Two Late Pleistocene human femora from Trinil, Indonesia: Implications for body size and behavior in Southeast Asia.

Late Pleistocene hominin postcranial specimens from Southeast Asia are relatively rare. Here we describe and place into temporal and geographic context two partial femora from the site of Trinil, Indonesia, which are dated stratigraphically and via Uranium-series direct dating to ca. 37-32 ka. The specimens, designated Trinil 9 and 10, include most of the diaphysis, with Trinil 9 being much better preserved. Microcomputed tomography is used to determine cross-sectional diaphyseal properties, with an emphasis on midshaft anteroposterior to mediolateral bending rigidity (Ix/Iy), which has been shown to relate to both body shape and activity level in modern humans. The body mass of Trinil 9 is estimated from cortical area and reconstructed length using new equations based on a Pleistocene reference sample. Comparisons are carried out with a large sample of Pleistocene and Holocene East Asian, African, and European/West Asian femora. Our results show that Trinil 9 has a high Ix/Iy ratio, most consistent with a relatively narrow-bodied male from a mobile hunting-gathering population. It has an estimated body mass of 55.4 kg and a stature of 156 cm, which are small relative to Late Pleistocene males worldwide, but larger than the penecontemporaneous Deep Skull femur from Niah Cave, Malaysia, which is very likely female. This suggests the presence of small-bodied active hunter-gatherers in Southeast Asia during the later Late Pleistocene. Trinil 9 also contrasts strongly in morphology with earlier partial femora from Trinil dating to the late Early-early Middle Pleistocene (Femora II-V), and to a lesser extent with the well-known complete Femur I, most likely dating to the terminal Middle-early Late Pleistocene. Temporal changes in morphology among femoral specimens from Trinil parallel those observed in Homo throughout the Old World during the Pleistocene and document these differences within a single site.

Mosaic dental morphology in a terminal Pleistocene hominin from Dushan Cave in southern China.

Recent studies reveal high degrees of morphological diversity in Late Pleistocene humans from East Asia. This variability was interpreted as complex demographic patterns with several migrations and possible survival of archaic groups. However, lack of well-described, reliably classified and accurately dated sites has seriously limited understanding of human evolution in terminal Pleistocene. Here we report a 15,000 years-old H. sapiens (Dushan 1) in South China with unusual mosaic features, such as large dental dimensions, cingulum-like structures at the dentine level in the posterior dentition and expression of a "crown buccal vertical groove complex", all of which are uncommon in modern humans and more typically found in Middle Pleistocene archaic humans. They could represent the late survival of one of the earliest modern humans to settle in an isolated region of southern China and, hence, the retention of primitive-like traits. They could also represent a particularity of this group and, hence, reflect a high degree of regional variation. Alternatively, these features may be the result of introgression from some late-surviving archaic population in the region. Our study demonstrates the extreme variability of terminal Pleistocene populations in China and the possibility of a complex demographic story in the region.

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

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 Homo sapiens. 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.

New dating evidence of the early presence of hominins in Southern Europe.

The first "Out of Africa" migrations represent a seminal event in the history of humankind. At the gates of Europe, the first appearance of Hominins is recorded in Georgia, 1.8 million years ago (Ma); however, the picture of migration across the continent remains incomplete. Vallonnet Cave (France) is a Lower Paleolithic prehistoric site with traces of hominin activities including lithic remains and cut-marks on mammal bones. Here, we apply the uranium-lead (U-Pb) methods to two flowstones to date the intervening archaeological levels. The U-Pb data, coupled with paleomagnetic constraints, provide an age range from 1.2 to 1.1 Ma. The results conclusively demonstrate that Vallonnet Cave is one of the oldest European prehistoric sites in France with early hominin occupations associated with an Epivillafranchian fauna. Combined with data from other archaeological sites, the new precise chronology suggests a widespread occupation the Northern Mediterranean to Southwestern Europe at ~1.2 Ma.

The diet of the first Europeans from Atapuerca.

Hominin dietary specialization is crucial to understanding the evolutionary changes of craniofacial biomechanics and the interaction of food processing methods' effects on teeth. However, the diet-related dental wear processes of the earliest European hominins remain unknown because most of the academic attention has focused on Neandertals. Non-occlusal dental microwear provides direct evidence of the effect of chewed food particles on tooth enamel surfaces and reflects dietary signals over time. Here, we report for the first time the direct effect of dietary abrasiveness as evidenced by the buccal microwear patterns on the teeth of the Sima del Elefante-TE9 and Gran Dolina-TD6 Atapuerca hominins (1.2-0.8 million years ago - Myr) as compared with other Lower and Middle Pleistocene populations. A unique buccal microwear pattern that is found in Homo antecessor (0.96-0.8 Myr), a well-known cannibal species, indicates dietary practices that are consistent with the consumption of hard and brittle foods. Our findings confirm that the oldest European inhabitants ingested more mechanically-demanding diets than later populations because they were confronted with harsh, fluctuating environmental conditions. Furthermore, the influence of grit-laden food suggests that a high-quality meat diet from butchering processes could have fueled evolutionary changes in brain size.

A geometric morphometric analysis of hominin lower molars: Evolutionary implications and overview of postcanine dental variation.

Lower molars have been extensively studied in the context of hominin evolution using classic and geometric morphometric analyses, 2D and 3D approaches, evaluations of the external (outer enamel surface) and internal anatomy (dentine, pulp chamber, and radicular canals), and studies of the crown and root variation. In this study, we present a 2D geometric morphometric analysis of the crown anatomy of lower first, second, and third molars of a broad sample of hominins, including Pliocene and Lower, Middle, and Upper Pleistocene species coming from Africa, Asia, and Europe. We show that shape variability increases from first to second and third molars. While first molars tend to retain a relatively stable 5-cusped conformation throughout the hominin fossil record, second and third molars show marked distal reductions in later Homo species. This trend to distal reduction is similar to that observed in previous studies of premolars and upper second and third molars, and points to a correlated reduction of distal areas across the whole postcanine dentition. Results on lower molar variation, as well as on other postcanine teeth, show certain trends in European Pleistocene populations from the Atapuerca sites. Middle Pleistocene hominins from Sima de los Huesos show Neanderthal affinities and strong dental reduction, especially in the most distal molars. The degree of dental reduction in this population is stronger than that observed in classic Neanderthals. Homo antecessor hominins from Gran Dolina-TD6 have primitive lower teeth that contrast with their more derived upper teeth. The evolutionary implications of these dental affinities are discussed in light of recent paleogenetic studies.

Hominin teeth from the early Late Pleistocene site of Xujiayao, Northern China.

It is generally accepted that from the late Middle to the early Late Pleistocene (∼340-90 ka BP), Neanderthals were occupying Europe and Western Asia, whereas anatomically modern humans were present in the African continent. In contrast, the paucity of hominin fossil evidence from East Asia from this period impedes a complete evolutionary picture of the genus Homo, as well as assessment of the possible contribution of or interaction with Asian hominins in the evolution of Homo sapiens and Homo neanderthalensis. Here we present a comparative study of a hominin dental sample recovered from the Xujiayao site, in Northern China, attributed to the early Late Pleistocene (MIS 5 to 4). Our dental study reveals a mosaic of primitive and derived dental features for the Xujiayao hominins that can be summarized as follows: i) they are different from archaic and recent modern humans, ii) they present some features that are common but not exclusive to the Neanderthal lineage, and iii) they retain some primitive conformations classically found in East Asian Early and Middle Pleistocene hominins despite their young geological age. Thus, our study evinces the existence in China of a population of unclear taxonomic status with regard to other contemporary populations such as H. sapiens and H. neanderthalensis. The morphological and metric studies of the Xujiayao teeth expand the variability known for early Late Pleistocene hominin fossils and suggest the possibility that a primitive hominin lineage may have survived late into the Late Pleistocene in China.

Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus.

The Lower to Middle Paleolithic transition (~400,000 to 200,000 years ago) is marked by technical, behavioral, and anatomical changes among hominin populations throughout Africa and Eurasia. The replacement of bifacial stone tools, such as handaxes, by tools made on flakes detached from Levallois cores documents the most important conceptual shift in stone tool production strategies since the advent of bifacial technology more than one million years earlier and has been argued to result from the expansion of archaic Homo sapiens out of Africa. Our data from Nor Geghi 1, Armenia, record the earliest synchronic use of bifacial and Levallois technology outside Africa and are consistent with the hypothesis that this transition occurred independently within geographically dispersed, technologically precocious hominin populations with a shared technological ancestry.

Absolute and relative endocranial size in Neandertals and later Pleistocene Homo.

Eurasian Neandertals encompass the entire observed range of recent and fossil Homo sapiens in absolute, but not relative endocranial volume, and Neandertals attest an average EQ significantly lower than their Upper Pleistocene successors. While the cognitive, social, and evolutionary implications of this phenomenon have been emphasised, the statistical basis of a mean inference of EQ in the Neandertal hypodigm has not been appropriately demonstrated. A demonstrable male bias in the available postcranial, not cranial, series has skewed perceptions of Neandertal brain-to-body size scaling towards a rejection of the null hypothesis. A simple resolution to this problem is a concise assessment of paired associated covariates against a suitable recent human comparator series. Permutations of Fisher's z and Student's t statistics are valid metrics in tests of significance in single datum hypotheses. Bootstrapped single observation tests determined significance in body size, absolute and relative endocranial volume in Pleistocene archaic, early modern, and late Pleistocene H. sapiens. With respect to absolute ECV, all current Middle-Upper Pleistocene crania fall within the substantial recent Homo range. Nevertheless, simple indices derived from raw and modified data in normal and logarithmic space reveal that Western European Neandertal males approach the lower extremes of our observed size range in relative ECV, yet none exceed statistical significance. Results confirm that relative ECV/brain size in Neandertals was not significantly depressed relative to recent and fossil H. sapiens and this is consistent with a substantial body of data from living humans dismissing any simple correspondence of relative brain size with intelligence and, by extension, evolutionary success.

A re-examination of the human fossil specimen from Backi Petrovac (Serbia).

A fragmented human calotte was discovered during the early 1950s near Backi Petrovac (Serbia), in association with Palaeolithic stone tools. After its initial publication, the fossil specimen remained largely unknown outside of the Serbian academe and no detailed comparative study has ever been carried out. Since the whereabouts of the fossil itself are currently unknown, and given its potential significance for the Pleistocene human evolution, we re-examine the data published by Zivanovic (1966, 1975). Using the original measurements, mostly taken on the frontal bone, and a wide comparative sample of 68 fossil specimens, the fossil was compared and analyzed by statistical multivariate methods. We also conducted a visual examination of the morphology based on the available photographic material. Our analysis reveals phenetic similarity with Middle Pleistocene archaic Homo from Africa and anatomically modern Homo sapiens. However, the absence of primitive cranial traits in Backi Petrovac indicates a clear modern Homo sapiens designation. Although lost at the moment, there is a chance for the re-discovery of the fossil in the years to come. This would give us an opportunity to acquire absolute dates and to study the specimen in a more detailed manner.

U-series and radiocarbon analyses of human and faunal remains from Wajak, Indonesia.

Laser ablation U-series dating results on human and faunal bone fragments from Wajak, Indonesia, indicate a minimum age of between 37.4 and 28.5 ka (thousands of years ago) for the whole assemblage. These are significantly older than previously published radiocarbon estimates on bone carbonate, which suggested a Holocene age for a human bone fragment and a late Pleistocene age for a faunal bone. The analysis of the organic components in the faunal material show severe degradation and a positive δ(13)C ratio indicate a high degree of secondary carbonatisation. This may explain why the thermal release method used for the original age assessments yielded such young ages. While the older U-series ages are not in contradiction with the morphology of the Wajak human fossils or Javanese biostratigraphy, they will require a reassessment of the evolutionary relationships of modern human remains in Southeast Asia and Oceania. It can be expected that systematic direct dating of human fossils from this area will lead to further revisions of our understanding of modern human evolution.

Confirmation of a late middle Pleistocene age for the Omo Kibish 1 cranium by direct uranium-series dating.

While it is generally accepted that modern humans evolved in Africa, the specific physical evidence for that origin remains disputed. The modern-looking Omo 1 skeleton, discovered in the Kibish region of Ethiopia in 1967, was controversially dated at ~130 ka (thousands of years ago) by U-series dating on associated Mollusca, and it was not until 2005 that Ar-Ar dating on associated feldspar crystals in pumice clasts provided evidence for an even older age of ~195 ka. However, questions continue to be raised about the age and stratigraphic position of this crucial fossil specimen. Here we present direct U-series determinations on the Omo 1 cranium. In spite of significant methodological complications, which are discussed in detail, the results indicate that the human remains do not belong to a later intrusive burial and are the earliest representative of anatomically modern humans. Given the more archaic morphology shown by the apparently contemporaneous Omo 2 calvaria, we suggest that direct U-series dating is applied to this fossil as well, to confirm its age in relation to Omo 1.

Juvenile hominoid cranium from the late Miocene of southern China and hominoid diversity in Asia.

The fossil ape Lufengpithecus is known from a number of late Miocene sites in Yunnan Province in southern China. Along with other fossil apes from South and Southeast Asia, it is widely considered to be a relative of the extant orangutan, Pongo pygmaeus. It is best represented at the type site of Shihuiba (Lufeng) by several partial to nearly complete but badly crushed adult crania. There is, however, an additional, minimally distorted cranium of a young juvenile from a nearly contemporaneous site in the Yuanmou Basin, which affords the opportunity to better assess the relationships between Lufengpithecus and Pongo. Comparison with similarly aged juvenile skulls of extant great apes reveals no features suggesting clear affinities to orangutans, and instead reveals a morphological pattern largely consistent with a stem member of the hominid (great ape and human) clade. The existence at this time of other hominids in South Asia (Sivapithecus) and Southeast Asia (Khoratpithecus) with clear craniofacial affinities to Pongo suggests both more diversity among Asian Late Miocene apes and more complex patterns of dispersal than previously supposed. Major differences in the associated mammal faunas from the southern China sites and those from South and Southeast Asia are consistent with these findings and suggest more than one dispersal route of apes into East Asia earlier in the Miocene.

Europe's oldest jaw: evidence of oral pathology.

Atapuerca, in the north of Spain, is the archaeological site where the oldest hominid remains within Europe have been found. In 2008 a jaw fragment, corresponding to the symphyseal area, was discovered in the area called the 'Elephant's pit'. Its age has been estimated at 1.2 million years and it is considered to be the oldest human fossil found in Europe and is from the lower Pleistocene. This work analyses the dental and skeletal damage to the specimen, detected in a macroscopic study of possible horizontal and vertical bone loss at the level of support of the remaining teeth. The limited presence of dental scale, the pattern of destruction and the decreased bone density due to increased marrow spaces suggest the presence of possible periodontal disease.

The Vindija Neanderthal scapular glenoid fossa: comparative shape analysis suggests evo-devo changes among Neanderthals.

Although the shape of the scapular glenoid fossa (SGF) may be influenced by epigenetic and developmental factors, there appears to be strong genetic control over its overall form, such that variation within and between hominin taxa in SGF shape may contain information about their evolutionary histories. Here we present the results of a geometric morphometric study of the SGF of the Neanderthal Vi-209 from Vindjia Cave (Croatia), relative to samples of Plio-Pleistocene, later Pleistocene, and recent hominins. Variation in overall SGF shape follows a chronological trend from the plesiomorphic condition seen in Australopithecus to modern humans, with pre-modern species of the genus Homo exhibiting intermediate morphologies. Change in body size across this temporal series is not linearly directional, which argues against static allometry as an explanation. However, life history and developmental rates change directionally across the series, suggesting an ontogenetic effect on the observed changes in shape (ontogenetic allometry). Within this framework, the morphospace occupied by the Neanderthals exhibits a discontinuous distribution. The Vindija SGF and those of the later Near Eastern Neanderthals (Kebara and Shanidar) approach the modern condition and are somewhat segregated from both northwestern European (Neandertal and La Ferrassie) and early Mediterranean Neanderthals (Krapina and Tabun). Although more than one scenario may account for the pattern seen in the Neanderthals, the data is consistent with palaeogenetic evidence suggesting low levels of gene flow between Neanderthals and modern humans in the Near East after ca. 120-100 ka (thousands of years ago) (with subsequent introgression of modern human alleles into eastern and central Europe). Thus, in keeping with previous analyses that document some modern human features in the Vindija Neanderthals, the Vindija G(3) sample should not be seen as representative of 'classic'--that is, unadmixed, pre-contact--Neanderthal morphology.