| Fossil Hill Member | |
|---|---|
| Stratigraphic range: | |
| Type | Geological member |
| Unit of | Prida Formation, Favret Formation |
| Lithology | |
| Primary | Calcareous Shale |
| Other | Limestone |
| Location | |
| Region | Nevada |
| Country |  United States |
| Type section | |
| Named by | Kathryn Nichols and Norman Silberling |
The Fossil Hill Member is a Middle Triassic-aged rock unit. The Fossil Hill unit occurs as a member of both the Prida and Favret formations. It outcrops in multiple locations across Northwestern Nevada including the western Humboldt Range, Tobin Range, Augusta Mountains, and China Mountain. Calcareous shale, mudstone, and black limestones are the most common lithologies present within the unit.[1] The member was named for Fossil Hill, Nevada, a locality within the Humboldt Mountains where large quantities of Anisian-aged marine fossils were discovered in the early 20th century. Fossils are common throughout the Fossil Hill, and the unit is well known for preserving the remains of some of the earliest marine reptiles, including several genera of ichthyosaurs and a pistosaur.[2] Other fossils include bony fish, hybodont sharks, and invertebrates with ceratitid ammonoids being especially abundant.[3]
- ^ Nichols, K. M.; Silberling, N. J. (1977), "Stratigraphy and Depositional History of the Star Peak Group (Triassic), Northwestern Nevada", Geological Society of America Special Papers, vol. 178, Geological Society of America, pp. 1โ74, doi:10.1130/spe178-p1, ISBN 978-0-8137-2178-1, retrieved 2024-07-09
- ^ Sander, P. Martin; Griebeler, Eva Maria; Klein, Nicole; Juarbe, Jorge Velez; Wintrich, Tanja; Revell, Liam J.; Schmitz, Lars (2021-12-24). "Early giant reveals faster evolution of large body size in ichthyosaurs than in cetaceans". Science. 374 (6575). doi:10.1126/science.abf5787. ISSN 0036-8075.
- ^ Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database".