''Ginkgo'' is a
genus of non-flowering
seed plants. The scientific name is also used as the English name. The order to which it belongs,
Ginkgoales
Ginkgoales are a gymnosperm order containing only one extant species: ''Ginkgo biloba'', the ginkgo tree. It is monotypic, (the only taxon) within the class Ginkgoopsida, which itself is monotypic within the division Ginkgophyta . The order incl ...
, first appeared in the
Permian, 270 million years ago, and is now the only living genus within the order. The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the
Pliocene. The sole surviving species, ''
Ginkgo biloba'' is only found in the wild in China, but is cultivated around the world. The relationships between ginkgos and other groups of plants are not fully resolved.
Prehistory
The ginkgo (''Ginkgo biloba'') is a
living fossil, with fossils similar to the modern plant dating back to the
Permian, 270 million years ago. The closest living relatives of the clade are the
cycads, which share with the extant ''G. biloba'' the characteristic of
motile sperm. The ginkgo and cycad lineages are thought to have an extremely ancient divergence dating to the early
Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...
. Fossils attributable to the genus ''Ginkgo'' with reproductive organs similar to the modern species first appeared in the
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...
,
and the genus diversified and spread throughout
Laurasia
Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...
during the
Jurassic and
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually c