About the Authors
- Johan Lindgren
- Department of Earth and Ecosystem Sciences, Lund University, Lund, Sweden
- Michael J. Everhart
- Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas, United States of America
- Michael W. Caldwell
- Department of Earth and Atmospheric Sciences, and Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
The authors have declared that no competing interests exist.
Analyzed the data: JL MJE MWC. Wrote the paper: JL.