A new application of dental wear analyses: estimation of duration of hominid occupations in archaeological localities

Characterization of settlement patterns is one of the core concepts in archeological research. The duration of an occupation is usually estimated through zooarchaeology (e.g., density of remains, cementochronology) and is limited by taphonomic processes and sample size. We propose a new application of dental wear methods for estimating the relative duration of hominid settlements in Paleolithic sites. Dental microwear is known to be sensitive to seasonal changes in diet. In this new application we use microwear scratch counts to estimate the variation in the dietary signal of various ungulate species. We propose that this variation is correlated to the duration of site occupation. Each season presents a limited and different set of food resources available in the environment. If animals are sampled only during a specific season (i.e., during a short term occupation) then they would be expected to have a dental wear signal with little variation. On the other hand, a greater diversity of food is available across different seasons. Therefore, if game animals are hunted through various seasons during long occupation periods, then they would be expected to have more variable dental wear. The application of this technique to the Middle Paleolithic site of Arago Cave (France), where various types of occupations occurred, supports this hypothesis. When combined with multidisciplinary studies of archaeological localities (seasonality in particular), this new application of dental wear analysis presents valuable information about hominid settlements and behavior. We contextualize our data with results from lithic and zooarchaeological analyses from Arago. These results reveal the presence of both high and low mobility groups of Homo heidelbergensis throughout the sequence of the Arago Cave.     

Multi-proxy approach detects heterogeneous habitats for primates during the Miocene climatic optimum in Central Europe

The present study attempts to characterize the environmental conditions that prevailed along the western shores of the Central Paratethys and its hinterland during the early middle Miocene at the same time t primates reached their peak in species diversity in Central Europe. Based on faunal structure (using cenograms), paleotemperature reconstruction (using cricetid diversity), and dietary reconstruction of ruminants (using molar micro-wear analyses), four faunal assemblages are used to characterize the regional environmental context. The cenograms for Göriach and Devínska Novà Ves Zapfe's fissure site support the presence of mosaic environments with open areas under rather humid conditions. This is also supported by the dental micro-wear analyses of ruminants. The species of Palaeomerycidae were most probably the only predominant browsers. Surprisingly, the three cervids, Dicrocerus, Heteroprox, and Euprox, were highly involved in grazing. Pseudoeotragus seegrabensis was likely a generalist and the two specimens assigned to the second bovid, Eotragus clavatus, were browsers. The two species of tragulids plot between fruit browsers and generalists. Moreover, paleotemperatures based on cricetid diversity estimate mean annual temperature at about 18 °C with potential high seasonal variations. These data support the predominance of mosaic landscapes along the western shores of the Central Paratethys and its hinterland during the Miocene Climatic Optimum as primates reach a peak in species diversity. This result lends credence to the hypothesis that environmental heterogeneity favours radiation among mammals, and that the specific environmental context of the Central Paratethys western border might explain the high diversity of the middle Miocene primates.     

Microwear, mechanics and the feeding adaptations of Australopithecus africanus

Recent studies of dental microwear and craniofacial mechanics have yielded contradictory interpretations regarding the feeding ecology and adaptations of Australopithecus africanus. As part of this debate, the methods used in the mechanical studies have been criticized. In particular, it has been claimed that finite element analysis has been poorly applied to this research question. This paper responds to some of these mechanical criticisms, highlights limitations of dental microwear analysis, and identifies avenues of future research.     

石制品微磨痕分析的实验性研究

以扫描电子显微镜为主要手段,依据Keeley的实验方法,对实验和 “盲测” 的燧石制品进行了微磨痕 (microwear) 的观察分析,验证了该方法的可行性;表明在石制品的加工方式、加工对象与其可能的残留信息——石制品的使用痕迹,如以光泽、条痕、破损疤为主要特征的微磨痕之间所具有的某种实验模式,初步掌握了微磨痕研究的实验方法,取得了一些结果,并予以检验;利用扫描电镜观察 “晶体破损” 与否,可能是鉴定石制品使用或未使用的一种行之有效的方法。     

Microwear evidence for Plio-Pleistocene bovid diets from Makapansgat Limeworks Cave, South Africa

Makapansgat Limeworks Cave is a well-known Australopithecus africanus bearing locality that has spawned a considerable amount of paleoecological research because of its hominin component. Most recently, the paleoecology of this Plio-Pleistocene site has been studied by determining the diet and habitat of other extinct taxa, particularly the bovids. The diets of seven bovids (Aepyceros sp., Gazella vanhoepeni, Makapania broomi, Parmularius braini, Redunca darti, Tragelaphus sp. aff. T. angasii, and Tragelaphus pricei) have now been classified using taxonomic uniformitarianism, ecomorphology, stable carbon isotopes, and mesowear analysis. Here, dental microwear is applied to the same bovids for additional comparison and to further elucidate the strengths and weaknesses of each method. The different dietary proxy methods noted provide a temporal continuum, with genetic signals such as ecomorphology and taxonomic uniformitarianism indicating behavioral adaptations over geologic time, while nongenetic data such as stable carbon isotopes and mesowear reflect different aspects of average diet over extended portions of an animal's life, and dental microwear provides dietary snapshots.Microwear separated an extant baseline of ten bovid species into expected dietary categories and the Makapansgat bovids clearly fell into two groups with the same degree of separation as between extant grazers and browsers. The results indicate that a multidisciplinary approach produces a more accurate and robust reconstruction of past diets. In sum, the microwear analysis is in-line with the isotope and mesowear results, which suggest a stronger browsing component than either taxonomic uniformitarianism or ecomorphology imply.     

Microwear and morphology: functional relationships between human dental microwear and the mandible

Microscopic pits and scratches form on teeth during chewing, but the extent to which their formation is influenced by mandibular morphology is unknown. Digitized micrographs of the base of facet nine of the first, second, and third mandibular molar were used to record microwear features from an archaeological sample of modern humans recovered from Semna South in northern Sudan (n=38; 100 BC to AD 350). Microwear patterns of the molar row are correlated with mandibular corpus width and depth, and with mandibular length. Variations in shear and compression at the base of facet nine during chewing were inferred. It may be that some correlations between microwear and mandibular morphology are predictable, reflecting similar aspects of masticatory loading, though the full extent of the relationship remains to be resolved.     

Aspects of tool production, use, and hafting in Palaeolithic assemblages from Northeast Africa

A detailed microwear study was performed on several assemblages from Northeast Africa to provide an anthropological scenario of late middle and upper Pleistocene populations in the Nile Valley and adjacent zones. Results are presented from the wear analysis of five sites, and an interpretation is provided of the keystones of MSA behaviour and its evolution throughout about 150,000 years. Locally available raw materials were predominantly used. Different tool uses were identified based on wear evidence, and it was demonstrated that stone tools were hafted from at least the early MSA onwards. In particular stone tools for which hafting was a necessity for their use, such as percussion implements and projectiles, were hafted. Both tool functions remain important throughout the Middle Stone Age. For tools with other uses, such as knives, hafting was demonstrated in certain cases. Hafting proved to be integrated into the stone tool production process, indicating a certain degree of anticipation and planning. Ochre was present at most of the sites in different forms, and mainly seems to have served a utilitarian function, and a possible symbolic use. The included sites could be interpreted as specialised sites, and in all but one case were situated in a production context. The evidence indicates the existence of a regional settlement system with different logistic nodes.     

牙齿微痕研究在古食性重建中应用的简述

在古食性研究中,牙齿微痕是指动物在咀嚼食物的过程中在牙齿咬合面上产生的微观磨损痕迹。不同食性的动物具有不同的牙齿微痕特征,因此可以通过研究牙齿微痕特征来重建灭绝动物的古食性,为探讨动物演化和古生态环境变化提供重要信息。本文主要介绍牙齿微痕作为一种简单而高效的古食性重建方法在古生物领域中的应用。本文主要内容包括牙齿微痕的发展历史,形成机理与应用,以及近年来被广泛应用的牙齿微痕定量化分析——表面纹理分析法,并在最后浅谈了牙齿微痕研究未来可能研究的方向。     

激光共聚焦显微镜在微痕定量分析中的应用综述

微痕分析是石器、骨器、牙齿等工艺、功能研究的常用方法,但无论是高倍还是低倍等常用方法,受限于体式光学显微镜、扫描电镜等观察方法,微痕分析通常很难进行原位定量分析,因此微痕分析的定量化是目前学术界遇到的主要问题。近年来随着激光共聚焦显微镜（LSCM）在微痕分析中的应用,微痕定量化在西方学术界得到了新的实践和进展。本文主要介绍激光共聚焦显微镜的原理及其在微痕分析中的应用案例,以期促进微痕分析在中国的进一步发展。     

Folivory or fruit/seed predation for Mesopithecus, an earliest colobine from the late Miocene of Eurasia?

Here we compare dental microwear textures from specimens of the fossil genus Mesopithecus (Cercopithecidae, Colobinae) from the late Miocene of Eastern Europe with dental microwear textures from four extant primate species with known dietary differences. Results indicate that the dental microwear textures of Mesopithecus differ from those of extant leaf eaters Alouatta palliata and Trachypithecus cristatus and instead resemble more closely those of the occasional hard-object feeders Cebus apella and Lophocebus albigena. Microwear texture data presented here in combination with results from previous analyses suggest that Mesopithecus was a widespread, opportunistic feeder that often consumed hard seeds. These data are consistent with the hypothesis that early colobines may have preferred hard seeds to leaves.