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Crocodilian Synchrotron

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CaseHeader

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Case Type: 

ProposalDescription: 

The focus of this research is to non-destructively investigate the dental microstructures of the very earliest occurring fossil crocodilians and their closest relatives, rauisuchians. Fossil crocodilians were an extremely diverse group of animals, and vastly different from the sedentary semi-aquatic crocodiles that we know today. These fossil crocodilians had a great diversity of ecologies, including a terrestrial lifestyle, hyper-carnivory, herbivory and insectivory. Dental microstructures such as surface dental complexity, enamel-dentin junction thickness variances, dental histology can tell us alot about the ecology and lifestyles of fossil vertebrates. Dental research has been very promising in Mammalia and Dinosauria and has proven important for investigating taxonomy, physiology, phylogenetics and diet in these clades. However, this has yet to be investigated in fossil crocodilians. South Africa has one of the best fossil records of the very earliest crocodilians globally, and the ESI holds many of these specimens in its Karoo collections. Given the rarity of crocodilian fossils, the dental microstructures and histology must be investigated non-destructively, and synchrotron x-rays are able to penetrate dense fossil material and resolve structures at a submicron level. This presents an opportunity to investigate novel structures in fossil crocodilians.

Expanded_Motivation: 

Each specimen will be individually mounted in a plastic tube and will be scanned using white beam propagation phase contrast X-ray microtomography (PPC-SR-uCT) at the BM05 beamline at a range of voxel sizes (~6.5 to 0.35 microns). A multiresolution technique will be used to focus on regions of interest on the teeth. The scan data will be digitally reconstructed and analyzed in VG Studio Max 3.2 at the ESRF facility. Investigating dental microstructures such as daily enamel secretion rates requires very high-resolution scans (<< 10µm). A MicroCT scanner can typically achieve medium resolution (> 55 µm) on specimens of this size, which is helpful for investigating finer cranial anatomy details, but is insufficient to realize the resolution required to investigate the aforementioned dental microstructures. Other scanners available in South Africa, such as Stellenbosch’s nanotome, cannot resolve objects larger than 1cm and it would require removing and isolating individual teeth, or thin sectioning larger teeth. Synchrotron X-ray microtomography is therefore ideal for my study microstructures because is non-destructive and can provide high resolution on regions of interest relatively large object.

ApplicationDate: 

Monday, October 18, 2021 - 17:23

CaseID: 

17349

OtherReferences: 

ReferenceList: 

Images
BP/1/4770
BP/1/5163
BP/1/5290
BP_1_7979
BP/1/8120
BP/1/8354
BP/1/8713
BP/1/2715
AdditionalDocuments
  1. PDF icon Dollman_Croc_export_Specimen Images.pdf
 
 

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