Dental Wear Patterns Research Articles

The "Smile Design and Space" Concept for Altering Vertical Dimension of Occlusion and Esthetic Restorative Material Selection.

This article introduces the smile design and space (SDS) concept for managing the vertical dimension of occlusion (VDO) in full-mouth reconstructions and its influence on the selection of esthetic restorative materials. Limitations of traditional VDO adjustment methods are being addressed through a facially driven treatment approach that enhances esthetics improves function and minimizes invasiveness. The SDS concept involves detailed evaluations of the incisal edges of the maxillary central incisors in relation to the upper lip at rest and at full smile. This includes analyzing variations in incisal exposure due to differing lip mobility, which can significantly impact gingival esthetics, particularly in cases with gingival exposure during smiling. The concept employs a strategic formula to determine the necessary alterations in VDO based on specific dental relationships and wear patterns. The SDS concept provides guidelines for full-mouth reconstructions, emphasizing minimal invasiveness and the integration of esthetics with functional dynamics to enhance the predictability of clinical outcomes and reduce complications associated with traditional restoration techniques. The SDS concept enhances the precision of full-mouth reconstructions through individualized adjustment of the VDO, tailored to the esthetic and functional requirements of each patient.

An international, open-access dataset of dental wear patterns and associated broad age classes in archaeological cattle mandibles

Zooarchaeologists investigate past interactions between animals, humans, and their environments by analyzing the remains of archaeological fauna. Age-at-death distributions are fundamental to faunal analysis and are often estimated by comparing exposed dentine patterns to standardized tooth wear stages that have been associated with relative age classes. We present Bubona, an international dataset of dental wear patterns and associated broad age classes in archaeological cattle mandibles. Our open-access dataset of 1460 data entries from nine counties is being used to create tooth-type specific reference tables of probable age class attribution for cattle mandibles lacking complete dentition. Bubona is a valuable resource for the innovation of new systems of age estimation for cattle and it is the creators hope that researchers will continue to both help expand the dataset by contributing their own data, as well as utilize the data to refine and innovate age-at-death estimation methods.

Intraoral Scanning for Monitoring Dental Wear and Its Risk Factors: A Prospective Study.

Dental wear arises from mechanical (attrition or abrasion) and chemical (erosion) factors. Despite its prevalence and clinical significance, accurately measuring and understanding its causes remain challenging in everyday practice. This one-year study with 39 participants involved comprehensive examinations and full-arch intraoral scans at the start and after 12 months. Volume loss exceeding 100 µ on each tooth's surfaces (buccal, lingual/palatine and incisal/occlusal) was measured by comparing three-dimensional scans from both time points. This study also assessed factors such as abrasion and erosion through clinical exams and questionnaires. There were no significant differences in dental wear in participants with sleep bruxism. However, noticeable wear occurred in the front teeth of those with waking bruxism and joint-related symptoms. Increased wear was associated with frequent consumption of acidic drinks, regular swimming, dry mouth, nocturnal drooling and heartburn, while no significant wear was found in patients with reflux. The used methodology proved effective in accurately assessing the progression of dental wear, which is important as many patients may initially be asymptomatic. The variability observed in dental wear patterns underscores the need to develop specific software applications that allow immediate and efficient comparison of wear areas based on extensive analysis of patient databases.

Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia)

Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in the size of the posterior palatal teeth, an elongation of the premaxilla/rostrum, and a widening of the temporal region. These changes are presumably related to changes in dietary habits, which, we hypothesise, are due to changes in the type and quality of food they consumed. In the present study, the dental wear pattern of a total of nine European Middle to Late Triassic placodont species were investigated using 2D and 3D microwear analyses to demonstrate whether there could have been a dietary shift or grouping among the different species and, whether the possible changes could be correlated with environmental changes affecting their habitats. The 3D analysis shows overlap between species with high variance between values and there is no distinct separation. The 2D analysis has distinguished two main groups. The first is characterised by low number of wear features and high percentage of large pits. The other group have a high feature number, but low percentage of small pits. The 2D analysis showed a correlation between the wear data and the size of the enlarged posterior crushing teeth. Teeth with larger sizes showed less wear feature (with higher pit ratio) but larger individual features. In contrast, the dental wear facet of smaller crushing teeth shows more but smaller wear features (with higher scratch number). This observation may be related to the size of the food consumed, i.e., the wider the crown, the larger food it could crush, producing larger features. Comparison with marine mammals suggests that the dietary preference of Placochelys, Psephoderma and Paraplacodus was not exclusively hard, thick-shelled food. They may have had a more mixed diet, similar to that of modern sea otters. The diet of Henodus may have included plant food, similar to the modern herbivore marine mammals and lizards.

The role of climate change in the extinction of the last wild equids of Europe: Palaeoecology of Equus ferus and Equus hydruntinus during the Last Glacial Period

The last European wild equids —Equus ferus and Equus hydruntinus— were among the large mammals (or megafauna) that became extinct during the Late Quaternary Extinction Event disappearing from Europe during the Holocene. The role that the combined action of the major climatic changes of the Pleistocene/Holocene Transition and the human activities played in their extinction is not fully understood. The reduction of steppe-like biomes in Europe following the increase of mean global temperatures during the Holocene is usually regarded as the main event that triggered their disappearance, as both equids display typical morphological adaptations for open grasslands and grass eating. However, E. ferus and E. hydruntinus are found, often even co-occurring, in both warm and cold phases of the Late Pleistocene. Thus, the investigation of their niche occupation can help decipher whether their ecology and specialised dietary adaptations were the main reason of their decline following the early Holocene global warming. Here we investigate the feeding strategies of the two equids by studying their long- and short-term dietary adaptations through examination of their patterns of dental wear. As expected, dental mesowear points to a highly abrasive diet concordant with a grazing feeding behaviour for both E. ferus and E. hydruntinus which is consistent with their specialised morphological adaptations for open habitats. In contrast, dental microwear suggests a somewhat degree of plasticity in diets, as both species display microscopic features commonly recorded in modern mixed feeders. Such a flexibility may be the reason for which they could have persisted even when open grasslands were not the dominant landscape. Our findings provide a new line of evidence supporting the idea that human activities (e.g., competition with the first domestic forms brought from Eurasia and Africa) may have played a larger role in the extinction of some megafauna groups than climate change per se.

Enamel thickness per masticatory phases (ETMP): A new approach to assess the relationship between macrowear and enamel thickness in the human lower first molar

Many anthropological studies have examined the functional implications of enamel thickness in human dental crowns. Despite limitations, Enamel thickness (ET) values are still used to infer taxonomic attribution in the genus Homo, and to identify mechanisms of functional adaptation against macrowear. However, only a few studies have tried to describe the possible relationship between ET and dental wear patterns in permanent lower first molars (M1) aiming to observe whether an adaptive response to the environmental and cultural context is detectable. The present work aims to investigate a possible signal of ET adaptive response in M1 (wear stage 3; Molnar, 1971) belonging to individuals who lived between the Neolithic (early 6th millennium BCE) and the Bronze Age (second half of the 2nd millennium BCE) in Croatia to identify any signal of change in dental tissue proportions based on archaeologically documented shifts in population structure and subsistence strategies. In order to do so, we explored 3D Average Enamel Thickness (AET) of the entire crown and wear pattern distribution among individuals and across chronological groups. We then described a new method called “Enamel Thickness per Masticatory Phases” (ETMP) involving the creation of virtual sections cutting enamel and coronal dentine in three parts based on masticatory phases, and explored the distribution of 3D AET accordingly. Finally, we performed geometric morphometric analysis on dental crown to ascertain possible morphological differences between Neolithic, Eneolithic, and Bronze Age groups. Results show that Bronze Age individuals differ from previous groups due to 1) higher values of ET in both the entire crown and specifically in the buccal area, 2) to an extensive wear pattern localized on the buccal side, and 3) to the distal extension of the hypoconid together with an extended mesio-distal shape of the crown. These patterns may represent an adaptive response of dental tissue to varying functional demands (e.g. archaeologically documented dietary shift). The study of ETMP therefore offers a more nuanced method, in addition to morphology and macrowear analysis, to document biocultural processes of change over time in archaeological populations through dental tissues.

Dental microwear texture analysis correlations in guinea pigs (Cavia porcellus) and sheep (Ovis aries) suggest that dental microwear texture signal consistency is species-specific

Dental microwear texture (DMT) analysis is used to differentiate abrasive dental wear patterns in many species fed different diets. Because DMT parameters all describe the same surface, they are expected to correlate with each other distinctively. Here, we explore the data range of, and correlations between, DMT parameters to increase the understanding of how this group of proxies records wear within and across species. The analysis was based on subsets of previously published DMT analyses in guinea pigs, sheep, and rabbits fed either a natural whole plant diet (lucerne, grass, bamboo) or pelleted diets with or without added quartz abrasives (guinea pigs and rabbits: up to 45 days, sheep: 17 months). The normalized DMT parameter range (P4: 0.69 ± 0.25; M2: 0.83 ± 0.16) and correlation coefficients (P4: 0.50 ± 0.31; M2: 0.63 ± 0.31) increased along the tooth row in guinea pigs, suggesting that strong correlations may be partially explained by data range. A comparison between sheep and guinea pigs revealed a higher DMT data range in sheep (0.93 ± 0.16; guinea pigs: 0.47 ± 0.29), but this did not translate into more substantial correlation coefficients (sheep: 0.35 ± 0.28; guinea pigs: 0.55 ± 0.32). Adding rabbits to an interspecies comparison of low abrasive dental wear (pelleted lucerne diet), the softer enamel of the hypselodont species showed a smaller data range for DMT parameters (guinea pigs 0.49 ± 0.32, rabbit 0.19 ± 0.18, sheep 0.78 ± 0.22) but again slightly higher correlations coefficients compared to the hypsodont teeth (guinea pigs 0.55 ± 0.31, rabbits 0.56 ± 0.30, sheep 0.42 ± 0.27). The findings suggest that the softer enamel of fast-replaced ever-growing hypselodont cheek teeth shows a greater inherent wear trace consistency, whereas the harder enamel of permanent and non-replaced enamel of hypsodont ruminant teeth records less coherent wear patterns. Because consistent diets were used across taxa, this effect cannot be ascribed to the random overwriting of individual wear traces on the more durable hypsodont teeth. This matches literature reports on reduced DMT pattern consistency on harder materials; possibly, individual wear events become more random in nature on harder material. Given the species-specific differences in enamel characteristics, the findings suggest a certain species-specificity of DMT patterns.

3D surface scan dataset for the publication "Controlled feeding experiments with juvenile alligators reveal microscopic dental wear patterns associated with hard-object feeding"

3D surface scan dataset for the publication "Controlled feeding experiments with juvenile alligators reveal microscopic dental wear patterns associated with hard-object feeding"

More than they could chew: Activity‐induced dental modifications in a Portuguese medieval–modern rural population

AbstractNon‐masticatory dental lesions (e.g., notching, interproximal grooving, polished surfaces, lingual tilting, and dental trauma) may help evaluate the impact that dietary, individual, or social‐cultural habits had on ancient populations. Thus, this study aims to describe and discuss possible causes for dental wear and trauma recorded in 1206 commingled teeth recovered from a medieval‐modern ossuary in Miranda do Corvo (Coimbra, Portugal). All teeth were observed macroscopically under good light conditions. Dental wear and traumatic injuries were recorded according to their location. Atypical wear was divided into five categories—notches and grooves, polished surfaces, oblique wear plane, interproximal grooves, and lingual tilting. Higher mean values of occlusal dental wear were found in the anterior dentition (3.03 ± 1.457; n = 396), being the central incisors the more worn out (3.19 ± 1.28; n = 102). In all, 11.0% of the observed teeth presented atypical wear (130/1185), being anterior teeth (26.7%; 112/419) more affected than posterior (17.0%; 128/765). The most common alterations were notches/grooves (50.0% of the teeth with atypical wear; 65/130) and dental microtrauma (20.3% of the observed teeth; 240/1184). Furthermore, teeth presenting microtrauma were more affected by atypical wear, affecting 38.9% (48/130) of the worn teeth. An association between chipping and notches and/or grooves (62.5%; 30/48) was also noted. The obtained results, namely, the morphology and distribution of the “incisor‐dominant” dental wear and dental trauma patterns, suggest that many individuals of this population may have used their teeth as a “third hand” in routine practices. However, some types of atypical wear, namely, polished lingual surfaces of anterior teeth, may have had other causes, such as malocclusion. This study provides new insights into how ancient populations used their dentitions, even when the osteological remains are recovered from a commingled context.

Dental macrowear, diet, and anterior tooth use in Colobus polykomos and Piliocolobus badius

Two similarly-sized colobine species living sympatrically in the Ivory Coast's Taï Forest that differ in both diet and oral processing behavior provide an opportunity to explore the strength of associations between feeding behavior and dental wear patterns. Here we test the hypothesis that vigorous processing of tough, hard Pentaclethra macrophylla pods by Colobus polykomos manifests in greater anterior tooth wear relative to that observed in Piliocolobus badius, which does not exploit this resource. We assessed levels of anterior tooth wear in a sample of 160 upper incisors and 131 lower incisors from 18 adult Colobus polykomos and 62 adult Piliocolobus badius naturally deceased individuals from Taï National Park. We operationalized tooth wear by dividing the area of exposed dentin by total occlusal crown area. To assess relative degrees of incisor wear, we regressed incisor wear against molar wear (sample = 105 upper molars, 135 lower molars) for the pooled Colobus polykomos and Piliocolobus badius wear data and compared the number of individuals from each species that fell above and below the pooled regression curve for each model using Chi-square tests of independence and odds ratios. Under our hypothesis, we would expect more Colobus polykomos points above the pooled regression curve than Piliocolobus badius, indicating higher incisor wear relative to molar wear in Colobus polykomos. Nine of sixteen interspecific comparisons demonstrated this predicted pattern; however, none of the Chi-square tests or odds ratios were significant, indicating no difference between Colobus polykomos and Piliocolobusbadius incisor wear relative to molar wear. The absence of significant differences in incisor wear relative to molar wear highlights the challenge of identifying idiosyncratic feeding behavior in fossil taxa and the necessity for continued exploration of the relationship between diet and macrowear.

A Computerized Simulation of the Occlusal Surface in Equine Cheek Teeth: A Simplified Model.

Equine mastication, as well as dental wear patterns, is highly important for the development of treatments in equine dentistry. During the last decades, the stress and strain distributions of equine teeth have been successfully simulated using finite element analysis. Yet, to date, there is no simulation available for dental tooth wear in equines. In this study, we developed a simplified two-dimensional computer simulation of dental wear. It provides a first tentative explanation for the development of the marked physiological inclination of the occlusal surface and for pathological conditions such as sharp enamel points in equine cheek teeth. The mechanical properties of the dental structures as well as the movement of the mandible during the equine chewing cycle were simulated according to previously published data. The simulation setup was optimized in preliminary test runs. Further simulations were conducted varying the lateral excursion of the mandible and the presence or absence of incisor contact during the chewing cycle. The results of simulations showed clear analogies to tooth wear patterns in living equids, including the formation of wear abnormalities. Our analysis indicates that small variations in the pattern of movement during the masticatory cycle, as well as incisor contacts, are leading to marked changes in the occlusal tooth wear patterns. This opens new research avenues to better understand the development of dental wear abnormalities in equines and might have serious implications on captive animal health, welfare, and longevity.

Skeletal remains of a Pleistocene modern human (Homo sapiens) from Sulawesi.

Major gaps remain in our knowledge of the early history of Homo sapiens in Wallacea. By 70–60 thousand years ago (ka), modern humans appear to have entered this distinct biogeographical zone between continental Asia and Australia. Despite this, there are relatively few Late Pleistocene sites attributed to our species in Wallacea. H. sapiens fossil remains are also rare. Previously, only one island in Wallacea (Alor in the southeastern part of the archipelago) had yielded skeletal evidence for pre-Holocene modern humans. Here we report on the first Pleistocene human skeletal remains from the largest Wallacean island, Sulawesi. The recovered elements consist of a nearly complete palate and frontal process of a modern human right maxilla excavated from Leang Bulu Bettue in the southwestern peninsula of the island. Dated by several different methods to between 25 and 16 ka, the maxilla belongs to an elderly individual of unknown age and sex, with small teeth (only M1 to M3 are extant) that exhibit severe occlusal wear and related dental pathologies. The dental wear pattern is unusual. This fragmentary specimen, though largely undiagnostic with regards to morphological affinity, provides the only direct insight we currently have from the fossil record into the identity of the Late Pleistocene people of Sulawesi.

Evidence of habitual behavior from non-alimentary dental wear on deciduous teeth from the Middle and Upper Paleolithic Cantabrian region, Northern Spain

The use of ‘teeth as tools’ (non-masticatory or cultural-related dental wear) has largely been employed as a proxy for studying of past human behavior, mainly in permanent dentition from adult individuals. Here we present the analysis of the non-masticatory dental wear modifications on the deciduous dentition assigned to eight Neanderthal and anatomically modern human subadult individuals from Mousterian to Magdalenian technocultural contexts in the Cantabrian region (Northern Spain). Although preliminary, we tentatively suggest that these eight subadults present activity-related dental wear, including cultural striations, chipped enamel, toothpick grooves, and subvertical grooves. We also found evidence of habitual dental hygienic practices in the form of toothpicking on a deciduous premolar. Orientation of the cultural striations indicates similar handedness development as in modern children. Taken together, these dental wear patterns support the participation of young individuals in group activities, making them potential contributors to group welfare. This study potentially adds new evidence to the importance of the use of the mouth in paramasticatory activities or as a third hand throughout the Pleistocene, which can be confirmed with a more specific reference sample.

Feeding the sick: An insight into dietary composition at a Medieval leper hospital using dental wear pattern analysis

In the Middle Ages, palliative dietary regimens were fundamental to the treatment of disease. It was believed that the foods eaten were central to bringing balance to the human body. Alleviating the symptoms of leprosy required the consumption of foods considered moist and mild, which included certain kinds of meat. Medieval lepers were housed and treated in leprosaria (leper hospitals), often located on the outskirts of towns and cities. The quality of the food consumed at each institution, however, varied considerably according to its financial situation. The extent to which the diet of lepers corresponded to that advised by Medieval physicians, therefore, remains largely uncertain. Here, a method of 3D dental wear pattern analysis, called Occlusal Fingerprint Analysis, is used to infer the dietary composition of individuals interred at the cemetery associated with the medieval leprosarium and later almshouse of St James and St Mary Magdalene, Chichester (n = 24). It was found that the dental wear pattern of individuals with osseous changes consistent with lepromatous leprosy showed an enlargement of buccal phase I wear when compared to the rest of the cemetery and a comparative group interred at St Michael’s Litten lay cemetery, Chichester (n = 17). Differences in dental wear patterns suggest that the lepers at this cemetery had regular access to meat beyond the quantities consumed by the majority of the lower social strata of Medieval society and more consistent with the palliative care recommended by Medieval medical theory.

Dental wear patterns reveal dietary ecology and season of death in a historical chimpanzee population.

Dental wear analyses have been widely used to interpret the dietary ecology in primates. However, it remains unclear to what extent a combination of wear analyses acting at distinct temporal scales can be beneficial in interpreting the tooth use of primates with a high variation in their intraspecific dietary ecology. Here, we combine macroscopic tooth wear (occlusal fingerprint analysis, long-term signals) with microscopic 3D surface textures (short-term signals) exploring the tooth use of a historical western chimpanzee population from northeastern Liberia with no detailed dietary records. We compare our results to previously published tooth wear and feeding data of the extant and continually monitored chimpanzees of Taї National Park in Ivory Coast. Macroscopic tooth wear results from molar wear facets of the Liberian population indicate only slightly less wear when compared to the Taї population. This suggests similar long-term feeding behavior between both populations. In contrast, 3D surface texture results show that Liberian chimpanzees have many and small microscopic wear facet features that group them with those Taї chimpanzees that knowingly died during dry periods. This coincides with historical accounts, which indicate that local tribes poached and butchered the Liberian specimens during dust-rich dry periods. In addition, Liberian females and males differ somewhat in their 3D surface textures, with females having more microscopic peaks, smaller hill and dale areas and slightly rougher wear facet surfaces than males. This suggests a higher consumption of insects in Liberian females compared to males, based on similar 3D surface texture patterns previously reported for Taї chimpanzees. Our study opens new options for uncovering details of feeding behaviors of chimpanzees and other living and fossil primates, with macroscopic tooth wear tracing the long-term dietary and environmental history of a single population and microscopic tooth wear addressing short-term changes (e.g. seasonality).

Atypical dental wear patterns in individuals exhumed from a medieval Islamic necropolis of Santarém (Portugal)

Atypical dental wear patterns in individuals exhumed from a medieval Islamic necropolis of Santarém (Portugal)

Palaeoenvironmental and seasonal context of the Late Middle and Early Upper Palaeolithic occupations in Crimea: an approach using dental wear patterns in ungulates

The Crimean Peninsula has a rich archaeological record characterised by numerous multi-layered sites from the Middle Palaeolithic and by a number of important sites representing the transition from the Middle to the Upper Palaeolithic. Absolute dates place the region as one of the last Neanderthal refuges in Europe. Combining dental meso- and microwear analyses of worn molars found at faunal assemblages from different sites across Crimea, we can characterise the feeding habits of ungulates at different scales in their lifetime. The proxy data resulting from these analyses provide evidence not only on diet but also on (1) the habitat where fauna were hunted and (2) the duration of the events of human occupation in each archaeological level. For this palaeoecological reconstruction, we analysed three sites: Kabazi II and Chokurcha I from the Middle Palaeolithic and Siuren I from the Early Upper Palaeolithic. We focused particularly on the repeated Neanderthal subsistence pattern observed at Kabazi II throughout the sequence (around 80 to 48 ky). Analyses revealed that Equus hydruntinus (wild ass) was feeding on abrasive grasses, suggesting it was occupying open habitats, while Saiga tatarica (saiga antelope) was mixed feeding and probably consuming significant amounts of browse and lichens in relatively open habitats. Furthermore, variability in microwear signalled short seasonal occupations for all assemblages. During the Middle Palaeolithic and the early Upper Palaeolithic, these sites were occupied during the warm season.

Impact of Early and Middle Pleistocene major climatic events on the palaeoecology of Southern European ungulates

ABSTRACT The Early and Middle Pleistocene were characterised by two major climatic events: the onset of the Quaternary glaciations and the Early-Middle Pleistocene Transition (EMPT) with glacial cycles changing their periodicity. The present study reviews recent research on the palaeoecological adaptations of Pleistocene ungulates from Mediterranean Europe following these global climatic changes, through an examination of dental wear patterns and hypsodonty indices of 27 fossil taxa from 4 key localities. Ungulates from Coste San Giacomo (2.1 Ma) adopted a wide range of feeding behaviours suggesting the presence of heterogeneous environments in the region. Following the gradual deterioration of climatic conditions and drier habitats ungulates display narrower diet ranges with no incidence of obligated browsers as attested at Olivola (~1.8 Ma). The diffusion of open habitats from the Early Pleistocene onwards is also reflected by the reduction of brachydont taxa. Discrepancy between dental mesowear and microwear patterns of Vallparadís Estació (~1.0–0.6 Ma) and Fontana Ranuccio (0.4 Ma) ungulates points to an increase in seasonality during the EMPT and after its consolidation. All examined taxa display dietary plasticity through the Early and Middle Pleistocene with even specialised groups, such as equids, showing a certain flexibility in their diet.

Lateralized Feeding Behavior in a Paleozoic Reptile

Lateralized behaviors have been reported in a variety of extant vertebrates, including birds and reptiles [1-3] and non-human mammals [4-6]. However, evidence of lateralized behaviors in extinct vertebrates is rare, primarily because of the difficulty of identifying such behaviors with confidence in fossils. In rare instances, paleontologists can infer asymmetry in predatory or foraging behavior, including predation scars on trilobites [7], directionality of invertebrate traces [8], and even behavioral asymmetry in fossil non-human primates [9,10]. Because lateralized behaviors have been linked to hemispheric (brain) lateralization in some vertebrates [11-15], evidence of lateralized behaviors in ancient vertebrates might yield clues about the evolutionary origins of vertebrate brain lateralization. Here, we show the earliest evidence of lateralized behavior in a fossil reptile based on repeatable observations of tooth wear in a large sample of intact jaws. The patterns of dental wear along the tooth rows of nearly one hundred jaws of the small, early Permian (289 million years ago) reptile Captorhinus aguti indicate that it exhibited lateralized behavior, preferring to feed using the right side of the jaw. Discovery of such a feeding behavior in this ancient, terrestrial, and omnivorous animal provides direct evidence of the deep history of directional behavior among amniotes and may indicate an early origin of brain lateralization.

A method for constructing demographic profiles in Susscrofa using Logarithm Size Index scaling

Demographic profiling of archaeological assemblages offers a window into the shifting exploitation strategies practiced by ancient societies. High resolution sex-specific age profiles, in particular, have yielded new insights into the evolution of early management practices taken during the initial stages of animal domestication (Zeder, 2001). This paper is the third in a series seeking to develop a method for constructing demographic profiles for Sus scrofa — one of the earliest major livestock species noteworthy for being independently domesticated in both Southwest and East Asia. The first paper in this series (Lemoine et al., 2014) presented a new system for constructing high resolution age profiles using patterns of dental eruption and wear. The second (Zeder et al., 2015) presented a new method for computing high resolution age profiles based on long bone fusion. Both papers used a reference assemblage of modern Eurasian wild boar for developing these new aging schemes, which were then applied to the large assemblage of S. scrofa remains from the Early Holocene age site of Hallan Çemi (c. 11,600 cal. BP) in southeastern Anatolia — an assemblage that previous researchers claimed provided evidence for early steps toward management (Redding, 2005). Here we focus on a subset of this modern reference collection consisting of 34 wild boar skeletons from Turkey, Iran, and Iraq. We employ a Logarithm Size Index scaling (LSI) technique to examine the effect of factors such as age, locality, and, sex on body size in modern wild boar. We find that even though both age and locality have an impact on body size, LSI values derived from select measurements of various different post-cranial elements can be used to classify individual osteological specimens as belonging to immature animals, and, for animals older than about eight months of age, as female or male. We test the reliability of these classifications by comparing the known demographic profiles of the modern reference population against those derived from the LSI classifications. Finally, we apply this new method to the Hallan Çemi assemblage and propose a method for adjusting LSI values to account for temporal size differences encountered between the modern and ancient populations. We also present methods for assessing the reliability of these classifications in the ancient population. We conclude by offering guidelines for the application of this new method to other archaeological assemblages of S. scrofa and other ungulate species that demonstrate strong degrees of sexual dimorphism.