| Tamayama Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geological formation |
| Unit of | Futaba Group |
| Sub-units | Kohisagawa Member, Irimaza Member |
| Underlies | Unconformity with the Eocene Iwaki Formation |
| Overlies | Kasamatsu Formation |
| Thickness | ~ 150 metres |
| Lithology | |
| Primary | Sandstone |
| Other | Siltstone |
| Location | |
| Region | northern Honshu |
| Country |  Japan |
The Tamayama Formation is a Coniacian-Santonian geologic formation in Japan. Dinosaur remains not referrable to the genus level are among the fossils that have been recovered from the formation.[1] The lower and middle part of the formation consists of braided river sandstone, while the upper portion consists of upper shoreface to inner shelf sandstone.[2] Vertebrate taxa from the formation include Futabasaurus and Cretalamna, along with titanosauriform teeth and neosuchian remains. Seeds of the nymphaeales plant Symphaenale futabensis are also known from this formation.
- ^ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.
- ^ Ando, Hisao; Seishi, Masao; Oshima, Mitsuharu; Matsumaru, Tetsuya (1995). "Fluvial-Shallow Marine Depositional Systems of the Futaba Group (Upper Cretaceous). Depositional facies and sequences". Journal of Geography (Chigaku Zasshi). 104 (2): 284–303. doi:10.5026/jgeography.104.284. ISSN 0022-135X.