The Human Elements:
Skeletal Remains from Unar 2, Ras al-Khaimah

Introduction

Despite a relatively short history of archaeological research in the United Arab Emirates, a considerable number of Umm an-Nar tombs have been recorded. Results from surveys and excavations show that the tombs are located throughout the Oman Peninsula in coastal, piedmont and desert (oasis) environments. Despite the differences in location, there are a number of features which are common to all the tombs. These include the use of a circular shape for the design of the tomb, the use of un-worked stone, faced with a single outer ring-wall, and the fact that they are collective burials (for a summary of work on Umm an-Nar tombs see Potts, D.T. 1990. The Arabian Gulf in Antiquity. Vol. 1: 94-98).

Background

During the investigations of Unar 1 located on the Shimal plain in the northern Emirate of Ras al-Khaimah, the excavators commented on the fact that they were certain that other Umm an-Nar tombs existed in the surroundings. In late 1996 a new Umm an-Nar tomb just south of Unar 1 was discovered during the construction of a road in the Shimal area. Preliminary excavations of the site named Unar 2 (Fig. 1) took place in early 1997, followed by further work in early 1998 and completion in 1999. Constructed out of the local limestone, the circular tomb measures 14.3 m in diameter with 12 separate internal chambers (A-H, L-N), making it the largest communal tomb yet discovered in the Arabian Peninsula.

Findings

A number of ceramic vessels including typical Umm an-Nar funerary vessels as well as so called Kaftari ware (from Fars province in south-western Iran indicating some kind of contact with this area), bronzes, and thousands of beads were recovered. A vast quantity of disarticulated cremated and unburned human remains, as well as a number of unburned articulated remains were also retrieved. Only relative dates have been proposed for Unar 2. Preliminary assessment of the ceramics and the beads suggests the site is typical of the late Umm an-Nar period (although not the latest), that is, about 2300-2100 BC.

The Human Skeletal Remains

The human skeletal material recovered from Unar 2 was typical of remains found in most Umm an-Nar tombs in that it was disarticulated and relatively poorly preserved. This is more than likely a result of a combination of environmental (accidental) conditions and/or cultural (intentional) burial practices. A total of 21, 019 individual post-cranial and cranial elements have been recorded. In addition, two nearly complete crania were recovered from Chamber C, two articulated individuals, one in Chamber D and the other in Chamber G (which interestingly was also associated with an articulated animal burial of a dog), were also retrieved. Semi-articulations were recorded in Chambers D and K. Despite the fact that dentition usually survives in the archaeological record (due to the high degree of mineralisation), very few teeth were found at Unar 2. Almost all (90.7%) of the skeletal remains (n = 21,019) showed some degree of burning, with the majority (70.1%) of bones in each chamber being predominantly burnt white suggesting temperatures perhaps reached up to between 600-700 degrees C. While contributing to the hardness of the bone, the burning also caused considerable warping (Fig. 2).

Numbers of Individuals

Estimating the numbers of people contributing to past populations is important because interpretations may then be made about population densities, an influential factor in the spread of diseases, as well as the types of organisations which were needed to provide enough food and resources for that population.

Based on the left petrous part of the temporal bone (in the skull) a minimum of 431 individuals was estimated to have been buried in the tomb at Unar 2. Because the tomb consists of isolated chambers a MNI interred in the separate chambers was also established (Table 1).
 

Table 1: Showing comparison of the MNI in separate chambers at Unar 2.

Typical of most Umm an-Nar tombs, the majority of skeletal material could only be assigned to a general adult category, although evidence of the remains of foetal, infant, children and adolescents existed in each chamber. The articulated skeletons in Chambers D and G were also both adults.

Sex

Physical anthropologists are interested in attempting to determine the sex of individuals in communal burials because the differences in the percentages of women and men in a burial population may be significant in terms of the types of diseases affecting the population (that is some diseases affect men more than woman and vice versa), and/or the results may throw some light on burial practices( that is, were men and women buried together?)

Because determining the sex of an individual from the skeleton requires examining those parts of the body which are sexually dimorphic, particularly the head and the pelvis, it is often difficult to accurately attribute sex when the remains are disarticulated and/or fragmentary. Although 1477 adult diagnostic skeletal elements were recovered from Unar 2, the majority of these elements could not be assigned a sex because of the poor preservation. Of the elements which could be sexed, there was a relatively even spread of males and females represented in each chamber. Based on examination of the pelvis and cranium the articulated skeleton recovered from Chamber D was determined to be female, while the individual from Chamber G was male.

Dental and Skeletal Health

Because different diseases can often affect the same part of the body, the study of palaeopathology (defined as the scientific study of the history of disease and its change), ideally requires an investigation of the entire skeleton. Recovering complete and well preserved skeletal material from archaeological sites is however, often difficult As outlined above, the skeletal material recovered from Unar 2 was both disarticulated and fragmentary which limited the extent to which the health of the people buried at the site could be clearly understood. However, broad interpretations were possible.

Although relatively few teeth were recovered from Unar 2, those which were complete (n = 152 adult teeth) showed attrition (wear) similar to that observed on the dentition from other third millennium BC sites. While the anterior and molar teeth were worn, the attrition was not as extreme as that observed on teeth from sites dating to the fourth millennium BC. This is probably explained by the fact that by the Umm an-Nar period a shift in diet had occurred. Rather than relying solely on marine resources, people living in the Shimal area had access to a wider variety of foodstuffs probably as a result of the domestication of the date palm. The introduction of the date into the diet would also account for the occurrence of increased dental decay. 4.6% of all teeth from Unar 2 (n = 152) showed were affected by caries. Dental decay may also account for the increase in ante-mortem tooth loss (AMTL), that is, teeth lost while the individual is alive. Of the 517 adult mandible pieces recorded, 45.3% had evidence of AMTL of one or more teeth. Of the 250 adult maxillary fragments examined, 8.4% had evidence of ante-mortem tooth loss. This lower incidence observed in the maxilla is more than likely an artefact of preservation.

A number of examples of traumatic lesions were recorded on the skeletal remains from Unar 2. These included fractures to the arms bones, ribs, hands and feet, depression fractures on parts of the crania and trauma affecting the vertebrae. Interpreting the exact causes of these traumatic lesions is difficult. Possible explanations include the following: a blow to the head with a blunt object (whether intentional or accidental is impossible to determine) resulting in the cranial depression fractures; a combination of old age (perhaps accompanied by osteoporosis) and/or an impacting force such as carrying a heavy object resulting in the anterior depression of some of the vertebrae; the fractures observed on the axial skeleton may have resulted from anything from a fall (breaking the arm bone) or an object being dropped on the foot (breaking the toe bones).

While evidence of different kinds of trauma has been recorded at sites in the UAE dating to most periods, it is interesting to note that vertebral compression fractures have only been recorded at third millennium BC sites. This phenomenon may reflect alterations in daily activities, including the construction of monumental structures such as the towers and mud-brick platforms recorded on many Umm an-Nar sites. The notion that people during the third millennium BC were engaged in heavy strenuous labour is perhaps also supported by the occurrence (although only minimal) of other vertebral alterations such as Schmorl’s nodes (caused by the degeneration of the intervertebral disk, resulting in herniation) and spondylolysis (a defect caused by recurrent stresses and strains of bending and lifting in the upright posture which creates a gradual series of small fractures which ultimately fractures the bone).

Apart from the vertebral lesions described above, very little evidence of severe joint disease was observed at Unar 2. Most joint alterations were exhibited through the manifestation of osteophytes (“lipping” of the bone) and/or pitting on the joint surface. While such skeletal alterations may be indicative of a reaction to excessive pressure on the joint as a result of a fracture or a particular disease, it is also possible that the changes are a purely physiological response to old age in which the structure of the joints may alter. The only example of a severe joint disease observed at Unar 2 was a case of osteochondritis dessicans in the elbow. This disease is a form of ischemic necrosis probably caused by trauma.

Another category of disease which can affect bone is infection. Evidence of non-specific infection (that is, infection which may be a result of a bacteria which cannot be specifically distinguished) was recorded at Unar 2. In most cases alterations were manifested in the form of pitting on the bone. One of the more interesting cases of infection consisted of a destructive lesion recorded on the right side of a maxillary palatine process (Fig. 3). This lesion did not appear to be related to a dental abscess which usually develops in response to general dental diseases and involves an accumulation of pus, the pressure of which is relieved through the formation of a cavity within the supporting bone. The maxillary lesion is reminiscent of facial alterations associated with specific infectious diseases such as leprosy and treponemal disease. When the hard palate is involved in leprosy, inflammatory changes are seen including thinning, pitting and perforation. With treponemal infections the palate may have both destructive and healed lesions accompanied by marked osteosclerosis.

Both diseases are found in sub-tropical regions and are often described as “crowd diseases”. That is, with the advent of a sedentary lifestyle, larger groups of people appear to have been living in closer proximity, which more than likely promoted potential infectious environments for such diseases. Changing demographic conditions make the appearance of either leprosy or treponemal disease possible in the third millennium BC in the Oman Peninsula. Osteitic lesions affecting the hard palate are, however, only one aspect of these diseases. For example, in treponemal diseases such as yaws or endemic syphilis, the tibia is the most commonly involved bone, while in leprosy the hands, feet and skull are affected. As has been noted, destructive lesions which occur in single bones present considerable problems in classification. Thus, without the entire skeleton, providing a confident diagnosis is impossible. It should also be noted that to date, the earliest evidence for both of these diseases post-dates the third millennium BC. Differential diagnosis of the bone formation observed on this maxilla should also include neoplasms (tumours) which also have the potential to erode into the palate.

The final category of skeletal disease recorded at Unar 2 was metabolic. The most common lesion in this category was what is known as cribra orbitalia. While cribra orbitalia is a skeletal change indicative of anaemia, from the evidence of a fragmentary archaeological collections in which it is often difficult to associate cribra orbitalia with other vault lesions such as pitting, it is almost impossible to determine the exact type of anaemia (that is, genetic form such as sickle-cell or dietary such as iron deficiency) because of the similar ways the different types are expressed on the bones.

It is possible that the skeletal lesions are indicative of the genetic forms of anaemia, thalassaemia and sickle-cell anaemia. Both these types of anaemia are present in the UAE today, and although evidence for these specific forms has only been documented in nearby areas in the Arabian Gulf (Kuwait) as early as the Hellenistic period (330-150 BC), there is no reason to reject the possibility that they were in existence earlier.

It is also possible however, that such skeletal changes are indicative of a more common form of anaemia caused by iron deficiency, commonly associated with dietary changes and/or diseases such as gastro-intestinal or parasite infections. It is possible that such lesions developed as a result of insufficient iron intake, perhaps associated with dietary shifts discussed earlier. In order to fully understand the significance of frequencies of cribra orbitalia in the Umm an-Nar period, it would be necessary to compare frequencies from earlier material, for example from a population more dependent on marine resources. Given that infectious disease has also been seen as a major etiological factor in the development of iron-deficiency anaemia, it is interesting to note the results for frequencies of infection correspond to those of cribra orbitalia.

Conclusion

Given the importance of the entire skeleton in diagnosing specific diseases, the condition of human bone recovered from archaeological sites in the UAE is understandingly frustrating to many physical anthropologists. While preservation is a variable which must be considered, it should not be the justification for neglecting to pose questions about humans in the past. Archaeologists rarely have an ideal sample, and consequently skeletal remains of whatever preservation or number are considered potential contributors to the story of past human life styles.

Although poor preservation hindered a detailed understanding of age and sex ratios at Unar 2, it is clear that people of all ages were buried in the tomb with no apparent differential treatment of a particular sex. In terms of the health of the people living at Unar 2 in the past, it can be shown that a wide range of dental and skeletal diseases affected the people. While it is possible to propose differential diagnoses of specific diseases for some of the observed morphological changes, in the majority of cases it is only possible to propose broad categories of the types of diseases affecting the community. Archaeological evidence both for shifts in diet (with the introduction of the date palm) and the occurrence of monumental building programs (and therefore increased involvement in physical labour) around the mid-third millennium BC may well explain some of the pathological alterations, including examples of trauma, joint disease, and metabolic diseases observed at Unar 2.

Dr. Soren Blau.
Department of Archaeology
Research School of Pacific and Asian Studies
Australian National University
Canberra, ACT 0200
Australia
Ph: 61 2 6249 0309
Fax: 61 2 6 249 4917
Email: Soren@Coombs.anu.edu.au

Page  published: 27.7.99.

© National Museum &
Soren Blau
September 1999