Interproximal grooving and task activity in Australia

Interproximal grooving was recorded in 85 nineteenth century aboriginal skulls from Swanport in South Australia. One or more grooved teeth were noted in 41% of individuals, but the frequency of grooving in males was twice that in females. Distal surface grooving was noted in 93 teeth in contrast to only five instances of mesial grooving. The lesions were similar in appearance to those reported in many other populations--confined primarily to the premolar-molar region, located at the cementoenamel junction, directed horizontally, and usually clean-cut and free of caries. Stripping of animal sinews between the clenched posterior teeth has been recorded on film as a common task activity in traditional aboriginal society. In our opinion, task activity and not toothpicking was the likely cause of the observed interproximal grooving in the aboriginals.     

Brief communication: Subvertical grooves on interproximal wear facets from the El Sidrón (Asturias,Spain) Neandertal dental sample

The distribution of subvertical grooves on interproximal wear dental facets from the El Sidrón (Asturias, Spain) Neandertals is described and analyzed. Out of 93 teeth, 64.5% present subvertical grooves, including a high frequency (50%) on the anterior dentition. Contrary to some studies, subvertical grooves from adjacent facets perfectly overlap each other and do not interdigitate, probably forming small channels. Both the facet and the groove surface share the same polished appearance, suggesting a common origin. Statistical analyses reveal that the number of grooves is neither dependent on the degree of occlusal wear, nor on the position on the tooth or the individual's age. However, facet width is an important factor determining the number of subvertical grooves. The etiology of subvertical grooves formation on Neandertal teeth remains unclear. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Ontogenetic approach to variation in Middle Pleistocene hominids. Evidence from the Atapuerca-SH mandibles

The ontogenetic processes underlying the variation detected in the European Middle Pleistocene hominids are explored. Regulation of growth parameters of the ontogenetic trajectory of these hominid is discussed in the context of heterochrony schemes. The sample of mandibles coming from the Atauuerca-SH site is used as a study case. The variability shown by these mandibles can be arranged along a morphological gradient, and study of growth directions has shown that the remodelling patterns are in line with the existence of a single morphogenetic pattern controlling the process. In addition, the spectrum of morphology detected in the Atapuerca sample virtually encompasses the entire range of variability detected in European Middle Pleistocene samples. From a morphological viewpoint, a hypermorphic pattern seems to be the responsible for the individual variation detected in the sample. Yet, when this information is related to mandibular growth and craniofacial interactions, evidence of an interindividual gradient of somatic development for the Atapuerca hominids is provided. Several hypotheses concerning growth parameters, however, may account for this gradient. Time and rate hypermorphosis hypothesis are discussed. Coincidence of the gradient of variation detected in this sample and the general mandibular growth trajectory of living species, support the hypothesis that is “time of maturation” of the organism the key factor.     

Non-carious interproximal grooves in Arikara Indian dentitions.

The dentitions of adult Arikara Indians from the Larson site (39WW2) were examined to determine the frequency and etiology of noncarious interproximal grooves. The observations included groove morphology, loci and association with dental pathology. Approximately 30% of the individuals exhibit one or more pronounced grooves. The use of dental probes in conjunction with dietary grit is the likely responsible for interproximal grooves in this population sample.     

A review of the chronology of the European Middle Pleistocene hominid record

Over the last seventy years, European hominid fossils and associated archaeological remains have been dated by reference to the classical, fourfold glacial/interglacial subdivision of the Pleistocene. This method seemed relatively straightforward and precise especially as new discoveries were fitted into the schemes, apparently strengthening the correlations and increasing their validity. However, recent studies of deep-sea cores and terrestrial deposits, combined with new developments in relative and absolute dating, have shown that the fourfold schemes are oversimplified. This paper critically reviews some of the dating evidence from sites with hominid remains generally considered as Middle Pleistocene (ca. 700,000–128,000 BP). The hominid and archaeological remains are shown to require independent dating and a cautious approach is adopted towards the use of mammalian faunal remains as chronological indicators. The techniques and results of absolute dating are discussed with reference to present problems and future prospects. At a time of transition from an old framework to new correlations, it is inevitable that some conclusions seem tentative and others rather negative. Nevertheless, the Middle Pleistocene in Europe is more fully understood and better dated than the equivalent period in other parts of the world.     

Chin morphology and sexual dimorphism in the fossil hominid mandible sample from Klasies River Mouth

The site of Klasies River Mouth (KRM) in South Africa has produced a small sample of early Upper Pleistocene hominid remains that have been a focus for discussions of the origins of modern humans. Despite certain primitive characteristics exhibited by these fossils, proponents of a single recent origin have attributed them to early modern humans. Critics of this hypothesis have emphasized the significance of the archaic features evident in this sample, including the absence of pronounced chins among the mandibular specimens. This study compares the size range and chin morphology exhibited by the KRM mandibles with that of Neandertals, Upper Pleistocene humans, and recent humans. The extreme sexual dimorphism documented among the KRM fossils reflects the presence of a very small individual, and previous efforts to classify the KRM sample as archaic on the basis of their robusticity have failed to address the significance of this diminutive hominid. While each KRM fossil falls within the 95% envelope of variability established for chin development in a comparative modern sample, a similarly low frequency of pronounced chins is very unlikely to be found in any recent human population. The morphological pattern of the KRM mandibles is clearly distinct from that of Neandertals and of recent humans. © 1996 Wiley-Liss, Inc.     

A new molar from the Middle Pleistocene hominid assemblage of Yanhuidong,Tongzi, South China

1988年,贵州省博物馆对桐梓岩灰洞的支洞进行了最后一次发掘。2014年,在洞内第四层堆积物中鉴定出逾2000件的动物牙齿化石,以及一枚古人类上颊齿(编号:TZ-1)。1991年,铀系法测定这些次生堆积物的沉积年代约为距今24万年。本文运用高精度CT(巴黎自然历史博物馆)对TZ-1的釉质齿质界面(EDJ)和牙髓腔几何形态进行了分析。TZ-1的冠面形态有如下特征:次尖小且在远中舌侧不发育,咀嚼面轮廓呈四边形,颊舌径稍大过近中远中径,原尖舌侧齿带发育,齿尖从大到小依次为原尖、后尖、前尖和次尖。TZ-1牙髓腔的髓角与其釉质齿质界面以及釉质表面的形态都具有相关性。TZ-1的形态与M1虽有相似之处,但完全不同于1983年出土于同一层位的另两颗M1;其应被鉴定为dm2,并可被归入中中更新世的中国直立人支系。岩灰洞上臼齿PA 875的形态与建始龙骨洞PA 1279和周口店直立人等古老型直立人相似。岩灰洞另一枚刚萌发的臼齿PA 874具有凸出的次尖和长菱形的外廓,接近于爪哇型直立人Sangiran NG 91-G10;这也是智人和尼安德特人的共有衍征。但PA 874的冠面仍保留了亚洲型的齿带,因而被归入人属未定种。因出土自次生堆积,岩灰洞的三种古人类类型未必曾同时并存,但却揭示了华南地区人类演化进程中的多样面貌。     

The interpretation of patterns in dentitions

Studies of the fossil record indicate the sequence in which the shape of a phenotype has been modified during phytogeny. These data can provide a valuable starting point for theoretical embryology. Any theory which accounts for the development of a particular shape or pattern in recent animals should, by equivalent modifications, be able to account for the phylogenetic sequence of shapes. This argument is illustrated by the evolution and development of patterns in dentitions.     

New European fossil hominid material from an Acheulean site near Rome (Castel di Guido)

New fossil hominid material recovered from an Acheulean Italian archeological site is reported. It consists of two portions of femora, an occipital fragment, a fragmentary right maxilla, and a portion of parietal. Each specimen is described in detail and measurements are given. On the basis of the morphology, which includes primitive traits reminiscent of Homo erectus, and of the archeological, paleontological, and stratigraphical association, these new fossils are referred to the early European group.     

Changes in the pattern of tooth wear from prehistoric to recent periods in Japan

Although a number of studies have been performed on interpopulational variation of tooth wear patterns in recent humans, the major interest in the study of tooth wear so far has been in reconstructing the subsistence and behavior of prehistoric populations, and hence research on wear pattern changes in historic times has been superficial. The present study investigated temporal change in the pattern of wear on the permanent dentition of the Japanese through comparison of the following five groups: prehistoric hunter-gatherers, prehistoric agriculturists, medieval, premodern, and recent populations. The pattern of reduction of occlusal wear severity across thesechronological groups was not similar between the anterior and posterior portions of the dentition. Occlusal wear on the anterior teeth was noticeably lighter in the prehistoric agriculturists and later populations than in the prehistoric hunter-gatherers, while clear reduction of occlusal wear on the posterior teeth occurred after medieval times. The temporal variations in the degree of mesiodistal crown diameter loss due to wear and its anterior-posterior gradient within the dentition are generally consistent with those observed in the occlusal wear pattern. Possible causative factors of these temporal changes in the wear pattern are discussed. Am J Phys Anthropol 109:501–508, 1999. © 1999 Wiley-Liss, Inc.     

Changes in the lower premolar-size sequence during hominid evolution. Physlogenetic implications

The size relationship between the crown area of the lower canines (Cs), third (P3s) and fourth premolars (P4s), and first molars (M1s) in hominids is examined by means of the regression analysis. The lower P3 seem to be under the influence of those factors that control both the size of the anterior and posterior teeth, and the P4:P3 size ratio is related to the relative size of the anterior and posterior dentitions. So, the P4>P3 sequence is associated with the megadontia and hipermegadontia of the posterior teeth, whereas the expansion of the anterior teeth produces the P3>P4 sequence. We consider the P4:P3 size ratio as an excellent indicator of the taxonomic and philogenetic status of fossil hominids.     

The view from the Lincoln Cave: mid- to late Pleistocene fossil deposits from Sterkfontein hominid site, South Africa

The Lincoln-Fault cave system lies adjacent to the Sterkfontein Cave system in the Cradle of Humankind World Heritage Site, Gauteng Province, South Africa. Lincoln Cave contains a mid- to late Pleistocene fossiliferous deposit which has been dated using uranium series methods to between 252,600+/-35,600 and 115,300+/-7,700 years old. Although speleologists presumed that there was no connection between the Lincoln Cave and Sterkfontein Cave systems, results of excavations conducted in 1997 suggest a link between the deposits. Detailed comparisons of artifacts, fauna, hominid material, and a statistical correspondence analysis (CA) of the macromammalian fauna in the deposits strongly support this hypothesis. The recovery of Early Acheulean-type artifacts from the Lincoln Cave suggests that older artifacts eroded out of Sterkfontein Member 5 West and were redeposited into the younger Lincoln Cave deposits. The close physical proximity of these deposits, and the nature of the material recovered from them, indicates that the material was probably redeposited via a link between the two cave systems. Although faunal mixing is present, it is possible to say that large carnivorans become more scarce at Sterkfontein during the mid- to late Pleistocene, while small canids and felids appear to become more abundant, indicating that large and small carnivorans probably varied their use of the site through time. This may also reflect an increasing presence of humans in the Sterkfontein area during the mid- to late Pleistocene.     

Task activity and anterior tooth grooving in prehistoric California indians.

Abraded grooves have been observed on the anterior teeth of all the adults in a small population of prehistoric California Indians. These dental effects show considerable variety, appearing on maxillary and mandibular teeth, on approximal and occulusal surfaces, and either isolated or bilaterally aligned. Although many of the grooves are indistinguishable from those reported for other prehistoric populations, their variety illustrates the limited applicability of etiological hypotheses previously proposed to account for such effects. It is suggested that the grooves represent traces of a task activity involving the pulling of fibrous materials across the teeth.     

Newly recognized Pleistocene human teeth from Tabun Cave, Israel

Seven human teeth from Tabun Cave, Israel, curated at the Natural History Museum London since 1955, are of uncertain provenance and identity. They are all from the upper dentition, without duplications, and are characterized by a similar preservation. The Catalogue of Fossil Hominids (1975) suggested that they might have derived from Tabun Layer A (Bronze Age to Recent). However, one of us (AC) noted some distinctive features of these teeth that warranted further study. They are here assigned to a single individual, Tabun BC7. Their morphology and metrics were then compared with the frequency of Late Pleistocene and Early Holocene groups from Europe, North Africa and Middle East. A fragment of the right M3 crown of Tabun BC7 was removed for ESR and U-analysis, and it was determined that only samples from Layer B have similar dose values. Using the sediment dose values of layer B, preliminary age estimates of 82 +/- 14 ka (early U-uptake) and 92+/-18 ka (linear uptake) were obtained. U-series disequilibrium determined from other samples attributed to Layer B resulted in a U-uptake history close to linear uptake, giving a very comparable age estimate of 90(+30)(-16) ka. The dose value previously obtained on an enamel fragment from the Tabun C1 dentition is nearly double the value measured for BC7, and tentative age estimates for C1 were in the range of 143+/-37 ka. However, due to uncertainties in the exact provenance of the human fossils, we cannot confirm that C1 is older than the new tooth sampled here, and both C1 and BC7 can be attributed to Layer B on chronological grounds. On the basis of chronology, dental morphology and metrics, the specimen named Tabun BC7 was identified as a probable Neanderthal.     

中国旧石器时代早、中期石器技术多样性研究的新进展

关于中国石器技术发展轨迹和特点,其中一种观点认为,在更新世大部分时间内,中国石器技术以第1模式为主。本文结合近年的考古发现和研究成果,对中更新世早期至距今约4万年的中国石器技术面貌进行了简要总结。这段时间内的中国石器技术呈现出明显的多样性和复杂性,尤其自晚更新世以来,多种石器技术体系并存,其中包括以手斧、手镐和薄刃斧等大型工具为特色的阿舍利技术体系、以盘状石核和各类小型工具为特征的小型石片石器技术体系、以勒瓦娄哇石核和尖状器为特点的莫斯特技术体系、以及以基纳型刮削器为主的莫斯特技术体系,后两者具有明显的旧石器时代中期技术特点。多种石器技术体系共存,这一现象反映了技术发展的区域性和该阶段人群构成的多样性,这为探讨古人类环境适应行为以及区域间人群扩散交流提供了重要信息。