Titanosauriform teeth from the Cretaceous of Japan

Haruo Saegusa,Yukimitsu Tomida

doi:10.1590/s0001-37652011000100014

Abstract

Sauropod teeth from six localities in Japan were reexamined. Basal titanosauriforms were present in Japan during the Early Cretaceous before Aptian, and there is the possibility that the Brachiosauridae may have been included. Basal titanosauriforms with peg-like teeth were present during the "mid" Cretaceous, while the Titanosauria with peg-like teeth was present during the middle of Late Cretaceous. Recent excavations of Cretaceous sauropods in Asia showed that multiple lineages of sauropods lived throughout the Cretaceous in Asia. Japanese fossil records of sauropods are conformable with this hypothesis.

Highlights

More than twenty four dinosaur fossil localities have been known in Japan (Azuma and Tomida 1998, Kobayashi et al 2006, Saegusa et al 2008, Ohara 2008. Hirayama et al 2010), most of them have provided isolated teeth and/or fragmentary bones, except for the Tetori Group in Katsuyama City of Fukui Pref. and Sasayama Group in Tamba City of Hyogo Pref
During the Early Cretaceous, Barremian or older there were basal titanosauriforms existed in Japan, and it may be possible that the brachiosaurids were included in this group
During the mid Cretaceous, the titanosauriforms with peg like teeth were present in Japan, and Titanosauria with peglike teeth were present during the Coniacian (Fig. 3)

Summary

INTRODUCTION

More than twenty four dinosaur fossil localities have been known in Japan (Azuma and Tomida 1998, Kobayashi et al 2006, Saegusa et al 2008, Ohara 2008. Hirayama et al 2010), most of them have provided isolated teeth and/or fragmentary bones, except for the Tetori Group in Katsuyama City of Fukui Pref. and Sasayama Group in Tamba City of Hyogo Pref. More than twenty four dinosaur fossil localities have been known in Japan Hirayama et al 2010), most of them have provided isolated teeth and/or fragmentary bones, except for the Tetori Group in Katsuyama City of Fukui Pref. Sasayama Group in Tamba City of Hyogo Pref. Sauropod fossils have so far been reported from 8 localities in Japan (Hasegawa et al 1991, Tanimoto and Suzuki 1997, Azuma and Tomida 1998, Tomida et al 2001, Barrett et al 2002, Saegusa et al 2008, Azuma and Shibata 2010).

MATERIALS AND METHODS

DISCUSSION