Names of all participants: Dr. Jonah N. Choiniere, Senior Researcher, Evolutionary Studies Institute, University of the Witwatersrand,011 717 6684, [email protected], PI in charge of the project and transporting skull Kimberley Chapelle, MSc student, Evolutionary Studies Institute, University of the Witwatersrand, 011 717 6684, [email protected], student doing the research and transporting eggs Dr. Vincent Fernandez, Postdoctoral Fellow, European Synchrotron Radiation Facility, Imaging Group, +33 (0)4 76 88 28 56, [email protected], scientist in charge of scanning experiment. Paul Tafforeau, Beamline Responsible, European Synchrotron Radiation Facility, Imaging Group, 00 +33 (0)4 38 88 19 74, [email protected], scientist in charge of Dr. Fernandez

Name and address of the facility, including address, it is being scanned at; European Synchrotron Radiation Facility, 71 avenue des Martyrs, 38000 Grenoble, France

Additional information: The scanning being conducted at the ESRF will allow us to digitally reconstruct the anatomy of the embryos within the eggs, and to study the fine microstructure of the eggshells themselves. Together, these data will be used for several publications investigating dinosaur reproductive strategies. The scanning of the skull being conducted at the ESRF will allow us to digitally reconstruct the anatomy of the adult specimen ofMassospondylus, which serves as an important data point for understanding the growth trajectory of the species as a whole. Both scans have been attempted at the CT scanning facility at Wits University, and in both cases the resulting scans were not of sufficient quality to digitally extract the information necessary to address these research objectives. The skull was found by James Kitching in March, 1980 and belongs to a partial specimen consisting of the front half of the body (the pelvic girdle and tail are missing). It was discovered on the farm Bormansdrift 133, located on Map 2827CD (Mekoatleng’s Nek). The eggs and skull are both approximately 200 million years old, from the upper part of the Elliot Formation of the Stormberg Group. No absolute dates yet exist for the Stormberg Group or the Elliot Formation, and this age estimate is based on global biostratigraphic comparison. The skull is a single, well-indurated unit that has been fully prepared from rock matrix externally. The egg cluster is in a single slab, and two eggs have been manually prepared to reveal embryos lying within. The remaining eggs have not been prepared but are embedded in a homogeneous red sandy mudstone.

Methodology: The European Synchrotron radiation Facility (ESRF) is the most powerful synchrotron radiaton source in Europe. The stadium sized machine generates many beams of bright X-ray light. Each beam passes through a set of lenses and instruments where the Xrays illuminate and interact with the fossils studied (this set of instruments is called a beamline). Using propagation phase contrast X-ray synchrotron microtomography (PPC-SR-μCT) is the only non- invasive method currently capable of accurately detecting differences in bone categories and ossification. The clutch of eggs (BP/1/5347A ) will be scanned on the ID19 beamline (Three-dimensional X-ray Imaging Beamline) and was allocated a beamline time of 15 shifts (120 hours). ID19 is mainly devoted to 3D imaging (microtomography, laminography), with an intensive use of phase contrast. These techniques are applied to a wide variety of topics, with a present emphasis on palaeontology (ID19 specs: Energy range: 6.0 - 250.0 keV; Beam size: Minimum (H x V) 0.1 x 0.1 mm² - Maximum (H x V) 60.0 x 15.0 mm²). The neotype skull (BP/1/4934) will be scanned on the BM05 beamline (X-ray Imaging and Optics Beamline) and was allocated 3 to 4 shifts of beamline time (24 to 32 hours) (BM05 specs: Energy range: 6.0 - 200.0 keV; Beam size: Minimum (H x V) 1.0 x 1.0 µm² - Maximum (H x V) 40.0 x 8.0 mm²).

Statement why this cannot be done in SA: Both specimens were scanned using X-Ray microtomography (µCT) at the University of the Witwatersrand. However, the latter yielded inadequate data for the purpose of this study. In the case of the embryos, BP/1/5347A, the small size of the embryonic bones made it that the scans were not of high enough resolution to differentiate between bone and matrix. It would therefore not be possible to digitally reconstruct detailed and internal morphologies. In the case of the skull, BP/1/4934, the density separation between internal matrix and bone, as well as the resolution were not adequate for virtual reconstruction. Synchrotron scans are known for their ability to resolve both of these issues.

The figure captions for each of the attached files are as follows: 4934 scan.jpg: CT scan of the skull, showing deficiency in obtaining the correct density separation between matrix and bone 4934 skull.jpg: Skull of Massospondylus 5347A scan.jpg: CT scan of egg cluster, showing deficiency in obtaining the correct density separation between matrix and bone 5347A.jpg: image of the actual fossil egg clutch with individual eggs numbered