Thaynes Formation | |
---|---|
Stratigraphic range: Triassic | |
Type | Formation |
Underlies | Ankareh Formation |
Overlies | Woodside Formation |
Lithology | |
Primary | Limestone |
Location | |
Region | Montana, Idaho, Wyoming |
Country | United States |
The Thaynes Formation is a geologic formation in Montana and Idaho, United States. It was recently elevated to group status, as the Thaynes Group.[1]
It preserves fossils dating back to the Triassic period, such as Ammonoidea, Actinopterygii, Actinistia, Conodonta, Gastropoda, Nautiloidea, Ichthyosauria, and others. A diverse fauna known as the Paris biota[2] has been described from the Thaynes Formation.