The first record of a long-snouted choristodere (Reptilia, Diapsida) from the Early Cretaceous of Ishikawa Prefecture, Japan

Abstract

A longirostrine choristoderan reptile is described from the Early Cretaceous Tetori Group on the basis of an associated specimen from the Kuwajima Formation, Ishikawa Prefecture. This is the first report of Neochoristodera from Japan. However, the brevirostrine Monjurosuchus has already been reported from the same deposit, and the long-necked Shokawa was recovered from the Okurodani Formation, which is a lateral equivalent of the Kuwajima Formation. This new material demonstrates that the three known choristoderan morphotypes (short-necked longirostrine, short-necked brevirostrine and long-necked brevirostrine) were all present in the Early Cretaceous deposits of the Tetori Group. Until now, the Jiufotang Formation of China was the only deposit where all three were known to have co-occurred.

Keywords::

• Choristodera
• Neochoristodera
• Japan
• Cretaceous
• biogeography

Acknowledgements

The material described here was prepared by Akemi Wakimoto (formerly of Shiramine Board of Education, Ishikawa Prefecture, Japan) and Tatsuya Sakumoto (formerly of Shiramine Board of Education, Ishikawa Prefecture, Japan). The authors thank Masatoshi Okura (Aichi Prefecture) for taking photographs of these specimens; Utako Kikutani (Kanagawa Prefecture) for drawing the reconstruction in Figure 6; Yoshitaka Yabumoto (Kitakyusyu Museum of Natural History & Human History) and Shinichi Fujiwara (Nagoya University) for comments and suggestions on the reconstruction in Figure 6;Yuan Wang (IVPP) for arranging access to Chinese choristoderan specimens; Zhijie Jack Tseng (IVPP) for help in taking photographs of IVPP specimens; the mayors and administrations of Kuwajima District (Shiramine, Hakusan City, Ishikawa Prefecture, Japan) for their generous hospitality and support over a number of years; Pavel Skutschas (Saint Petersburg State University) and an anonymous reviewer for comments on an earlier version of the manuscript. RM acknowledges funding from the Palaeontological Association, England, and Japan Society for the Promotion of Science.

Notes

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