Auricular exostoses in the prehistoric population of Gran Canaria

Oral conditions of the pre-Hispanic mummies of Gran Canaria (Canary Islands, Spain)

OBJECTIVE

To analyse the oral conditions of pre-Hispanic mummies from Gran Canaria (5th-11th centuries AD), comparing the results with published data from the non-mummified population.

MATERIALS

440 teeth and 764 alveoli of 30 adult mummies.

METHODS

Macroscopic examination of pathological and non-pathological features of the oral cavity, using standardized criteria.

RESULTS

The mummies reveal frequent dental caries (11.8%), especially affecting molars (27.6%), a high prevalence of calculus (66.3%) and periodontal disease (34.9%). The average wear is characterized by extensive dentine exposure. Periapical lesions (10.6%) and antemortem tooth loss (AMTL) (15.9%) are common. A high percentage of individuals exhibit linear enamel hypoplasia (LEH) (84%). Except for periodontitis, the data indicate the absence of significant statistical differences between the mummies and the skeletonized sample.

CONCLUSIONS

The profile of the dental pathologies of the mummies indicates a carbohydrate-rich diet that contained abrasive grit from the stone querns used to grind cereals. Comparison of the oral conditions of mummified and skeletonized remains shows no differences in access to food resources, reinforcing the recent rejection of the traditional interpretation of the mummies as the pre-eminent status group of Canarian society.

SIGNIFICANCE

This is the first study to delve into the oral conditions of pre-Hispanic mummified remains from Gran Canaria. The results have implications for the framing of research questions based on the social status of these mummies.

LIMITATION

The preserved sample of mummified remains of ancient Canarians is small.

SUGGESTION FOR FURTHER RESEARCH

Comparative analysis from a diachronic perspective would improve understanding of the historical development of ancient Canarians.

External auditory exostoses and early Neolithic aquatic resource procurement in Cyprus: Results from Cypro-PPNB Kissonerga-Mylouthkia in regional context

OBJECTIVE

This research is designed to evaluate the occurrence of external auditory exostoses (EAEs) in skeletal remains from the oldest known water wells in the world (Kissonerga-Mylouthkia, Cyprus, 8,200-7,200 BCE).

MATERIALS

Six individuals (MNI = 6), five fragmentary temporalia, two preserved auditory canals.

METHODS

Macroscopic and microscopic (up to x30) observation, with illumination; presence, type, side, severity, occlusion, number, and position of bony growths recorded.

RESULTS

Bony growths within two auditory canals were discovered. Differential diagnosis includes osteomata and external auditory exostoses, with the latter consistent with the bony growths (Grade 1 EAEs, two adult males, one with single, another with two EAEs).

CONCLUSIONS

The emergence of the Neolithic in Southwest Asia is thought to involve increases in dietary breadth among foraging societies (Broad-Spectrum Revolution). EAEs likely indicate maritime activity in this context, given the lack of freshwater bodies, and zooarchaeological evidence points to dietary and other uses of maritime organisms.

SIGNIFICANCE

This EAE evidence is the oldest known in maritime contexts in Eastern Mediterranean and the Middle East, and first in Cyprus. It contributes towards understanding the initial colonization events by Neolithic farming communities in the 9th millennium BC, and the emergence of broad-spectrum economies at the dawn of the Neolithic in Southwest Asia, crucial for re-considerations of paradigms on the transition to the Neolithic way of life in the Near East.

LIMITATIONS

Only a few skeletal remains from these prehistoric contexts were available for observation.

SUGGESTIONS FOR FURTHER RESEARCH

Further intensive review of Cypriot skeletal collections for EAEs is advised.

New Insights into Activity-Related Functional Bone Adaptations and Alterations in Neolithic Liguria (Northwestern Italy)

This study offers a combined analysis of longbone mechanical properties (cross-sectional geometry, CSG), upper-limb enthesopathies (entheseal changes, ECs), and external auditory exostoses (EAEs) among Neolithic people from Liguria (Italy). Previous CSG studies have suggested a high degree of mobility in mountainous terrain and sexual dimorphism in the upper limbs, with males being more oriented toward unimanual activities and females performing strenuous bimanual tasks. The aims of the study were to: 1) increase the sample size of the CSG analysis via the acquisition of surface 3D models, 2) provide a solid chronological framework through direct dating in order to allow for subsampling of individuals dated to the Impresso-Cardial Complex (ICC, c. 5800–5000 BCE) and the Square-Mouthed Pottery culture (c. 5000–4300 BCE), 3) integrate the results of CSG analysis with information on ECs of the humeral epicondyles, and 4) assess possible marine activities through analysis of EAEs. Results from the CSG analysis confirmed those of previous studies, with no significant diachronic change. ECs in the humeral medial epicondyle parallelled CSG adaptations: males tended to display more changes, especially unilaterally. Only one individual from the ICC period showed bilateral EAE, suggesting that marine activities were not prevalent. This study adds to our knowledge on activity patterns in the Neolithic in Liguria, and shows that integrating structural adaptations with information from specific entheseal alterations and exostoses can improve reconstructions of past habitual activities.

External auditory exostoses and hearing loss in the Shanidar 1 Neandertal

The Late Pleistocene Shanidar 1 older adult male Neandertal is known for the crushing fracture of his left orbit with a probable reduction in vision, the loss of his right forearm and hand, and evidence of an abnormal gait, as well as probable diffuse idiopathic skeletal hyperostosis. He also exhibits advanced external auditory exostoses in his left auditory meatus and larger ones with complete bridging across the porus in the right meatus (both Grade 3). These growths indicate at least unilateral conductive hearing (CHL) loss, a serious sensory deprivation for a Pleistocene hunter-gatherer. This condition joins the meatal atresia of the Middle Pleistocene Atapuerca-SH Cr.4 in providing evidence of survival with conductive hearing loss (and hence serious sensory deprivation) among these Pleistocene humans. The presence of CHL in these fossils thereby reinforces the paleobiological and archeological evidence for supporting social matrices among these Pleistocene foraging peoples.

Aural exostoses (surfer's ear) provide vital fossil evidence of an aquatic phase in Man's early evolution

For over a century, otolaryngologists have recognised the condition of aural exostoses, but their significance and aetiology remains obscure, although they tend to be associated with frequent swimming and cold water immersion of the auditory canal. The fact that this condition is usually bilateral is predictable since both ears are immersed in water. However, why do exostoses only grow in swimmers and why do they grow in the deep bony meatus at two or three constant sites? Furthermore, from an evolutionary point of view, what is or was the purpose and function of these rather incongruous protrusions? In recent decades, paleoanthropological evidence has challenged ideas about early hominid evolution. In 1992 the senior author suggested that aural exostoses were evolved in early hominid Man for protection of the delicate tympanic membrane during swimming and diving by narrowing the ear canal in a similar fashion to other semiaquatic species. We now provide evidence for this theory and propose an aetiological explanation for the formation of exostoses.

Water-related occupations and diet in two Roman coastal communities (Italy, first to third century AD): correlation between stable carbon and nitrogen isotope values and auricular exostosis prevalence

The reconstruction of dietary patterns in the two Roman imperial age coastal communities of Portus and Velia (I-III AD) by means of stable isotope analysis of bone remains has exposed a certain degree of heterogeneity between and within the two samples. Results do not correlate with any discernible mortuary practices at either site, which might have pointed to differential social status. The present study tests the hypothesis of a possible connection between dietary habits and occupational activities in the two communities. Among skeletal markers of occupation, external auricular exostosis (EAE) has proved to be very informative. Clinical and retrospective epidemiological surveys have revealed a strong positive correlation between EAE development and habitual exposure to cold water. In this study, we show that there is a high rate of occurrence of EAE among adult males in both skeletal samples (21.1% in Portus and 35.3% in Velia). Further, there is a statistically significant higher prevalence of EAE among those individuals at Velia with very high nitrogen isotopic values. This points to fishing (coastal, low-water fishing) as the sea-related occupation most responsible for the onset of the ear pathology. For Portus, where the consumption of foods from sea and river seems to be more widespread through the population, and where the scenario of seaport and fluvial activities was much more complex than in Velia, a close correlation between EAE and fish consumption by fishermen is less easy to establish.

An Evaluation of Auditory Exostoses in 621 Prehistoric Human Skulls from Coastal Brazil

Auditory exostoses are bone anomalies located on the floor of the external auditory canal. They frequently develop in individuals who participate in water sports and other aquatic activities. Their etiology is probably multifactorial; development seems to be triggered by regular exposure to cold water, as well as to low air temperatures and/or cold winds. The presence of auditory exostoses has been recorded in human skull fossils that date back approximately 250,000 years. We conducted a study of auditory exostoses in 621 skulls of adult humans who had been part of a marine-dependent population that lived on the Brazilian coast between 5,400 and 800 years ago. The overall frequency of exostoses was 22%, but there was a great variance among different subgroups (0 to 56%). In this article, we propose some possible explanations for this variance. We also hope that our study will stimulate multidisciplinary research aimed at deciphering the intricate bony messages contained in cryptic archaeologic remains.

Auditory exostoses as an aquatic activity marker: a comparison of coastal and inland skeletal remains from tropical and subtropical regions of Brazil

Auditory exostoses are bone masses located in the external auditory canal. Currently, most researchers agree that the environment (especially water temperature, but also atmospheric temperature and wind action) plays a pivotal role in the development of this trait. This article discusses whether the presence of auditory exostoses can be used as an aquatic activity marker in bioarchaeological studies, especially in groups that inhabited tropical and subtropical regions. We analyzed 676 skeletons (5,000 years BP to historical times) from 27 coastal and inland native Brazilian groups. Very low frequencies of auditory exostoses were found in the inland groups (0.00-0.03), but the expected high frequency of auditory exostoses in the coastal groups was not always observed (0.00-0.56). These differences might be explained by the combination of water and atmospheric temperatures in conjunction with wind effects. In areas with mild atmospheric temperatures and wind chill factors, the coastal populations analyzed do not show high frequencies of auditory exostoses. However, high frequencies of auditory exostoses develop where cold atmospheric temperatures are further lowered by strong wind chill. Therefore, the association between aquatic activities, low atmospheric temperature, and wind chill is strongly correlated with the presence of auditory exostoses, but where these environmental factors are mild, the frequencies of auditory exostoses are not necessarily high. Concluding, auditory exostoses should be cautiously used as a marker of aquatic activity in bioarchaeological studies in tropical and subtropical regions, since these activities do not always result in the presence of this trait.

Dental caries among the prehispanic population from Gran Canaria

The island of Gran Canaria was inhabited in pre-Hispanic times by people of North African origin who arrived on the island towards the second half of the first millennium BC. In previous studies, we reported that there are some differences between the coastal inhabitants from Gran Canaria, mainly buried in tumuli, and those from the central mountains, mainly buried in caves. For example, the prevalence of auricular exostoses is higher among the population interred in coastal tumuli when compared with the inland population. This finding may be explained by the practice of marine activities, as supported by chroniclers' reports, by archaeological data, and by bone trace-element analysis, which point to a more intense consumption of marine products by the inhabitants of the coastal regions. Dental caries epidemiology is one of the most important ways in which the diet of past populations can be reconstructed. The purpose of this study is to assess the prevalence and intensity of caries among the pre-Hispanic population of Gran Canaria, in order to increase our knowledge about the dietary habits of these people, and to search for differences among the population buried in caves and that buried in tumuli. We studied a total of 791 individuals. Sex was estimated in 561 cases, and age at death, following Brothwell's criteria, in 549. We found that 66.95% of individuals buried in caves and 58.91% of those buried in tumuli showed at least one carious lesion. The proportion of carious teeth was significantly higher among the population buried in caves (median = 15.71%, interquartile range (IR) = 0-33.33%) than among the population buried in tumuli (median = 6.25%, IR = 0-20%, P = 0.001). Type of burial is the main factor associated with the proportion of carious teeth.These data suggest that the population buried in caves had a different dietary pattern from that of those buried in tumuli.

[Prevalence of exostoses among surfers of the Basque Coast]

Exostoses of the External Auditory Canal are benign bony tumours very common in individuals who frequently practice water activities. The objective [corrected] of this study is to determine the prevalence of exostoses in a population of surfers of the Basque Coast. We have studied the correlation between years surfing and the prevalence and severity of exostoses. We have done a cross-sectional epidemiological study giving a questionnaire Twenty-five of the 41 surfers had surfer's ear (61%) and the prevalence was significantly higher in those who had surfed for more than 10 years (p < 0.05). Severity was also higher in the first group (p < 0.05). The relation between the hours dedicated to the sport showed similar results. only one of the 24 cases needed surgery (4%).

Palatine torus in the pre-conquest inhabitants of the Canary Islands

An unusually high frequency of palatine torus in prehistoric Canary Islands skeletal remains is investigated in terms of population origins, evolutionary forces (gene flow and genetic drift) and environmental effects. Palatine torus frequencies (percent presence) are compared between the Canary Islands sample and skeletal samples from proposed ancestral regions, including northwest Africa, northeast Africa, sub-Saharan Africa, southern Europe, northern Europe and western Asia. The frequency of palatine torus is much higher in the Canary Islands sample (23.8%) than in samples from Northern and sub-Saharan Africa (1.8-6.1%), southern Europe (7.5%) and western Asia (2.1%), but is much lower than in the sample from northern Europe (57.4%). Because biological and archaeological evidence provide strong support for a northwest African origin for indigenous Canary Islands populations, the relatively high occurrence of palatine torus in the Canary Islands populace cannot be explained by an alternative ancestry; rather, it may be best explained by either evolutionary forces such as genetic drift or gene flow, or by environmental forces, such as hard chewing or a heavy dependence on marine foods. Genetic drift and gene flow seem less likely, since frequencies of other dental traits known to be under strong genetic control do not differ greatly between the prehistoric Canary Islands and northwest African samples. Environmental factors such as diet seem the most likely explanation and may include heavy consumption of marine foods, which has been implicated in torus formation.

Auricular exostoses among the prehistoric population of different islands of the Canary archipelago

It is generally believed that auricular exostoses are due to prolonged exposure to cold water, so their existence in ancient remains may inform us about economic activities in the past. This study was performed to analyze the prevalence of auricular exostoses among 150 pre-Hispanic individuals of different islands of the Canary archipelago. Individuals from Gran Canaria (6/26), Fuerteventura (1/15), and Tenerife (2/64), but not from El Hierro (0/45), showed auricular exostoses, thus supporting the hypothesis of a greater reliance on fishing and shellfishing in the former 3 islands.

Paleonutritional analysis of the pre-Hispanic population from Fuerteventura (Canary Islands)

In this study, from histological and chemical perspectives, we analyse the human remains belonging to the pre-Hispanic inhabitants from Fuerteventura (one of the Canary Islands) and compare the results with those obtained on a sample of pre-Hispanic inhabitants from Gran Canaria (Canary Islands). We observe that trabecular bone mass was normal in the samples from Fuerteventura except for an elderly woman; this result is in sharp contrast with the decreased bone mass observed in the population from Gran Canaria. The pre-Hispanic population from Fuerteventura showed lower bone strontium, Sr/Ca ratio, and bone barium, but slightly higher bone copper, than that from Gran Canaria. All these data indicate a greater consumption of marine products by the population of Fuerteventura. The high prevalence of osteoporosis observed in the population from Gran Canaria may be interpreted as a consequence of protein-calorie malnutrition, a condition which seemed to be not so prevalent in the population of Fuerteventura.