Ginkgophytes

Maidenhair trees

The genus Ginkgo, represented today by the widely-cultivated Chinese species Ginkgo biloba, has an evolutionary lineage that dates back to the Jurassic, and the group probably dates back to the Permian. Ginkgoes were very successful during the Jurassic and Early Cretaceous, but started to decline in diversity in the Late Cretaceous with the advent of angiosperms. By the Paleocene, 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 mainly distributed in the northern regions due to the tropical environment at that time. As the Earth's climate cooled during the Oligocene, the species took on a more southerly distribution than it had occupied previously. In addition, the number of fossil sites decreases sharply. Approximately seven million years ago it disappeared from the fossil record of North America.

Ginkgo adiantoides was particularly abundant in Europe at the start of the Pliocene, but disappeared from that region by about 2.5 million years ago. There are very limited numbers of fossils found from the Pliocene, and for the Pleistocene, no fossils of Ginkgo are known. Western scientists thought that Ginkgo had become extinct, but it managed to survive in China until modern times. Ginkgo were mainly found in monasteries in the mountains, where they were cultivated by Buddhist monks. The Ginkgo was brought out of these mountains by approximately 1,100 AD and spread quickly throughout temperate Asia. It was first planted in Europe in the early 1700's and in America later that century. It now is a common street tree throughout North America and Europe due to its adaptability to urban environments.

Ecology & Form

Stems

Leaves 

Roots

Reproductive Structures

Male

Female

Above: Leaves of Ginkgo, showing the bilobed morphology of long shoot leaves

Classification

Embryophytes

└Polysporangiophytes

   └Tracheophytes

      └Euphyllophytes

         └Lignophytes

            └Spermatophytes

               └Ginkgophytes   

Geologic Range

Diversity

Baiera †

Eretmophyllum  †

Ginkgo

Ginkgodium nathorsti †

Ginkgoites †

Ginkgoitocladus  †

Karkenia henanensis † 

Nehvizdyella bipartita †

Pseudotorellia nordenskioeldii †

Sphenobaiera ikorfatensis †

Toretzia longifolia †

Trichopitys heteromorpha † 

Umaltolepis mongoliensis † 

Yimaia † 

Above: Ginkgoites huttoni † from the Middle Jurassic

Above: Baiera gracilis †

Above: Sphenobaiera digitata †

Above: Reconstructions of the leaves and seed-bearing structures of three different extinct ginkgo-like plants discovered and described by Zhou Zhiyan from the Middle Jurassic, about 170 Mya, at the Yima mine in Henan Province, China. Left: Ginkgo yimaensis showing lobed leaves and seeds borne on short stalks; top right: Yimaia recurva showing deeply-lobed leaves with linear leaf segments and seeds borne in clusters; bottom right: Karkenia henanensis showing deeply-lobed leaves with linear leaf segments and seeds borne in elongated, cone-like, aggregations. Photographs: Peter Crane. Drawing (c) by Pollyanna von Knorring (From Crane 2018, Fig. 1)

Above: Reconstruction of Trichopitys heteromorpha

Above: Nehvizdyella bipartita † (from Fig 39, Kvacek et al. 2005)

Above: Reconstruction of Umaltolepis mongoliensis and attached Pseudotorellia resinosa leaves (from Fig 4, Herrera et al. 2017)

Above: Ginkgo gardneri †

Above: Ginkgo adantoides †

Above: Reconstruction of Baiera † 

Above: Reconstruction of Ginkgo apoda † 

Above: Reconstruction of Ginkgo adantoides †  

Additional Reading