Double Sided Ginkgo Fossil Plate (with stand)By the time of the Paleocene epoch, diversity in the genus Ginkgo was reduced to a single polymorphic species, often referred to as Ginkgo adiantoides, which produced leaves virtually indistinguishable from modern day Ginkgo biloba. This species was distributed in the northern regions due to the hot and humid tropical environment. As the climate changed in in the Oligocene epoch, the Ginkgo moved more south because of the cooler weather. Approximately