Tuesday, 8 October 2019


A beautiful block of marine fossils found in bedrock outcrops of the West Humboldt Mountains, Nevada. Perhaps the most famous and important locality for the Middle Triassic (Anisian/Ladinian) of North America. These beautiful hills are home to Triassic ammonoid outcrops and plentiful ichthyosaur fossils.

J.P. Smith published on the marine fauna in the early 1900s. They formed the basis for his monograph on North American Middle Triassic marine invertebrate fauna published in 1914. N. J. Siberling from the US Geological Survey published on these outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species.

Smith was a surface collector and it showed in his research. His collections consisted mainly of weathered material and were made without stratigraphic control because he believed that most, if not all, of these species, were coexistent.

The fossiliferous beds found here, as well as localities in north-western Nevada, were designated the 'Daonella dubia' zone. Dubious would be closer to the truth. Smith joined the 1905 Expedition of the University of California’s Department of Geology in Berkeley funded by the beautiful and bold, Annie Alexander, the women to whom the UCMP owes both its collection and existence.