首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
Over the past four decades several workers have argued that the orientations of striations on the labial surfaces of the front teeth of Middle and Late Pleistocene fossils attributed to Neanderthals and antecedent archaic hominids can tell us something about handedness. These researchers have suggested that such scratches result from stone tools scraping across the incisors during ‘stuff‐and‐cut’ behaviours, and that they reflect directions of hand movements and handedness. In this study, we examine comparable wear features on the incisors of anatomically modern humans to determine whether striation angle may reflect handedness. The teeth from 66 individuals representing four groups with known differences in subsistence practices (Aleut, Arikara, Illinois Bluff, and Puye) were examined. Photomicrographs were made of the maxillary central incisor labial surfaces of all individuals at 56× magnification. These photomicrographs were scanned to image files, and orientations of all visible wear striations were measured using a semi‐automated image analysis procedure. Approximately three‐quarters of all labial surfaces showed a preferred striation orientation. Of those, most had preferred apico‐cervical or vertical striation orientations, independent of cultural affiliation. Few showed the tendency toward diagonally‐oriented scratches expected if handedness is related to scratch orientation. We found no evidence for ‘stuff‐and‐cut’ striations, despite the fact that at least one of the groups studied—the Aleut—are documented to have used this behaviour. In sum, there is evidently no relationship between striation orientation and handedness in the groups studied. It is, therefore, unlikely that labial scratch orientation in Middle and Late Pleistocene hominids reflects handedness if they used their front teeth in a manner comparable to that of any of the anatomically modern groups considered here. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

2.
A sample of 82 anterior teeth from Krapina (Croatia) was studied using a light binocular microscope and a scanning electron microscope to document the presence of non-dietary dental scratches. The patterns of distribution, location and orientation of these marks suggest two different aetiologies: scratches on the labial-occlusal enamel border appear to be related to the action of clenching abrasive materials between teeth, while the scratches primarily in the centre of the labial face correspond to cutmarks as described by other researchers. These scratches may have been produced when flake tools involved in processing materials held between the anterior teeth came into contact with the labial enamel face. Alternatively, they may simply reflect some consistent operation which pulled hard objects across the labial surfaces of the anterior teeth. In either case, the marks on the central face of the labial surface provide evidence for manual dexterity in the Neanderthals. Of the seven Krapina individuals which show a predominant pattern, one shows a pattern of left oblique marks, while six provide evidence of right-handedness. Coupled with other Neanderthal or Upper Pleistocene individuals with these patterns, right-handedness is the dominant pattern in 90 per cent of the documented cases. One complicating factor in the analysis of these scratches in the Krapina hominids is that marks of a similar morphology are found in several anterior teeth of Ursus spelaeus from the site. While resembling the marks on the hominid incisors, the scratches on the bears lack a dominant orientation on the labial face and appear to be more variable in their widths. Despite the occurrence of some similarities in the enamel scratches between ursids and hominids at Krapina, the study of anterior dental marks provides information about manipulative activities which are unique to ancient humans. © 1997 by John Wiley & Sons, Ltd. Int. J. Osteoarchaeol., 7 : 133–149 (1997) No. of Figures: 9. No. of Tables: 5. No. of References: 34.  相似文献   

3.
Dental pathologies and enamel defects in East Asian hominins have rarely been reported. Here, we systematically document and describe a suite of enamel defects in the Xujiayao juvenile maxilla, an East Asian hominin from the early Late Pleistocene that may represent an unknown hominin lineage. In addition, we determine the chronology of growth disruptions represented by matched linear enamel hypoplasias, evaluate the long‐held hypothesis that the large brownish pit on the I1 is evidence of dental fluorosis and assess the utility of micro‐computed tomography (micro‐CT) techniques in analyzing enamel defects. With the use of binocular microscopy, scanning electron microscopy (SEM) and micro‐CT imaging techniques, the Xujiayao teeth were found to exhibit a high number of pit‐form defects seldom seen in the fossil record. By matching the timing of linear enamel hyperplasia across multiple teeth, a minimum of five developmental disruptions were identified, indicating that the Xujiayao juvenile experienced several growth disturbances during its short lifespan. Our SEM and micro‐CT analyses suggest that the large pit on the I1 is an enamel hypoplasia due to its morphology and pre‐eruptive enamel thinning. It is not a post‐eruptive fluorotic pit, and there is no evidence of chalkiness or opacity associated with dental fluorosis. The micro‐CT technique made it possible to verify the presence of enamel hypoplasia and to more precisely quantify defect dimensions, especially in unerupted teeth and shallow hypoplasias that are difficult to detect by binocular microscopy or SEM. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

4.
While the study of dental wear has enjoyed wide popularity for over 100 years, dental chipping, or microfractures of the tooth crown, has received little attention. Observations on dental chipping in populations from the Arctic (St. Lawrence Island, Alaska) and Europe (medieval Norway and Spain) reveal patterns of microtrauma that provide insights into the dietary and tooth‐tool use behaviour of earlier populations. St. Lawrence Island Inuit, with an emphasis on consuming tough and frozen foods, in combination with extensive tooth‐tool use, exhibit a pattern of chipping that is characterised as ‘molar dominant’. The two European samples exhibit an ‘incisor‐dominant’ pattern but contrast markedly in frequencies, with medieval Norwegians showing significantly more chipping than medieval and post‐medieval Spanish. The systematic study of chipping promises to provide a new perspective on how populations used and/or abused their dentitions in earlier times. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

5.
ABSTRACT

South Africa's northern Namaqualand coastal desert is the southern extension of the Namib. Today, this region is semi-desert with patchy subsistence resources and scarce, unpredictable rainfall. Yet this ancient desert landscape possesses residues of human activity stretching back into the Middle Pleistocene, evidenced by heavily weathered surface finds, including handaxes and Victoria West cores. Such old finds in so harsh an environment raise important questions: how do human movements into this area relate to local palaeoenvironmental changes, and how has this relationship changed through time? While no dated Middle Pleistocene sites presently exist to reconstruct the earliest hominin dispersals, several late Pleistocene sites now have chronostratigraphic sequences that can be brought to bear on these questions. This article presents chronological and subsistence-settlement data for one such site, Spitzkloof A Rockshelter in northern Namaqualand's rugged Richtersveld. Humans are shown to have visited the site very sporadically between ~50,000 and 17,000 cal BP. Unlike most of the subcontinent, the most intensive occupations occur during early Marine Isotope Stage 2, when multiple proxies suggest enhanced humidity associated with intensified winter rainfall. We examine these data using the region's better-developed Holocene archaeological record to create predictions about the earliest coastal desert dwellers.  相似文献   

6.
A parsimony analysis of the Narmada cranium from central India and a number of other demes and species of Homo concludes that the Narmada hominin shares a closer relationship with the European Steinheim specimen, than with Asian H. erectus or H. pekinensis. This suggests that the population represented by the Narmada cranium is likely to have had its origins in Europe rather than in Asia. Overall the available evidence supports an ‘Out of Africa’ scenario, as the early Asian hominins belong to a distinct clade which has no extant descendants and thus appear to represent an evolutionary ‘dead end’. The later African and European hominins are defined by a clade including early H. sapiens from Africa. The main difference between these two distinct clades is that the H. erectus lineage is defined by increasing degrees of neuro‐orbital disjunction associated with increased anterior cranial base extension, while the lineage leading to early H. sapiens is characterized by the opposite condition of reduced neuro‐orbital disjunction associated with increased anterior cranial base flexion. While there is also evidence of differential patterns of head and neck musculature between these two clades, they are of secondary importance. Preliminary dating of bovid remains found in association with the hominin cranium by the gamma spectrometric U‐series dating technique suggests a tentative minimum age of not less than 236,000 years. This is in agreement with evidence from biostratigraphical studies of the Boulder Conglomerate, which place these deposits in the Middle Pleistocene. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

7.
The specimen reported here presents a rare form of dental variant—a permanent, mandibular labial canine talon cusp. This anomaly has not previously been reported in the clinical or archaeological literatures and is currently unique. The affected individual is an adult male from the Early Holocene cemetery of Gobero located in the Sahara Desert in the Republic of Niger. The age of this site (ca. 9500 bp) makes this the first archaeological case of labial talon cusp from Africa and the oldest reported talon cusp of any kind (lingual or labial, maxillary or mandibular, incisor or canine) in the world. Previous case studies, population frequency data, sexual dimorphism patterns and distribution within the dentition are discussed for labial talon cusp. The morphological aetiology of talon cusps is reviewed with respect to this specimen. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

8.
The aim of this work is to investigate the potential of wear on the earliest erupting teeth, the deciduous central incisors, for studying weaning in human skeletal populations. The study group is from mediaeval Wharram Percy, where existing δ15N data indicate cessation of breastfeeding occurred by about 24 months post‐partum. The hypothesis tested is that there should be an increase in dental wear as breast milk is replaced with solid foods during weaning. Incisor wear is monitored using crown heights, measured from photographs using image analysis. Results provide little evidence for alteration in incisor wear rates with the attenuation of breastfeeding, perhaps because abrasive foods were used as supplements well before breastfeeding declined. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

9.

Pleistocene water crossings, long thought to be an innovation of Homo sapiens, may extend beyond our species to encompass Middle and Early Pleistocene Homo. However, it remains unclear how water crossings differed among hominin populations, the extent to which Homo sapiens are uniquely flexible in these adaptive behaviors, and how the tempo and scale of water crossings played out in different regions. I apply the adaptive flexibility hypothesis, derived from cognitive ecology, to model the global data and address these questions. Water-crossing behaviors appear to have emerged among different regional hominin populations in similar ecologies, initially representing nonstrategic range expansion. However, an increasing readiness to form connections with novel environments allowed some H. sapiens populations to eventually push water crossings to new extremes, moving out of sight of land, making return crossings to maintain social ties and build viable founder populations, and dramatically shifting subsistence and lithic provisioning strategies to meet the challenges of variable ecological settings.

  相似文献   

10.
This paper presents evidence for increased recovery of organic residues from archaeological pottery through use of a microwave‐assisted liquid chromatography protocol. C16:0 and C18:0 saturated fatty acids were obtained from archaeological potsherds recovered from nine Neolithic settlements in the Middle East dating between 4700 and 7300 cal bc , including materials that had not produced evidence for the survival of any lipid species through use of ‘conventional’ solvent extraction techniques. Compound‐specific isotopic analyses of C16:0 and C18:0 fatty acids in potsherd extracts subsequently revealed δ13C/δ12C compositions consistent with modern subcutaneous fats of wild boar and goats pastured on lands adjacent to the Jordan Valley, and residues from a modern pottery vessel used in the manufacturing of butter, cheese and yogurt in central Turkey. These results are presented as an illustration of capabilities of the microwave‐assisted recovery protocol. The reclamation of saturated and unsaturated fatty acids from archaeological pottery fragments recovered from a number of the earliest ceramic horizons in the Middle East is herewith reported, and the extraction methods and instrumental analytical techniques are described.  相似文献   

11.
This article examines how and in which societal and political contexts nationhood is expressed and symbolised in reunified Germany. This ‘rediscovery’ of nationhood since the 1990s mixes new and old motifs of the cultural repertoire of ‘the national’ for different purposes. Three main contexts triggered a rediscovery of ‘the national’ after 1989: reunification, immigration and the retrenchment of the social state. I argue, by analysing ethnographic material and political discourses, that these contexts, on the one hand, rearticulate old forms of ethnic and cultural nationalism and, on the other hand, create new images and symbols of an open civic society and immigration country. There are ‘playful’ forms, such as campaigns of nation branding, that symbolically include the ‘productive’ and ‘useful’ immigrant into the national project. Moreover, such campaigns serve to legitimatise the downsizing of the national state that – according to a neoliberal attitude – relies on a new community spirit of entrepreneurial, ‘activated’ citizens who ‘help themselves’. Thus, focusing on these pluralised renationalisation processes makes evident how polyvalent ‘the national’ still is. It can be employed by those who attempt to ‘reunite’ the East and West Germans, by businesses to sell their goods and ideas and by almost any political orientation, be it right‐wing or left‐wing.  相似文献   

12.
The ‘Castle Hill’ represents the core territory of Vilnius, around which gravitated urban development, eventually culminating in the foundation of the capital of Lithuania. However, we know very little about the earliest occupation on Castle Hill - how it developed over time, and what the activities were of the people that inhabited the site. While the study of plant remains can provide a crucial insight into human staple foods, agricultural activities and the palaeoenvironment, previous attempts of archaeobotanical investigations of such an important cultural heritage site was cut short due to the outbreak of World War II. Here is presented the first archaeobotanical analyses from the territory of Castle Hill together with new radiocarbon dates stretching from the 8th century BC until the 14th century AD. The primary archaeobotanical analyses in combination with published datasets from adjacent regions around Castle Hill show that the diversification of crops and the introduction of various crop rotation practises during the 8-13th centuries AD. Here, for the first time, attention is drawn to the agricultural strategies in medieval Vilnius that likely played a pivotal role in the formation and development of the city.  相似文献   

13.
The stone technology from Mata Menge on Flores, Indonesia, is described, providing the first detailed analysis of the largest stone artefact assemblage from a stratified and securely dated Middle Pleistocene site in Southeast Asia. Technological analysis indicates a reduction sequence based on the centripetal, or “radial”, reduction of transported blanks. The implications for early hominin behaviour on Flores are considered.  相似文献   

14.
Grass silica short cell phytoliths were sampled from the four lowermost archaeological strata in excavation 1 at Wonderwerk Cave and offer an independent record of climatic change during an episode of Early Stone Age hominin occupation at the cave. Linked to differences in growing season temperature and the geographic distribution of C3 and C4 grasses in southern Africa, fossil grass phytoliths were used to trace palaeoenvironmental shifts at the site. The results suggest that Early Pleistocene environmental conditions at the cave fluctuated: between wetter and drier summer–rainfall growing conditions (C4) towards the end of the Olduvai subchron and the beginning of the subsequent interval of reversed polarity, to mostly dry and cooler winter–rainfall growing conditions (C3), that continued throughout the interval. It ended with a shift towards increased summer rainfall aridity at around one million years ago. The fluctuation between markedly wetter and drier C4 conditions at the cave (NADP-me grass types vs. NAD-me grass types) does not support the premise that the expansion of C4 grasslands was always coupled with increased aridity.  相似文献   

15.
A new genus and species of dasyurid is described on the basis of P3, M1–M3 and M2–3 collected from the middle Pliocene Chinchilla Local Fauna of south-eastern Queensland. Character analysis supports the placement of this new taxon within the dasyurid subfamily Dasyurinae. Derived dasyuromorphian features common to A. chinchillaensis and most dasyurines include: reduction of P3, reduction of stylar cusp B on M1; reduction of metaconids; approximation of stylar cusp B and the metacone on M1; alignment of the postmetacrista on M1 with the long axis of the maxilla and an oblique orientation of the hypocristids with respect to the long axis of the teeth. However in most instances, A. chinchillaensis is less specialised than other members of the subfamily for characters considered. One derived dental feature, reduction of the entoconid, may indicate a special relationship with ‘parantechinines’, Dasyuroides and/or Dasycercus. Additionally, the presence of this feature is suggestive of an open woodland/seasonal habitat. Autapomorphic P3 morphology compounds difficulties with the phylogenetic placement of this taxon.  相似文献   

16.
This paper presents direct evidence of subsistence practices and pottery use at a Late Neolithic site at al-Basatîn, northern Jordan. Measurable concentrations of C16:0 and C18:0 were recovered from 8 of 10 archaeological pottery fragments through use of a microwave-assisted silica gel and aminopropyl solvent protocol developed for the isolation and concentration of free fatty acids in marine sediments. Subsequent isotopic analysis of the surviving C16:0 and C18:0 saturated fatty acids revealed ∂13C ratios consistent with those of adipose fats of ruminant and non-ruminant animals pastured on lands adjacent to the Jordan Valley. The high recovery of diagnostic compounds from the al-Basatîn material is discussed in context of a wider examination of the initial development and use of pottery in the Fertile Crescent, and the emerging debate concerning the efficacy of stable carbon isotope values in characterizing organic residues embedded in pottery fragments recovered from the earliest ceramic horizons in the Middle East and Europe.  相似文献   

17.
Dental microwear texture analysis has proven to be a valuable tool for inferring aspects of subsistence behaviour in human groups and diet in other mammals. Studies have to date been limited to molar teeth. Here we report on the first microwear texture analysis of incisors. Five bioarcheological groups were included in this analysis: Aleuts from various islands in the Bering Sea (n = 24), Arikara from the Mobridge site in South Dakota (n = 18), ethnic Chinese cannery workers from Kodiak Island (n = 16), a Late Woodland Bluff sample from Jersey County, Illinois (n = 18) and Puye Pueblo from Pajarito Plateau in New Mexico (n = 18). First, point clouds with 0.18 µm lateral spacing and 0.005 µm vertical resolution were obtained from maxillary central incisor labial surfaces using a white‐light confocal profiler. Four adjoining fields were sampled for a total area of 276 µm × 204 µm for each specimen. Surface data were then imported into scale‐sensitive fractal analysis software for texture characterisation. Results indicate significant variation among groups in anisotropy, fill volume and heterogeneity. These differences are likely related to differences in diet, degrees and types of non‐dietary incisor use, as well as exposure to abrasives. This study also suggests that texture variables most useful for characterising and comparing incisor microwear may differ from those most useful for distinguishing molar microwear patterns. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

18.
Geological storage of CO2 in depleted oil and gas reservoirs is one of the most promising options to reduce atmospheric CO2 concentrations. Of great importance to CO2 mitigation strategies is maintaining caprock integrity. Worldwide many current injection sites and potential storage sites are overlain by anhydrite‐bearing seal formations. However, little is known about the magnitude of the permeability change accompanying dilatation and failure of anhydrite under reservoir conditions. To this extent, we have performed triaxial compression experiments together with argon gas permeability measurements on Zechstein anhydrite, which caps many potential CO2 storage sites in the Netherlands. Our experiments were performed at room temperature at confining pressures of 3.5–25 MPa. We observed a transition from brittle to semi‐brittle behaviour over the experimental range, and peak strength could be described by a Mogi‐type failure envelope. Dynamic permeability measurements showed a change from ‘impermeable’ (<10?21 m2) to permeable (10?16 to 10?19 m2) as a result of mechanical damage. The onset of measurable permeability was associated with an increase in the rate of dilatation at low pressures (3.5–5 MPa), and with the turning point from compaction to dilatation in the volumetric versus axial strain curve at higher pressures (10–25 MPa). Sample permeability was largely controlled by the permeability of the shear faults developed. Static, postfailure permeability decreased with increasing effective mean stress. Our results demonstrated that caprock integrity will not be compromised by mechanical damage and permeability development. Geofluids (2010) 10 , 369–387  相似文献   

19.
The capillary‐sealing efficiency of intermediate‐ to low‐permeable sedimentary rocks has been investigated by N2, CO2 and CH4 breakthrough experiments on initially fully water‐saturated rocks of different lithological compositions. Differential gas pressures up to 20 MPa were imposed across samples of 10–20 mm thickness, and the decline of the differential pressures was monitored over time. Absolute (single‐phase) permeability coefficients (kabs), determined by steady‐state fluid flow tests, ranged between 10?22 and 10?15 m2. Maximum effective permeabilities to the gas phase keff(max), measured after gas breakthrough at maximum gas saturation, extended from 10?26 to 10?18 m2. Because of re‐imbibition of water into the interconnected gas‐conducting pore system, the effective permeability to the gas phase decreases with decreasing differential (capillary) pressure. At the end of the breakthrough experiments, a residual pressure difference persists, indicating the shut‐off of the gas‐conducting pore system. These pressures, referred to as the ‘minimum capillary displacement pressures’ (Pd), ranged from 0.1 up to 6.7 MPa. Correlations were established between (i) absolute and effective permeability coefficients and (ii) effective or absolute permeability and capillary displacement pressure. Results indicate systematic differences in gas breakthrough behaviour of N2, CO2 and CH4, reflecting differences in wettability and interfacial tension. Additionally, a simple dynamic model for gas leakage through a capillary seal is presented, taking into account the variation of effective permeability as a function of buoyancy pressure exerted by a gas column underneath the seal.  相似文献   

20.
The Pleistocene archaeological record of the Arabian Peninsula is increasingly recognized as being of great importance for resolving some of the major debates in hominin evolutionary studies. Though there has been an acceleration in the rate of fieldwork and discovery of archaeological sites in recent years, little is known about hominin occupations in the Pleistocene over vast areas of Arabia. Here we report on the identification of five new Middle Palaeolithic sites from the Nejd of central Arabia and the southern margins of the Nefud Desert to the north. The importance of these sites centers on their diversity in terms of landscape positions, raw materials used for lithic manufacture, and core reduction methods. Our findings indicate multiple hominin dispersals into Arabia and complex subsequent patterns of behavior and demography.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号