ACKNOWLEDGMENTS
The author thanks G. Jackson, D. Chapman, M. Ryan, and other staff of the Cleveland Museum of Natural History for access to specimens and for their assistance, and R. Motani and G. Vermeij (University of California Davis) for improving the early version of the manuscript. J. Kriwet is thanked for constructive comments during the review process. This project was supported by a scholarship to the author from the Japan Society for the Promotion of Science (Japan).
Handling editor: Charlie Underwood.