Ginkgos originated in the late Paleozoic and flourished during the Mesozoic (about 250 million years ago to 65 million years ago). The ginkgophytes are all woody trees, some large, that tend to look like flowering plants with their broad leaves. But it was competition with flowering plants that likely brought about their decline during the Cenozoic. Later, when Pleistocene temperatures stressed temperate forests, ginkgos nearly went extinct. The only species living today is the maidenhair tree (Ginkgo biloba), often called a living fossil because it is similar to some fossil ginkgos from the Mesozoic. It has been kept in Asian temple gardens and cultivated in Europe and the United States as an ornamental plant. Leaf shape in fossil ginkgos is variable and historically was used to assign to species and genera, but has been found to be unreliable for classification. More fossil reproductive structures may help paleobotanists sort out whether the closest relatives of ginkgos are conifers or cycads.

Plants on Earth began life in the water. The earliest plants were aquatic algae, living in the warm seas more than 500 million years ago. By the Silurian and possibly the latest Ordovician (as much as 440 million years ago), plant life on land had begun. While terrestrial plants had more access to sunlight, challenges included supporting their weight and distributing water throughout their tissues. During the Devonian explosion (55 million years, which is brief in geologic time), plants evolved from small, simple forms to a huge variety of larger, complex forms adapted to life on land. Club mosses, horsetails, ferns, and probably sphenopsids originated. The incredible seed, which safely packages the developing plant embryo, also evolved. Plants extended their reach underground with root systems, providing the anchor and water supply to support large trees. Although plants were to undergo many changes over time, by the end of the Devonian (the golden age of plant evolution), the groundwork had been laid for the terrestrial ecosystems of today.