Akaiwa Formation
Early Cretaceous geologic formation in Japan
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The Akaiwa Formation (Japanese: 赤岩層, romanized: Akaiwa-sō) is an Early Cretaceous (Aptian) geologic formation in central Honshu, Japan.[2] Fossils of the turtle Kappachelys and indeterminate ornithischians are known from the formation, as well as fossil ornithopod tracks.[3][4]
| Akaiwa Formation | |
|---|---|
| Stratigraphic range: Aptian ~ | |
| Type | Geological formation |
| Unit of | Tetori Group |
| Underlies | Kitadani Formation |
| Overlies | Kuwajima Formation |
| Lithology | |
| Primary | Sandstone, conglomerate |
| Location | |
| Coordinates | 36.2°N 136.7°E |
| Approximate paleocoordinates | 46.1°N 138.3°E |
| Region | Honshu |
| Country | Japan |
  Akaiwa Formation (Japan) | |
Fossil content
The following fossils have been reported from the formation:[5]
- Osteichthyes indet. - 'fish scales'
- Reptiles
- Turtles
- Kappachelys okurai[3]
- Crocodylomorpha indet. - isolated teeth of small crocodiles[6]
- ?Euornithopoda indet.
- Neochoristodera indet. - a nearly complete right premaxilla[7]
- Ornithopoda indet. - isolated teeth of small ornithopods
- ?Theropoda indet.
- Ichnofossils
- Ornithischia indet. - tracks[8]