This is a two-for-one fossil: two undescribed fossil leaves partially overlapping one another along the same bedding plane of a chunk of feldspar-rich shale from the Middle Eocene Ione Formation, western foothills of the Sierra Nevada. Both leaves display well-preserved midribs (primary veins) and margins; the leaf margins are entire--that is, the edges of the fossils are smooth and non-serrated. Paleobotanists should be able to identify these specimens, eventually. Reddish-brown coloration is due to the presence of the mineral iron oxide, which formed during Eocene times in a semi-tropical, humid, chemically reducing paleoenvironment. Note that there are several other fragmental leaf specimens present on this same chunk of Eocene shale. The roughly 45 million-year-old specimens came from an extraordinarily rich locality on private property in Amador County--a specific site currently under formal paleobotanical study by Dr. Jack A. Wolfe (retired member of the United States Geological Survey) and Howard E. Schorn (retired Collections Manager of Fossil Plants at the University California Museum of Paleontology in Berkeley), among others, who hope to use the fossils to help approximate the paleoelevation of the ancestral Sierra Nevada region during the geologic past.
Please note: All fossil localities in the Ione Formation of Amador County, California, presently occur on private property; explicit permission from the land owners must be secured before collecting fossils there.