Paleocene Period, circa 56 million years B.P. A finely detailed fossil Ginkgo Cranei leaf in a sub-rectangular matrix; apanied by a white card collector's tray. 249 grams, 10 cm (4 in.). From the Sentinel Butte Formation, Morton County, North Dakota, USA. From a Cambridgeshire, UK, collection. Ginkgo biloba,monly known as ginkgo or gingko, also known as the maidenhair tree, is the only living species in the division Ginkgophyta, all others being extinct. It is a member of a very old genus, with some fossils dating back 270 million years. As they have remained virtually unchanged for this time, they are often referred to as living fossils. [No Reserve]