Temporary export: ESRF scanning cynodont skull and postcranial bones

I request permission to temporarily export the skulls and postcranial bones of 38 derived cynodont specimens from the Triassic-Jurassic of South Africa's Main Karoo Basin. These specimens will undergo high-resolution synchrotron scanning at the European Synchrotron Radiation Facility in Grenoble, France, on the BM05/BM18 beamlines, for approved experiment LS3437 (see attached proposal and invitation letter). The purpose of this scanning is three-fold: 1) to non-destructively image the growth marks of the lower jaw and limb bones, with the goal of determining ontogenetic age at death and deriving growth curves; 2) to non-destructively image the annual incremental cementum lines at the tooth-root/alveolar interface, with the goal of obtaining an independent ontogenetic age assessment; and 3) to non-destructively image the daily incremental dentin lines in the tooth crown, with the goal of assessing the age of each tooth and replacement patterns among tooth positions. My lengthy experimental history at the ESRF facility, coupled with published work of other collaborators (e.g., Newham see attached proposal) strongly indicate that this experiment will be successful and that no damage will be done to the fossils we hope to scan. The specimens proposed for export document the transitional stages along the cynodont stem leading to crown mammals, providing a critical baseline for understanding changes in growth and tooth replacement during this major evolutionary transition. There is no comparable instrument capable of doing this experiment on the African continent, and our outstanding working relationship with the ESRF staff (including similar previous experiments) ensures that this work will be done at the highest possible levels of scientific rigor and caution.

Please see the attached approved experimental application form, a written summary of the project, and invitation letter from the ESRF for the full details and confirmation of acceptance of the experiment. Please note that although the experiment is scheduled from June 26-July 1, I've asked for additional time on the export permit to accommodate any potential issues regarding the beamtime, so that we may be able to rectify errors or shortfalls during the experimental period. The specimens will be secured in the custom locksafe at the BM18 facility and temporarily transported to the BM05 beamline for scanning, after which they will be returned to their safe position.

Please note that only one of the proposed fossil specimens is a type, BP-1-6106 Elliotherium kersteni. This specimen has been CT-scanned at the Wits Microfocus facility at 50micron resolution and surface scanned at 100 micron resolution in advance of the export, with files for these scans reposited at the Wits ESI. All additional cranial material requested for loan here has been CT-scanned at the Wits MicroFocus facility at resolutions between 28-100microns, and the resulting scan data is reposited on the Wits CT data archive.