1. Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
2. Section of Vertebrate Paleontology, Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, PA 15213, USA
3. Department of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK
4. Council for Geoscience, Private Bag X112, Pretoria 0001, South Africa