The environmental contexts of early human occupation of Georgia (Transcaucasia)

The hominid mandible and a third metatarsal found in Dmanisi (Republic of Georgia) are accompanied by a rich faunal assemblage and a core-chopper stone tool industry. The mandible represents a somewhat isolated morphological type of Homo erectus that appears, given the combination of its primitive and advanced traits and specific dental morphology, to be a forerunner of both late H. erectus and early archaic H. sapiens. The faunal assemblage mostly consists of Villafranchian mammals, with the majority of the species assigned to an early phase of the Upper Villafranchian (Late Villanian and Early Biharian). Faunal and paleobotanical evidence as well as the depositional nature of the site indicate that hominid occupation took place in a mosaic environment of open steppe and gallery forests. Both the concentration of resources and the warm climatic conditions in the Dmanisi region at the beginning of the early Pleistocene were favorable for hominid occupation. It is possible that hominids reached the Caucasus through the Levantine corridor, and that the environment of this region allowed them to establish a stronghold and later colonize adjacent areas.     

On the taxonomic affinities of the Dmanisi mandible (Georgia)

The recent discovery of unexpectedly ancient human remains has fuelled interest about the first dispersion of Homo outside Africa. The Dmanisi mandible is perhaps one of the most interesting findings, as it supposedly represents one of the oldest hominids outside of Africa. Recently, different interpretations have been published about this specimen. Our comparison of the Dmanisi mandible with a large sample of mandibles and teeth has led us to a new interpretation. In our view, the Dmanisi mandible exhibits a unique combination of traits. Some of its features, taken in isolation, may be attributed to morphological extremes within the genus Homo. The architecture of the mandible as well as the morphology and dimensions of incisors, canines, and P3s are clearly primitive. However, dental traits such as the reduction of the talonid in the P4s and a distally decreasing molar series seems to be derived. Some combinations of these traits are found in specimens of Homo ergaster and differ from those generally present in later hominids. Thus, we propose that the Dmanisi mandible might be taxonomically classified as Homo sp. indet. (aff. ergaster). Furthermore, some aspects of the dentition in Dmanisi display close similarities to Asian Homo erectus. If the 1.8–1.6 Myr dating for the Dmanisi mandible is correct, the differentiation of the Asian branch of the genus Homo could be regarded as a very ancient event. Am J Phys Anthropol 107:145–162, 1998. © 1998 Wiley-Liss, Inc.     

The enigma of the Sangiran 4 palate revisited

The Sangiran 4 palate has been controversial since its discovery in the 1930s because it retains a number of more primitive morphologies such as projecting canines and precanine diastemata. These characters have led some workers to question the hominid status of the palate, suggesting that it is both too large and too primitive to belong to the same individual as the Sangiran 4 cranial fragments. The palate has instead been diagnosed as a new species of Pongo. The present study re-evaluates this controversy through the analysis of new metric data and comparisons with more recently published fossil discoveries. This analysis shows that the Sangiran 4 palate is not unique, and shares several of these putative pongid traits with other Javan hominid fossils as well as recently described hominid specimens from Dmanisi, Georgia. These results suggest that the evolution of the earliest Asians was more complex than has previously been appreciated.     

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. Am J Phys Anthropol 156:224–240, 2015. © 2014 Wiley Periodicals, Inc.     

Locomotor anatomy and biomechanics of the Dmanisi hominins

The Dmanisi hominins inhabited a northern temperate habitat in the southern Caucasus, approximately 1.8 million years ago. This is the oldest population of hominins known outside of Africa. Understanding the set of anatomical and behavioral traits that equipped this population to exploit their seasonal habitat successfully may shed light on the selection pressures shaping early members of the genus Homo and the ecological strategies that permitted the expansion of their range outside of the African subtropics. The abundant stone tools at the site, as well as taphonomic evidence for butchery, suggest that the Dmanisi hominins were active hunters or scavengers. In this study, we examine the locomotor mechanics of the Dmanisi hind limb to test the hypothesis that the inclusion of meat in the diet is associated with an increase in walking and running economy and endurance. Using comparative data from modern humans, chimpanzees, and gorillas, as well as other fossil hominins, we show that the Dmanisi hind limb was functionally similar to modern humans, with a longitudinal plantar arch, increased limb length, and human-like ankle morphology. Other aspects of the foot, specifically metatarsal morphology and tibial torsion, are less derived and similar to earlier hominins. These results are consistent with hypotheses linking hunting and scavenging to improved walking and running performance in early Homo. Primitive retentions in the Dmanisi foot suggest that locomotor evolution continued through the early Pleistocene.     

Hominin occupations at the Dmanisi site, Georgia, Southern Caucasus: raw materials and technical behaviours of Europe's first hominins

Dmanisi is the oldest site outside of Africa that records unquestioned hominin occupations as well as the dispersal of hominins in Europe and Asia. The site has yielded large numbers of artefacts from several periods of hominin occupation. This analysis of Dmanisi stone tool technology includes a review of all the pieces recovered during the last 15 years of excavations. This lithic assemblage gives insights into the hominin behaviour at 1.7-1.8 Ma in Eurasia. Dmanisi hominins exploited local rocks derived from either nearby riverbeds or outcrops, and petrographic study provides data on patterns of stone procurement. Recent geological surveys and technological studies of the artefacts illustrate the roles of hominins in composing the assemblage. Dmanisi hominins selected two types of blanks, including cobbles and angular blocks, of basalt, andesite, and tuffs. Many complete cobbles, pebbles, and rolled blocks in basalt were unmodified, and geological analyses and surveys indicate that hominins brought manuports back to the site, suggesting a complex procurement strategy. Cores, flakes and debris show that all stages of flaking activity took place at the site. Numerous unifacial cores suggest that knapping was not very elaborate. Centripetal knapping is observed on some flake-cores. Knapping was influenced by the blank shape and natural angles. Most flaked objects were either cores or chopper-cores. Flakes predominate while flake tools are rare. The Dmanisi lithic assemblage is comparable to Oldowan sites in Africa in terms of reduction sequence, organisation of the removals, platform types, and the lack of retouched flakes. Dmanisi artefacts and may have been produced by the original hominins in Europe and Asia.     

Early Pleistocene human mandible from Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain): a comparative morphological study

We present a detailed morphological comparative study of the hominin mandible ATE9-1 recovered in 2007 from the Sima del Elefante cave site in Sierra de Atapuerca, Burgos, northern Spain. Paleomagnetic analyses, biostratigraphical studies, and quantitative data obtained through nuclide cosmogenic methods, place this specimen in the Early Pleistocene (1.2-1.3 Ma). This finding, together with archaeological evidence from different European sites, suggests that Western Europe was colonised shortly after the first hominin expansion out of Africa around the Olduvai subchron. Our analysis of the ATE9-1 mandible includes a geometric morphometric analysis of the lower second premolar (LP₄), a combined and detailed external and internal assessment of ATE9-1 roots through CT and microCT techniques, as well as a comparative study of mandibular and other dental features. This analysis reveals some primitive Homo traits on the external aspect of the symphysis and the dentition shared with early African Homo and the Dmanisi hominins. In contrast, other mandibular traits on the internal aspect of the symphysis are derived with regard to African early Homo, indicating unexpectedly large departures from patterns observed in Africa. Reaching the most occidental part of the Eurasian continent implies that the first African emigrants had to cross narrow corridors and to overcome geographic barriers favouring genetic drift, long isolation periods, and adaptation to new climatic and seasonal conditions. Given these conditions and that we are dealing with a long time period, it is possible that one or more speciation events could have occurred in this extreme part of Eurasia during the Early Pleistocene, originating in the lineages represented by the Sima del Elefante-TE9 hominins and possibly by the Gran Dolina-TD6 hominins. In the absence of any additional evidence, we prefer not include the specimen ATE9-1 in any named taxon and refer to it as Homo sp.     

Taxonomic affinities and evolutionary history of the Early Pleistocene hominids of Java: dentognathic evidence

Temporal changes, within-group variation, and phylogenetic positions of the Early Pleistocene Javanese hominids remain unclear. Recent debate focused on the age of the oldest Javanese hominids, but the argument so far includes little morphological basis for the fossils. To approach these questions, we analyzed a comprehensive dentognathic sample from Sangiran, which includes most of the existing hominid mandibles and teeth from the Early Pleistocene of Java. The sample was divided into chronologically younger and older groups. We examined morphological differences between these chronological groups, and investigated their affinities with other hominid groups from Africa and Eurasia. The results indicated that 1) there are remarkable morphological differences between the chronologically younger and older groups of Java, 2) the chronologically younger group is morphologically advanced, showing a similar degree of dentognathic reduction to that of Middle Pleistocene Chinese H. erectus, and 3) the chronologically older group exhibits some features that are equally primitive as or more primitive than early H. erectus of Africa. These findings suggest that the evolutionary history of early Javanese H. erectus was more dynamic than previously thought. Coupled with recent discoveries of the earliest form of H. erectus from Dmanisi, Georgia, the primitive aspects of the oldest Javanese hominid remains suggest that hominid groups prior to the grade of ca. 1.8-1.5 Ma African early H. erectus dispersed into eastern Eurasia during the earlier Early Pleistocene, although the age of the Javanese hominids themselves is yet to be resolved. Subsequent periods of the Early Pleistocene witnessed remarkable changes in the Javanese hominid record, which are ascribed either to significant in situ evolution or replacement of populations.     

Palaeopathology of the Pleistocene specimen D2600 from Dmanisi (Republic of Georgia)

Here we present a detailed palaeopathological study of the hominin mandible D2600 recovered at the Dmanisi site, Republic of Georgia. The Dmanisi assemblage represents the earliest evidence of hominins outside Africa with an age of 1.8 Ma. D2600 is the holotype of Homo georgicus species and its taxonomic assignment is still under debate. Our study reveals severe and unusual dental wear accompanied of extensive root exposure and dental axial migration, periapical abscesses and enamel fractures. In addition, there is evidence of post-eruptive tooth rotation and temporomandibular arthropathy. We propose that the wear pattern observed in this individual is related to a diet with a high intake of fibrous and abrasive foods such as fruits and plants, as it is usually recorded in chimpanzees and gorillas and unlike the wear pattern observed in other Homo specimens of our comparative sample. The rounded occlusal surfaces and highly polished labio-lingual surfaces of D2600 anterior teeth could be mainly the consequence of pre- and/or para-masticatory activities such as gripping and stripping. This type of food would be also the origin of the highly cupped occlusal morphology of the posterior dentition in combination with relatively slight approximal attrition. However, the lesions exhibited by D2600 have not significantly altered the morphology of the mandible and do not prevent a proper taxonomic assessment.     

Post-cranial remains of the miocene lorisidae of East Africa

Post-cranial fragments of Early Miocene lorisids from Kenya and Uganda are described. All these early forms, seemingly impossible to assign to subfamily on the basis of cranial and dental material, had a post-cranial skeleton and presumably locomotor habits as in living members of the Galaginae. Whether or not this new evidence indicates that all the Miocene forms were of that subfamily will depend upon a reassessment of the validity of the two accepted subfamilies. There now seems to be a strong possibility that the lorisine morphological habit has been derived several times from a primitive galagine one. It is much less certain that the two subfamilies represent a single division of a basic stock.     

The place of Neandertals in the evolution of hominid patterns of growth and development

This study uses the two developmental fields of dental maturation and femoral growth to determine if the pattern of growth and development in Neandertals (archaic Homo sapiens) was intermediate between that of Homo erectus and recent modern humans. Specimens used in the analysis included Neandertals and Upper Palaeolithic early modern Homo sapiens from Europe and individuals from two recent modern human populations. Ontogenetic data for the H. erectus adolescent KNM-WT 15000 and for Gorilla gorilla were included for comparison. Previous reports have indicated that H. erectus demonstrates a pattern of ontogeny characterized by earlier and more rapid linear growth than in modern humans. Results reported here demonstrate that Upper Paleolithic early modern Homo sapiens display a growth trajectory indistinguishable from that of recent modern humans. The pattern of Neandertal ontogeny is not intermediate between the pattern displayed in H. erectus and the derived pattern seen in the modern reference samples and the early modern H. sapiens sample. The Neandertal growth trajectory is consistent with either slow linear growth or advanced dental development.     

The histiocyte in human foetal tissues its morphology,cytochemistry, origin,function, and fate

Summary Based upon a material comprising human foetuses cytochemical studies of a widespread type of cell were carried out. Apart from amoeboid mobility the cell is characterized by pinocytotic and phagocytotic activity.In early development stages these cells are seen intravascularly and penetrating the vessels. Later they are seen in connection with the formation of the vascular epiphyseal cartilaginous canals and in the vitreous body, the synovial joints and dental anlage. Furthermore these cells are seen at the removal of the epithelial cells of the dental lamina and the junctional epithelium in the two palatine processes. The cells concerned are seen also in the deep periosteal layer at the centre of the diaphysis synchronously with the vaseularization of the periosteum and prior to the periosteal invasion. Based upon morphology and cytochemistry the theory is advanced that these cells form the chondroclasts and the multinucleated osteoclasts. By contrast, the diaphysial osteoblasts are derived from invading pre-osteoblasts from the cambium-layer of the periosteum.These cells are also seen along the basal surface of the neural apparatus and invading the brain vesicles.On the basis of morphology and cytochemistry the cell type is designated a histiocyte and its origin is traced back to primitive leucocytes.This work has been supported by grants from the Danish State Research Foundation, the Rask-Ørsted Foundation and The Association for the Aid of the Crippled Children, New York.     

Liang Bua Homo floresiensis mandibles and mandibular teeth: a contribution to the comparative morphology of a new hominin species

In 2004, a new hominin species, Homo floresiensis, was described from Late Pleistocene cave deposits at Liang Bua, Flores. H. floresiensis was remarkable for its small body-size, endocranial volume in the chimpanzee range, limb proportions and skeletal robusticity similar to Pliocene Australopithecus, and a skeletal morphology with a distinctive combination of symplesiomorphic, derived, and unique traits. Critics of H. floresiensis as a novel species have argued that the Pleistocene skeletons from Liang Bua either fall within the range of living Australomelanesians, exhibit the attributes of growth disorders found in modern humans, or a combination of both. Here we describe the morphology of the LB1, LB2, and LB6 mandibles and mandibular teeth from Liang Bua. Morphological and metrical comparisons of the mandibles demonstrate that they share a distinctive suite of traits that place them outside both the H. sapiens and H. erectus ranges of variation. While having the derived molar size of later Homo, the symphyseal, corpus, ramus, and premolar morphologies share similarities with both Australopithecus and early Homo. When the mandibles are considered with the existing evidence for cranial and postcranial anatomy, limb proportions, and the functional anatomy of the wrist and shoulder, they are in many respects closer to African early Homo or Australopithecus than to later Homo. Taken together, this evidence suggests that the ancestors of H. floresiensis left Africa before the evolution of H. erectus, as defined by the Dmanisi and East African evidence.     

中国直立人牙齿特征变异及其演化意义

以往研究发现,中国直立人化石呈现较大的形态变异。对于这种变异程度及造成变异的原因,在古人类学界有不同的认识。有学者提出在直立人阶段,中国古人类已经呈现明显的区域性差异,但也有人认为这些差异似乎没有规律性。近年,本文作者采用不同方法对若干地点的中国直立人牙齿特征及其变异进行了系列研究,取得了一些新的发现和认识。本文在回顾总结这些研究的基础上,结合对其它一些地点中国直立人牙齿特征的观测对比,对中国直立人牙齿特征表现特点及变异作了进一步的分析。本研究发现,中国直立人牙齿特征具有较大的变异范围。这些变异似可分为两种主要类型,元谋、建始、郧县梅铺、和县牙齿呈现出较多的原始特点,代表一种原始类型;周口店、沂源等地点的标本特征相对进步,表现出更多的典型直立人特征。其它一些地点的直立人化石呈现出混合或中间状态。值得注意的是部分呈现出原始牙齿特征类型的中国直立人的生存年代相对较晚,其牙齿特征的原始性与生存时代不具有对应关系。作者认为中国直立人牙齿特征类型反映了更新世早期和中期不同直立人群的演化状态。原始类型牙齿特征的形成不仅与演化时序性和地理分布有关,还在一定程度上反映了一些中国直立人群的演化隔离。     

Brief communication: Is variation in the cranial capacity of the Dmanisi sample too high to be from a single species?

This study uses data resampling to test the null hypothesis that the degree of variation in the cranial capacity of the Dmanisi hominid sample is within the range variation of a single species. The statistical significance of the variation in the Dmanisi sample is examined using simulated distributions based on comparative samples of modern humans, chimpanzees, and gorillas. Results show that it is unlikely to find the maximum difference observed in the Dmanisi sample in distributions of female-female pairs from comparative single-species samples. Given that two sexes are represented, the difference in the Dmanisi sample is not enough to reject the null hypothesis of a single species. Results of this study suggest no compelling reason to invoke multiple taxa to explain variation in the cranial capacity of the Dmanisi hominids.     

Evolution of P3 morphology in Australopithecus afarensis

The Australopithecus afarensis dental sample exhibits a wide range of variation, which is most notable in the morphology of the lower third premolar (P3). P3 morphology in the A. afarensis sample ranges from the primitive sectorial extreme in AL 128-23 to the derived, bicuspid (molarized) extreme in AL 333w-1. In this paper, the degree and patterning of variation of the 20 known A. afarensis P3s are examined and the evolutionary implications are discussed. Initially, a series of dental and mandibular metric criteria are evaluated to determine whether this sample may be analyzed as a single species. From the metrics, it is clear that the single species hypothesis cannot be rejected. Next, a series of morphological criteria is devised to measure P3 molarization. Taken as a whole, the A. afarensis P3 sample displays more variation than a sample of modern hominoids (Pan troglodytes) and shows a slight trend toward increased molarization through time. When separated by sex, the A. afarensis sample still displays greater variation than the chimpanzee sample; however, only the male A. afarensis specimens show a trend toward increased molarization. Additionally, the male A. afarensis P3s are more molarized than the female, a pattern that is seen as well (though less markedly) in the chimpanzee sample. The trend toward increased molarization over time indicates selection for grinding in A. afarensis. The sexual differences parallel those seen in the postcrania (cf. Stern and Susman: Am. J. Phys. Anthropol. 60:279-318, 1983), as the females tend to retain the primitive condition, while the males display the derived morphology. Consequently, a model of sexual differences in niche exploitation, with the females exploiting a more arboreal environment, would seem to be supported by both the dental and postcranial evidence.     

Ecological polarity in primate tion

Relationships of the catarrhine primates based on morphological similarity are presented and then combined with habitat data to determine polarity of ecological change in the catarrhines. The ancestral habitat of two sister-groups is estimated by combining that of the sister groups, so that if they share one habitat type the ancestral condition is taken to be that type, or if they differ the ancestral condition is taken to be both alternatives. Analysed in this way the ancestral habitat preference of the Catarrhini is tropical lowland forest, and while the Hominoidea retain this primitive condition, the Cercopithecoidea are derived with a savanna habitat preference. Most hominoids retain the primitive forest habitat condition, and those groups that are associated with woodland-savanna habitats, notably the ramapitbecines and hominines, therefore share a derived habitat preference. There is no evidence, however, that this arose through common ancestry, and it is concluded that the functional similarities between the two groups could have arisen through parallel adaptation to the same habitat type. Similarly, many of the extant cercopithecoid groups that are now forest living may have re-entered forest independently. The derived savanna habitat preference of the cercopithecoids is linked with a number of morphological characters that also are derived with respect to catarrhine ancestry, and these include their terrestrial and/or their above-branch adaptations, and their specialized digestive, dietary and dental adaptations. In contrast, the hominoids that retain the primitive catarrhine habitat preference also retain the primitive condition in all these characters.