Ornithischian dinosaur material from the Kuwajima Formation (Tetori Group: Lower Cretaceous) of Ishikawa Prefecture, Japan

Abstract

The Kumajima Formation (Lower Cretaceous: ?Hauterivian–Barremian) of Ishikawa Prefecture, central Honshu, Japan, has yielded a diverse vertebrate fauna that includes a variety of dinosaur taxa. Here, we describe teeth and cranial elements that are referable to an indeterminate styracosternan iguanodontian, an additional unnamed small ornithischian (represented by an isolated maxilla) that is distinct from Albalophosaurus, and other indeterminate ornithischian remains that may belong to the unnamed taxon, Albalophosaurus or another ‘basal’ ornithischian taxon. Iguanodontian specimens are numerically dominant in the available sample of dinosaur material. The Kuwajima Formation has yielded the most diverse dinosaur fauna from Japan and provides a useful point of comparison with other better-known East Asian dinosaur faunas, such as that of the Chinese Jehol Biota.

Keywords::

• Ornithischia
• Iguanodontia
• Lower Cretaceous
• teeth
• skull bones

Acknowledgements

It is a pleasure to dedicate this paper to Yukimitsu Tomida in honour of his retirement from the National Science Museum. With his amazing energy and broad interests, Yuki has done much to document the fossil vertebrate diversity of Japan, ranging from mammals to dinosaurs, and working with him on the monograph of the NSM Apatosaurus (Upchurch et al. 2004) was a highlight of P.M. Barrett's early career. We would like to thank many colleagues for access to material in their care and P.M. Barrett would also like to thank these same individuals for their help, collaboration and hospitality in Japan over the course of several trips to the Hakusan area, especially M. Manabe and S. E. Evans, and also S. Isaji, I. Yamaguchi, M. Yamaguchi, H. Matsuoka, R. Hirayama, Y. Kakegawa, R. Matsumoto and Y. Yabumoto. K. Otsuka is thanked for providing several of the photographs used here. T. Hübner, an anonymous referee and the editor provided useful comments on an earlier draft of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

^1. Email: [email protected]

Additional information

Funding

Funding for P.M. Barrett's trips was provided by the Royal Society of London (to S.E. Evans), the National Science Museum, Tokyo and Trinity College, University of Cambridge.