Cordilleran Section - 121st Annual Meeting - 2025

Paper No. 7-4
Presentation Time: 8:00 AM-5:30 PM

BIVALVE TURNOVER ACROSS THE TRIASSIC-JURASSIC BOUNDARY AT NEW YORK CANYON, NEVADA


JOHNSON, Claira1, ANTHONY-PETERSEN, Luke1, MCGAUGHEY, Gary2 and HODGES, Montana1, (1)Geological Sciences & Engineering, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, (2)Department of Biological Sciences, Idaho State University, 921 South 8th Avenue, Pocatello, ID 83209

New York Canyon (NYC) in the Gabbs Valley Range of Nevada, U.S.A., is known for its depositional consistency and fossiliferous marine strata that span the Triassic-Jurassic boundary. The unique snapshot of Panthalassa during this time covered the end-Triassic mass extinction in the Luning and Gabbs formations. Here we systematically describe bivalves of the NYC strata including, below, within, and above the end-Triassic mass extinction boundary. The bivalve fossils are shown in context to other specimens including a recently unearthed in situ late Rhaetian Triassic ichthyosaur just below the extinction boundary. The identification and geochronological signature of the bivalves reiterate the continuous deposition at NYC demonstrating taxa specific to both the Triassic and Jurassic period and the radiation, collapse, and recovery across the extinction boundary.