Dental Wear Patterns Research Articles

Biocultural diversity in Late Pleistocene/Early Holocene Africa: Olduvai Hominid 1 (Tanzania) biological affinity and intentional body modification.

The dentition of Olduvai Hominid 1 (OH1) exhibits an anomalous pattern of dental wear that was originally attributed to either intentional cultural modification (filing) or plant processing behaviors. A differential diagnosis of the wear and assessment of the biological affinity of OH1 is presented. Macroscopic and microscopic observations of all labial and buccal tooth surfaces were undertaken to assess wear patterns. A multivariate analysis of mandibular morphology of OH1 compared to other Late Pleistocene, Holocene, and recent modern humans was used to ascertain biological affinity. The morphological variation of the OH1 mandible is closely aligned with variation in penecontemporaneous fossils from Africa and outside that of recent humans. The concave wear facets exposing dentin on the labial surfaces of all three preserved mandibular incisors is confirmed. Substantial loss of labial/buccal surfaces was documented on the surfaces of all in situ maxillary and mandibular canines, premolars, and molars ranging from distinct facets with well-defined edges, to blunting or "polishing" around areas of maximum buccal curvature. The wear on both the anterior and postcanine teeth closely resemble that caused by adornments ("labrets") worn in lower-lip and buccal facial piercings known from bioarchaeological and ethnographic contexts. The wear pattern suggests that the OH1 wore three facial piercings-two buccal/lateral and a medial one in the lower lip. Our findings suggest that the expression of social identities through intentional body modification is more diverse than previously documented elsewhere in Africa during the Late Pleistocene (i.e., ablation) and Early Holocene (i.e., ablation, chipping, and filing).

Skull reconstruction of the late Miocene ape Rudapithecus hungaricus from Rudabánya, Hungary

We report on a computer-based reconstruction of a well-preserved ape skull from late Miocene deposits in Rudabánya, Hungary. Based on micro-computed tomographic scans of the original Rudapithecus hungaricus partial cranium RUD 200 and the associated mandible RUD 212 we realign displaced bone fragments, and reconstruct the shape of the upper and lower jaws guided by occlusal fingerprint analysis of dental wear patterns. We apply geometric morphometric methods based on several hundred landmarks and sliding semilandmarks to estimate missing data, and create multiple reconstructions of the specimen. We then compare the reconstructed overall cranial shape, as well as the volume and shape of the endocast, with extant primates. Multiple reconstructions of RUD 200 yield an average endocranial volume of 234 cc (S.D.: 9 cc; range: 221–247 cc). RUD 200 is most similar to African apes in overall cranial shape, but in a statistical analysis of endocranial shape the specimen falls closest to extant hylobatids. Our data suggest that R. hungaricus from the late Miocene in Europe displays aspects of the overall cranial geometry typical of extant African great apes, but it does not show an evolutionary reorganization of the brain evident in Pan, Gorilla, and Pongo.

Non‐masticatory dental wear patterns in individuals exhumed from the Middle Bronze Age rock‐cut tombs of Torre Velha 3 (Serpa, Portugal)

AbstractDental examination of 21 individuals (11 females, nine males and one undetermined sex) exhumed from the rock‐cut tombs of Torre Velha 3 (Serpa, Portugal), dating from the 2nd millennium BC, revealed dental wear features and oral lesions that can be linked to non‐masticatory activities and/or dietary habits. A total of 471 teeth were macroscopically analyzed. One young‐adult female and a middle‐age adult of unknown sex display lingual surface attrition of the maxillary anterior teeth (LSAMAT). A middle‐age adult female has LSAMAT, anterior occlusal surface groove (AOSG) and chipping. Two other middle‐age adult females have oblique wear planes (OWP), one of them also with chipping. Overall variation and low frequencies of the observed alterations suggest that multiple activities and/or dietary habits could have caused these wear patterns. The hypothesis that atypical wear patterns are sex biased was tested using Fischer's exact test, and results were not statistically significant (p‐value = 0.09). Thus, it is possible to infer that these individuals had possible dietary or cultural idiosyncratic behaviors, besides repetitive non‐masticatory task related‐activities.

Enamel hypoplasia and dental wear of North American late Pleistocene horses and bison: an assessment of nutritionally based extinction models

AbstractApproximately 50,000–11,000 years ago many species around the world became extinct or were extirpated at a continental scale. The causes of the late Pleistocene extinctions have been extensively debated and continue to be poorly understood. Several extinction models have been proposed, including two nutritionally based extinction models: the coevolutionary disequilibrium and mosaic-nutrient models. These models draw upon the individualistic response of plant species to climate change to present a plausible scenario in which nutritional stress is considered one of the primary causes for the late Pleistocene extinctions.In this study, we tested predictions of the coevolutionary disequilibrium and mosaic-nutrient extinction models through the study of dental wear and enamel hypoplasia ofEquusandBisonfrom various North American localities. The analysis of the dental wear (microwear and mesowear) of the samples yielded results that are consistent with predictions established for the coevolutionary disequilibrium model, but not for the mosaic-nutrient model. These ungulate species show statistically different dental wear patterns (suggesting dietary resource partitioning) during preglacial and full-glacial time intervals, but not during the postglacial in accordance with predictions of the coevolutionary disequilibrium model. In addition to changes in diet, these ungulates, specifically the equid species, show increased levels of enamel hypoplasia during the postglacial, indicating higher levels of systemic stress, a result that is consistent with the models tested and with other climate-based extinction models. The extent to which the increase in systemic stress was detrimental to equid populations remains to be further investigated, but suggests that environmental changes during the late Pleistocene significantly impacted North American equids.

New hominoid fossils from Moroto II, Uganda and their bearing on the taxonomic and adaptive status of Morotopithecus bishopi

The early Miocene site of Moroto II, Uganda has yielded some of the oldest known hominoid fossils. A new partial mandible (UMP MORII 03'551) is notable for its long tooth row and large, narrow M2 with well-developed cristids - a morphological combination previously unknown for large bodied catarrhines of the Early Miocene and suggesting folivory. The tooth proportions are compatible with belonging to the same taxon as the maxilla UMP 62-11, the holotype of Morotopithecus bishopi; likewise, the long tooth row and vertical planum of UMP MORII 03'551 suggest that it may represent the same taxon as mandible(s) UMP 66-01 and UMP 62-10. Canine size strongly suggests UMP MORII 03'551 is a female. Comparisons of the tooth crown morphology and tooth row proportions, relative enamel thickness, enamel-dentine junction morphology, long-period line periodicity, and dental wear patterns support significant morphological, developmental, and inferred dietary differentiation, and therefore generic-level distinctiveness, among Afropithecus, Morotopithecus and the Proconsul clade. An isolated M1 (UMP MORII 03'559) is morphologically dissimilar, and much smaller than the actual or inferred size of molars in UMP MORII 03'551, UMP 66-01 and UMP 62-10, supporting the presence of two hominoid taxa at Moroto II, M. bishopi and a smaller bodied proconsulid. Given the high level of body mass dimorphism inferred for Morotopithecus and other early Miocene catarrhines, the known postcrania from Moroto II could be attributable to either taxon. However, UMP MORII 03'551 and the femora UMP MORII 94'80 derive from the same stratigraphic interval, while the isolated M1 was deposited later, increasing the likelihood that the mandible and femora are from the same individual. These new fossils expand our understanding of the taxonomic and adaptive diversity of early Miocene catarrhines.

Dietary Adaptations of Early and Middle Pleistocene Equids From the Anagni Basin (Frosinone, Central Italy)

The intermontane Anagni Basin (Frosinone, central Italy) is an important region for Italian biochronology and paleoecology due to the presence of two rich fossil assemblages dated to the Early (Coste San Giacomo) and Middle Pleistocene (Fontana Ranuccio). These sites have yielded a vast collection of large fossil mammals with a well-documented presence of fossil equids in both localities (represented mostly by isolated teeth). Coste San Giacomo is dated to around 2.1 Ma, thereby having recorded the effects of the onset of the Quaternary glacial cycles, which led to a gradual trend towards colder and more arid conditions in the Northern Hemisphere. The fossil equids of this site belong to the first group of grazing stenonid equids of the genus that spread to the Italian Peninsula during the so called Elephant- Equus event, which marked the appearance of new large mammals living in herds in open and arid environments. The site of Fontana Ranuccio is dated to around 400 ka, close to the MIS 12 – 11 succession (the Mid-Brunhes event), which marked the end of the Middle Pleistocene Transition. The fossil horses from Fontana Ranuccio represent one of the oldest caballoid (or true horses) populations of the Italian Peninsula. The Anagni Basin, thus, provides important data to investigate paleoecological adaptations of these groups of equids in response to two critical environmental and climatic shifts of the Pleistocene. We explore their niche occupation by examining long-term dental wear patterns and tooth enamel carbon and oxygen stable isotopic composition. Both taxa appear to have exhibited a narrow dietary niche, displaying a clear abrasive (highly specialized) grass-rich diet. In particular, caballoid equids from Fontana Ranuccio show a more abrasion-dominated mesowear signature. Stenonid equids from Coste San Giacomo exploited broader and more diverse landscapes during the Early Pleistocene, whereas caballoid horses from Fontana Ranuccio appeared to have limited their dietary adaptations to a stricter grazing behavior in more closed environments.

The effects of the “0.9 Ma event” on the Mediterranean ecosystems during the Early-Middle Pleistocene transition as revealed by dental wear patterns of fossil ungulates

The Early-Middle Pleistocene Transition (EMPT) (ca. 1.4–0.4 Ma) represents a fundamental transformation in the Earth's climate state, starting at 1.4 Ma with a progressive increase in the amplitude of climatic oscillations and the establishment of strong asymmetry in global ice volume cycles. The progressive shift from a 41kyr–100kyr orbital rhythm was followed by the first major build-up of global ice volume during MIS 24-22, the so-called “0.9 Ma event”. The Vallparadís Section (Vallès-Penedès Basin, NE Iberian Peninsula) is one of the few Pleistocene series in Europe that spans the onset of the transition (from 1.2 to 0.6 Ma), thus representing a pivotal array of localities to investigate the effect of glacial dynamics on environmental conditions in Southern Europe. Here we inspect the effects of the EMPT on terrestrial ecosystems by examining the dietary adaptations (through dental meso- and microwear patterns) of fossil ungulates from the Vallparadís Section dated before and after the “0.9 Ma event”. Results show a steady presence of open grasslands before MIS 22 and more humid conditions at MIS 21. Both before and after MIS 22, a consistent presence of ungulates with long-term patterns that point to a grazing or grass-rich mixed feeding behaviour is observed, while noticeably, short-term patterns point to increased seasonality right after the “0.9 Ma event” glacial period. This increment of seasonality may have had an important effect on the Mediterranean habitats leading to recurring changes in the quality of plant resources available to large herbivores, which in response periodically adopted more mixed feeding behaviours widening their dietary breadth to consume also sub-optimal food items during adverse seasons.

Forest Floor Leaf Cover as a Barrier for Dust Accumulation in Tai National Park: Implications for Primate Dental Wear Studies

Mastication causes distinct use wear scars on teeth that can aid in dietary reconstructions of fossils. However, the role played by exogenous grit in dental wear complicates the association between wear and diet. Dental wear analyses often assume that foods closer to the soil contain more exogenous grit than those in the forest canopy. Yet, a layer of leaf litter covering many forest floors may trap grit from the soil, keeping it from settling on surrounding vegetation or becoming part of atmospheric dust. Cercocebus atys is frequently referenced in dental wear studies because of its dependence on hard Sacoglottis gabonensis seeds collected from the forest floor. Here we examine quantities of dust deposition at different forest levels and assess its potential role in wear patterns observed in C. atys. We collected grit from S. gabonensis seeds (N = 64) found under the leaf litter and compared them to grit samples taken from the surface of leaves at different forest strata (N = 450) in Ivory Coast’s Tai National Park. Seeds underneath the leaf litter were coated with significantly more grit than leaves above the leaf material and we conclude that leaf litter is a significant barrier to grit particles originating from the soil. Given that evidence points to a significant difference in grit amount between foodstuffs on the ground and foods near the ground, the findings lead to a prediction of differences in dental wear patterns between purely arboreal foragers and those incorporating terrestrial food sources.

Tooth Wear Rates for Propithecus diadema in the Fragmented and Pristine Forests of Tsinjoarivo, Madagascar

Primate teeth wear through time in response to their environment. This change in topography has the potential to affect nutrient absorption if mastication is less effective at reducing food particle size. Lemurs exhibit a broad range of diets and life history strategies, as well as adaptations for surviving in an unpredictable environment. Previous studies on diademed sifakas (Propithecus diadema) in Tsinjoarivo, Madagascar show that groups in fragmented forests eat a less diverse diet and use fallback foods year‐round, while sifakas living in pristine forests eat less preferred foods only during the lean season. Groups persist in fragments, yet these dietary changes may increase rates of tooth wear and have consequential deleterious effects on their lifetime fitness and population viability.Previous studies examining tooth wear over time have mainly focused on changes in slope, angularity, and surface relief, but frequently these studies use individuals with estimated age. By examining known‐aged individuals through time, specific patterns of dental wear can be correlated to variation in diet, sex, age, and habitat differences. In this study, dental molds of 75 individuals from 10 groups of Propithecus diadema were taken over a 15‐year period in both the fragmented and pristine forests of Tsinjoarivo. Tooth casts were scanned and analyzed with Geographic Information System (GIS) software to obtain values for relief index, slope, and angularity. All three of these factors decreased with age and show some significance among specific groups of sifakas but results show no effect of overall forest type on rates of tooth wear. Thus, while forest disturbance has demonstrated impact on diet, tooth wear did not accelerate as predicted. Future research should incorporate additional tooth wear data as these known‐aged lemurs advance in years, and examine the functional consequences of tooth wear more directly.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Dietary response of early Pleistocene ungulate communities to the climate oscillations of the Gelasian/Calabrian transition in Central Italy

Climatic oscillations at the Gelasian/Calabrian transition modified terrestrial palaeoenvironmental settings in the European region. A gradual drop in global temperatures beginning about 2.7 Ma led to drier conditions and to a reduction in, and subsequent disappearance of, sub-tropical vegetation in the central Mediterranean area by ca 1.2 Ma. Large ungulates are sensitive to vegetation changes and faced with harsher environmental settings may shift their feeding strategies to exploit available food resources in different ecosystems. In fossil assemblages such dietary adaptations are reflected by tooth morphology (a phylogenetic signal) and tooth wear degree (a direct signal of the species' diet). In this paper, we investigate how large herbivores responded to palaeoenvironmental changes that occurred at the passage between the Gelasian and Calabrian ages in the Italian Peninsula, analysing the dental wear patterns and hypsodonty of the early Pleistocene fossil ungulates assemblage of Olivola (Aulla, Central Italy). We found that while ungulate feeding behaviours during the Gelasian spanned from browsers to grazers, in the locality of Olivola this group of herbivores display a narrower range of diet types with many taxa adopting a mixed feeding behaviour. Cervids in particular, whose fossils are often associated only with wooded environments, as a response to the reduction of covered sub-tropical vegetation, shifted from a strict browsing diet in mostly closed habitats to a more abrasive one taking advantage of the spread of open landscapes. We also provide new data on the feeding behaviour of the rare fossil caprines, Procamptoceras and Gallogoral meneghinii, suggesting a grass-rich mixed diet for the former and a certain degree of dietary plasticity for the latter. Our research thus contributes to the better understanding of how ungulates adapted in the past to exploit different resource types during pivotal climatic changes and how environments changed in Central Italy on the onset of colder and more arid conditions.

Resource and niche differentiation mechanisms by sympatric Early Pleistocene ungulates: the case study of Coste San Giacomo

Resource competition and niche partitioning among the exceptionally high number of sympatric ungulates of the Early Pleistocene site of Coste San Giacomo (Central Italy) is here examined through the study of their dietary proclivities and body size. The main aim of this study is to investigate the niche differentiation mechanisms that let the fossil ungulates coexist in the same region. We also provide information about the complementarity of two different methodologies that observe diet variation at a different time scales (inner and outer mesowear) in the study of dental wear patterns of fossil ungulates. Results from analyses of dental wear degree and body masses predictions show that a wide range of feeding behaviours were adopted by the taxonomical groups (i.e., cervids, bovids and equids) in order to avoid competition. Among larger ungulates diet ranges from strict browsing (Eucladoceros sp., Gazellospira torticornis), to mixed feeding (Gallogoral meneghinii, Leptobos sp.) to pure grazing (Equus stenonis), whereas smaller taxa are more selective feeders (Axis cf. lyra, Croizetoceros cf. ramosus) with only one exception (Gazella borbonica). When taxa with the same feeding behaviour occurred in the same habitat, competition was minimised by differences in body size.

Childhood intelligence and early tooth wear patterns

Objective: The aim of this study is to explore the relationships between early dental wear patterns and preschool IQ (Intelligence Quotient, by Stanford–Binet) of the child to illuminate the historic relationship of mental queries and bruxism.Methods: The dental study participants were 864 Euro-American preschool and school children whose IQs were tested for school maturity purposes at the age of 4 years, followed by dental data in a cross-sectional manner at the mean age of 7.8 years. Worn dentitions were classified as “symmetric” or “right-” and “left-sided,” based on the faceting of the teeth.Results: In general, the relationships of tooth wear and intelligence were scarce, reflecting social background factors. Statistically significant results between asymmetric wear and gender groups suggest that direction of jaw function has a role in the regulation of processes responsible for individual mental performance in childhood.Discussion: Increased left-side tooth wear and early advantage in the intelligence test in girls is intriguing due to the fact that they reach maturity earlier than boys in verbal articulation, controlled in most cases by the limited area on the left side of the brain.

Dental wear patterns in early modern humans from Skhul and Qafzeh: A response to Luca Fiorenza and Ottmar Kullmer

It is common knowledge, that in archaic populations teeth could have been used as tools, such behavior can be studied by evaluating occlusal attrition patterns. Fiorenza and Kullmer suggested a digital approach to distinguish between masticatory and non-masticatory wear facets in archaic and modern populations. In their last response to our letter (Fiorenza and Kullmer, 2015), they used comparative modern samples to demonstrate that described para-facets in Skhul and Qafzeh individuals could not have been produced by dental occlusal anomalies and also since they claimed that more than 50% of the sample analyzed in their study are characterized by para-facets, it is highly unlikely to be the result of dental pathologies. What the authors neglected to mention is that misalignment of teeth and/or malocclusion features in the Qafzeh specimens for example are present in 55.5% of the individuals, and therefore, malocclusions should be at least reconsidered as a possible cause for the para-facets formation. Also, dental cross-bite may involve functional shift and mandibular deflection and therefore, should also be considered as a possible cause for untypical occlusal contacts. In the current reply, we indicate the disadvantages of the occlusal fingerprints analysis in archaic fragmented samples.

How did the Qesem Cave people use their teeth? Analysis of dental wear patterns

Dental wear pattern is an important source of information regarding dietary habits, food preparation, and human economic behavior. In the current study we present our preliminary analysis of the dental wear patterns of the Middle Pleistocene (420–200 kya) Qesem Cave teeth. Five types of tooth wear were studied: Occlusal wear, interproximal wear, subvertical grooves, buccal microwear and root striations. We found mild to moderate occlusal wear (stage range 2–4), the largest proximal facet on the M2 medial was 15.3 mm2, presence of three subvertical grooves on the M2 distal surface, a variety of microwear scratches (many are >200 mμ long and >5 mμ wide) and two types of root striations. The data obtained suggests that the Qesem Cave people possessed a strong masticatory system producing massive anterior component of force, and used small flints as food choppers.

Mechanical food properties and dental topography differentiate three populations of Lemur catta in southwest Madagascar

Determining the proximate causes of tooth wear remains a major focus of dental study. Here we compare the diets of three ring-tailed lemur (Lemur catta) populations and examine how different dietary components may contribute to patterns of wear-related tooth shape. Casts were made from dental impressions collected between 2003 and 2010 from lemurs in the gallery and spiny/mixed forests of the Bezá Mahafaly Special Reserve (BMSR; Parcels 1 and 2) and the spiny/mixed forests of Tsimanampesotse National Park (TNP), Madagascar. Tooth shape variables (occlusal relief and slope, angularity) were analyzed using dental topographic analysis. Focal observations and food mechanical properties (FMPs: toughness, hardness, elastic modulus) were conducted and tested, respectively, during wet and dry seasons from 2008 to 2012. We found that FMPs correlate with patterns of dental topography in these three populations. Specifically, food toughness and elastic modulus correlate with the dental variables, but hardness does not. Average food toughness and elastic modulus, but not hardness, are highest in BMSR Parcel 2, followed by BMSR Parcel 1 and TNP. Occlusal relief and slope, which serve as proxies for tooth wear, show the greatest wear in Parcel 2 and the least in TNP. Angularity is also more pronounced in TNP. Further, dental topographic patterns correspond to reliance on Tamarindus indica (tamarind) fruit. Both BMSR populations consume tamarind at high frequencies in the dry season, but the fruits are rare at TNP and only occasionally consumed. Thus, high seasonal tamarind consumption and its mechanical values help explain the low dental relief and slope among BMSR lemurs. By investigating the ecology of a single widespread species across a variety of habitats, we have been able to link specific components of diet to patterns of dental topography in this species. This provides a context for interpreting wear-related tooth shape changes more generally, illustrating that populations can develop different dental wear patterns resulting from a mix of intrinsic factors (thin enamel) and local conditions (food properties, frequency of consumption).

Diachronic analysis of cultural dental wear at the Atapuerca sites (Spain)

Abstract Cultural dental wear provides useful information about the use of anterior teeth for non-masticatory purposes. Non-alimentary tasks are usually related to economic and cultural activities. The presence of cultural dental wear has been checked in four different Homo species from the Sierra de Atapuerca sites (Sima del Elefante, Gran Dolina-TD6, Sima de los Huesos and El Mirador cave). The chronology of these sites ranges from more than one million to 4000 years ago. Evidence of dental wear has been documented in the four Homo species analysed, confirming that hominins began using their teeth as tools as far back as one million years ago. Each species exhibits specific typologies and frequencies of dental wear features. Also, dental features are located on different dental surfaces and tooth types, indicating a diversity of activities carried out using the anterior teeth as a tool. The use of the teeth as a tool was a widespread habit in the genus Homo . However, the diversity of dental wear patterns can be related to cultural and economic activities, broadening our knowledge of the behaviour of ancient hominins.

Paleoenvironments and climatic changes in the Italian Peninsula during the Early Pleistocene: evidence from dental wear patterns of the ungulate community of Coste San Giacomo

Quaternary glacial/interglacial alternations, influenced by orbital obliquity cycles with a 41-ka long periodicity, started in the northern hemisphere around 2.6 Ma ago. Such alternations affected the terrestrial ecosystems, especially those of the Mediterranean region, with changes in the floristic communities and the dispersal and radiation of a number of large mammal open dwellers. Analyses of tooth wear patterns of ungulates from the Early Pleistocene site of Coste San Giacomo allow for a more objective reconstruction on the paleoenvironments and the climate in the Italian Peninsula during this epoch. Our results show that this area was composed by a mosaic of biomes, in particular by steppe and woodlands/wetlands. Evidence of such heterogeneity is provided by the wide spectrum of feeding behaviours found among the numerous ungulate herbivores here recorded, with cervids (Axis cf. lyra, Croizetoceros cf. ramosus and Eucladoceros sp.) exhibiting browser diets, most of the bovids (Gazella borbonica and Leptobos sp. and Gallogoral meneghinii) being intermediate feeders and the equid Equus stenonis showing a strict grazer behaviour. These results provide new insights for a timing of changing ecosystems in Southern Europe and reveal the environmental legacy of this global climatic shift, which is essential for understanding the early occupation of Homo in Europe. Thus, our data provide new evidence that such an environmental heterogeneity and a wide spectrum of available food resources could have been the main factors favouring the settlement of early species of Homo in this area.

Dental wear patterns in early modern humans from Skhul and Qafzeh: A response to Sarig and Tillier

The use of teeth as tools for manipulating objects and simple food-processing methods was common among prehistoric and modern hunter-gatherer human populations. Paramasticatory uses of teeth frequently produce enamel chipping and distinctive types of dental wear that can readily be related to specific tool functions. In particular, the presence of unusual occlusal wear areas (named para-facets) on maxillary teeth of prehistoric, historic and modern hunter-gatherers has been associated with cultural habits involving extensive use of teeth (Fiorenza et al., 2011; Fiorenza and Kullmer, 2013). However, Sarig and Tillier (2014) believe that this wear had been caused by pathological occlusal relationships rather than by the use of teeth as tools. In this contribution, we show how occlusal contacts are created and how it is possible to distinguish between masticatory and non-masticatory wear facets by using an innovative digital approach called Occlusal Fingerprint Analysis. Statistical results from the analysis of comparative modern samples clearly demonstrate that described para-facets in Skhul and Qafzeh could not have been produced by dental occlusal anomalies such as malocclusions and crossbites. Moreover, dental pathologies in prehistoric humans were extremely rare. Only with the adoption of the modern lifestyle between 18th and 19th centuries, did the emergence of malocclusions become significantly more common. Because more than 50% of the Skhul and Qafzeh individuals analysed in our study are characterised by this distinctive type of wear, it is highly unlikely that their para-facets occurred as a result of dental pathologies.

Division of labor by sex and age in Neandertals: an approach through the study of activity-related dental wear

The analysis of activity-related dental wear patterns in prehistoric anatomically modern humans and modern hunter-gatherers has shown sex differences attributable to a gendered division of labor. Neandertals are known to have extensive anterior dental wear related to the use of their front teeth as a tool. In this study we analyze the i) cultural striations (scratches on the labial surface of the anterior teeth with a cut-mark morphology), and ii) dental chipping (ante-mortem microfracture involving enamel or both enamel and dentine) in 19 Neandertal individuals from the l'Hortus (France), Spy (Belgium), and El Sidrón (Spain) sites, and compare the characteristics of those traits with the age and sex estimation for the individuals and among samples. The study reveals that all individuals have cultural striations, but those detected on the adult females are longer than the striations found in adult males. Regarding the distribution of dental chipping, the prevalence of this trait is higher in the maxillary dentition of males whereas females have the majority of dental chipping on their mandibular teeth. The differences detected on the overall activity-related dental wear pattern denote a difference or a division of labor by age and sex in Neandertals while using the mouth as a third hand, i.e., in activities other than the provisioning of food, and provide new evidence for the lifestyle of this Pleistocene fossil human species.

Human remains from Nemrik, Iraq. An insight into living conditions and burial customs in a Pre-Pottery Neolithic village

Nemrik 9/ 10 is a Pre-Pottery Neolithic site in Northern Iraq that was excavated in 1985-1989 by S. K. Kozłowski. The remains of at least 96 individuals were found in the excavated strata, most of which were dated to ca 9100– 8600 BP. The bones were in poor condition, but several observations of taphonomic effects and indicators of diet, stress, physical activity, trauma and diseases were possible. First, a major change in burial practices occurred in Nemrik after ca 8900 BP. Prior to this date both adults and subadults were buried in domestic contexts. Moreover, there is some evidence of prolonged exposure of bodies. Later, the extramural cemetery was established for adults and multiple burials (of commingled elements) were replaced by single burials with no evidence of post mortem exposure. Inhabitants of Nemrik were farmers who based their diet on roughly processed cereals, but the pattern of dental wear suggests that it may have been comparable or even softer on average, than the diet of later Northern Mesopotamia inhabitants. Dental caries was extremely rare, but a high rate of linear enamel hypoplasia suggests stressful living conditions. The pattern of trauma and injuries is typical for a farming population and no evidence of interpersonal violence or injuries related to hunting was observed. In this respect Nemrik differs strikingly from the Proto-Neolithic cemetery found in the Shanidar Cave.