Kuwajima Formation
The Kuwajima Formation is an Early Cretaceous rock layer in Japan, part of the Tetori Group. It is made mostly of sandstone and mudstone and lies between the Gomijima Formation (below) and the Akaiwa Formation (above). Its exact age is uncertain, but it is now thought to be Barremian (earlier ranges included Valanginian to Hauterivian). In the upper part of the formation, at the Kaseki-kabe fossil bluff, fossils of dinosaurs and other vertebrates have been found. Fossils include the multituberculate mammals Hakusanobaatar matsuoi and Tedoribaatar reini, as well as Montirictus kuwajimaensis, a member of the Tritylodontidae.
This page was last edited on 2 February 2026, at 11:49 (CET).