1. School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FE, UK.
2. Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
3. Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
4. Museum of the Rockies, Montana State University, Bozeman, Montana 59717, USA.
5. Honors Program, Chapman University, Orange, California 92866, USA.