Mark Skinner

The speed of post mortem change to the human skeleton and its taphonomic significance

The aim of this study was to assess the potential speed of post mortem alteration to skeletal microstructure by examining human material drawn from differing environmental contexts and time periods. The material was taken from terrestrial, intertidal and lacustrine contexts and extended over a range of 3 months to 83 years post mortem. The examination was conducted using backscattered electron imaging which provided information on microstructure and relative density. The results from this study have significantly brought forward the time of known onset for post mortem alteration for 3 morphological types of microstructural change, the earliest of which was 3 months post mortem. The contribution of the depositing environment was also shown to influence significantly the microstructural/ morphological type of post mortem alteration. It is hypothesized that microstructural changes to bone could occur within days of death as a result of endogenous bacterial migration to the skeleton. Further studies are required to establish definitively the earliest moment that such change can occur prior to skeletonisation.

Guidelines for International Forensic Bio-archaeology Monitors of Mass Grave Exhumations

The systematic exhumation of mass graves is becoming a frequent occurrence globally. Historically, it has been mostly anthropologists with their particular expertise in osteology that have been engaged by non-governmental organizations (NGO) to monitor mass grave exhumations and postmortem examinations, conducted by a host country or international forensic team, to ensure competence and a concern for justice. The excavation of graves and examination of their contents for the purposes of personal identification of victims and/or collection of evidence for prosecution require the creation of standards that meet international concerns for forensic investigation of the highest quality. However, many anthropologists are not experienced with large sites; do not have much, if any, expertise in archaeology; and are not equipped by training to assess the quality of a forensic pathologists autopsy. This contribution is directed to both the NGO and the bio-archaeologist who are involved in the exhumation of mass graves. The experience and skills appropriate for the bio-archaeological monitor are outlined; similarly, the policies and standard operating procedures (SOPs) of the NGO that will enable the bio-archaeologist to perform their task are detailed. It is becoming increasingly clear that how a grave site was created, filled, and concealed, along with subsequent processes of site formation (e.g. slumping, robbing, animal scavenging and taphonomic alteration), require the expertise of a forensic archaeologist to discover and record site complexity along with associated forensic evidence. Similarly, the bodies themselves which are often skeletonized, fragmented and commingled pose challenges for the anthropologists and pathologists whose postmortem examinations must be critically evaluated. A model protocol for observations to make at the site as well as at the mortuary facility is provided to guide the monitor and to provide a structure for reports which are of standardized content suitable for international agencies concerned with mass grave investigation.

Planning the archaeological recovery of evidence from recent mass graves

Mass graves commonly contain hundreds of putrefying bodies, which bear evidence of torture and extrajudicial execution. These require careful excavation using archaeological techniques to recover the bodies for identification and to obtain associated evidence which document human rights abuses. In order to derive forensically defensible conclusions, exhumation of a mass grave may take weeks or months. Specialized protective suits and breathing apparatus will permit the investigating team to take the time required to retrieve even subtle evidence from repellent remains. Strategies for sampling tissues and bodies which reduce the magnitude of the recovery operation are described.

Variation in Birth Timing and Location of the Neonatal Line in Human Enamel

The location of the neonatal line in 173 primary teeth from 43 children was investigated and shown to differ significantly among pre-term, term, and post-term births. Approximately 75% of the neonatal lines that lie beyond 2SD of the mean location of the line in term births are from children born outside of 38 to 42 weeks gestation. The duration of pregnancy accounts for about 36% of the variation in location of the neonatal line in non-term births. Based on the small proportion of non-term births whose neonatal line is located beyond 2SD of the mean location of the neonatal line in term births, it is estimated that this technique will provide individualizing information in about 3% of immature skeletonized remains in a forensic context. The relative timing of pre- and postnatal pathological striae in the enamel of primary teeth can be evaluated in terms of the variation, documented here, in the location of the neonatal line due to individual and birth timing differences. Determination of the timing of pathological enamel striae will aid in the identification of both children and adults for whom histological examination of enamel is undertaken.

Prevalence and Etiology of Linear Enamel Hypoplasia in Monkeys and Apes from Asia and Africa

Ninety-seven specimens of sympatric monkeys and apes from East Malaysia and 115 monkeys and apes from West Africa are examined in order to evaluate the magnitude and nature of the great ape-monkey linear enamel hypoplasia (LEH) ‘dichotomy’. This study demonstrates that great apes from both regions have a higher incidence of LEH and repetitive LEH than do gibbons and monkeys. However, the authors find that the dichotomy is not as clear-cut as previous research suggests, since some monkey samples exhibit high LEH frequencies. The authors evaluate the potential influence of great ape-monkey differences in crown height on this dichotomy. They show that canine crown height variation is weakly associated with LEH variation. Differences between monkeys and great apes in their crown formation spans and in their experience of environmental stress may be more likely causes of the dichotomy.

Bee brood consumption: an alternative explanation for hypervitaminosis A in KNM-ER 1808 (Homo erectus) from Koobi Fora, Kenya

Abstract A Homo erectus individual (KNM-ER 1808) from Koobi Fora, Kenya dating from 1·6 ± 0·1 million years exhibits pathological apposition of bone on long bone shafts. This was originally attributed to hypervitaminosis A from the consumption of carnivore livers. Bee brood has a sufficiently high concentration of vitamin A that protracted ingestion could theoretically produce hypervitaminosis A. The ecology of the East African bee, Apis mellifera scutelatta , is investigated to show that the density of nests with their brood contents within a reasonable foraging area of early Homo erectus would yield an ample and reliable energy source with deleteriously high vitamin A content. A potential role of honey gathering and insect larvae consumption in hominine behavioural and physical evolution is discussed.

Individualization and Enamel Histology: A Case Report in Forensic Anthropology

The cranium of a native Indian child about six years old was found in 1979 near Taseko River, British Columbia, Canada. While the remains matched the report of a child missing for eight years in terms of race, age at death, locale, and elapsed time since death, the cranium and dentition were basically unidentifiable because of the claimed lack of medical or dental history. There was no dental work, and the parents were unknown or dead. We report the presence, in the dental enamel of the primary and secondary dentition, of stress markers, termed striae of Retzius, whose locations correspond well with anecdotal reports and recently discovered medical records which describe the timing of specific episodes of stress. The enhanced probability of personal identification from dental histological stress markers is evaluated.

The use of forensic archaeology in the investigation of human rights abuse: Unearthing the past in East Timor

Abstract This paper examines the ways in which the relatively new, yet rapidly expanding discipline of forensic archaeology may contribute to the investigation of human rights abuses. A brief history of the development and applications of forensic archaeology in the investigation of global human rights abuses is provided. The paper then outlines the current procedures for investigating human rights abuses in East Timor and focuses on a case study of a reported, but officially unrecognised, massacre in East Timor, that of the 1991 Santa Cruz massacre. We discuss the ways in which forensic archaeologists can potentially assist in the investigation of this massacre and examine the ramifications of such an investigation for the future development of East Timor.

Anthropological and Radiographic Comparison of Antemortem Surgical Records for Identification of Skeletal Remains

Abstract:  This case review illustrates the important contributions of forensic archeological methods and forensic anthropological analysis to the identification of found skeletal remains. After reassociation of skeletal remains found in two locations, anthropological analysis provided the basis for a presumptive identification and a request for antemortem medical records. Partial DNA profiles were supportive but not conclusive and antemortem dental records were not available. Comparison of antemortem traumas, skeletal morphology, and surgical artifacts with antemortem radiographs and surgical records led to positive identification of an individual missing for almost a decade.

Personal identification of cold case remains through combined contribution from anthropological, mtDNA, and bomb-pulse dating analyses.

In 1968, a childs cranium was recovered from the banks of a northern Canadian river and held in a trust until the “cold case” was reopened in 2005. The cranium underwent reanalysis at the Centre for Forensic Research, Simon Fraser University, using recently developed anthropological analysis, “bomb‐pulse” radiocarbon analysis, and forensic DNA techniques. Craniometrics, skeletal ossification, and dental formation indicated an age‐at‐death of 4.4 ± 1 year. Radiocarbon analysis of enamel from two teeth indicated a year of birth between 1958 and 1962. Forensic DNA analysis indicated the child was a male, and the obtained mitochondrial profile matched a living maternal relative to the presumed missing child. These multidisciplinary analyses resulted in a legal identification 41 years after the discovery of the remains, highlighting the enormous potential of combining radiocarbon analysis with anthropological and mtDNA analyses in producing confident personal identifications for forensic cold cases dating to within the last 60 years.