, and understanding the mode of accumulation of the archaeological occurrences. In addition to the field stratigraphic description of the archeological profiles, samples were systematically collected for sedimentological and micromorphological analyses. The micromorphological analysis is particularly important for assessing the actual physical context in which the hominid activities took place, and identifying anthropogenic and biogenic effects. At the laboratory, sediment samples were impregnated with polyester resin, and 100 thin sections of 14x16 cm format were made. The thin sections are analyzed to describe and measure components, fabric and features in soils.
We carried out paleomagnetic and Electron Spin Resonance (ESR) dating studies. In terms of paleomagnetism, a 22m thick magnetostratigraphic section was sampled throughout the sedimentary sequence. The samples were analyzed at the CENIEH Archaeomagnetism Laboratory. Both normal and reversed polarities were documented allowing a solid correlation of the local magnetic polarity stratigraphy to the Global Polarity Time Scale. The successive archaeological localities at Ain Hanech are placed along the magnetostratigraphic sequence. To tighten up the dating, samples were collected for US-ESR dating of fossil teeth (two teeth) and ESR dating of optically bleached quartz grains. The natural radioactivity in the sediment was measured in situ with a portable gamma spectrometer at the exact location of the samples. The dating analysis for the ESR on quartz grains is completed and the one on teeth enamel is mostly completed including preliminary data showing no apparent Uranium leaching of the fossil teeth, which suggests that the US-ESR dating technique may reveal reliable results.
We carried out archaeological excavations at two main localities: Ain Boucherit and El-Kherba, using a Total Station for a quick data collection and an accurate documentation of the provenance of archaeological remains. At Ain Boucherit, we opened an area of 30 m2 for long term excavation. At El-Kherba we expanded the excavations started earlier to incorporate a much larger area and to recover a larger sample of lithic artifacts and fossil bones, and delineate the margins of the site. At both excavations, we recovered rich faunal and stone artifact assemblages, which are analyzed for paleoecological and behavioral inferences.
The ecology of Ain Hanech and El-Kherba sites is reconstructed based on excavated faunas and isotope studies. Fossil faunas were studied in details primarily bovids as they constitute a good ecological indicator. Then, they were compared to 1) the well-dated specimens from East Africa for chronological control, and to 2) modern analogs of the African savanna ecological system for paleoecological inferences. In order to reconstruct the paleovegetation biomass, soil samples were collected throughout El-Kherba stratigraphic profile and analyzed in the laboratory for stable carbon isotope of pedogenic carbonates.
In terms of lithic studies, besides the collection of lithic artifacts from the Ain Boucherit bearing stone tool deposit (Unit P/Q), the excavations at Ain Boucherit (R), Ain Hanech and El-Kherba yielded rich lithic assemblages. The lithic assemblages, are analyzed in terms of raw materials sources and manufacture, technological and typological patterns, and artifact use and discard.
We conducted thorough investigations of the El-Kherba excavated faunal assemblage in order to document early hominid subsistence patterns and discern their role in the accumulation of the remains at the site. We analyzed 611 fossil bone specimens using taphonomic and zooarchaeological approaches, In addition, we carried out a usewear analysis on a sample of 50 stone tools in order to determine on which food resources and material they were used.

The following results are drawn from our investigations:

1) Based on paleomagnetic and biochronological evidence, the age is estimated to 2.3-2.2 Ma for Ain Boucherit (Unit P/Q), ~2.0 Ma for Ain Boucherit (Unit R), 1.8-1.7 Ma for Ain Hanech and El-Kherba (figure 1). A maximum date of 2.2 Ma provided by ESR dating technique on bleached quartz grains enhances the paleomagnetically and biochronologically estimated age for Ain Bocherit Unit P/Q. Thus, Ain Boucherit currently represents the oldest archaeological occurrences in North Africa with evidence of stone tools and cut marks. The Ain Boucherit evidence also shows that ancestral hominins inhabited the Mediterranean fringe much earlier than previously known. In addition, like East Africa, the multiple Oldowan occupations at Ain Hanech, indicates that North Africa was inhabited by early hominids continuously during the Plio-Pleistocene.

2) Paleoecologically, the fauna indicates an increasingly open landscape, which is supported by the pedogenic carbonate data showing a change that is consistent with the documented Plio-Pleistocene continental trend of increasing aridification and grassland expansion. The paleoenvironmental change likely impacted hominid foraging activities.

3) The study of the excavated lithic assemblages reveals that they are Oldowan (figure 1) and are technologically and typologically similar (if not identical) to Plio-Pleistocene Oldowan assemblages from East Africa such as those known at Olduvai Gorges (Tanzania) and at Koobi Fora (Kenia). The Oldowan technology is characterized by a simple technology and a low degree of standardization with categories of artifacts comprising unifacial and bifacial choppers, polyhedrons, subspheroids, spheroids, whole flakes, retouched pieces, and various fragments.

4) The subsistence analysis indicates that early hominids were largely responsible for bone modification at the site. The mammalian archaeofauna preserves numerous cutmarked and hammerstone-percussed bones. In addition, evidence of usewear traces is found on several edges of the flint artifacts, indicating meat processing by early hominids. At 1.8 Ma, the cutmarked bones recovered from El-Kherba represent the earliest known evidence for ancestral hominid butchery activities and large animal foraging capabilities in northern Africa.

In sum, the results show that early hominids inhabited North Africa between 2.3 and 1.7 Ma, which is earlier than it was commonly assumed. The environment in which they lived consisted of a relatively open and arid habitat with a network of rivers and channels supporting a savanna-like fauna and flora. This kind of ecology constituted an ideal environmental setting for early hominid activities. The hominids were primarily attracted by the availability of raw materials in river beds and plenty of animal games. The Oldowan technology they used is basic but efficient enough for processing animal carcasses and meat/bone marrow acquisition. Future studies will shed light on the paleoenvironmental evolution of North African basins in the Early Pleistocene such as the Ain Hanech and Ain Boucherit research area and their relation to human occupation and expansion towards Eurasia. Actually, the recent advent of old chronologies of Paleolithic sites from southernmost Europe (levels TE9 and TD6 in Atapuerca and Barranco Leon near Orce in Spain) older than 1.0 Ma raises the likelihood of North Africa as a plausible routes for hominid expansion into Europe, a possibility that needs to be tested through future research.

In addition to contributing to the knowledge on human evolution in Algeria and North Africa, the PALEONORTHAFRICA research project has broader socioeconomic impacts, including training students and benefiting local people. In terms of training, the research project provided a strong educational component by training both post-graduate and graduate Archaeology and natural sciences students, as well as modernizing Paleolithic Archaeology in Algeria. For instance, post-graduate students are given the opportunity to study the rich fossil bone and lithic artifact assemblages yielded by Ain Hanech excavations for their doctoral dissertation including: 1) The function of the oldest stone tools by Veronica Mardones from the University of Burgos, 2) Early hominid cognitive abilities in manufacturing and manipulating stone tools by Lucia Rodriguez Gonzalez from the University of Burgos, 3) early hominid subsistence activities by Nadia Kandi from the University of Algiers. The principal investigator is also affiliated with the Institute of Archaeology of the University of Algiers, and had an average of 30 archaeology undergraduate students who attended the Ain Hanech fieldwork. They greatly benefited from learning the whole process of Paleolithic excavations and curation of archaeological remains. The Ain Hanech project has also contributed to modernize archaeological studies in Algeria by introducing the multidisciplinary character of paleolithic studies, applying new methods and excavation techniques, and exposing local archaeologists and students to contact with scientists from many parts of the world participating in the project.

The village, in which our investigations took place, has also benefited socio-economically from our research project. First, during each fieldwork we have provided modest salaries to several local people for occasional labor assistance such as digging and removing sediments near the excavation, and cooking for the excavation team. Second, we presented lectures and organized an open house for local people to visit our excavation where they had the opportunity to see closely the retrieved archaeological materials. In all these events, we emphasized the pertinence of the excavated cultural heritage for the region and for the human evolutionary studies.

In addition, research project has wider societal impacts, including gender equality, involvement of other actors, and cultural heritage awareness. In terms of gender equality, the Ain Hanech project involved in the research female scientists who played a major role in both fieldwork and laboratory analyses. For instance, Dr. Isabel Caceres has led the taphonomic and archaeozoological components of the project, and Technicians Pilar Fernandez-Colon and Elena Lacasa were responsible for the preservation and restauration of the fossil bone assemblages. There are also currently three female post-graduate students working on pertinent scientific aspects of the project for their doctoral degrees. Furthermore, numerous female Archaeology students from the University of Algiers and the University of Sétif attended fieldwork as part of their training for pursuing their Bachelor of Arts degree in Archaeology.

The researcher has also made all the effort to involve other actors for the promotion of our research and outreach such as museums. In this respect, the researcher is collaborating with the Bardo National Museum in Algeria for long-term storage of the excavated archaeological remains from Ain Hanech, as well as providing the scientific information and fossil bone and stone tool samples generated from the project for a permanent exhibit on early hominid occupation in North Africa. The inauguration of the exhibit is scheduled for May 2015. Furthermore, the researcher has helped establishing two scientific and academic cooperation agreements between the host institution (CENIEH) and two Algerian institutions, namely the Institute of Archaeology of the University of Algiers and the National Center for Prehistoric, Anthropological and Historical Research (CNRPAH). The agreements will allow CENIEH scientists to carry out research in Algeria in collaboration with their Algerian colleagues, and Algerian young scientists and post-graduate students will benefit from training in the CENIEH state of the art scientific facilities.