1. Ocean and Earth Science, National Oceanography Centre, Southampton; University of Southampton; Southampton SO14 3ZH UK
2. Dinosaur Trackers Research Group; University of Colorado Denver; CB 172 Denver CO 80217-3364 USA
3. Wyoming State Office; Bureau of Land Management; 5353 Yellowstone Road Cheyenne WY 82003 USA
4. National Operations Center; Bureau of Land Management, Denver Federal Center; Building 50 Denver CO 80225 USA