Heritage Cases

Histological Analysis of the fossil phocid seal from Langebaanweg

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ProposalDescription: 

An early anatomical study described a relatively low incidence of pathologies in the early Pliocene (about 5MYA) fossil seals at Langebaanweg (only 0.73%). In the current study we propose to examine pathologies evident in modern seals, and then undertake a detailed comparative analysis of the fossil seals so that we can assess the fossil seals response to trauma/disease. The study will involve anatomical analysis, CT scanning and histological analysis.This study will be carried out in the western Cape.

Expanded_Motivation: 

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.

ApplicationDate: 

Friday, February 9, 2018 - 09:00

CaseID: 

12204

OtherReferences: 

ReferenceList: 

Citation Type Date Retrieved
Govender, R., Avery, G. and Chinsamy, A., 2011. Pathologies in the early Pliocene phocid seals from Langebaanweg, South Africa. South African Journal of Science, 107(1-2), pp.1-6. Journal
Siniff, D.B. and Bengtson, J.L., 1977. Observations and hypotheses concerning the interactions among crabeater seals, leopard seals, and killer whales. Journal of Mammalogy, 58(3), pp.414-416. Journal
Laws, R.M., 1956. The Elephant Seal (Mirounga leonina, Linn.): II. General, social and reproductive behaviour (Vol. 13). HMSO. Book
Images
pathological seal radius
damaged seal ulna
seal acetabulum fragment
fractured seal metapodial
diseased seal tibia
pathological seal humerus
pathological seal humerus
pathological seal distal femur
pathological seal metapodial
pathological seal skull fragment
 
 

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