Ohyamashimo Formation

Ohyamashimo Formation
Stratigraphic range: Albian ~112.1–106.4 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Sasayama Group
Underlies	Sawada Formation
Overlies	Basement (Unconformity)
Thickness	1300 metres
Lithology
Primary	Conglomerate, Sandstone, Mudstone
Other	Tuff
Location
Coordinates	35°06′N 135°06′E / 35.1°N 135.1°E / 35.1; 135.1
Approximate paleocoordinates	47°54′N 132°48′E / 47.9°N 132.8°E / 47.9; 132.8
Region	Hyogo prefecture
Country	Japan
Type section
Named for	Ohyamashimo, Tamba-Sasayama
Named by	Hayashi et al., 2017[1]
Ohyamashimo Formation (Japan)

The Ohyamashimo Formation(大山下層) is an Early Cretaceous (Albian) geologic formation in Japan. It has been dated to the early-mid Albian, between 112.1 ± 0.4 Ma and 106.4 ± 0.4 Ma. Dinosaur remains have been discovered from this formation, including the sauropod Tambatitanis, the theropod Hypnovenator and the ceratopsian Sasayamagnomus. Other representative fossils from the formation include the monstersaurian lizard Morohasaurus and eutherian mammal Sasayamamylos. The depositional environment represents a fluvial system with a subhumid to semi-arid climate.