Thaynes Group

The Thaynes Group, Thaynes Formation in older literature, is a geologic group in eastern Idaho, western Wyoming, Utah and eastern Nevada. It includes the Sinbad Formation, Virgin Formation and Shnabkaib Formation.[1] The Thaynes Group is of marine origin. Its formations are interbedded with layers of the non-marine Moenkopi Group.[1]

Thaynes Group
Stratigraphic range: Triassic
Type	Group
Sub-units	Sinbad Formation, Virgin Formation, Shnabkaib Formation
Underlies	Chinle Group
Overlies	Kaibab Formation
Lithology
Primary	Limestone
Other	Shales, Siltstone
Location
Region	Idaho, Nevada, Utah, Wyoming
Country	United States
Type section
Named by	T.H. Goodspeed

It preserves fossils dating back to the Early Triassic epoch (Olenekian stage). The Lower Limestone Member contains the Paris biota lagerstätte, one of the first diverse assemblages of the Mesozoic era.[2]