1. School of Earth and Geographical Sciences, University of Western AustraliaPerth, Western Australia 6009, Australia
2. Department of Earth and Planetary Sciences, Western Australian MuseumLocked Bag 49, Welshpool, Western Australia 6896, Australia
3. Museum VictoriaPO Box 666, Melbourne, Victoria 3001, Australia
4. School of Earth and Marine Sciences, Australian National UniversityCanberra, Australian Capital Territory 0200, Australia