Hominin Sites Research Articles

How to survive the glacial apocalypse: Hominin mobility strategies in late Pleistocene Central Asia

Previous research concerning the biogeography of hominin populations in Central Asia indicates persistence across interglacial/glacial sequences. Hominin groups are present on the landscape during the coldest episodes of the Last Glacial Period. Moreover, the Inner Asian Mountain Corridor (IAMC) likely served as a geographic conduit for human groups that found refuge in the foothill regions of the Altai Mountains as well as those of the southwestern horn of the Tien Shan; this conduit can be construed as the stage upon which hominin admixture occurred. The present study broadens the geographic focus of previous work to include the steppe and steppe/desert zones immediately adjacent to the biologically productive foothills of the IAMC. Using an ecological threshold model, four abiotic variables that best predict hominin site locations are analyzed to examine differences in fundamental niche structure when the IAMC foothills are compared to the adjacent steppic zones. Our null hypothesis is that the foothills and adjacent steppe present similar abiotic profiles. Our results, however, indicate significant differences between these regions, suggesting the foothills would have presented hominins with a more attractive landscape in both glacial and interglacial time periods than the steppe. Counterintuitively, these differences are actually more extreme during interglacial time periods. This preliminary model of hominin-environment interactions serves as a useful example for the ways by which mid-scale hominin dispersal trajectories are mapped and interpreted.

The Hominin sites and Palaeolakes Drilling Project: testing hypotheses of climate-driven human evolution and dispersal at Chew Bahir, Ethiopia

There are numerous hypotheses linking climatic trends, events and variability to human origins, evolution and dispersal. Long palaeoenvironmental records from continental sites that may allow tests of these hypotheses are only now becoming available, but most are distant from fossil human sites. The Hominin Sites and Palaeolakes Drilling Project (HSPDP) aims to obtain long continuous sediment cores spanning critical intervals of evolutionary history from lacustrine sites close to globally significant hominin sites in East Africa. Together, the five sites – Northern Awash and Chew Bahir, Ethiopia; West Turkana, Baringo Basin and Lake Magadi, Kenya – will provide multi-proxy records spanning the last 4 million years. This will allow us to correlate and compare environmental changes to the more fragmentary record of evolution, dispersal, extinction and cultural innovation. The project team will evaluate models of climatic and tectonic forcing of environmental processes and landscape resources. We will test hypotheses linking climate variability to physical and cultural evolution. The project is supported by the International Continental Drilling Program (ICDP), NSF (USA), DFG (Germany) and by NERC (UK). Drilling began in June 2013 in Kenya. NERC funded research focuses on the Chew Bahir site in Ethiopia, where a survey of basin sediments using 2D electrical resistivity tomography was completed in October 2013 and drilling of a 400m core is scheduled for November 2014. A team of UK Quaternary scientists will work with German and Ethiopian colleagues to produce a multi-proxy record which is anticipated will cover the last c. 500,000 years. Detailed analysis will focus on identifying the nature of climate variability during the penultimate glacial-interglacial transition (Termination II: c. 125–135 ka), once an outline chronology has been established. Key proxies are: high-resolution geochemistry; isotopes (δ13C, δ18Ocarb, δ18Odiatom, δ18Oostracod); biomarkers (including GDGTs and compound specific leaf wax δ13C and δD); pollen; diatoms; ostracods and magnetic properties. The chronological framework will be constructed using radiocarbon, Post-IR IR stimulated luminescence and 40Ar-–39Ar dating along with tephrochronology, which will be used to correlate between sites where possible. The record of climatic and ecological change, from Chew Bahir, along with previous data from Lake Tana, will be used as model input to test the hypothesis that periods of high climatic variability correlate with key biological and cultural transitions.

The Hominin Sites and Palaeolakes Drilling Project (HSPDP): Collecting palaeolake drill cores from the East African Rift Valley to document the environmental context of human origins

The Hominin Sites and Palaeolakes Drilling Project (HSPDP): Collecting palaeolake drill cores from the East African Rift Valley to document the environmental context of human origins

Comparing the Quaternary palaeoenvironments of two major Hominin sites: the Olorgesailie and Koobi Fora Basins, Kenya

Comparing the Quaternary palaeoenvironments of two major Hominin sites: the Olorgesailie and Koobi Fora Basins, Kenya

The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits

Abstract. The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.

The Qesem Cave hominin material (part 2): A morphometric analysis of dm2-QC2 deciduous lower second molar

The Qesem Cave Middle Pleistocene hominin site has yielded a well preserved lower second deciduous molar (dm2-QC2), among several other human dental remains. It has been previously described by Hershkovitz et al. using traditional methods. In this study, we used multiple approaches in order to characterize the outer and inner morphology of dm2-QC2, namely a descriptive investigation of the inner morphology, analysis of the dental tissues, and comparative 3D geometric morphometric investigation of various aspects of the dental crown based on data gathered from μCT images. Dm2-QC2 was compared to a sample of 44 specimens, including recent and fossil modern humans, Neanderthals, and Homo erectus.Our comprehensive quantitative investigation agrees with Hershkovitz et al. with regard to the mixed morphology of this specimen. Dm2-QC2 allies morphologically with Neanderthals and Skhul X for its squared cervical outline, but is intermediate between modern humans and Neanderthals for its mildly distally expanded crown outline. Dm2-QC2 falls within Neanderthal variability in having relatively high dentine horns with inwardly bent tips. It is peculiar for its mesio-distal elongation of the occlusal marginal ridge at the enamel–dentine junction. The relative enamel thickness delivers different results if measured at the mesial section (intermediate but closer to modern humans) or at the entire crown (close to the Neanderthal distribution). In terms of size, dm2-QC2 and Qafzeh 15 are among the largest specimens in our sample.Dm2-QC2 shows a mosaic of features, with a prevalence of those typical or at least frequent in Neanderthals. Among the latter, the mid-trigonid crest and taurodontism are only slightly expressed. On the basis of this isolated dental evidence, and considering the paucity of information available on human evolution in the Levantine Middle Pleistocene, we do not attempt a taxonomic classification of this single tooth. However, dm2-QC2 indicates that Neanderthal features were already present in the Middle Pleistocene Levant. We cannot rule out the possibility that the dm2-QC2 population contributed to later Levantine or other Eurasian populations, but this is too speculative given the information currently available.

U-series dating of hominin fossil-bearing Panlong Cave in Guangdong Province, southern China

Two hominin teeth and an abundance of faunal remains were recovered from Panlong Cave in Guangdong Province, southern China in 1987. The site has remained largely unknown to the prehistoric community mainly for the lack of reliable chronological constraints. This paper reports high-precision mass spectrometric U-series dating of eight calcite samples from the extant cross-section. Based on the dates on the overlying flowstone layers, the hominin teeth should be definitely older than 292 ± 10 ka. Furthermore, as indicated by the U-series ages on the secondary calcite formations the fossiliferous deposits should be older than 441 ± 18 ka. These dates support the paleontological inference that Panlong Cave may predate the nearby Maba hominin site. The hominin specimens from the site may thus represent an early member of the Ailuropoda-Stegodon fauna and one of the oldest non-erectus Middle Pleistocene hominin fossils in southern China.

Evidence of fatal skeletal injuries on Malapa Hominins 1 and 2.

Malapa is one of the richest early hominin sites in Africa and the discovery site of the hominin species, Australopithecus sediba. The holotype and paratype (Malapa Hominin 1 and 2, or MH1 and MH2, respectively) skeletons are among the most complete in the early hominin record. Dating to approximately two million years BP, MH1 and MH2 are hypothesized to have fallen into a natural pit trap. All fractures evident on MH1 and MH2 skeletons were evaluated and separated based on wet and dry bone fracture morphology/characteristics. Most observed fractures are post-depositional, but those in the right upper limb of the adult hominin strongly indicate active resistance to an impact, while those in the juvenile hominin mandible are consistent with a blow to the face. The presence of skeletal trauma independently supports the falling hypothesis and supplies the first evidence for the manner of death of an australopith in the fossil record that is not attributed to predation or natural death.

Tephrostratigraphy and depositional environment of young (

The Pliocene Hadar Formation, exposed throughout the lower Awash Valley, Ethiopia, chronicles the evolution and paleoenvironmental context of early hominins. Deposition of the Hadar Formation continued until at least 2.94 Ma, but what transpired in the Hadar Basin after this time remains poorly documented due to an erosional event that truncated the formation throughout much of the valley. Here we present geologic mapping and stratigraphic analysis of a 26 m-thick section of sedimentary rocks and tephras exposed in the Ledi-Geraru project area in the region of Gulfaytu. The section contains Hadar Formation strata younger than 2.94 Ma, and sediments that we interpret are Busidima Formation in age, <2.7 Ma. We use this record to place additional constraints on depositional environments and the tectonic and paleogeomorphic history of the region. The lower ∼20 m of section contains lacustrine deposits that conformably overly a 2.94 Ma marker bed (BKT-2U) that previously served as the uppermost dated tephra in the Hadar Formation. We identified seven post-BKT-2U tephras; three were analyzed for glass chemistry, and one yielded an 40Ar/39Ar age of 2.931 ± 0.017 Ma (1σ). Based on these analyses, the newly mapped deposits at Gulfaytu extend the top of the Hadar Formation, representing ca. 20 kyr of post-BKT-2 sedimentation. The Hadar Basin remained depositional following the BKT-2 eruptions, and paleolake Hadar was present at Gulfaytu at this time. An erosional surface marked by a conglomerate truncates the Hadar strata suggesting that the Gulfaytu region was also was influenced by significant changes to basin architecture well-documented elsewhere in the lower Awash Valley. In addition, geophysical models suggest that central Ledi Geraru hosts a thick subsurface lacustrine sedimentary record within the Hadar Basin. The results of this paper provide the outcrop and near surface characterization for the Hominin Sites and Paleolakes Drilling Project (HSPDP) effort at Gulfaytu.

Experimental stone tool replication at the Early Stone Age site of Sterkfontein, Gauteng, South Africa

Between 1999 and 2000 a large experimental knapping programme was carried out at the early hominin site of Sterkfontein, South Africa. Its purpose was to assess aspects of the technology of lithic production found in the Oldowan and Acheulean deposits at the site. The data was used to inform technological analysis of the Sterkfontein stone tool assemblages. In the light of more recent research on raw material selection and transport at East African Oldowan sites, we report on the conclusions drawn from the analysis of the experimental cores to assess their contribution to understanding the influence of raw materials on knapping in the Oldowan and Acheulean at Sterkfontein. Hominins practised raw material selectivity and adapted their knapping strategies to fit clast shape and lithology. The experimental programme offered the opportunity to analyse some of the variables commonly involved in reconstructing lithic behaviour from artefacts and found, as with other studies reported elsewhere, that linear relationships based on one, or a few supposedly diagnostic variables do not stand up to scrutiny.

Papio Cranium from the Hominin-Bearing Site of Malapa: Implications for the Evolution of Modern Baboon Cranial Morphology and South African Plio-Pleistocene Biochronology.

A new partial cranium (UW 88-886) of the Plio-Pleistocene baboon Papio angusticeps from Malapa is identified, described and discussed. UW 88-886 represents the only non-hominin primate yet recovered from Malapa and is important both in the context of baboon evolution as well as South African hominin site biochronology. The new specimen may represent the first appearance of modern baboon anatomy and coincides almost perfectly with molecular divergence date estimates for the origin of the modern P. hamadryas radiation. The fact that the Malapa specimen is dated between ~2.026–2.36 million years ago (Ma) also has implications for the biochronology of other South African Plio-Pleistocene sites where P. angusticeps is found.

A field guide to Charles Dawson's discredited sites implicated in the Piltdown hoax

Charles Dawson, FSA, FGS (1864–1916), was discoverer and presumed forger of Piltdown Man and the less well-known Barcombe Mills Man in East Sussex. Although the fossils were either fakes or salted from elsewhere, Dawson's geology was accurate apart from his over-estimate of the height of the Piltdown terrace above the River Ouse, leading to it being correlated with the 100ft (30m) terrace of the River Thames. This was corrected by Francis Hereward Edmunds, MA, FGS (1893–1960), who recognised it as a 50ft terrace, but this determination was largely ignored until the detection of the forgery in 1953. Subsequently, Piltdown has been the subject of palaeoanthropological speculation ad nauseum – essentially, who dunnit? – but the historical interest taken in the geology has been minimal. A field guide to Dawson's false hominin sites follows the valley of the River Ouse and its terraces. The so-called Piltdown Man II site near Sheffield Park was probably at Netherhall Farm. The type locality of Piltdown Man, Eoanthropus dawsoni, is marked by a memorial stone, but is on private property. The third site, on a hill above Barcombe Mills railway station (closed) and erroneously called Piltdown Man III in the literature, is a younger terrace and produced remains not considered to be E. dawsoni. The total length of the walk is about 16.4km on flat to gently undulating topography in a Quaternary landscape carved by the River Ouse.

Pliocene hominin biogeography and ecology

Australopithecus bahrelghazali, its origin and palaeobiology are not well understood. Reported from only one location some several thousand kilometres away from East African Pliocene hominin sites, it appears to have predominantly fed on C4 sources. Yet, it lacks the morphological adaptations of other primate C4 consumers like Paranthropus boisei and Theropithecus oswaldi. Furthermore, although considered to belong to Australopithecus afarensis by most researchers, A. bahrelghazali appears to differ from the former in a key aspect of its morphology: enamel thickness. To assess the phylogeny and palaeobiology of A. bahrelghazali, I first evaluate the dietary adaptations and energetics of A. bahrelghazali using empirical data of the feeding ecology of extant baboons, Papio cynocephalus. Information published on A. bahrelghazali morphology and habitat preference is used to select C4 foods with the appropriate mechanical properties and availability within the environment to create the models. By altering the feeding time on various food categories, I then test whether A. bahrelghazali could have subsisted on a C4 diet, thus accounting for the δ13C composition of its dental tissue. The effects of body mass on the volume of food consumed are taken into account. The outcomes of these simulations indicate that A. bahrelghazali could have subsisted on a diet of predominantly sedges, albeit with limitations. At higher energy requirements, i.e., above 3.5 times the BMR, it would be difficult for a medium-sized primate to obtain sufficient energy from a sedge-based diet. This is apparently due to constraints on foraging/feeding time, not because of the nutritional value of sedges per se. These results are discussed against the backdrop of A. bahrelghazali biogeography, palaeoenvironment, and phylogeny. The combined evidence makes it plausible to suggest that Northern Chad may have been a refugium for migrating mammals, including hominins, and throws new light on the deep history of A. bahrelghazali.

Coupled ESR and U-series dating of fossil teeth from Yiyuan hominin site, northern China

Coupled ESR and U-series analyses of mammalian fossil teeth were carried out on two localities of Yiyuan hominin site (Locality 1 and 3) in northern China. The U-migration history of the fossil samples could be reconstructed by the combination of the two techniques, and overcome the limitation of stand-alone ESR and U-series age estimation. We obtained a combined ESR/U-series age (AU model) range from ∼420 to 320 ka from nine teeth recovered from the two localities, which pinpoints the deposition of hominin layer of Yiyuan site to MIS 11 to 9. The age results in this study places Yiyuan site at the same time range of Zhoukoudian Locality 1 and Hexian Homo erectus sites. Comparing with other hominin sites, this study of Yiyuan Homo erectus site highlights the possibility of coexistence between Homo erectus and archaic H. sapiens in China.

Initial 26Al/10Be burial dating of the hominin site Bailong Cave in Hubei Province, central China

With the discovery of Homo erectus teeth, stone artifacts and a rich fauna, Bailong Cave in northern Hubei Province is an important hominin/archaeological site in China. However, due to the lack of suitable dating methods, the previous age estimates all come from biostratigraphic correlations. Here we report the first application of a radio-isotopic dating method to the site. Three 26Al/10Be measurements of two quartz samples give a weighted mean burial age of 0.76 ± 0.06 million years (Ma, 1σ). Taking into account possible bias of the dating method, stratigraphic order and evidence for rapid sedimentation, the cultural deposits of the site should be somewhat younger than the above date. This is consistent with previous biostratigraphic age estimates at around the Early/Middle Pleistocene transition, and possibly indicates an earlier human coexistence with Stegodon–Ailuropoda fauna than previously estimated.

Age of Maba hominin site in southern China: Evidence from U-series dating of Southern Branch Cave

Maba hominin, one of the key representatives of archaic Homo sapiens in China, was originally attributed to around the Middle-Late Pleistocene transition (∼130 ka) based on biostratigraphic correlation and alpha-spectrometric U-series dating of fossil teeth. This paper reports mass-spectrometric U-series dates on speleothem samples intercalated with the deposits in Southern Branch Cave. Also presented here is a new survey of the entire Second Level Caves, which provides evidence that the so-called Southern Branch Cave is in fact the front section of the main corridor, and its obstruction marked the end of depositional processes throughout the caves at this level. Accordingly, the capping flowstone in Southern Branch Cave marks the minimum age of all fossiliferous deposits of the site. Maba hominin should thus be at least 230 ± 5 ka (2σ) old, most probably older than 278 ± 4 ka (2σ). This is consistent with an earlier interface between H. erectus and archaic H. sapiens, and would allow for an earlier presence of modern H. sapiens in eastern Asia.

Landscape distribution and ecology of Plio-Pleistocene avifaunal communities from Lowermost Bed II, Olduvai Gorge, Tanzania

Plio-Pleistocene avifaunal communities are used to reconstruct Lowermost Bed II landscapes at the early hominin site of Olduvai Gorge, Tanzania. These deposits are laterally extensive, have strong chronostratigraphic control, and were excavated using a landscape archaeological approach. Such factors allow for horizontal spatial-correlation of avian communities across the paleolandscape over a geologically short time frame (approximately 65,000 years). Lowermost Bed II avifaunal communities point to an extensive freshwater wetland system across the extent of paleo-Lake Olduvai's eastern margin.

Vegetation of Northern Tanzania during the Plio-Pleistocene: A synthesis of the paleobotanical evidences from Laetoli, Olduvai, and Peninj hominin sites

More than 40 years of scientific investigations of the hominin bearing Plio-Pleistocene sediments of northern Tanzania have provided a number of paleobotanical data, which, taken as a whole, provide today a way to investigate vegetation changes between 4 and 1 Ma, at a time when our early ancestors emerged. Here, I have integrated the data from all vegetation proxies obtained for the paleontological sites of Laetoli, Olduvai, and Peninj (i.e. macroscopic plant remains, pollen and phytolith assemblages, carbon and oxygen isotopic ratios measured on carbonates, and organic biomarkers). This important, yet discontinuous botanical record suggests some similarities between past and present-day vegetation at the regional scale: Afromontane forests with Olea, Podocarpus, Juniperus, Hagenia abyssinica in the highlands, and wooded grasslands with grasses and drought-adapted Acacia, Commiphora, Capparidaceae, and Chenopodiaceae and/or Amaranthaceae in the lowlands were present in the southern Serengeti–Crater Highlands region since 4 Ma. Grasses of the C4 photosynthetic type made their first appearance in the record at ∼3.7 Ma, i.e. during the mid-Pliocene, ∼700 ky before major pCO2 and temperature decline. C4 grasses became dominant in the vegetation soon after (∼3.66 Ma), probably in response to reduced precipitation. At ∼2.6 Ma, phytolith and isotope indicate grassland with abundant C4 xerophytic grasses that document strong aridity during the Intensification of Northern Hemisphere Glaciation period (∼2.7–2.5 Ma). After 2 Ma, the detailed and diverse record at Olduvai indicates complex vegetation patterns linked to oscillating precipitation, varying lake levels, and the presence of geological faults. Hence, despite low (basin-averaged) reconstructed paleo-precipitation amounts of ∼250–700 mm/y, C4-grasslands, closed woodlands, wetlands, and palm-groves co-occurred on short spatial scales near saline Lake Olduvai. Freshwater wetlands and palm-rich woodlands occurred in highly localized areas on the lake margins, where aquifer barriers and/or outcrops caused by geologic faults allowed groundwater discharge. Botanical evidence of paleo-springs at Laetoli, Olduvai, and Peninj includes the marked presence of Typha (cattail) and Hyphaene (palm tree) in association with Acacia pollen grains, and (at Olduvai) abundant forest indicator phytoliths and organic and isotopic biomarkers. At Olduvai, freshwater wetlands were most developed when lake level and fluvial competence where low, i.e. during dry periods. When wet–dry climate variability was extreme in East Africa (∼1.9–1.7 Ma), freshwater springs may therefore have offered a sustainable habitat (i.e. refuge) for several species, including hominins, and favored hominin and artifact concentration at these specific places, particularly during environmentally stressful times.

Newly discovered Palaeolithic artefacts from loess deposits and their ages in Lantian, central China

Eight new Palaeolithic open-air sites were identified and 770 stone artefacts were collected from 2009 to 2011 in the Lantian area of the Bahe River valley, central China. Because the famous Homo erectus fossils were unearthed at the Gongwangling and Chenjiawo localities, and more than 30 Palaeolithic open-air sites were investigated in the 1960s in this region, the catchment of Bahe River is regarded as one of the most important hominin sites from the late early Pleistocene to the middle Pleistocene. These eight newly discovered open-air sites are located at the second (n = 6), third (n = 1) or higher terraces (n = 1) of the Bahe River. The Diaozhai section on the second terrace was sampled in detail. Two samples were collected for optically stimulated luminescence dating (OSL). The OSL results suggest that a buried lithic artefact layer at the Diaozhai site spans approximately 70-30 ka. The lithic assemblage analysis suggests that the stone artefacts were made of local pebbles/cobbles such as greywacke, quartz, sandstone and igneous rocks. The main percussion techniques that were used were direct hard hammer percussion and bi-polar techniques. The lithic artefacts comprise hammer stones, cores, flakes, retouched tools and flaking debris. Acheulian-type large cutting tools (LCTs) such as hand-axes, picks and cleavers were indentified in the Lantian region as well. This is the first time Acheulian-type LCTs from the late Pleistocene have been identified in this region. This study distinguishes age gaps between Western world and East Asian Acheulian-type tools.

Taphonomic estimates of competition and the role of carnivore avoidance in hominin site use within the Early Pleistocene Olduvai Basin

It has become increasingly clear among paleoanthropologists that Early Pleistocene sites sample a diversity of behaviors and no one model is sufficient to explain every collection of archaeological debris. With this comes the realization that hominins reacted to an equally diverse set of ecological parameters, each of which determined to some extent where, when, and how they chose to concentrate, or not concentrate, their activities across ancient landscapes. Competition with, and predation risk from, large carnivores is thought to be an especially critical factor, particularly when large mammal tissues became a component of hominin diets after 2.6 million years ago. Here, the degree to which carnivore avoidance influenced patterns of hominin site use is evaluated with a sample of faunal and lithic assemblages from Beds I and II at Olduvai Gorge, Tanzania. Multivariate measures of bone destruction, as proxies for levels of on-site competition and thus predation risk, show little systematic relationship with patterns of lithic discard and butchery. This suggests that while carnivore avoidance was probably part and parcel of hominin daily life in the Early Pleistocene Olduvai Basin, other considerations such as water, tree cover, dry land, and toolstone played more proximate roles.