Dental Metrics Research Articles

Variation in white‐tailed and mule deer dental metrics is associated with precipitation gradients in the Americas

AbstractInvestigating the relationship between the physical environment and organismal adaptation is crucial to understanding the selective pressures that drive mammalian evolution. Of the varied approaches to exploring this relationship, macroscopic tooth wear analyses have become widely used due to their economic and simple methodologies. However, more work is needed to understand how assessments of wear patterns operate within finer levels of dietary and environmental contexts. It is specifically unclear if and how tooth wear differs inter‐ and intraspecifically between geographically widespread, large‐bodied mammalian populations. This project characterizes molar hypsodonty indices and mesowear scores of white‐tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) populations across North and Central America, investigating if and how molar wear and morphology vary over the deer's large and ecologically variable geographic distribution. While mesowear scores generally do not strongly track environmental signals within and between Odocoileus species, hypsodonty indices reveal a strong correlation between crown height and aridity, which likely represents an adaptive response to abrasive diets in areas with low precipitation.

High‐precision body mass predictors for small mammals: a case study in the Mesozoic

AbstractBody mass is a pivotal quantity in palaeobiology but must be inferred from an imperfect fossil record. We analyse the performance of regression models derived from various dentoskeletal predictors in mammals to inform fossils from the early, Mesozoic history of this radiation. Our focus is on the critical small end of the size spectrum; critical because the earliest mammals were small, because small size persisted onto the stems of the major extant radiations, and because small mammals compose a large proportion of crown diversity. The sampling strategy is diverse in terms of both phylogeny and skeletal predictors: the former allows a general application, while the latter enables comparison of various models. Linear regressions based on extant small mammals indicate a universal correlation of body mass with observed measurements, but with clear differences in precision. Postcranial predictors outperform jaw and dental metrics, with certain femoral joint dimensions providing surprisingly precise predictions. Our results indicate complex patterns of size evolution within the small‐bodied category, including the possibility that multiple Mesozoic species approached the theoretical lower limit of mammalian body size. The ability to study such dynamics only becomes possible when predicting body mass within a strict, highly focused phylogenetic context. The heuristic value of the models we provide here is not limited to the Mesozoic but is applicable to small‐bodied mammals of any geologic age.

STARC OSTEOARCH: An open access resource for recording and sharing human osteoarchaeological data

AbstractThis paper introduces an open access resource for recording and sharing macroscopic data on archaeological human skeletal remains: STARC OSTEOARCH. The resource was developed using a cloud collaboration service, Airtable, and it accommodates data collection on individual skeletons as well as disassociated commingled remains. The attributes covered include key information on demography (sex and age‐at‐death), taphonomy (zonation, anatomical preservation, weathering, fragmentation, and other types of post‐mortem alteration), diet (dental diseases and dental wear), mechanical stress (entheseal changes, osteoarthritis, Schmorl's nodes, and vertebral arthritis), biodistances (cranial metrics and nonmetrics and dental metrics and nonmetrics), and various pathological lesions. References and key descriptions of the categories per attribute have been incorporated in the resource to facilitate raw data sharing, which can be achieved using Airtable's sharing functionality. This initiative aims at promoting standard practices in the field and facilitating data collection and sharing.

Plio-Pleistocene African megaherbivore losses associated with community biomass restructuring.

Fossil abundance data can reveal ecological dynamics underpinning taxonomic declines. Using fossil dental metrics, we reconstructed body mass and mass-abundance distributions in Late Miocene to recent African large mammal communities. Despite collection biases, fossil and extant mass-abundance distributions are highly similar, with unimodal distributions likely reflecting savanna environments. Above 45 kilograms, abundance decreases exponentially with mass, with slopes close to -0.75, as predicted by metabolic scaling. Furthermore, communities before ~4 million years ago had considerably more large-sized individuals, with a greater proportion of total biomass allocated in larger size categories, than did later communities. Over time, individuals and biomass were redistributed into smaller size categories, reflecting a gradual loss of large-sized individuals from the fossil record paralleling the long-term decline of Plio-Pleistocene large mammal diversity.

Agreement and error rates associated with standardized data collection protocols for skeletal and dental data on 3D virtual subadult crania

Observer error and agreement rates for craniometrics, odontometrics, and cranial and dental morphological traits have been inconsistently evaluated on three-dimensional cranial reconstructions and almost never assessed on subadult individuals. This study uses a computed tomography (CT) scan sample of 12 subadults aged between birth and 20 years from the Subadult Virtual Anthropology Database (SVAD) to evaluate intra- and inter-observer error and agreement rates associated to these four types of data on virtual crania. Forty-eight cranial landmarks, 33 standard inter-landmark distances (ILDs), 13 cranial macromorphoscopic traits, four permanent and four deciduous dental landmarks and measurements per tooth, and 21 permanent and 12 deciduous dental morphological traits were collected on each individual. Results matched or improved on published standards for dry bones, teeth, or dental casts. Technical Error of Measurement (TEM) associated with metric data ranged from 0.00 mm to 0.99 mm and relative TEM ranged from 0% to 5.76%. Cohen’s kappa coefficient values for agreement on morphological traits scores were above K = 0.5 for 90% of the traits. Type III cranial landmarks showed higher error rates than Type I and II cranial landmarks. Agreement on dental morphology scores seemed influenced by observer experience and rater agreement improved when using di- or tri-chotomized grades. Skeletal maturity did not significantly affect error rates, meaning most craniofacial and dental metrics and morphological traits can be reliably obtained from virtual subadult crania.

Assessing error in human dental measurements: a comparison of resin casts, plaster casts, and dental enamel

Technical advances in 3D morphometrics and other forms of digital analysis allow for detailed measurements of dental metrics yet, consistently, dental anthropologists show a publishing preference for measurements using dental calipers. It is possible that this preference reflects the often complex field settings, wide global distribution of sample collections, or the simple fact that calipers are a relatively low maintenance and low cost technology. Similarly, in bioarchaeological studies, dental casts are often measured when field seasons or collections based trips do not allow ample time to measure the original teeth. As such, this study aimed to assess differences among measurements of plaster casts, resin casts, and dental enamel to determine if variables such as material softness could lead to measurement error. Results of a paired t-test demonstrate no statistically significant difference in dental measurements. Likewise, while plaster casts exhibited overall smaller mean (and individual) measurements than enamel and resin the differences (around 0.039 mm on average) are negligible. We, therefore, conclude that casts can be used in place of original teeth, where needed, and which material type is “best” can be determined by the researcher’s preferred medium.

Bridging the gap: Using biological data from teeth to comment on social identity of archeological populations from early Anglo-Saxon, England

Human teeth are storytellers, in that, through analysis of their size and shape osteoarchaeologists are able to ‘talk’ to the dead and translate biological data into social meaning. This concept has been explored in parts of the world through investigations of biological similarity and kinship, but few have focused in depth on early medieval populations who emphasized the importance of family and kinship. This paper presents the results from four early Anglo-Saxon cemeteries which highlight the utility of dental metrics in identifying biological similarity within the skeletal assemblages. 5988 mesiodistal and buccolingual measurements were recorded from the identifiable permanent dentition of adult individuals from early Anglo-Saxon cemeteries in the UK counties of Cambridgeshire and Kent. Results from statistical hierarchical cluster analysis of dental metric data revealed that it was possible to identify individuals within the cemetery sites that were more similar to one another according to their dental metrics. This similarity was not attributed statistically to biological sex or shared familial environment, as similarity between individuals could be found between males and females and few significant differences were found across the sites sampled. It was found that tooth metrics provided a meaningful biological dataset from which current theories regarding the identity of Anglo-Saxon individuals and families could be refined and improved. These types of data are useful as building blocks which help to bridge the gap between social constructs and human skeletal remains in order to substantiate interpretations about past populations in more significant ways. This work supports the need for multidisciplinary approaches to bioarchaeological investigations of past people while highlighting the utility of human dentition to enhance such areas of study.

Reassessment of the cranial and dental data from the Upper Paleolithic site of Kostenki 15

In the article we present new results of the study of the child skull found in a burial at the Upper Paleolithic site of Kostenki 15 (Gorodtsov site). While the CT analysis of the earlier reconstructed skull revealed high level of destruction of the morphologically important landmarks which prevents from using the conventional cranial metric characteristics of the individual in population studies, the analysis of its dental morphology was shown to be much more informative. Our study revealed that the upper incisors and lower molars of the sample display a specific complex of non-metric traits which combine European (4-cusped first molars) traits with such Asian characteristics as shovel-shaped upper lateral incisors, odontoglyphic patterns on the first lower molars, and morphology of the second lower deciduous molars. The results of the statistical analysis of the dental metrics does not match with the hypothesis on close biological affinities of the Kostenki 15 child with Předmostí and Dolní Věstonice populations put forward by Yakimov but again revealed intermediate European-Asian position of the Kostenki 15 sample. Several European samples including those from the Pavlov, Cap Blanc and Grotte de la Balauzière sites and one Siberian sample from the Malta settlement demonstrate the highest level of similarity with the Kostenki 15. Apparently, it can be argued that the results of our study suggest long distance migrations in Eurasia as early as the Upper Paleolithic.

Evaluación de la métrica dental para la estimación sexual en restos humanos del sudeste de Pampa y noreste de Patagonia

El objetivo de este trabajo es poner a prueba un método odontométrico para estimar el sexo a partir de la medida de los diámetros bucolinguales del cuello del canino superior y de ambos segundos molares permanentes, así como discutir su utilidad y aplicación en contextos mortuorios de cazadores-recolectores del Holoceno tardío, correspondientes al curso inferior del río Colorado, el curso medio del río Negro, la región de San Blas-Isla Gama y el área Interserrana. De los 41 individuos analizados con información sexual previa, obtenida mediante procedimientos osteológicos convencionales, fue posible estimar el sexo desde la métrica dental en el 87,8% (36 individuos). En el 83,3% de los casos, el sexo inferido coincide con la información previamente conocida. Las medidas obtenidas para el canino superior en primer lugar y para el segundo molar superior en segundo, ofrecen una alta confiabilidad para la estimación sexual, mientras que para el segundo molar inferior los porcentajes de casos correctamente estimados son relativamente menores. El método es útil para ser aplicado en individuos prehispánicos procedentes de la transición pampeano-patagónica oriental y noreste de Patagonia, y en menor medida, en aquellos recuperados en el área Interserrana de la región pampeana. Se destaca la importancia de la puesta a prueba de este método con anterioridad a su aplicación en restos bioarqueológicos de otras regiones vecinas.

Factors affecting molar size in Sus scrofa

Teeth are thought to be less affected than post-cranial elements by factors such as age, region, sex, and post-Pleistocene climate change, making changes in tooth size a better gage of domestication-induced morphological change in Sus scrofa. Rigorous empirical evaluation of this assumption, however, has been lacking. Here we examine the impact of multiple factors on molar size in an assemblage of modern wild boar from Southwest Asia, as well as a large assemblage of ancient S. scrofa from an archaeological site in southeastern Turkey dated to 11,600 cal. BP. We find that age related interstitial wear has a profound impact on molar lengths. Comparisons of length measurements of S. scrofa molars should only be made if one strictly controls for the state of wear, as well as the stage of crown development and eruption in third molars. Breadth measurements, on the other hand, are little affected by progressive wear and, as a result, are preferable to length measurements in the analysis of molar size in S. scrofa. We also evaluate the impact of logarithm size index (LSI) scaling on molar dimensions. Molar lengths are subject to a number of factors that distort meaningful patterning rendering LSI values of length dimensions of little utility in the evaluation of molar size in S. scrofa. With the exception of the upper first molar, LSI values of molar breadths appear to both capture and amplify patterns seen among unconverted measurements of individual teeth. Our evaluation also confirms the assumption that the size of post-cranial elements is more profoundly affected than molars by factors such as region and Post-Pleistocene climate change. While sexual dimorphism also has a greater impact on the size of post-crania than on molars, the degree of sexual dimorphism in molar breadths, as well as in M3 lengths, is still substantial and must be taken into account in any study of S. scrofa molar size. Before interpreting downward shifts in molar size as an indicator of domestic status, archaeozoologists need to first to consider the possible impact of differences in the proportions of males and females in archaeological assemblages. We conclude with a number of recommendations for new protocols for the analysis of S. scrofa dental metrics. We also offer observations about the impacts of factors like region, sex, and change over time on the size of the molars of this species that may open up new areas of research.

Dental Variation in Megabats (Chiroptera: Pteropodidae): Tooth Metrics Correlate with Body Size and Tooth Proportions Reflect Phylogeny

Variation in the dentition yields insight into the evolutionary history of Mammalia. However, to date, there has been limited research on the dental variation in Pteropodidae, a family of bats found throughout sub-Saharan Africa, Southeast Asia, and Oceania. Most species are large, diurnal, non-echolocating, and eat fruit or nectar. Pteropodids are of significant concern in conservation due to rapidly declining populations resulting from habitat loss, climate change, and their impacts on agriculture and disease. We collected dental metrics from the mandibular postcanine teeth of 101 pteropodid specimens spanning six species within the family to test three hypotheses: H1) dental metrics are significantly different across pteropodid species; H2) variation in pteropodid dental metrics is associated with variation in body size; and H3) variation in pteropodid dental proportions is associated with phylogenetic relatedness. We find that dental linear metrics vary significantly across pteropodids and are significantly associated with body size. In contrast, dental proportions of pteropodids reflect phylogenetic relationships. We propose that the combination of approaches for quantifying postcanine dental variation can elucidate and refine our understanding of the various selective forces that shaped the Pteropodidae radiation.

Genetic contributions to dental dimensions in brown-mantled tamarins (Saguinus fuscicollis) and rhesus macaques (Macaca mulatta).

The use of dental metrics in phylogenetic reconstructions of fossil primates assumes variation in tooth size is highly heritable. Quantitative genetic studies in humans and baboons have estimated high heritabilities for dental traits, providing a preliminary view of the variability of dental trait heritability in nonhuman primate species. To expand upon this view, the heritabilities and evolvabilities of linear dental dimensions are estimated in brown-mantled tamarins (Saguinus fuscicollis) and rhesus macaques (Macaca mulatta). Quantitative genetic analyses were performed on linear dental dimensions collected from 302 brown-mantled tamarins and 364 rhesus macaques. Heritabilities were estimated in SOLAR using pedigrees from each population, and evolvabilities were calculated manually. Tamarin heritability estimates range from 0.19 to 0.99, and 25 of 26 tamarin estimates are significantly different from zero. Macaque heritability estimates range from 0.08 to 1.00, and 25 out of 28 estimates are significantly different from zero. Dental dimensions are highly heritable in captive brown-mantled tamarins and free-ranging rhesus macaques. The range of heritability estimates in these populations is broadly similar to those of baboons and humans. Evolvability tends to increase with heritability, although evolvability is high relative to heritability in some dimensions. Estimating evolvability helps to contextualize differences in heritability, and the observed relationship between evolvability and heritability in dental dimensions requires further investigation.

Anthropological and Forensic Aspects of Odontological Variation in Two Contemporary Australian Populations

The utilization of odontometric variation as a discriminator between modern human groups continues to decline, despite its value in both anthropological and forensic contexts. Traditional odontometric methods, coupled with advanced statistical methods, are applied to illustrate the continuing usefulness of these techniques. The ability to discriminate between the major population groups (Caucasoid and Mongoloid) in the Sydney region of Australia, absed on dental dimensions, is extremely valuable in the forensic identification of individuals. Furthermore, metric variation in the dentition of these contemporary populations is poorly understood in this region of the world. The utility of variation in tooth dimensions in discriminating between these two groups is explored. Dental stone casts of the permanent maxillary and mandibular dentition of 198 individuals were made, and mesiodistal and buccolingual crown diameters were recorded for each tooth. Both univariate and multivariate analyses were used to investigate differences in linear and areal dimensions, as well as the predictive value of these measures in a forensic contect, using discriminant function analysis (DFA). DFA produced separation of Caucasoids and Mongoloids with a success rate of 93.9% on the basis of these measurements. Separation of the groups was most apparent in the mesiodistal and buccolingual dimensions of the maxillary first premolar (P1), the mesiodistal diameter of the maxillary second premolar (P2), and the mesiodistal dimension of the mandibular first premolar (P1). The results from this study further highlight the usefulness of dental metrics in forensic applications and contribute to our knowledge of the variation of these features in contemporary human populations.

A new multivariate method for determining sex of immature human remains using the maxillary first molar.

This study investigated the use of sexually dimorphic metrics of the first permanent maxillary molar (M1 ) to determine sex in adult and immature individuals within and between populations. Ten M1 dimensions were measured in 91 adults (19-55 years) and 58 immatures (5-18 years) from two English populations, one of documented sex (Spitalfields crypt) and another of morphologically-assigned sex (Black Gate). Preliminary statistical analysis was undertaken to explore bilateral differences and variation by age and sex, followed by multivariate analyses to predict sex from dental metrics. Both cross-validated linear discriminant analysis and binary logistic regression predicted biological sex consistent with known sex in 94.6% of adults and 90.9% of immatures. When functions extracted from the Spitalfields data were used to assign sex to Black Gate adults, consistency with morphological sex varied from 83.3% to 57.7%. A new function developed on Black Gate resulted in only a 4.8% increase in maximum accuracy but reduced bias. The immature cohort comprised 19 (52.8%) males and 17 (47.2%) females. This study demonstrates substantial sexual dimorphism in a single tooth which is commonly preserved in archaeological and forensic contexts. It successfully assigns biological sex to immatures from 5 years of age with substantially greater accuracy than any other morphological or metric method. We suggest that accurate cross-population functions based on dentition require a trade-off between accuracy and applicability, and that functions extracted from populations of documented sex can be used to assign sex to other archaeological and forensic remains.

Dental size variability in Central African Pygmy hunter-gatherers and Bantu-speaking farmers.

Odontometric studies of African populations show high within-group variation in tooth size. Overall, North Africans exhibit smaller dimensions than groups from eastern and southern sub-Saharan regions, but no previous studies have analyzed the full dental metrics among extant African Pygmy hunter-gatherers and Bantu-speaking farmers. Furthermore, the population variability in tooth crown sizes from equatorial rainforest regions remains to be elucidated. The mesiodistal and buccolingual diameters of the permanent teeth (I1-M2) were measured in vivo using high-resolution replicas from Baka Pygmies and Mvae and Yassa Bantu-speakers from Cameroon (western Africa). Analyses of variance were used to record sex-related and population-level differences in tooth sizes, and a principal component analysis of geometrically scaled measures was used to plot the odontometric variability among groups. Cameroonian Baka Pygmies differ in dental size from their Bantu-speaking neighbors. Molar teeth are larger in Pygmies than in Bantu individuals, while the anterior dentition is larger in the Bantu. Baka males exhibit significantly larger teeth than females, whereas sexual dimorphism in non-Pygmies is only present in the anterior dentition. Odontometric patterns and the degree of sexual dimorphism in dental size differ among Central African groups, indicating adaptation to their different forager and farmer lifestyles. In particular, the admixture of Bantu-speakers in Baka populations is smaller than that in other western Pygmy groups. The greater dental phenetic diversity in Baka compared to that of the smaller-toothed farmers suggests that ecogenetic and microevolutionary factors are influencing a particular divergence scenario.

Was Mesopithecus a seed eating colobine? Assessment of cracking, grinding and shearing ability using dental topography

Extant colobine monkeys have been historically described as specialized folivores. However, reports on both their behavior and dental metrics tend to ascribe a more varied diet to them. In particular, several species, such as Pygathrix nemaeus and Rhinopithecus roxellana, are dedicated seasonal seed eaters. They use the lophs on their postcanine teeth to crack open the hard endocarp that protects some seeds. This raises the question of whether the bilophodont occlusal pattern of colobine monkeys first evolved as an adaptation to folivory or sclerocarpic foraging. Here, we assess the sclerocarpic foraging ability of the oldest European fossil colobine monkey, Mesopithecus. We use computed microtomograpy to investigate the three-dimensional (3D) dental topography and enamel thickness of upper second molars ascribed to the late Miocene species Mesopithecus pentelicus from Pikermi, Greece. We compare M. pentelicus to a sample of extant Old World monkeys encompassing a wide range of diets. Furthermore, we combine classic dietary categories such as folivory with alternative categories that score the ability to crack, grind and shear mechanically challenging food. The 3D dental topography of M. pentelicus predicts an ability to crack and grind hard foods such as seeds. This is consistent with previous results obtained from dental microwear analysis. However, its relatively thin enamel groups M. pentelicus with other folivorous cercopithecids. We interpret this as a morphological trade-off between the necessity to avoid tooth failure resulting from hard food consumption and the need to process a high amount of leafy material. Our study demonstrates that categories evaluating the cracking, grinding or shearing ability, traditional dietary categories, and dental topography combine well to make a powerful tool for the investigation of diet in extant and extinct primates.

Cranial sexual dimorphism in the Kinda baboon (Papio hamadryas kindae).

The smallest extant member of genus Papio, the Kinda baboon exhibits low sexual dimorphism and a distinctive cranial shape. Ontogenetic scaling accounts for most cranial-shape differences within Papio, but studies have shown that the Kinda follows a separate ontogenetic trajectory. If so, its cranial-dimorphism pattern should differ from other subspecies. To evaluate this hypothesis, morphometric analysis was used to investigate cranial dimorphism in Papio. Three-dimensional landmarks were digitized on 434 adult crania representing six Papio subspecies. Size- and shape-dimorphism magnitudes were quantified using centroid size and Procrustes distances. Patterns of sex- and size-related variation were explored using MAN(C)OVA, multivariate regression, and form-space PCA. Canine dimorphism was investigated using dental metrics. Kinda size and shape dimorphism are significantly lower than in other Papio subspecies. The relative magnitude of Kinda shape dimorphism is similar to other southern baboons; Kinda canine dimorphism is unremarkable. MAN(C)OVA results support subspecies differences in cranial dimorphism and scaling. Allometric and dimorphism vectors differ significantly in some subspecies, and their vector-angle matrices are strongly correlated. The Kinda's allometric vector angles are divergent. Form-space PC3, summarizing size-independent dimorphism, separates the Kinda from other subspecies. The Kinda baboon exhibits significantly lower size and shape dimorphism than other baboons, but its relative dimorphism levels are unexceptional. The Kinda differs from other subspecies in patterns of allometry, size-related shape dimorphism, and residual shape dimorphism. Kinda facial shape is "masculinized" relative to size, especially in females, suggesting female sexual selection contributed to the evolution of Kinda dimorphism.

Sensitivity of Dental Phenotypic Data for the Identification of Biological Relatives

AbstractUsing modern samples of known kin, this paper evaluates two fundamental aspects of kinship analysis in archaeological contexts: (1) choice of data (dental metrics or morphology) and (2) analytical approach (multivariate, distance‐based approach or a ‘rare trait’ analysis). Stone dental casts were analysed from 155 female individuals from four sampling locations in Kenya. Of these 155 individuals, only three pairs were close kin: mother–daughter, sister–sister, and first‐cousin–first‐cousin dyads. After variable winnowing, inter‐individual distances or similarities were calculated using 11 odontometric variables and 25 dental morphological variables. Resulting distance matrices were ordinated in two dimensions using multidimensional scaling. Odontometric data performed relatively well at identifying known relative pairs, but the results were heavily affected by choice of similarity measure (e.g. Euclidean distances vs. Gower coefficients) and pre‐analysis data treatments (e.g. raw data vs. principal components). Dental morphological data performed comparably with odontometric data but were slightly less effective. Rare traits were identified and compared among relative pairs for concordance, with mixed results. Rare morphological features were randomly distributed throughout the population and were not exclusively found in close kin. In combination, results indicated the sister–sister dyad was most consistently identified; however, in no analysis were relatives more phenotypically similar than all random pairs of unrelated individuals. A multivariate, distance‐based approach was more effective than rare traits at identifying relative pairs, but even under ideal circumstances, there is not enough variation present in the dentition to faithfully identify close relatives in the absence of contextual archaeological data. Copyright © 2017 John Wiley & Sons, Ltd.

Determinación del sexo a través de la métrica dental en cazadores recolectores de la transición pampeano-patagónica oriental

El objetivo de este trabajo es evaluar la pertinencia de la métrica dental para obtener información sexual en individuos que habitaron el curso inferior del río Colorado durante el Holoceno tardío (ca. 3000-250 años AP), discutir el grado de dimorfismo sexual e identificar las variables cuantitativas de la dentición que permitan discriminar el sexo de nuevos individuos que se incluyan en futuros análisis. Se estudiaron las medidas máximas bucolinguales y mesiodistales del cuello de los dientes correspondientes a 26 individuos adultos. Las variables más dimórficas corresponden al diámetro bucolingual del canino superior y de ambos segundos molares; en estos casos, las diferencias entre los sexos son estadísticamente significativas. Los resultados obtenidos sobre el dimorfismo sexual se ubican en el extremo superior de los valores correspondientes a diferentes poblaciones humanas. Varios individuos que no contaban con información sexual a través de los métodos tradicionales pudieron ser clasificados desde la métrica dental, lo cual da cuenta del importante potencial de las medidas dentales para contribuir a las caracterizaciones paleodemográficas de conjuntos bioarqueológicos, especialmente en contextos perturbados y con escasa integridad esqueletal.

Cranial Variation and Biodistance in Three Imperial Roman Cemeteries

AbstractAncient Roman populations are expected to exhibit considerable biological variation because of extensive trade networks and migration patterns throughout Europe and the circum‐Mediterranean. The purpose of this research is to examine regional biological variation in Italy during imperial Roman times (1st to 3rd centuries ad) using three samples exhibiting distinctive class and economic systems. The individuals buried at Isola Sacra and Velia represent middle‐class tradesmen and merchants from coastal port populations from Central and Southern Italy, respectively, while the individuals from Castel Malnome represent an inland population near Rome of freed slaves and other lower‐class individuals involved in heavy labour associated with salt production. Data were recorded from 25 three‐dimensional cranial coordinate landmarks and analysed using Procrustes superimposition and associated multivariate statistics in MorphoJ.Procrustes analysis of variance statistics were unable to detect any significant group differences for centroid size (p = 0.595), but did detect differences in shape (p = 0.0154), suggesting some variation between the three samples. Canonical variates analyses based on Procrustes distance values suitable for small sample sizes indicated that while Castel Malnome was not significantly different from either of the coastal sites (Isola Sacra, p = 0.2071 and Velia, p = 0.8015), Isola Sacra and Velia were significantly different (p = 0.0119). The similarity of Castel Malnome to the other sites may reflect inherent heterogeneity in the sample, as it represents a group of freed slaves likely originating from various geographic locations. The separation of the two coastal sites is not unexpected, as Velia's location was influenced by an influx of Greek populations in the southern Italian Peninsula. This work supports previous studies using traditional craniometrics and dental metrics showing group similarity across the Italian Peninsula and a separation between more northern and southern groups. Copyright © 2017 John Wiley & Sons, Ltd.