Tomohito Nagaoka

The Pacopampa site is one of the largest Formative Period sites in Peru’s northern highlands. In the 2013 field season, we uncovered human remains from the stairs between the second and third platforms and found a rare case of a depressed skull fracture on the cranial vault of a middle-aged male. This study aims to describe the fracture and explore chronological changes in violence in Peru’s northern highlands. The radiocarbon date of this male is 910 ± 30 ¹⁴C yr BP, which corresponds to the Late Cajamarca Period (AD 950–1200). The fracture is elliptical in shape, 23.7 mm long and 23.3 mm wide. Depressed debris, adhering to part of the vault, entered the cranial cavity and may have compressed dura mater and brain substance. A healing reaction formed a smooth edge around the fracture, suggesting that it is an antemortem fracture and that the individual survived the injury. It is reasonable to infer that the presence of trauma on the Pacopampa cranium is consistent with the sociopolitical background, typified by high social tension and the appearance of organized warfare in Andean societies.

The Pacopampa site is one of the largest Formative Period sites in Peru’s northern highlands. This study describes newly excavated human remains from the site, compares them with previous findings, and provides bioarchaeological approaches to assess social stratification in Formative Period Andes, leading to an understanding of how social stratification emerged in the Andean civilization. The human remains studied were two individuals from an elite tomb (the ‘Serpent-Jaguar Priests’ tomb) at the ceremonial center of the site. At the bottom of the tomb, a middle-aged female was laid over the remains of a young male. The central position of the tomb and the rich repertoire of grave goods suggest that these individuals had symbolic importance and belonged to an elite social group. The possible presence of artificial cranial deformation in the female suggests that the buried individuals were socially different from the other burial individuals of this site. There is no dental caries in these two individuals. The comparison of caries frequencies between these two individuals and non-elites showed lower caries frequencies in the former than in the latter. Taking into consideration existing isotopic data of Formative Period sites, the social differences in the caries frequencies can be attributed to the elites’ dietary patterns—which contained fewer cariogenic foods. Thus, this study revealed the emergence of social stratification in Peru’s northern highlands and its possible pathological impacts.

Little is known about the precise date of the emergence of decapitation in a ritual context and the presence of systematic postmortem modification patterns in the ancient Central Andes. The ceremonial complex at Pacopampa in the northern Peruvian highlands provides early osteological evidence of decapitation in six individuals dating to the latter half of the Late–Final Formative Periods (500–50 BC) and to the Early Cajamarca Period (AD 200–450). Based on osteological evidence, and when taken together with archaeological settings and settlement patterns, researchers can be certain that those whose heads were disembodied were not likely to have been involved in organized battles. In addition, the similarities in the cut-mark distribution, direction, and cross-sectional morphology of each individual's remains, as well as the characteristics of selected individuals, imply that the decapitated individuals were carefully prepared using a standardized method and that those who modified the heads may have been professional decapitators. This study offers indisputable bioarchaeological evidence of ritualistic offerings of human skulls and systematic postmortem modification patterns, which is consistent with a contemporaneous iconographic motif of decapitation and extends the chronology of this practice back to the Formative Period in the northern Peruvian highlands.

Many medieval skulls from Kamakura, Japan were found to be characterized by dolichocephaly, although these medieval people are most likely to be the ancestors of the modern Japanese. The specificity in the metric cranial traits has been repeatedly demonstrated by archaeological findings from other medieval sites in Kamakura City. It is not known whether these specific features were shared by the descendants of the medieval Kamakura people due to a complete lack of the skeletal remains belonging to the later half of the medieval period. Fortunately, we obtained access to a new series of skeletal remains of the later half of the medieval period from the Nozoji-ato site, and examined the variation in craiometric traits during the medieval period. The results revealed that the Nozoji-ato series were more brachycephalic than the populations within medieval Kamakura City and demonstrated the presence of secular changes within the Japanese medieval period. New data from the Nozoji-ato series thus showed that the medieval people within Kamakura City exhibited wider intra-regional variations in cranial measurements than previously anticipated. It is concluded that this contrasts with the commonly accepted theory that medieval populations were homogeneous in terms of dolichocephaly.

The early modern Edo period in Japan denotes a chronological division between the AD 17th and 19th centuries when social structure was stratified. This study aimed to examine the occurrence of dental caries in the deciduous teeth of commoner children in Sakai City (Osaka, Japan), comparing them with those excavated in other regions, eventually clarifying variations in prevalence of deciduous caries and the causative factors contributing to such variations. Results indicated a biased distribution pattern in caries prevalence. Caries were frequently present in maxillary incisors whereas few occurrences in the mandibular counterparts were observed. Another important finding was the population‐level differences in caries prevalence—the Sakai sample displayed systematically lower frequencies of caries than warriors and commoners from Kyushu in western Japan; thus, causative factors can be hypothesized to be not only social classes but also regional differences in living conditions. These findings proved the presence of intrapopulation and interpopulation variation in deciduous caries based on children's skeletons from socially stratified societies in different geographical regions and demonstrated that deciduous caries provide bioarchaeologists with information on population diversity apparent in caries prevalence and cariogenic diets.

Pacopampa, a ceremonial complex in Peru’s northern highlands, reveals early evidence of trauma in the Middle to Late Formative Period coinciding with the emergence of social stratification in the area. We examine the prevalence of trauma in human remains found at the site and present evidence of the circumstances surrounding the deaths of individuals who lived during the early stages of Andean civilization. The materials are the remains of 104 individuals (38 non-adult and 66 adult) from the Middle to Late Formative Periods. We explored trauma macroscopically and recorded patterns based on skeletons’ locations, age at death, sex, social class, and chronology. We detected trauma in remains over the Middle to Late Formative Periods. While the prevalence of trauma was minimal in the Middle Formative Period, skeletons from the subsequent era exhibit more severe disturbances. However, all the skeletons show signs of healing and affected individuals experienced a low degree of trauma. Given the archaeological context (the remains were recovered from sites of ceremonial practices), as well as the equal distribution of trauma among both sexes and a lack of defensive architecture, it is plausible that rituals, rather than organized warfare or raids, caused most of the exhibited trauma. Pacopampa was home to a complex society founded on ritual activity in a ceremonial center: this is indicated by the presence of ritual violence in a society that built impressively large, ceremonial architecture and developed social stratification without any political control of surplus agricultural goods.

Cribra orbitalia is characterized by an aggregation of small apertures in the orbital roof in response to marrow hypertrophy. This pathological change is indicative of biological stress during youth. We examined the prevalence of this lesion in Pacopampa, a ceremonial center of the formative period, located in the northern highlands of Peru. Using this evaluation of cribra orbitalia, we reconstructed aspects of the population’s health and nutritional status during the formation of Andean civilization. We examined 41 orbits of 27 adult individuals (13 males, 14 females) and recorded the macroscopic presence or absence of cribra orbitalia. The presence or absence of cribra orbitalia was the same bilaterally for all 14 individuals having both orbits preserved. The pathology was present in two of the 13 males (15.4%), one of the 14 (7.1%) females, and three of 27 individuals (11.1%) for both sexes combined. There was no difference in the frequency between sexes. The prevalence of cribra orbitalia was found to be lower in Pacopampa than in the comparative data of coastal populations. It is reasonable to assume that the increase in social complexity in Pacopampa was probably unrelated to the decline in overall health of the people.

The early modern Edo period in Japan refers to the division of chronological age dated from the seventeenth to nineteenth centuries. During that period, the social structure was stratified, with warriors at the top, followed by farmers, and finally townsmen at the bottom. I aimed to examine carious lesions in deciduous teeth in the commoners from the city of Edo (now Tokyo), to compare them with those in the warriors and commoners from Kyushu, and to reveal differences in the incidence of caries across social classes and regions. I examined 843 deciduous teeth of 115 individuals from the Hitotsubashi site in Tokyo. The comparative samples were obtained from warriors and commoners whose remains were excavated from the Sougenji and Kyoumachi sites, respectively, in Kyushu [Oyamada et al. ( 2008 ) Anthropol Sci 116:9–15]. The caries frequency in the Hitotsubashi sample was 11.3 %. Carious lesions in the upper teeth were more frequent than those in the lower teeth in all age groups. The upper incisors exhibited the highest frequency of caries, while there was almost no caries in the lower incisors and canines. I also found population differences in deciduous caries among the Edo populations. Remains of teeth excavated from Hitotsubashi were found to have a mild degree of caries compared to remains of teeth excavated from Sougenji and Kyoumachi in Kyushu in terms of caries frequency and location. Thus, the influence of regional differences in diet and living circumstances was stronger than expected, and the variation observed in the frequency of deciduous caries among the Edo populations cannot be explained by social class alone.