The Reconstruction of the Late Pleistocene and Holocene Vegetation Dynamics in Lake Eyasi Basin, Northern Tanzania

Lake Eyasi Basin of northern Tanzania plays a pivotal role in the study of human-environment interactions and in understanding human flexibility and adaptability through technological innovations over time and space. In this study, phytoliths from ancient soils and fossil pollen proxies from radiocarbon-dated sequences from Kisimangeda on the north-eastern edge of the Lake Eyasi Basin, are used to interpret trends in climatic changes recorded since the Last Glacial Maximum (LGM) to the present. We used pollen and phytolith abundances from a core that was recovered on the northern margin of saline Lake Eyasi at the depth of five metres. The application of principal component and cluster analysis, together with linear regression provides insight into dataset structure and grouping with reference to the modern comparative datasets that in turn allow us to classify the various palaeoenvironments and paleohabitats occupied by the late Later Stone Age, Pastoral Neolithic, and Iron Age inhabitants of Kisimangeda. The chronological order, pollen and phytolith records in the studied part of the basin signify palaeoenvironments analogous to the Somalia-Maasai bushland and grassland ecosystems of today. Keywords:  Palaeoenvironments; Late Pleistocene; Holocene; pollen; phytoliths; human adaptatio

Mollusc Shells from Neolithic Contexts in the Lake Eyasi Basin, Northern Tanzania

The study of the Neolithic period in the Lake Eyasi Basin was dominated by attempts to formulate the area’s chronology, mobility, settlement patterns, subsistence, and cultural capabilities of Neolithic people as attested by domesticated animals, pottery, and lithic artefacts. Occasionally, studies on molluscs were mentioned, but rarely described in detail. Neolithic sites across the Lake Eyasi Basin have yielded remains of both terrestrial (gastropods) and freshwater mollusc shells (mussels). The abundance of mollusc shell remains in the archaeological records of the Lake Eyasi Basin have played a great role in chronological settings, mobility and community integrations, studies of settlement patterns, and other analyses. Mollusc remains have often been widely interpreted as a food supplement to other reliable food resources such as meat, vegetables and fish. Archaeological excavations and detailed analysis of the shells from Mumba rock shelter, Jangwani 3 and Laghangasimjega 2 have shown that molluscs played different roles. They were effectively used in tool manufacturing, as practical implements for handling objects, as scraping tools, as harpoons for fishing weapons, and sometimes for symbolism and in rituals. Terrestrial and freshwater molluscs coexisted in the Lake Eyasi Basin and were utilised equally by the Neolithic people during the Mid-Holocene period. Keywords: Mollusc shells; Neolithic; Lake Eyasi Basin; Northern Tanzani

Middle Stone Age human teeth from Magubike rockshelter, Iringa Region, Tanzania

<div><p>In 2006, six isolated hominin teeth were excavated from Middle Stone Age (MSA) deposits at the Magubike rockshelter in southern Tanzania. They comprise two central incisors, one lateral incisor, one canine, one third premolar, and one fourth premolar. All are fully developed and come from the maxilla. None of the teeth are duplicated, so they may represent a single individual. While there is some evidence of post-depositional alteration, the morphology of these teeth clearly shares features with anatomically modern <i>Homo sapiens</i>. Both metric and non-metric traits are compared to those from other African and non-African dental remains. The degree of biological relatedness between eastern and southern African Stone Age hunter-gatherers has long been a subject of interest, and several characteristics of the Magubike teeth resemble those of the San of southern Africa. Another notable feature is that the three incisors are marked on the labial crown by scratches that are much coarser than microwear striations. These non-masticatory scratches on the Magubike teeth suggest that the use of the front teeth as tools included regularly repeated activities undertaken throughout the life of the individual. The exact age of these teeth is not clear as ESR and radiocarbon dates on associated snail shells give varying results, but a conservative estimate of their minimum age is 45,000 years.</p></div

Middle Stone Age human teeth from Magubike rockshelter, Iringa Region, Tanzania - Fig 11

<p>A. Scanning electron microscope (SEM) image of the labial surface of the right central incisor, showing grooves exposing the prismatic structure of the enamel (white arrows). B. SEM image of the labial surface of the left central incisor, showing microwear striations (a) and nonmasticatory striations (b).</p

Uranium content for tooth enamel and dentine.

<p>Uncertainty for all values is 0.02 ppm.</p

Comparative crown measurements (in mm).

<p>Comparative crown measurements (in mm).</p

Middle Stone Age human teeth from Magubike rockshelter, Iringa Region, Tanzania - Fig 12

<p>Photos of A. the occlusal surface of the right lateral incisor showing: a: shovelling; b: cingulum pit; c: tuberculum dentale. B. the occlusal surface of the right canine and third premolar showing: a: double shovelling; b: mesial canine ridge; c: distal accessory ridge; d: mesial interruption of sagittal sulcus and associated buccal and lingual mesial accessory ridges; e: buccal cusp distal accessory ridge; f: buccal cusp median ridge; g: lingual cusp median ridge; h: sagittal sulcus runs over mesial margin; i: anterior fovea; j: posterior fovea. C. the occlusal surface of the left fourth premolar showing: a: mesial and distal triangular grooves; b: bridge across junction of distal triangular groove and sagittal sulcus. D. the lingual surface of the right canine and third premolar showing: a: mesially placed lingual ridge and E. the lingual surface of the left fourth premolar showing: a: medially placed buccal cusp; b: mesially placed lingual cusp; c: concave distal margin of buccal cusp.</p

Crown area comparisons, Group A: African <i>H</i>. <i>heidelbergensis</i>, archaic <i>H</i>. <i>sapiens</i>, Aterian.

<p>Group B: sub-Saharan Middle Stone Age to mid Holocene <i>H</i>. <i>sapiens</i>.</p

Effect of changing sedimentary dose assumptions on sample age.

<p>Error bars are ± 1σ.</p

Magubike rockshelter, Iringa Region, southern Tanzania (map produced by Jeffrey Werner).

<p>Magubike rockshelter, Iringa Region, southern Tanzania (map produced by Jeffrey Werner).</p