考古标本微磨痕初步研究

从周口店第1地点和马鞍山遗址选取了20件燧石制品,以微磨痕的实验研究为基础,以扫描电子显微镜 (简称电镜) 为主要手段,通过对比分析,尝试了不同遗址间考古标本的微磨痕分析。结果表明,周口店第1地点和马鞍山遗址的石制品的功能都具有多样性;“楔” 的功能见于马鞍山遗址,并为周口店第1地点 “使用石片较多” 的说法提供了微磨痕方面的新证据。     

Ecogeographic variation in Neandertal dietary habits: evidence from occlusal molar microwear texture analysis

In the late Middle and early Late Pleistocene, Neandertals inhabited a wide variety of ecological zones across western Eurasia during both glacial and interglacial times. To elucidate the still poorly understood effects of climatic change on Neandertal subsistence patterns, this study employs dental microwear texture analysis to reconstruct the diets of Neandertal individuals from various sites across their wide temporal and geographic ranges. The results of this study reveal environmentally-driven differences in the diets of Neandertal groups. Significant differences in microwear signatures, correlated with paleoecological conditions, were found among Neandertal groups that lived in open, mixed, and wooded environments. In comparison to recent hunter-gatherer populations with known, yet diverse diets, the occlusal molar microwear signatures of all the Neandertal groups indicate that their diet consisted predominantly of meat. However, the results of this study suggest that plant foods did form an important part of the diet of at least some Neandertal groups (i.e., those that lived in mixed and wooded habitats). Overall, the proportion of plant foods in the Neandertal diet appears to have increased with the increase in tree cover.     

Dental microwear texture analysis and diet in the Dmanisi hominins

Reconstructions of foraging behavior and diet are central to our understanding of fossil hominin ecology and evolution. Current hypotheses for the evolution of the genus Homo invoke a change in foraging behavior to include higher quality foods. Recent microwear texture analyses of fossil hominin teeth have suggested that the evolution of Homo erectus may have been marked by a transition to a more variable diet. In this study, we used microwear texture analysis to examine the occlusal surface of 2 molars from Dmanisi, a 1.8 million year old fossil hominin site in the Republic of Georgia. The Dmanisi molars were characterized by a moderate degree of surface complexity (Asfc), low textural fill volume (Tfv), and a relatively low scale of maximum complexity (Smc), similar to specimens of early African H. erectus. While caution must be used in drawing conclusions from this small sample (n = 2), these results are consistent with continuity in diet as H. erectus expanded into Eurasia.     

河北泥河湾盆地下卜庄遗址端刮器功能的实验分析

端刮器常见于旧石器时代晚期的细石器工业中,形制比较固定,在探讨人类行为、生计以及环境适应等方面具有重要的研究价值.国外的研究涉及制作工艺、使用方式与功能等多个方面,而国内的研究多为类型学分析,对其功能的研究相对薄弱.河北泥河湾盆地下 卜庄遗址出土了一定数量的端刮器遗存,本文通过模拟打制与使用实验,结合微痕分析方法,对它...     

Craniofacial biomechanics and functional and dietary inferences in hominin paleontology

Finite element analysis (FEA) is a potentially powerful tool by which the mechanical behaviors of different skeletal and dental designs can be investigated, and, as such, has become increasingly popular for biomechanical modeling and inferring the behavior of extinct organisms. However, the use of FEA to extrapolate from characterization of the mechanical environment to questions of trophic or ecological adaptation in a fossil taxon is both challenging and perilous. Here, we consider the problems and prospects of FEA applications in paleoanthropology, and provide a critical examination of one such study of the trophic adaptations of Australopithecus africanus. This particular FEA is evaluated with regard to 1) the nature of the A. africanus cranial composite, 2) model validation, 3) decisions made with respect to model parameters, 4) adequacy of data presentation, and 5) interpretation of the results. Each suggests that the results reflect methodological decisions as much as any underlying biological significance. Notwithstanding these issues, this model yields predictions that follow from the posited emphasis on premolar use by A. africanus. These predictions are tested with data from the paleontological record, including a phylogenetically-informed consideration of relative premolar size, and postcanine microwear fabrics and antemortem enamel chipping. In each instance, the data fail to conform to predictions from the model. This model thus serves to emphasize the need for caution in the application of FEA in paleoanthropological enquiry. Theoretical models can be instrumental in the construction of testable hypotheses; but ultimately, the studies that serve to test these hypotheses - rather than data from the models - should remain the source of information pertaining to hominin paleobiology and evolution.     

Incisor microwear of Sumatran anthropoid primates

Several studies have suggested that incisor microwear reflects diet and feeding adaptations of anthropoids. However, such studies have been largely qualitative, and interpretations have relied on anecdotal references to diet and tooth use reported in the socioecology literature. The current study relates incisor microwear in four anthropoid primates to specific ingestive behaviors and food types. Central incisor casts of wild-shot museum specimens of Hylobates lar, Macaca fascicularis, Pongo pygmaeus, and Presbytis thomasi were examined by scanning electron microscopy, and analyzed using a semiautomated image analysis procedure. Microwear patterns were used to generate predictions regarding diet and anterior tooth use. These predictions were evaluated using data collected during a 1 year study of feeding behavior of these same taxa in the wild (Ungar, 1992, 1994a, b). Results suggest that (1) enamel prism relief is associated with the effectiveness of etching reagents in foods, (2) dental calculus buildup results from a lack of incisor use and perhaps the ingestion of sugar-rich foods, (3) striation density varies with degree of anterior tooth use in the ingestion of abrasive food items, (4) striation breadth is proposed to relate to the ratio of exogenous grit to phytoliths consumed; and (5) preferred striation orientation indicates the direction that food items are pulled across the incisors during ingestion. It is concluded that incisor microwear studies can contribute to the understanding of diets and feeding behaviors of extinct primates. © 1994 Wiley-Liss, Inc.     

射击类带尖石制品使用微痕动态形成过程的实验研究

石镞主要是旧石器时代晚期出现的一种投射类复合武器的尖端,其使用方式一直为学术界所关注。本文以山西吉县柿子滩遗址环境背景和石器原料为参照,通过微痕实验,探讨射击类带尖石制品重复使用过程中微痕的动态形成过程。作者对21件实验标本分阶段累计射击337次,微痕观察121次。分析结果显示,射击类带尖石制品的重复使用情况可以通过微痕进行佐证。形态变化过程表明,尖端变化较为显著,指示应以动态思维考量出土石镞形态及其暗示的人类行为;测量数据显示,尖端及侧刃较为锋利、长度适中的标本,射击效果更好,存在多次使用的可能;微痕分析指示,若尖端产生层叠大中型折断式、阶梯式疤痕,装柄部位产生连续小型折断式或羽翼式疤痕,部分出现磨圆与光泽时可以考虑重复使用的可能。本项研究为揭示石镞背后所蕴含的狩猎策略、生计方式等人类行为信息提供了数据参考。     

新疆吐鲁番胜金店墓地人骨的牙齿微磨耗

本文使用不同倍率的超景深电子显微镜,对新疆吐鲁番胜金店墓地中出土的13例臼齿的颊侧微磨耗形态进行了观察和研究。通过对臼齿颊侧表面凹坑和条痕形态微磨耗的测量和统计,计算出每例牙齿的微痕数量、均长、均宽、凹坑百分比和L_h/L_v比值,按照性别和年龄分组进行人群内的数据对比分析。研究结果表明,该人群中年龄较大的个体摄入更高比例的植物类食物;两性的食物结构不存在显著性差异,男性摄入植物类食物比例略高,女性的食物结构在不同的年龄阶段有所差异。将胜金店墓地人群与不同生计方式人群的L_h/L_v比值进行人群间的差异性分析,并结合胜金店墓地的随葬品特点推测,胜金店墓地人群的食物结构以肉类食物为主,其生计模式以游牧业为主,兼营种植类经济。     

Dental microwear texture analysis: technical considerations

Dental microwear analysis is commonly used to infer aspects of diet in extinct primates. Conventional methods of microwear analysis have usually been limited to two-dimensional imaging studies using a scanning electron microscope and the identification of apparent individual features. These methods have proved time-consuming and prone to subjectivity and observer error. Here we describe a new methodological approach to microwear: dental microwear texture analysis, based on three-dimensional surface measurements taken using white-light confocal microscopy and scale-sensitive fractal analysis. Surface parameters for complexity, scale of maximum complexity, anisotropy, heterogeneity, and textural fill volume offer repeatable, quantitative characterizations of three-dimensional surfaces, free of observer measurement error. Some results are presented to illustrate how these parameters distinguish extant primates with different diets. In this case, microwear surfaces of Cebus apella and Lophocebus albigena, which consume some harder food items, have higher average values for complexity than do folivores or soft fruit eaters.     

The assessment of jaw movement direction from dental microwear

In order to resolve several controversies about unusual jaw movements such as thegosis and orthal retraction, information about direction of jaw movement is essential. Ryan (1979a,b) proposed that asymmetry of microwear striations might provide such data. In vivo occurrences of asymmetric striations on chimpanzee molars are presented and analyzed. Results suggest that either thegosis contacts commonly occur on chimpanzee molars or that Ryan's model, as developed in vitro, does not accurately apply to naturally occurring molar microwear.