Malocclusion and methodology: The problem and relevance of recording dental malalignment in archaeology

The study of incorrectly positioned teeth has a long history, especially in relation to human groups and domestic dogs. Dental and orthodontic specialists have been particularly concerned to establish ways of recording and comparing such anomalies. However, Colyer and others have established that anomalous dental positioning occurs in a wide variety of species, and might at times even have had adaptive advantage. In the case of dogs, some modern varieties clearly have severe malocclusion problems, while others are little affected. Because it has been suggested that early domesticated dogs already display some degree of dental crowding or malpositioning, it seems important to consider the methodology for recording such anomalies. It is suggested that a quick and easy method of recording and comparing tooth positioning is by angular measurements (preferably taken on standard photographs of occlusal views). In the British archaeological dog samples selected, it was found that tooth malpositioning (and thus malocclusion of upper and lower dentitions) was only slight, compared to the overall occurrence of such anomalies in modern dogs. It is suggested that this kind of simple procedure may be of value in the investigation of secular trends in the frequency of malpositioning and malocclusion of dogs, if not other species, through time.     

Problems and pitfalls in the diagnosis of linear enamel hypoplasia in cheek teeth of cattle

Prevalence and intensity of enamel hypoplasia have been used as markers of generalized physiological stress during dental development in a wide range of mammalian taxa. We studied cattle (Bos taurus) cheek teeth exhibiting morphological characteristics that are of relevance to the diagnosis of enamel hypoplasia in this and other bovid species. These characteristics were multiple, more or less horizontally arranged (waveform) lines or grooves in the cementum of the tooth crown and the adjacent root area, leading to an imbricated appearance of the cementum. On macroscopic examination of tooth surfaces, these lines resembled linear enamel hypoplasia (LEH). Microscopic analysis of tooth sections, however, revealed that the lines occurred in the cementum only, and that the underlying enamel did not exhibit morphological irregularities. In cheek teeth of older cattle, a thick cementum layer is regularly found in the cervical crown portion and the adjacent root area. Apposition of this cementum is related to the uplifting of the teeth from their alveoli, a process that compensates for the shortening of the tooth crowns due to occlusal wear. In the studied specimens, a pronounced periodic nature of tooth uplifting and the related deposition of cementum is the likely cause for the observed imbricated appearance of the cementum. While this phenomenon may be misinterpreted as representing a case of LEH, presence of enamel hypoplasia in bovid teeth may be overlooked when the defects become filled with coronal cementum and are therefore not apparent on external inspection. This was the case in one of the cattle teeth analyzed by us, in which the hypoplastic enamel defects were, however, clearly discernible in ground sections. Microscopic analysis of tooth sections is recommended for recording of LEH in bovid teeth in cases where macroscopic examination of tooth surfaces alone does not produce unequivocal results.     

The Middle Stone Age human remains from Diepkloof Rock Shelter (Western Cape,South Africa)

In the course of recent excavations at Diepkloof Rock Shelter (South Africa), three human remains were found in the Middle Stone Age layers. These human remains are two pedal phalanges (intermediate and distal) from a fifth ray, which belong to the same individual, and a deciduous first lower molar. The layers in which they were found represent the end of the Howiesons Poort and the beginning of post-Howiesons Poort occupation, and are radiometrically dated to MIS 3, between 45 and 65 kyr ago. They are thus very close in time to the assumed period of anatomically modern humans (AMH) dispersal out of Africa into Eurasia, a period for which very few remains are available in the African fossil record. Here, we describe these new remains and compare their morphology and dimensions to samples of African and Eurasian Pleistocene and Holocene humans. Our results show that the human remains from Diepkloof Rock Shelter fall well within the range of variation of AMH. The phalanges are of very small size and indistinguishable from those of recent humans. In addition, our analysis of the dm₁ underlines a large size variation at the end of the MIS 4/beginning of the MIS 3 in the Western Cape. The discovery of human remains at Diepkloof Rock Shelter, albeit limited to three small bones, enriches a poorly represented chronological period of the African hominin fossil record.     

Can morphospace shed light on cave bear spatial-temporal variation? Population dynamics of Ursus spelaeus from Romualdova pe?ina and Vindija, (Croatia)

Cave bear (Ursus spelaeus) behavioural ecology, as evidenced through population dynamics, is crucial for improving our understanding of why this species went extinct. Despite the fact that the bones of this species have been recovered in very large quantities, allowing for extensive study, fundamental questions regarding its life-ways remain unanswered. We present research using geometric morphometrics (GMM) on molars to investigate population structure based on morphological variation over space and through time. This preliminary work deliberately restricts the geographic catchment area for sampling, allowing for a meaningful appraisal of scale of variation within a spatially conservative framework. Our results demonstrate no significant morphological variation evident temporally and a small but statistically significant degree of shape variation geographically despite the proximity of the study localities. These findings suggest that an accurate quantitative exploration of morphospace may be an important source of evidence on environmental and climatic shifts and the resulting influence on animal morphology.     

Evaluation of uniradicular teeth for age-at-death estimations in a sample from a Pampean hunter-gatherer cemetery (Argentina)

Age-at-death estimation is one of the most important aspects of bioarchaeological and forensic investigations. A set of analysis carried out with the osteological sample recovered from Chenque I site (Lihué Calel National Park, La Pampa province, Argentina) aims to test the applicability of multiple methods to obtain reliable information about its demographic composition and structure. In the present paper the results of the evaluation of the structure of uniradicular teeth are presented and discussed. It has been previously stated that chronological age is highly correlated with pulp dimensions in these teeth, because dentine deposition continue during all life. Strong correlation has been also identified with periodontal retraction and apical translucency. The analysis of the structure of these teeth offers useful information in order to obtain age-at-death estimations of the individuals they belonged to. Dental age-at-death estimations of the control sample were obtained evaluating some skeletal markers (pubic symphysis and auricular surface of coxae), and then compared with the dental analysis. The formulae whose results showed strong correlations with the skeletal estimations were applied to another sample, composed of teeth that were not associated with any skeletal marker of age. The evaluation of premolars and lower central incisors offers estimations that are consistent with those obtained from the evaluation of the pelvic bones, so that the application of these formulae is an alternative method to obtain estimations in archaeological samples from similar contexts.     

Dental root dentine translucency used in age determination of medieval Norwegians from Trondheim

A pilot study on eight skulls from the churchyard of St Olav's church in Trondheim, excavated in 1988–1989, was carried out to compare age determined by root dentine translucency with the age assessed by a physical anthropologist. The difference in mean age between the two methods was not significant (p = 0.06). Age determinations based on root dentine translucency were then performed on removable teeth from the adults among the 248 skeletons found in the same churchyard, excavated in 1984–1985. A comparison between the ages determined using root dentine translucency and the ages previously determined by the direct inspection method was performed. A significant systematic difference was seen between the two methods (p = 0.000). The root dentine translucency method gave an age range for the cohort excavated in 1984–1985 between 30 and 72 years, whereas the direct inspection method gave a range between 15 and 63 years. Because evaluation of many criteria are required to achieve reasonably accurate estimates of age in connection with the direct inspection method, expertise in skeletal biology is necessary. The method of measuring root dentine translucency as a tool in archaeological and anthropological work and fieldwork and in forensic science seems to have advantages because the method can be used without previous extensive training.     

Radiocarbon and U-series dating of the endemic deer Praemegaceros cazioti (Depéret) from “Grotta Juntu”, Sardinia

Radiocarbon and U-series methods (²³⁰Th/U and ²³¹Pa/²³⁵U) for absolute age determination have been applied to some fossil samples from Grotta Juntu, in North Eastern Sardinia (Italy). The remains belong to the endemic deer species Praemegaceros cazioti, which is here represented by an almost complete skeleton. The three dating methods lead to concordant ages of about 7500 years BP, indicating that the skeleton was maintained as closed system after burial. Taking into consideration these results, Praemegaceros cazioti from Grotta Juntu is now the youngest representative of this species in Sardinia.     

Early Neolithic pig domestication at Jiahu,Henan Province,China: clues from molar shape analyses using geometric morphometric approaches

The zooarchaeology of pig domestication in China is a challenging task due to its wild boar ancestors being widespread throughout Eurasia. However using geometric morphometric approaches on molar tooth (M₂), shape and size variations, from modern and Neolithic suids, using Yangshao pigs as a surrogate for the Neolithic domestic form, we have addressed the identification of morphological change during the early step of domestication in three early Neolithic sites where claims of pig domestication have been made. Phenetic relationships here have revealed clear and interpretable phenotypic signatures in the samples of modern and Neolithic pigs; which provide evidence for pig domestication at the site of Jiahu from at least 6600 BC cal., re-establishing the Yellow River region as one of the earliest centre of independent Chinese pig domestication.     

New datings of Amudian layers at Qesem Cave (Israel): results of TL applied to burnt flints and ESR/U-series to teeth

Because only a few radiometric data are actually available, the chronology of the Amudian – a blade-dominated industry of the Acheulo-Yabrudian Cultural Complex (AYCC) of the late Lower Paleolithic in the Levant – is still not well constrained. Qesem Cave offers the opportunity to enhance our knowledge of the chronological position of this industry which is unique to the Levant. The Qesem Amudian bearing layers yielded also human remains showing affinities with those of modern populations recovered in the Middle Paleolithic sites of Skhul and Qafzeh. The results presented here are the first attempt to apply the TL and ESR/U-series dating methods at this site and these methods yielded results which are generally in agreement. They support a time interval of hominid-bearing occupation of the areas of the cave where Amudian lithic artifacts were recovered during MIS 8 and likely 9 for the Deep Pit Area, and during MIS 8 and possibly 7 for the Upper part of the sequence (Square K/10 and the Eastern Microfauna-Bearing Area). An older occupation of the cave is also conceivable on the base of two dating results (MIS 11).