Heritage Cases

Rationale There is little comparative data on skeletal pathologies of modern Phocid seals (Govender et al. 2011) and this study aims to recognize a few of these so that they can be applied to fossil evidence in future similar studies. This study will examine pathologies of 3 extant seals viz, a vertebra and skull fragment from leopard seals, and a broken and healed fracture of a maxilla of an elephant seal. These will be examined through anatomical descriptions, CT scanning, and histological methods. These samples will be compared to similar ones exhibited in the fossil seals to better understand the nature and causes of the pathologies present. Thus this study will allow extrapolation to the fossil record, and assist in understanding the Pliocene seals skeletal response to disease and trauma. This could be especially important in the light of changing climate. Leopard Seals inhabit the ice-packs around Antarctica (Siniff et al. 1977), and Elephant Seals have a more varying range around the Southern Ocean and south Atlantic/Pacific Oceans (Laws 1956). Both regions have been subject to numerous climate change studies in recent years. Though the topic will probably not be covered in this project; it could, however, set a precedent for future studies. Aims of the research: The aims of this research include 1. a gross anatomical description of the modern and fossil pathological skeletal material 2. CT scanning of the all pathological bones 3. Description of the microanatomy and histology of the pathological bones Materials and methods Materials: The bones that are to be analysed all belong to individuals of the family Phociae. They include a vertebrae with evidence of deterioration and fissures that is from a Leopard seal, and two bones from Elephant Seals i.e. a skull fragment with severe thickening and evidence of infection, and a fractured and oddly healed mandible belonging to a juvenile. Fossil seal material previously identified by Govender et al (2011) that shows similar morphological trauma/disease will also be studied. Methods: All the material will be CT scanned to assess the trauma 3 dimensionally at a microanatomical level. Thin sections will be made of the modern elements, and we are currently applying for permits to section the pathological fossil material. The study will involve anatomical descriptions of the individual specimens, CT scanning and various histological methods.