ACKNOWLEDGMENTS

This paper has benefited from discussions with M. Purnell of The University of Leicester, N. Eastaugh of The Pigmentum Project and the comments of the anonymous reviewers. We are grateful to P. Barrett and S. Chapman, Natural History Museum, C. Norris, C. Mehling and J. Kelly, American Museum of Natural History, W. Joyce and M. Fox, Yale Peabody Museum, M. Lamanna and A. Henrici, Carnegie Museum, M. Carrano, Smithsonian Institution, D. Siveter and P. Jeffery, Oxford University Museum of Natural History and M. Munt and L. Steel, Dinosaur Isle Museum, for granting access to and permission to clean the dinosaur teeth. J. Larkham of Coltène Whaledent is thanked for donating polyvinylsiloxane molding compound.