1. Department of Palaeontology, The Natural History MuseumCromwell Road, London SW7 5BD, UK (r.cocks@nhm.ac.uk)
2. Center for Geodynamics, Geological Survey of NorwayLeif Eirikssons vei 39, N-7491 Trondheim, Norway
3. Institute for Petroleum Technology and Applied Geophysics, Norwegian University of Science and Technology (NTNU)Trondheim N-7491, Norway
4. School of Geosciences, Private Bag 3, University of WitwatersrandWITS 2050, South Africa