| Kuwajima Formation | |
|---|---|
| Stratigraphic range: | |
| Unit of | Tetori Group |
| Sub-units | Lower Member, Upper Member |
| Underlies | Akaiwa Formation |
| Overlies | Gomijima Formation |
| Lithology | |
| Primary | Sandstone, Mudstone |
| Location | |
| Country |  Japan |
The Kuwajima Formation is an Early Cretaceous geologic formation in Japan. Its precise age is uncertain due to a lack of identifying fossils, and it was previously considered likely Valanginian to Hauterivian in age.[1] However, it is now considered to probably be Barremian in age.[2] Dinosaurs and other vertebrates has been recovered from the Kaseki-kabe "Fossil-bluff" locality in the uppermost part of the formation.[3]
The multituberculate mammals Hakusanobaatar matsuoi and Tedoribaatar reini are known from the Kuwajima Formation.[4] A member of Tritylodontidae, Montirictus kuwajimaensis, has also been recovered from the unit.[5]
- ^ Fujita, M. (2003). "Geological age and correlation of the vertebrate-bearing horizons in the Tetori Group". Memoir of the Fukui Prefectural Dinosaur Museum. 2: 3–14.
- ^ Amiot, Romain; Kusuhashi, Nao; Saegusa, Haruo; Shibata, Masateru; Ikegami, Naoki; Shimojima, Shizuo; Sonoda, Teppei; Fourel, François; Ikeda, Tadahiro; Lécuyer, Christophe; Philippe, Marc; Wang, Xu (2021-01-01). "Paleoclimate and ecology of Cretaceous continental ecosystems of Japan inferred from the stable oxygen and carbon isotope compositions of vertebrate bioapatite". Journal of Asian Earth Sciences. 205: 104602. Bibcode:2021JAESc.20504602A. doi:10.1016/j.jseaes.2020.104602. ISSN 1367-9120.
- ^ Ohashi, T.; Barrett, P. M. (2009). "A new ornithischian dinosaur from the Lower Cretaceous Kuwajima Formation of Japan". Journal of Vertebrate Paleontology. 29 (3): 748–757. Bibcode:2009JVPal..29..748O. doi:10.1671/039.029.0306. S2CID 128546047.
- ^ Kusuhashi, Nao (September 2008). "Early Cretaceous Multituberculate Mammals from the Kuwajima Formation (Tetori Group), Central Japan". Acta Palaeontologica Polonica. 53 (3): 379–390. doi:10.4202/app.2008.0302. ISSN 0567-7920.
- ^ Hiroshige Matsuoka, Nao Kusuhashi and Ian J. Corfe (2016). "A new Early Cretaceous tritylodontid (Synapsida, Cynodontia, Mammaliamorpha) from the Kuwajima Formation (Tetori Group) of central Japan". Journal of Vertebrate Paleontology. Online edition: