The Favret outcrops in the Augusta, New Pass and Fish Creek ranges of north central Nevada and consists of limestone, shale and siltstone.
Although they overlap substantially, the two formations do not share precisely the same age, the Prida unit dates from the Middle to Late Anisian, while the Favret unit dates only from the Late Anisian, between approximately 244 and 242 million years ago.
The paleoenvironment preserved in the Fossil Hill contains some of the earliest marine reptile communities including Ichthyosaurs and Pistosaurs.
Other fossils from this unit include invertebrates such as ceratitid ammonoids and bivalves as well as hybodont sharks and bony fish like Saurichthyes and Birgeria.
This article about a specific stratigraphic formation in the United States is a stub.