The Thaynes Formation is a geologic formation in Montana and Idaho, United States. It was recently elevated to group status, as the Thaynes Group.

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 biotaBrayard et al. (2017): Unexpected Early Triassic marine ecosystem and the rise of the Modern evolutionary fauna. Science Advances 3 (2):e1602159; doi:10.1126/sciadv.1602159 https://www.science.org/doi/10.1126/sciadv.1602159 has been described from the Thaynes Formation.

See also

List of fossiliferous stratigraphic units in Montana Paleontology in Montana Paleontology in Idaho

References