Akaiwa Formation

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 ~121 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
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 / 36.2; 136.7
Approximate paleocoordinates	46.1°N 138.3°E / 46.1; 138.3
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]

See also

• List of dinosaur-bearing rock formations
• List of stratigraphic units with indeterminate dinosaur fossils
  • List of stratigraphic units with ornithischian tracks
    • Ornithopod tracks