Dental caries, enamel composition, and subsistence among prehistoric Amerindians of Ohio

An unusual member of the solid solution series between cristobalite and potassium ferrate(III) obtained from hydroflux

Dark octahedral crystals of K1−x [Fe1−x Si x O2] with x ≈ 0.2 were synthesized under ultra-alkaline conditions in a KOH hydroflux at 200 °C. The compound is a member of the solid solution series between SiO2 and K[FeO2]. Due to its SiO2 content, K0.8[Fe0.8Si0.2O2] is much less sensitive to moisture than K[FeO2]. The crystal structure is a stuffed cristobalite with a charged framework of vertex-sharing [MO4/2] tetrahedra (M = Fe3+, Si4+) and potassium counter ions in the large voids of the framework. It has the pseudo-symmetry and metrics of the cubic space group F d 3 ‾ m $Fd\overline{3}m$ , but adopts the tetragonal space group I41 md with four formula units in the cell. Unlike other tectosilicates of this type, the [MO4/2]− tetrahedra are not regular but distorted to disphenoids. The O atom can be modeled by a huge disk-shaped ellipsoid or, better, by split atom positions forming a six-membered ring with a diameter of 1.1 Å. The M–O distances range from 1.66(2) to 1.96(2) Å, the M–O–M angles are 135(2)°, 137(1)°, and 151(1)°.

Dental health in Northern Chile's Atacama oases: evaluating the Middle Horizon (AD 500-1000) impact on local diet

As one of the few areas apt for horticulture in Northern Chile's arid landscape, the prehistory of the Atacama oases is deeply enmeshed with that of the inter-regional networks that promoted societal development in the south central Andes. During the Middle Horizon (AD 500-1000), local populations experienced a cultural apex associated with a substantial increase in inter-regional interaction, population density, and quantity and quality of mortuary assemblages. Here, we test if this cultural peak affected dietary practices equally among the distinct local groups of this period. We examine caries prevalence and the degree of occlusal wear in four series recovered from three cemeteries. Our results show a reduction in the prevalence of caries for males among an elite subsample from Solcor 3 and the later Coyo 3 cemeteries. Dental wear tends to increase over time with the Late Middle Horizon/Late Intermediate Period cemetery of Quitor 6 showing a higher average degree of wear. When considered in concert with archaeological information, we concluded that the Middle Horizon was marked by dietary variability wherein some populations were able to obtain better access to protein sources (e.g., camelid meat). Not all members of Atacameño society benefited from this, as we note that this dietary change only affected men. Our results suggest that the benefits brought to the San Pedro oases during the Middle Horizon were not equally distributed among local groups and that social status, relationship to the Tiwanaku polity, and interment in particular cemeteries affected dietary composition.

Who were the ancient Egyptians? Dental affinities among Neolithic through postdynastic peoples

Qualitative and quantitative methods are employed to describe and compare up to 36 dental morphological variants in 15 Neolithic through Roman-period Egyptian samples. Trait frequencies are determined, and phenetic affinities are calculated using the mean measure of divergence and Mahalanobis D2 statistics for discrete traits; the most important traits in generating this intersample variation are identified with correspondence analysis. Assuming that the samples are representative of the populations from which they derive, and that phenetic similarity provides an estimate of genetic relatedness, these affinities are suggestive of overall population continuity. That is, other than a few outliers exhibiting extreme frequencies of nine influential traits, the dental samples appear to be largely homogenous and can be characterized as having morphologically simple, mass-reduced teeth. These findings are contrasted with those resulting from previous skeletal and other studies, and are used to appraise the viability of five Egyptian peopling scenarios. Specifically, affinities among the 15 time-successive samples suggest that: 1) there may be a connection between Neolithic and subsequent predynastic Egyptians, 2) predynastic Badarian and Naqada peoples may be closely related, 3) the dynastic period is likely an indigenous continuation of the Naqada culture, 4) there is support for overall biological uniformity through the dynastic period, and 5) this uniformity may continue into postdynastic times.

Population continuity vs. discontinuity revisited: Dental affinities among late Paleolithic through Christian-era Nubians

The present study revisits a subject that has been a source of long-standing bioarchaeological contention, namely, estimation of Nubian population origins and affinities. Using the Arizona State University dental anthropology system, frequencies of 36 crown, root, and intraoral osseous discrete traits in 12 late Pleistocene through early historic Nubian samples were recorded and analyzed. Specifically, intersample phenetic affinities, and an indication of which traits are most important in driving this variation, were determined through the application of correspondence analysis and the mean measure of divergence distance statistic. The results support previous work by the author and others indicating that population discontinuity, in the form of replacement or significant gene flow into an existing gene pool, occurred sometime after the Pleistocene. This analysis now suggests that the break occurred before the Final Neolithic. Samples from the latter through Christian periods exhibit relative homogeneity, which implies overall post-Pleistocene diachronic and regional population continuity. Yet there are several perceptible trends among these latter samples that: 1) are consistent with documented Nubian population history, 2) enable the testing of several existing peopling hypotheses, and 3) allow the formulation of new hypotheses, including a suggestion of two post-Pleistocene subgroups predicated on an age-based sample dichotomy.

Life stress on the Roman limes in continental Croatia

The purpose of the paper is to analyze and compare the demographic profiles and disease frequencies between a skeletal series from Zmajevac, a settlement on the Danubian limes, and a composite "non-limes" skeletal series consisting of human osteological remains from three large urban settlements to the west of the limes; roman Mursa (modern Osijek), Cibalae (Vinkovci) and Certissia (Strbinci). To determine if life stresses were different in settlements on the limes the age and sex distribution in Zmajevac was compared to the composite "non-limes" series. All skeletons were also analyzed for the presence of dental pathology, dental enamel hypoplasia, cribra orbitalia, trauma, and physical stress. Data collected from the skeletal series show that, with the exception of some indicators of physical stress, no significant differences in quality of life is evident. Both series are characterized by an under-representation of subadults from the youngest age category and by similar average adult male and female ages at death. In Zmajevac the average ages at death for adult males and females were 40.0 and 39.0 years respectively, in the composite "non-limes" series 37.4 years for both males and females. The frequencies of dental disease, subadult stress indicators, and trauma are similar in both series. The only consistent difference between the two series is noted in the frequencies of skeletal markers of physical stress, in particular the frequencies of vertebral osteoarthritis and Schmorl's defects. Total male and total female vertebral osteoarthritis frequencies in the two series are significantly different, as is the difference in total male frequencies of Schmorl's defects. Young adult males in the Zmajevac series seem to have been experiencing particularly heavy physical strain on the vertebral column. They exhibit significantly higher frequencies of both vertebral osteoarthritis and Schmorl's defects than young adult males from the composite non-limes series.

Ancient teeth and modern human origins: An expanded comparison of African Plio-Pleistocene and recent world dental samples

Previous research by the first author revealed that, relative to other modern peoples, sub-Saharan Africans exhibit the highest frequencies of ancestral (or plesiomorphic) dental traits and, thus, appear to be least derived dentally from an ancestral hominin state. This determination, in conjunction with various other lines of dental morphological evidence, was interpreted to be supportive of an African origin for modern humans. The present investigation expands upon this work by using: 1) direct observations of fossil hominin teeth, rather than data gleaned from published sources, 2) a single morphological scoring system (the Arizona State University Dental Anthropology System) with consistent trait breakpoints, and 3) data from larger and more varied modern human comparative samples. As before, a multivariate distance statistic, the mean measure of divergence, was used to assess diachronic phenetic affinities among the Plio-Pleistocene hominins and modern humans. The present study also employed principal components analysis on dental trait frequencies across samples. Both methods yielded similar results, which support the previous findings; that is, of all modern human samples, sub-Saharan Africans again exhibit the closest phenetic similarity to various African Plio-Pleistocene hominins-through their shared prevalence of morphologically complex crown and root traits. The fact that sub-Saharan Africans express these apparently plesiomorphic characters, along with additional information on their affinity to other modern populations, evident intra-population heterogeneity, and a world-wide dental cline emanating from the sub-continent, provides further evidence that is consistent with an African origin model.

Dental anthropology of central-southern, Iron Age Italy: the evidence of metric versus nonmetric traits

Discrete and metric dental traits are used to assess biological similarities and differences among 13 bioarchaeological populations located on each side of the Apennine mountains in central-southern Italy and dated to the first millennium BC. An initial hypothesis, that the mountain chain might provide a significant geographical barrier for population movement (resulting in greater biological affinities among those groups on the same side), is not supported. Instead, the samples appear to cluster more on the basis of time than geography. Archaeological evidence, however, supports an association between populations on opposite sides of the mountains and thus is in accord with the dental data. As anticipated, discrete dental traits appear to be more useful than metric dental traits in assessing such population affinities. This research represents a beginning to a better comprehension of the complexity of the biological and cultural dynamics of Italian populations during recent millennia.

Deciduous dental morphology of the prehistoric Jomon people of Japan: comparison of nonmetric characters

Morphological variations of the deciduous dentition are as useful as those of the permanent dentition for determining the biological affinities of human populations. This paper provides material on morphological variations of deciduous teeth of the prehistoric Japanese population from the Late and the Latest Jomon Period (ca. 2000-ca. 300 B.C.). The expression of nonmetric traits of the deciduous teeth in the Jomon sample shows a closer affinity with modern Japanese and Native American samples than with American White, Asiatic Indian, and African samples. However, the frequency of shoveling in deciduous upper incisors in the Jomon sample is lower than those in modern Japanese and Native American samples. The Jomon sample also expresses a much higher frequency of cusp 6 in deciduous lower second molars than seen in modern Japanese, Ainu, and Native American samples. The frequency in the Jomon sample is equal to that in the Australian Aboriginal sample, which shows cusp 6 most frequently among the samples compared. A somewhat low incidence of incisor shoveling in the Jomon sample was also reported in the permanent dentition (Turner [1976] Science 193:911-913, [1979] Am. J. Phys. Anthropol. 51:619-635, [1987] Am. J. Phys. Anthropol. 73:305-321, [1990] Am. J. Phys. Anthropol. 82:295-317; T. Hanihara [1992] Am. J. Phys. Anthropol. 88:163-182, 88:183-196). However, the frequency of cusp 6 in the Jomon sample shows no significant difference from those of Northeast Asian or Native American samples in the permanent dentition (Turner [1987] Am. J. Phys. Anthropol. 73:305-321; T. Hanihara [1992] Am. J. Phys. Anthropol. 88:163-182, 88:183-196). Evidently, some nonmetric traits express an inter-group difference only in the deciduous dentition.