Multimodal spatial mapping and visualisation of Dinaledi Chamber and Rising Star Cave

The Dinaledi Chamber of the Rising Star Cave has yielded 1550 identifiable fossil elements – representing the largest single collection of fossil hominin material found on the African continent to date. The fossil chamber in which Homo naledi was found was accessible only through a near-vertical chute that presented immense practical and methodological limitations on the excavation and recording methods that could be used within the Cave. In response to practical challenges, a multimodal set of recording and survey methods was thus developed and employed: (1) recording of fossils and the excavation process was achieved through the use of white-light photogrammetry and laser scanning; (2) mapping of the Dinaledi Chamber was accomplished by means of high-resolution laser scanning, with scans running from the excavation site to the ground surface and the cave entrance; (3) at ground surface, the integration of conventional surveying techniques as well as photogrammetry with the use of an unmanned aerial vehicle was applied. Point cloud data were used to provide a centralised and common data structure for conversion and to corroborate the influx of different data collection methods and input formats. Data collected with these methods were applied to the excavations, mapping and surveying of the Dinaledi Chamber and the Rising Star Cave. This multimodal approach provides a comprehensive spatial framework from individual bones to landscape level

Osteopathology and insect traces in the Australopithecus africanus skeleton StW 431

We present the first application of high-resolution micro computed tomography in an analysis of both the internal and external morphology of the lumbar region of StW 431 – a hominin skeleton recovered from Member 4 infill of the Sterkfontein Caves (South Africa) in 1987. The lumbar vertebrae of the individual present a number of proliferative and erosive bony processes, which were investigated in this study. Investigations suggest a complex history of taphonomic alteration to pre-existing spinal degenerative joint disease (SDJD) as well as post-mortem modification by an unknown insect. This study is in agreement with previous pathological diagnoses of SDJD which affected StW 431 and is the first time insect traces on this hominin are described. The results of this analysis attest to the complex series of post-mortem processes affecting the Sterkfontein site and its fossil assemblages

Calculation of likelihood ratios for inference of biological sex from human skeletal remains

It is common in forensic anthropology to draw inferences (e.g., inferences with respect to biological sex of human remains) using statistical models applied to anthropometric data. Commonly used models can output posterior probabilities, but a threshold is usually applied in order to obtain a classification. In the forensic-anthropology literature, there is some unease with this “fall-off-the-cliff” approach. Proposals have been made to exclude results that fall within a “zone of uncertainty”, e.g., if the posterior probability for “male” is greater than 0.95 then the remains are classified as male, and if the posterior probability for “male” is less than 0.05 then the remains are classified as female, but if the posterior probability for “male” is between 0.05 and 0.95 the remains are not classified as either male or female. In the present paper, we propose what we believe is a simpler solution that is in line with interpretation of evidence in other branches of forensic science: implementation of the likelihood-ratio framework using relevant data, quantitative measurements, and statistical models. Statistical models that can implement this approach are already widely used in forensic anthropology. All that is required are minor modifications in the way those models are used and a change in the way practitioners and researchers think about the meaning of the output of those models. We explain how to calculate likelihood ratios using osteometric data and linear discriminant analysis, quadratic discriminant analysis, and logistic regression models. We also explain how to empirically validate likelihood-ratio models

Response to Thackeray (2016) – The possibility of lichen growth on bones of Homo naledi: Were they exposed to light?

Thackeray1 questions the hypothesis of deliberate body disposal in the Rising Star Cave by Homo naledi, as proposed by Dirks and colleagues2. Thackeray proposes that lichens produced mineral staining on the skeletal remains of H. naledi. As lichens require some exposure to light, in Thackeray’s opinion, the presence of mineral staining necessitates either a direct entrance deep into the Rising Star Cave that once admitted light into the Dinaledi Chamber, or relocation of mineral-stained bones from a location exposed to light. Here we consider multiple lines of evidence that reject Thackeray’s hypothesis that lichens deposited mineral staining upon the surface of these skeletal remains. We welcome the opportunity to address the inferences presented by Thackeray, and further hope that this response may dispel misinterpretations of our research2, and of other areas of the scientific literature that bear upon site formation processes at work within the Rising Star Cave system

Earliest hominin cancer: 1.7-million-year old osteosarcoma from Swartkrans Cave, South Africa

The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirmed cases of Middle or Later Pleistocene dates reported. It has generally been assumed that premodern incidence of neoplastic disease of any kind is rare and limited to benign conditions, but new fossil evidence suggests otherwise. We here present the earliest identifiable case of malignant neoplastic disease from an early human ancestor dated to 1.8–1.6 million years old. The diagnosis has been made possible only by advances in 3D imaging methods as diagnostic aids. We present a case report based on re-analysis of a hominin metatarsal specimen (SK 7923) from the cave site of Swartkrans in the Cradle of Humankind, South Africa. The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient specimens. Such tumours are not related to lifestyle and often occur in younger individuals. As such, malignancy has a considerable antiquity in the fossil record, as evidenced by this specimen

Evidence of fatal skeletal injuries on Malapa Hominins 1 and 2

Malapa is one of the richest early hominin sites in Africa and the discovery site of the hominin species, Australopithecus sediba. The holotype and paratype (Malapa Hominin 1 and 2, or MH1 and MH2, respectively) skeletons are among the most complete in the early hominin record. Dating to approximately two million years BP, MH1 and MH2 are hypothesized to have fallen into a natural pit trap. All fractures evident on MH1 and MH2 skeletons were evaluated and separated based on wet and dry bone fracture morphology/characteristics. Most observed fractures are post-depositional, but those in the right upper limb of the adult hominin strongly indicate active resistance to an impact, while those in the juvenile hominin mandible are consistent with a blow to the face. The presence of skeletal trauma independently supports the falling hypothesis and supplies the first evidence for the manner of death of an australopith in the fossil record that is not attributed to predation or natural death.The National Research Foundation of South Africa (NRF)http://www.nature.com/scientificreportsam201

New fossil remains of Homo naledi from the Lesedi Chamber, South Africa

The Rising Star cave system has produced abundant fossil hominin remains within the Dinaledi Chamber, representing a minimum of 15 individuals attributed to Homo naledi. Further exploration led to the discovery of hominin material, now comprising 131 hominin specimens, within a second chamber, the Lesedi Chamber. The Lesedi Chamber is far separated from the Dinaledi Chamber within the Rising Star cave system, and represents a second depositional context for hominin remains. In each of three collection areas within the Lesedi Chamber, diagnostic skeletal material allows a clear attribution to H. naledi. Both adult and immature material is present. The hominin remains represent at least three individuals based upon duplication of elements, but more individuals are likely present based upon the spatial context. The most significant specimen is the near-complete cranium of a large individual, designated LES1, with an endocranial volume of approximately 610 ml and associated postcranial remains. The Lesedi Chamber skeletal sample extends our knowledge of the morphology and variation of H. naledi, and evidence of H. naledi from both recovery localities shows a consistent pattern of differentiation from other hominin species

Burnt Human Remains Part II: Identification and Laboratory Analysis

Part I of Burnt Human Remains (see Chapter 6) detailed how to properly document, excavate and package elements found in the field. The second part presented here, will describe the subsequent methods of laboratory analysis and identification techniques. While fire scene investigation and any recovered fire debris may provide strong evidence with regard to the cause, mechanism and development of the fire (electrical, chemically accelerated, accidental, arson, etc.), burnt remains also have the potential to provide information concerning the temperature, duration and procession of the fire from the analysis of macro- and microstructural changes in skeletal tissue. They may also provide biochemical evidence for the use of ignitable liquids such as accelerants, or yield heattransformed chemical markers from the destruction of soft tissues, clothing, and other components of the fire environment (DeHaan et al., 2004; DeHaan, 2008; DeHaan and Icove, 2012; DeHaan and Nurbakhsh, 2001). Depending on the nature of the fire, the circumstances (non-suspicious, suspicious, arson, confirmed homicide, etc.) and condition and level of preservation, the tissues may undergo differing laboratory analyses by a variety of specialists; this may include the forensic pathologist or medical examiner, forensic odontologist, forensic entomologist, toxicologist, forensic botanist, fire investigator and forensic anthropologist. Each specialist will bring their own expertise in addressing medico-legal questions relating to the identity of the deceased, time since death, physiological and chemical status, and manner and cause of death. Here we will focus on the avenues of enquiry available when remains are severely burnt, skeletonised, and disrupted; such analyses are primarily the purview of the forensic anthropologist

Burnt Human Remains Part I: Fire Dynamics and Body Recovery

This chapter will detail fire dynamics and the effects on human remains, as well as body recovery techniques including methods of documentation and excavation in the field. The second part of the discussion relating to burnt human remains will address methods of identification and laboratory analysis (see Chapter 7)

Skeletal trauma

AbstractThe question of existence of a maximal subgroup in the multiplicative group D∗ of a division algebra D finite-dimensional over its center F is investigated. We prove that if D∗ has no maximal subgroup, then deg(D) is not a power of 2, F∗2 is divisible, and for each odd prime p dividing deg(D), there exist noncyclic division algebras of degree p over F