Description
Miocene
Esmeralda Formation
Nye County, NV, USA
Two tiny 0.2 inch fine acorn cups.
Seed,
Quercus is the genus for oak trees. The earliest confidently-known fossils are pollen from the Late Paleocene of Austria, and by the Middle Eocene, Quercus is known from North America, Europe, and Asia. While oaks originated in tropical forests, they continued to thrive as climates became drier and cooler across the Oligocene and Miocene while other trees retreated to lower latitudes. Some modern species appeared by the end of the Miocene.