A new basal hadrosauroid (Dinosauria: Ornithopoda) from the Turonian of New Mexico

ABSTRACT

MSM P4166, a specimen from the Moreno Hill Formation (middle Turonian) of New Mexico, is described as the holotype of a new genus and species of hadrosauroid dinosaur. Jeyawati rugoculus, gen. et sp. nov., is diagnosed by a rugose texture that covers the entire lateral surface of the postorbital and the presence of a large neurovascular foramen at the base of the jugal process of the postorbital, as well as a unique combination of characters. A preliminary phylogenetic analysis reveals that Jeyawati is a basal hadrosauroid more derived than Probactrosaurus, Eolambia, and Protohadros, but more basal than Shuangmiaosaurus, Bactrosaurus, and Telmatosaurus. Assessment of ontogenetic criteria indicates that MSM P4166 represents a subadult or adult individual. Even with the recognition of Jeyawati, Late Cretaceous hadrosauroid biogeography remains somewhat ambiguous because of the lack of material from the late Turonian–early Santonian in western North America.

ACKNOWLEDGMENTS

This paper is dedicated to the memory of our dear friend and project collaborator Thomas J. Robira (1942–2008) in honor of his ceaseless hard work and geniality in the field. MSM P4166 was collected under Paleontological Resource Use Permit MSM-8172-RS-97–1, issued by the U.S. Bureau of Land Management; we specifically thank K. Carson, P. Hester, and M. O’Neill for their assistance. Deb Boaz, D. Carlson, B. Chinnery-Algeier, P. and B. Dent, R. Denton, O. and O. Gutierrez, N. Kay, S. Nesbitt, P. Platt, D. and T. Rust, R. and B. Sims, C. Wolfe, S. and S. Zimmerman, and Dinamation International Society assisted with the recovery of MSM P4166. The Mesa Southwest Museum (Arizona Natural History Museum), Southwest Foundation, Museum Guild, and Southwest Paleontological Society are acknowledged for assistance with field and preparation expenses. We are very grateful to H. and P. Bollan for their expert preparation of MSM P4166 and to R. Gaston for producing casts. S. Bolander and H. Wolfe provided assistance ranging from logistics to field documentation. A.T.M. is very grateful to the staffs of the CEUM (J. Bartlett and J. Bird) and SMU (L. Jacobs and D. Vineyard) for access to and assistance with specimens under their care, and to R. Corner of the University of Nebraska State Museum (UNSM) for helping to arrange the loan of MSM P4166 to the UNSM for research purposes. We thank K. Carpenter, R. Denton, P. Dodson, D. Evans, T. Gates, J. Horner, Y. Kobayashi, M. Lamanna, S. Lucas, D. Norman, A. Prieto-Márquez, A. Tumarkin-Deratzian, D. Weishampel, T. Williamson, and H. You for their correspondence and discussion. Thanks to P. Dodson and H. You for reading a rough draft of this paper and offering comments. Thanks to P. Godefroit and an anonymous reviewer for critiques that improved the manuscript. We extend deepest thanks to L. Panzarin for his superb restoration of Jeyawati. A.T.M. is very grateful to R. Hunt and D. Loope, his faculty advisors at the University of Nebraska–Lincoln, and to P. Dodson, his advisor at the University of Pennsylvania, for their discussions, dedication, and advice. A.T.M.'s research was funded by grants from the Paleontological Society and the Western Interior Paleontological Society, and by the University of Nebraska UCARE Program.

Notes

^†Current address: Department of Earth and Environmental Science, University of Pennsylvania, 254-b Hayden Hall, 240 South 33rd Street, Philadelphia, Pennsylvania 19104, USA, [email protected]