Strontium isotope evidence of migration and diet in relation to ritual tooth ablation: a case study from the Inariyama Jomon site,Japan

Ritual tooth ablation was extensively practiced among Jomon (Japanese Neolithic) societies in their final phase (ca. 3000-2300 BP). This tradition includes two different tooth ablation patterns, type 4I and type 2C, referring to extraction of the mandibular incisors and canines, respectively. However, the reason for this difference is unclear. Previous carbon and nitrogen stable isotope analysis of human remains from the Inariyama shell mound revealed that type 4I individuals were more dependent on terrestrial resources and type 2C individuals on marine resources. To test this hypothesis, we performed strontium (Sr) isotope (⁸⁷Sr/⁸⁶Sr) analyses on the same skeletal remains and on modern plants around the site. Because Sr isotope ratios of plants differ according to the local geology and seawater has a consistent Sr isotope ratio, the Sr isotope ratios of tooth enamel can reveal both migration and diet. Comparing Sr isotope ratios in plants and seawater with those of tooth enamel, we identified four possible immigrants. Type 4I locals had significantly higher Sr isotope ratios than type 2C locals. The ratios of the type 4I and type 2C locals were close to those of terrestrial plants and seawater, respectively, suggesting that type 4I locals had incorporated much Sr from terrestrial resources and type 2C locals from marine resources. These results support the hypothesis that ritual tooth ablation reflects dietary differences throughout an individual’s life, and they suggest possible occupational differentiation among the Jomon people.     

Strontium isotope analysis to reveal migration in relation to climate change and ritual tooth ablation of Jomon skeletal remains from western Japan

A gradual population increase accompanying climate cooling has been evinced as having occurred in western Japan during the Middle (ca. 5000–4000 years BP) to Late-Final Jomon period (ca. 4000–2300 years BP). We test the hypothesis that this population change paralleled increasing human migration. We also test the archaeological hypothesis that types of ritual tooth ablation can be used to distinguish between locals and immigrants during the Late-Final Jomon period. We measured strontium isotope ratios in human skeletal remains from the Middle Jomon Ota and the Late-Final Jomon Tsukumo sites located in the Sanyo region of western Japan. Tooth enamel and bone were analyzed, and modern plant samples were collected in the areas surrounding the two sites to make a map of environmental strontium isotope ratios. The biosphere strontium isotope ratios correlated well with the underlying geology, enabling us to put forth a hypothesis of immigrants’ origins. There were no migration pattern differences between the Middle and Late-Final Jomon groups, indicating that the gradual population increase was caused by an increase in the indigenous population. All the Tsukumo individuals are locals, and this finding indicates that types of tooth ablation did not distinguish between locals and immigrants. Alternative hypotheses for the presence of different tooth ablation types in the Jomon society should be explored.     

A strontium isotope analysis on the relationship between ritual tooth ablation and migration among the Jomon people in Japan

Distinct patterns can be discerned in the extensive ritual tooth ablation found among the human skeletal remains of the Late–Final Jomon period (ca. 3200–2800 cal BP) in Japan. Based on comparative observations of sex and grave patterns in the skeletal remains, two major patterns in ritual tooth ablation, termed type 4I and type 2C, have been assigned to locals and immigrants, respectively. In order to test this hypothesis, strontium (Sr) isotope (⁸⁷Sr/⁸⁶Sr) analyses were performed on human skeletal remains from the Yoshigo shell mound in Aichi Prefecture, central Japan. Plants in the surrounding area were also examined to illustrate the geographic ⁸⁷Sr/⁸⁶Sr distribution. The Sr isotopic variation in human tooth enamel (⁸⁷Sr/⁸⁶Sr = 0.70868–0.71028) was greater than that in human bones (⁸⁷Sr/⁸⁶Sr = 0.70871–0.70943). Individuals with higher Sr isotope ratios in their tooth enamel than seawater Sr values of 0.7092 can be identified as immigrants (36% of population). The presence of these isotopically identified immigrants between both type 2C and type 4I individuals does not support the previous hypothesis. The intra-population ⁸⁷Sr/⁸⁶Sr distribution of tooth enamel of type 2C individuals showed a significantly higher mean ratio than that of type 4I individuals, suggesting a higher proportion of immigrants among the former.     

Carbon and nitrogen stable isotope analysis on the diet of Jomon populations from two coastal regions of Japan

We report on a stable isotope paleodietary reconstruction of Jomon populations in Japan during the Middle to Final Jomon period (ca. 5000–2300 years BP), focusing on dietary differences within and among populations and between regions. Carbon and nitrogen isotope analysis was performed on human and faunal bone collagen from six coastal sites along the Inland Sea in the Sanyo (Ota, Funamoto, and Tsukumo) region and along Mikawa Bay and the Pacific Ocean in the Tokai (Kawaji, Yoshigo, and Inariyama) region. We found that carbon and nitrogen isotope ratios were positively correlated, indicating that the Jomon people consumed a mixed diet of marine (shellfish and marine fish) and terrestrial (C₃ plants and terrestrial mammals) protein. In the Ota samples (n = 25, during the Middle Jomon period, 5000–4000 years BP), sex was one of the main reasons for the intra-population dietary variation. Ota males consumed greater amounts of marine food, while Ota females consumed greater amounts of terrestrial food; these dissimilar diets may have been related to the sexual division of labor. Significant inter-population dietary differences were found, which may have been related to differences in age or site location. Notably, the two coastal regions showed clear isotopic differences. Nitrogen isotope ratios of individuals from the Sanyo region were significantly higher than ratios of individuals from the Tokai region. The individuals in the Sanyo region might have consumed a diet high in aquatic foods, particularly high trophic level marine fish, whereas the individuals in the Tokai region might have consumed a lot of marine shellfish. Another possible reason for the regional isotopic difference might have been different baseline of nitrogen isotope ratios of the marine ecosystems.     

Tooth Ablation in Prehistoric Southeast Asia

A sample of skeletons excavated from an undisturbed prehistoric (4000–3500 years BP) burial site in Thailand included a high proportion of individuals with anterior teeth missing in distinctive, mostly symmetrical, patterns. The patterns, types and numbers of teeth missing have been compared between males and females, with age at death, with depth of burial and among spatially distinct groups within the cemetery. The patterns of missing teeth changed over time. In early burials, lateral maxillary incisors were most commonly missing. Two-thirds of the adults had missing teeth. There were no significant differences between the sexes or with age. In later burials, central maxillary incisors and mandibular incisors were most commonly missing. All adults and some children as young as 11 years had missing teeth. There were no significant changes with age but females had more missing teeth than males. Loss as a result of extreme wear inflicted through the use of teeth as tools, congenital absence and ritual ablation are discussed as explanations for the absence of the teeth. The evidence suggests that ritual ablation is the most likely explanation, although the loss of mandibular incisors in some early burials may be as a result of industrial use of the teeth. The ablation of maxillary lateral incisors, found in the early burials, has been recorded at another prehistoric site in the west of Thailand and at sites in southern China.     

Pig exploitation in the southern Kanto region,Japan

This study investigates changes in past human and animal relationships by focusing on pig (Sus scrofa) remains excavated from archaeological sites in southern Kanto, Japan. Pigs and humans have had a close relationship since prehistoric times and the process of change in this relationship, including possible domestication, is one of the major issues in Japanese zooarchaeology. This study attempts to gain a better understanding of the nature of past interaction between humans and pigs by investigating their relative importance compared with other vertebrate remains, kill‐off patterns, and changes in their size and shape at these sites. The materials used for this study date from the Earliest to Final Jomon (ca. 10,000–2500 BP), Yayoi (ca. 2500–1700 BP) and Kofun (ca. 1700–1300 BP) periods. The relative proportions of pigs were calculated to show the overall trend of pig exploitation in each site. Age at death was obtained based on the state of tooth eruption. Bucco‐lingual crown measurements were taken on the third and fourth premolars and on each cusp of the first and second molars of the mandible, and the logarithmic ratio technique was then applied to these data. The age structure of Sus varies between different sites in the Jomon Period, and significant changes were observed in the Yayoi and Kofun Periods. A decrease in the relative proportion of pigs in the faunal assemblages was observed from Jomon to Kofun. Three major differences were observed in the size of pigs. The overall size of pigs significantly increased from Early to Middle Jomon, whilst a decrease in size occurred in the Yayoi Period. Finally, overall size increased significantly during the Kofun Period. Together with the archaeological evidence—such as the ritual burial of pigs accompanying human burial—we suggest that the interaction between pigs and humans became gradually stronger at some sites during the Late Jomon Period, and the relationship intensified in the Yayoi Period. Copyright © 2006 John Wiley & Sons, Ltd.     

Pottery production on Rishiri Island,Japan: perspectives from X‐ray fluorescence studies

Energy‐dispersive X‐ray fluorescence (EDXRF) was used to determine the minor and trace element composition of 54 sherds of pottery dating from the Final Jomon to Okhotsk periods. The majority of the sherds came from Rishiri Island, Japan. Principal component (PC) scores were calculated using the log transformed concentration values, and groups were sought in the PC scores using kernel density estimates (KDEs). Two main groups were found in the data; linear and quadratic discriminant analysis classified both groups successfully. Significant differences in the concentrations of Cu, Fe, K, Nb, Pb, Rb, Th and Zr were found to exist between the two groups. The lack of correspondence between chronological ware types and geochemical groups implies that the same raw materials and paste recipes were in use during the Epi‐Jomon and Okhotsk eras on Rishiri Island. One possiblity is that the Epi‐Jomon and Okhotsk potters used the same clays and tempers, since no other alternatives were available. Alternatively, the Okhotsk potters could have adopted the same paste recipes as the Epi‐Jomon potters, or the Okhotsk pottery tradition could be descended from the Epi‐Jomon pottery tradition.     

Fruits of Their Labour: Urbanisation,Orchard Crops,and Dental Health in Early Bronze Age Jordan

The analysis of dental remains, which outlast most other tissues in the human body, provides insight into past diet, activity patterns and ancestry. The remains from Bab edh‐Dhra' represent the only skeletal sample available to assess the impact of agricultural intensification in the Early Bronze Age of the southern Levant (ca. 3500–2000 bce ). This era ushered in a period of ‘urbanisation’, evidenced by fortified towns, planned roadways, developments in irrigation and growing population density. During this time, the cultivation, trade and consumption of orchard taxa (such as figs, grapes and olives) increased. This paper examines changes in the teeth associated with agricultural intensification involving orchard crops as well as grains. Dental caries, ante mortem tooth loss and dental wear are examined for Early Bronze IA (EBIA; 3500–3300 bce ) and Early Bronze II–III (EBII–III; 3100–2300 bce ) teeth from the site of Bab edh‐Dhra', located in modern‐day Jordan. Due to the commingling, general tooth groups (e.g. molars) and specific tooth types (e.g. lower left canine) were used to compare periods. Although age and sex could not be identified for every tooth, analyses of crania and os coxae showed no significant difference in demographic profiles of EBIA and EBII–III. No statistically significant increase was found over time in dental caries frequency; however, teeth for which the cause of pulp exposure could be determined suggested that caries increasingly led to exfoliation. Indeed, ante mortem tooth loss rose significantly with time, whereas dental wear decreased. In general, changes in oral health were consistent with an archaeological record of greater consumption of softer, stickier foods, such as fruits. Copyright © 2013 John Wiley & Sons, Ltd.     

Prehistoric hunting pressure estimated by the age composition of excavated sika deer (Cervus Nippon) using the annual layer of tooth cement

Age of excavated sika deer was determined not only by the cement-annuli method but also by the observation method to avoid unnecessary destruction of archaeological materials. The observation method is based on tooth replacement, wear index and the appearance of cervical lines on the molar teeth. Stepwise discriminant analysis was used to establish a criterion for the age determination of excavated mandibles. Then the annulation method was carried out for well-preserved specimens older than 3–5 years. The age composition of excavated deer mandibles seems to have changed through the Jomon Period. Age composition at the Torihama sites (the Early Jomon Period) was characterized by an abundance of aged individuals, showing a close similarity with that of the recent deer population under protected conditions. Deer from the Kidosaku and Yahagi sites (the Late Jomon Period) and the SambuUbayama site (the Latest Jomon Period) were composed mainly of deer younger than 5 years, which seems to correspond to that of the recent hunted population living under natural conditions in Hokkaido. These data suggest that the hunting pressure increased during the Late and Latest Jomon Periods and compares with the pressures on recent hunted populations of sika deer.     

Laser ablation depth profiling of U-series and Sr isotopes in human fossils

We have explored laser depth profiling to obtain data sets for U-series as well as Sr analyses. Laser probing with an 81 μm spot size allows for the exploration of low uranium domains of up to 400 μm below the outer surface in tooth enamel. These low U domains will contain Sr isotope compositions of the individual, that are least affected by diagenetic Sr overprints. The small holes drilled for U surveying are not visible to the naked eye. Using larger spot sizes of around 233 μm, laser drilling can be used to obtain reliable U-series isotope data to a depth of approximately 1000 μm in enamel and around 1300 μm in bone. Furthermore, meaningful ⁸⁷Sr/⁸⁶Sr isotope data can also be obtained with this spot size. Using our sampling strategy, the overall damage to a human tooth is minute, as demonstrated on a Neanderthal tooth from Moula-Guercy. We expect that laser ablation depth profiling will become routine for gaining insights into the age of human fossils and the migrations of ancient humans.     

A Bioarchaeological and Biogeochemical Study of Warfare and Mobility in Andahuaylas,Peru (ca. ad 1160–1260)

Warfare impacts how people and populations can move about the landscape. Ethnographers have posited that internal warfare, conflict that takes place within a single society, is strongly associated with female abduction. In contrast, external warfare, combat between different societies, is often accompanied by the in‐migration of men for purposes of defence. To test this assertion, we evaluate human remains from one of the most violent eras in Andean prehistory, the Late Intermediate Period (ad 1000–1400). In the south‐central highlands of Andahuaylas, Peru, this era witnessed the coalescence of two formidable polities, the Chanka and the Quichua. Ethnohistoric accounts describe internal warfare among the Chanka and external warfare between the Quichua and their neighbours. In this study, bioarchaeological and biogeochemical methods are marshalled to elucidate ancient patterns of violence and mobility with greater nuance. We employ strontium isotope analysis of tooth enamel apatite to inform on residential origin, and we reconstruct patterns of violent conflict through analysis of cranial trauma. In all, 265 crania were excavated from 17 cave ossuaries at two Chanka sites and one Quichua site. Data were collected on age, sex and cranial modification—an indicator of social identity and cranial trauma. A representative subsample of molars from 34 individuals subjected to strontium isotope analysis demonstrates that among the Chanka, violence was significantly directed towards social groups within society, marked by modified crania. The presence of two nonlocal women with signs of increased morbidity and mistreatment points to possible mobility‐by‐abduction. In contrast, among the Quichua, men have significantly more trauma, and wounds are concentrated on the anterior. Trauma on women is lower, nonlethal, and concentrated on the posterior. This divergent pattern is commonly observed in external warfare (raids and community defence), where men face attackers and women escape them. The presence of two nonlocal men supports a mobility model of strategic in‐migration. In sum, osteological and isotopic data sets are shown to reveal divergent life‐course experiences not captured by the archaeological data or historic records alone. Copyright © 2014 John Wiley & Sons, Ltd.     

Pottery Styles during the Early Jomon Period: Geochemical Perspectives on the Moroiso and Ukishima Pottery Styles

Energy‐dispersive X‐ray fluorescence (EDXRF) was used to determine the minor and trace element chemistry of 92 Early Jomon pottery sherds. The sherds came from four contemporary sites in the Kanto region and belong to either the Moroiso or Ukishima style of pottery. Principal components analysis (PCA) and discriminant analysis indicate that there are four major groups in the data set, which correspond to site location. Furthermore, for sites having both Moroiso and Ukishima pottery, the statistical tests indicate that both styles of pottery were made from the same or geochemically similar raw materials. This suggests that both styles were probably made at the same site, and indicates that if the different pottery styles are reflecting ethnic identity, then intermarriage between ethnic groups is occurring. Alternatively, the pottery styles could be reflecting some sort of social interaction between groups.     

On the pharyngeal tooth remains of crucian and common carp from the neolithic Tianluoshan site,Zhejiang Province,China, with remarks on the relationship between freshwater fishing and rice cultivation in the Neolithic Age

The pharyngeal tooth remains of crucian and common carp from the Tinaluoshan site of the Hemudu Cultural Stage, Zhejiang Province, China, were analysed. The body‐lengths (BLs) of the fish were estimated from tooth size and plotted as bar diagrams. Based on these, we infer that Neolithic dwellers used gill nets to efficiently catch fish of a specific size during the breeding season. The BL distribution of common carp there is similar to those from Jomon sites in Japan, and we therefore infer that the technology for controlling water for rice cultivation in paddy fields had not yet been developed. The abundance of tooth remains of crucian carp unearthed at the Tianluoshan site is reminiscent of similar finds in Western Japan, and we thus infer that the culture trait of utilizing crucian carp as a major protein resource was distributed from the Yangtze River basin to Western Japan. Analysis of pharyngeal tooth remains of carp at various Japanese archaeological sites shows that freshwater fishing was conducted quite differently before and after the establishment of paddy fields. With this fact in mind, one of the present authors tried to model the development of freshwater fishing, with reference to the relation of fishing to rice cultivation (Nakajima, 2010 ). In Phase I, artisanal fishing became an active and technically developed endeavour, and people began to cultivate rice at fishing site. In Phase II, people began to cultivate rice purposefully in irrigated paddy fields while also fishing there. Comparing the present results of the pharyngeal tooth remains from the Tianluoshan site with those from the Jomon Period, we see that the Tianluoshan site was in the same stage as the end of Phase I in Japan, which rice cultivation was done as a supplementary activity at fishing site. Copyright © 2010 John Wiley & Sons, Ltd.     

Lead isotope ratios: Tracking the migration of European‐Americans to Grafton,Illinois in the 19th century

Lead isotope analysis was conducted using inductively coupled plasma mass spectrometer (ICP‐MS) instruments on local soil samples and human premolar tooth enamel from a 19th century population from Grafton, Illinois, USA. The goal of the study was to determine if lead isotope analysis could be used to infer place of birth and patterns of 19th century migration into the city of Grafton. Five soil core samples from a location near Grafton, Illinois, five grave soil samples from the city cemetery and the tooth enamel of 19 human premolars were analysed. The results of the soil core analysis indicated that the lead isotopic signature of Grafton differs significantly from isotope ratios of other geographic areas associated with recorded places of birth of 19th century Jersey County residents. Elemental and isotope analysis of the soil samples indicated that diagenesis was not a factor in the analysis of lead isotopic signatures of enamel. From the lead isotope analysis of human premolars, the geographic origin of 13 of the remaining 15 individuals could be inferred. The inferred geographic origin was supplemented by an analysis of 1860 mortality and census records and demonstrated the utility of using lead isotope analysis in bio‐archaeological investigations. Copyright © 2010 John Wiley & Sons, Ltd.     

Dental Wear and Pathology in the Precolonial Caribbean: Evidence for Dietary Change in the Ceramic Age

This study investigates temporal changes in dietary practices in the Caribbean archipelago during the Ceramic Age (400 BC–AD 1500), through analyses of dental wear and pathology. Some previous studies in the region have suggested that diet and subsistence practices changed over time due to increasing sociopolitical complexity, climate change, or adaptation to island environments rich in marine resources. Both horticultural/agricultural intensification and increased marine focus of the diet over time have been posited, based among other things on faunal and botanical remains, and early ethnohistorical accounts. Local and micro‐regional stable isotope studies of temporal dietary variation have found few indications for change over time, and large regional isotope studies are still lacking. Dentitions from sites throughout the region dating to the Early Ceramic Age (400 BC–AD 600/800) and the Late Ceramic Age (AD 600/800–1500) were analysed in order to assess temporal differences. Intra‐individual rates of wear were calculated using the difference in degree of wear between the adjacent molars and the two groups were compared with principal axis analysis. Caries, antemortem tooth loss, abscesses and dental calculus were recorded per individual and per tooth/socket, and population caries and antemortem tooth loss rates were assessed and compared by age group, tooth class and sex. Comparisons between the two occupation periods revealed significant differences in the rate of dental wear and pathology, indicating a shift in dietary practices over time, coinciding with known social changes. The increase in pathology rates suggests a rise in the consumption of cariogenic foods or preparation techniques that increase cariogenicity. The decrease in rate of wear over time indicates a reduction in abrasivity of the diet. Together these data suggest that there was a growing focus on refined, cariogenic foods, likely horticultural/agricultural produce. Copyright © 2014 John Wiley & Sons, Ltd.     

Tooth Wear Related to Marine Foraging,Agro‐Pastoralism and the Formative Transition on the Northern Chilean Coast

Occlusal surface wear scores were examined in a sample of 200 Formative period (1500 bc–ad 500) skeletons from the lower Azapa Valley in northwest Chile. Wear rate and plane (angle) were additionally evaluated using a subsample of paired first and second mandibular molars. The Formative period represents the transition from marine foraging to agro‐pastoral dependence in the region, and differences in oral pathology indicate that diet varied by site location (coast vs valley interior) but not by archaeological phase (early vs late). We predicted that occlusal wear would demonstrate similar patterns, resulting from differences in food consistency, and therefore hypothesised that in coastal groups consuming greater quantities of foraged foods, occlusal surfaces should wear faster and exhibit flat molar wear, whereas among valley interior groups consuming greater quantities of agro‐pastoral products, these should wear slower but exhibit more angled molar wear. Heavier posterior tooth wear was identified among coastal residents, but rate and angle of molar occlusal attrition did not differ significantly by location. Heavier overall wear and a steeper molar wear plane were identified during the early phase indicating that food consistency varied somewhat over the course of the Formative period. Overall, the results indicate that, although limited differences in tooth wear exist by site location, wear varied more over time likely reflecting a gradual transition from foraging to agro‐pastoral dependence in the lower Azapa Valley. Although oral health indicators point to differences in dietary investment by location, maintenance of a mixed subsistence economy likely sustained a comparative consistency of foodstuffs. Copyright © 2011 John Wiley & Sons, Ltd.     

Healed bone fractures in a jomon skeletal population from the Yoshigo shell mound,Aichi Prefecture,Japan

Healed bone fractures were quantitatively analyzed in an ancient Japanese population. The sample studied consisted of the skeletal remains of 160 adult individuals from the Yoshigo shell mound (ca. BP 3400‐2400), Aichi prefecture, Japan. Healed fractures were diagnosed from the presence of callus formation and/or angular deformity. Fractures were frequently seen in small bones of the hand and foot such as the metacarpals, rather than in large long bones such as the clavicle, humerus, radius, ulna, femur, tibia and fibula. Of a total of 517 intact large long bones, only four fractures (0.8%) were recognized. The prevalence and pattern of bone fractures in the Yoshigo population reflects the relative lack of stress in their life‐style. Copyright © 1999 John Wiley & Sons, Ltd.     

Evaluation of carnivory in inland Jomon hunter–gatherers based on nitrogen isotopic compositions of individual amino acids in bone collagen

Archaeological studies including stable carbon and nitrogen isotope analyses of bone collagen from human remains have suggested their heavy dependence on terrestrial foods during the Jomon period in the inland central region in Japan. However, it is not easy to quantitatively evaluate the extent of carnivory for archaeological human remains based on the bulk collagen chemistry, because of variable ¹⁵N-enrichment factor along the trophic step and background isotopic variations in ecosystems. In order to overcome these problems and more precisely evaluate diets of prehistoric humans who strongly adapted to terrestrial environment, in this study we applied nitrogen isotope analysis of individual amino acids in bone collagen to two inland human populations in the Jomon period. Our results suggest that the two populations were predominantly dependent on the C₃-plant-based terrestrial ecosystem and consumed little aquatic resources. Furthermore, their mean trophic positions (2.7 for both cases) are closer to that of the fox (2.8–3.0) rather than those of pure herbivores (2.0–2.2), and show little change over time. These results are the first evidence that inland Jomon populations may have had more carnivorous diets than is traditionally considered.     

Reconstructing patterns of systemic stress in a Jomon period subadult using incremental microstructures of enamel

This study reconstructs systemic stress patterning using incremental microstructures of enamel in a subadult from the Yoshigo cemetery (3200 through 2800 BP), Aichi Prefecture, Japan, with the goal of providing an improved methodological and theoretical framework for interpreting systemic stress among Jomon people. High resolution impressions and replicas were collected for each anterior maxillary tooth. Each replica was studied under 50, 100, or 200× magnification on a measuring microscope. Perikymata spacing and enamel surface profiles were recorded using specialized software. Linear enamel hypoplasia (LEH) defects were identified as accentuated spacing in perikymata combined with a depression in the enamel surface. Each defect was placed within a chronological sequence based on decile location. Stress duration was estimated by counting the perikymata in the occlusal wall of each defect and multiplying that value by the modal periodicity for striae formation. Percentage of enamel growth disruption was estimated by dividing the number of perikymata within the occlusal wall of each matched defect by the total number of perikymata within the imbricational enamel. Eight LEH defects were chronologically matched. Chronology of LEH defects ranged between 1.2 through 3.5 years. Number of perikymata located within the occlusal wall of each defect ranged from one through 20. Estimated durations of stress ranged from 12 through 129.6 days. These durations overlapped with Neandertals, though Point Hope foragers had greater durations of stress with no overlap in interquartile ranges. Disrupted enamel growth ranged from 8.1% in the maxillary left canine to 50.7% in the maxillary right central incisor.     

IN‐SITU ELEMENTAL AND Sr ISOTOPE INVESTIGATION OF HUMAN TOOTH ENAMEL BY LASER ABLATION‐(MC)‐ICP‐MS: SUCCESSES AND PITFALLS*

Trace element and Sr isotope data were obtained by laser ablation‐ and solution mode‐(MC)‐ICP‐MS analysis for tooth enamel from remains excavated at the New Kingdom period Egyptian colonial and Nubian cemetery site of Tombos (Sudan). Elemental abundances determined by both methods of ICP‐MS analysis yielded comparable values; however, ⁸⁷Sr/⁸⁶Sr values obtained by laser ablation were higher compared to their solution mode counterparts. This discrepancy is related to the production of a molecular interference—Ca + P + O (overlaps ⁸⁷Sr); hence the higher ⁸⁷Sr/⁸⁶Sr values recorded during ablation analyses. Laser ablation studies of enamel may provide relatively precise ⁸⁷Sr/⁸⁶Sr values rather quickly but cannot be used for accurately deciphering historical population migrations.