Late Ordovician—Early Silurian Conodont Biostratigraphy, Inyo Mountains, California
Conodonts from two measured sections of the slightly metamorphosed Ely Springs Dolomite in the central Inyo Mountains of California indicate that the Ordovician-Silurian systemic boundary occurs at the middle of the formation and not at the top as previously reported. The lower member of the formation contains conodonts characteristic of Late Ordovician (Cincinnatian) age; the middle and upper members contain conodonts characteristic of Early Silurian (Llandoverian) age. This is one of the first indications of a diverse conodont fauna within this stratigraphic interval in the southwestern Great Basin.