MZ sitewide

Physical anthropology

Laura Ramos – July 2009

Introduction

Archaeological context formed the basis for determining which remains were analyzed. At the beginning of the 2004 season, a total of 160 boxes containing the human remains from areas A, F, B, and OA were placed in the physical anthropology lab on site. Excavation units with the most complete and recent documentation were selected first for analysis, ensuring that photographs, location, and notes were available for each burial then proceeded in this manner. To date approximately 118 individuals have been analyzed from units A16, A15, J3, A7, A10, A2, A8, A9, A11, A12, J7, A14, A18, A17, and F2.

Earlier units such as A4, A5, A6, B5, and F1 have not been analyzed due to inadequate documentation but future work remains possible. This introduction provides a brief overview of the excavation and location of the human remains by area to understand where burials were found, the time period, and related structures associated with the burials. The skeletal reports are included under each unit.

Human osteology

Osteological work was initiated in 2004 seeking to asses the condition of the human remains to see if analysis was feasible and warranted further study. The assessment found adequate preservation of cortical bone but low overall completeness of the entire skeleton. The vertebral column showed the most extensive damage along with overall high fragmentation of bones, in particular the cranium. It was determined that demographic profiles could be constructed in terms of estimating biological sex, age, and general health although due to the high fragmentation rate of the skeletal material, exploring disease remains limiting.

Preservation and condition

Standard excavation procedure at Mozan includes placing all human remains in specially constructed wooden boxes lined with sheets of cotton immediately after excavation. This method provides adequate air to dry the bones out slowly while protecting them with cloth. The cranium if possible is “blocked” or removed by cutting a large block of dirt surrounding the cranium, carefully lifting and placing it inside a cardboard box or lined with foil where it is then excavated in the lab.

In the lab, each skeleton is typically cleaned using a soft brush if needed, wooden sticks used to remove harder encrustations, and in some cases cleaned using a diluted mixture of alcohol and water or acetone. Bones needing restoration were glued together using K60 PVA in alcohol (2:1) and if necessary, consolidated using diluted Primal (Acrysol) WS-24 in water. In the future, the use of PVA K-60 will be discontinued as studies indicate that Acryloid B-72 is a more preferred choice for porous materials such as bone. In some instances bones were labeled using archival pens and stored in acid free paper. The skeletons do show damage from earlier excavations in the form of scraping marks and puncture holes from the use of metal dental tools however this is minimal as the most damage appears caused by soil conditions and water seepage.

Biological sex

Determination of biological sex was estimated through observations of sexually diagnostic traits visible on the skeletal system. Although this seems to be generally understood, the term biological sex is used to refer to morphological features associated with biological differences between sexes and does not refer to the cultural constructs of gender or how sex was conceptualized in the past. Because bodies are highly variable, expression of sexual traits are within ranges requiring serration to understand what is considered “female” and “male” specific to a population.

At Mozan, the skull proved to be a poor indicator of sex with the overall shape of the cranium gracile as a female but with a robust jaw. The morphology of the pelvis expressed more typical sexual characteristics and was thus used as the main indicator of sex unless not available. If this was the case, the maximum length of the femoral head (Stewart 1979) was used as this correlated strongly with the skeletons whose sex was determined by the pelvis. Femoral diameters were found to be less than 41.8 for females and more than 46.6 for males. The skull was used for sex estimation only when the pelvis and femoral head were not available and were also noted as “possible” male or female.

A combination of traits from the skull and pelvis were compiled utilizing methods devised by Schwartz (1995), Ferembach et al (1980), Loth and Henneberg (1996), Krogman and Iscan (1986), and Phenice (1969). These methods were compiled in a list of 50 observable traits for examination devised by the University of Sheffield archaeology department. Immature skeletons were not sexed if they were determined to have yet developed sexual characteristics, typically under 15-18 years of age.

Biological age

Biological age refers to the general age of an individual at the time of death as expressed through age related morphological changes of the skeleton. This does not mean that the age ranges and subsequent identification labels such as infant and adult correspond to how age was perceived or quantified in the past. Age estimation is known to be highly inaccurate, suffering from age mimicry of the reference samples used to develop aging techniques and inherent probability statistical errors.

In order to alleviate some of the inaccuracies, age was estimated through multiple aging techniques (when available) then averaged to construct an age range. Adults were aged through changes of the pubic symphysis (Suchey and Brooks 1990), attrition rates of the mandibular molars (Miles 1962), deterioration of the auricular surface (Lovejoy et al 1985), and ectocranial suture closure (Meindle and Lovejoy 1995). For immature individuals, age was determined based on dental attainment (Smith 1991; Moorres et al. 1963), long bone diaphyseal length (Hoppa 1992), and ossification and epiphyseal fusion. All age groups are represented at ancient Mozan with a high infant mortality rate noted along with a lack of individuals aged over 55 years.

The lack of older skeletons may be a cultural phenomenon where elders were disposed of in a different way or buried elsewhere, however the aging techniques used do tend to cap out around this age. Only one skeleton in area A15 was found aged older than 55 years showing advanced osteoarthritis on her limbs and complete loss of her dentition. No other skeleton at Mozan shows these traits. One recommendation for future work is to utilize Buckberry and Chamberlain’s 2002 method which was found to be more accurate in aging middle age to 70 years when compared with Lovejoy’s method (Mulhern and Jones 2004). Boldsen et al 2002 transitional analysis should also be considered.