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

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. The Thaynes Group is of ma ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

dating back to the Triassic period, such as

Ammonoidea Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...

Actinopterygii Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

, Actinistia, Conodonta,

Gastropoda The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. ...

, 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.

References

* Triassic geology of Montana Triassic Idaho Triassic geology of Utah Triassic geology of Wyoming {{Triassic-stub

See also

References