Ginkgo Fossil range: Jurassic[1] to recent
Ginkgo adiantoides Eocene fossil leaf Tranquille Shale of British Columbia, Canada. The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning The Eocene epoch (558 ± 02 - 339 ± 01 Ma) is a major division of the Geologic timescale and the second epoch of the Palaeogene period in
Scientific classification
Kingdom: Plantae Division: Ginkgophyta Class: Ginkgoopsida Order: Ginkgoales Family: Ginkgoaceae Genus: Ginkgo L.
Species
†Ginkgo adiantoides Ginkgo biloba †Ginkgo digitata †Ginkgo huttonii †Ginkgo yimaensis
Synonyms
Salisburia Sm.[2]

Ginkgo is a genus of highly unusual non-flowering plants with one extant species, G. biloba regarded as a living fossil. Ginkgo ( Ginkgo biloba; in Chinese 銀杏 Pinyin romanization yín xìng) frequently misspelled as "Gingko" and also known Living fossil is an informal term for any living Species (or Clade) of organism which appears

Prehistory

Fossils recognisably related to modern Ginkgo biloba date back to the Permian, some 270 million years ago. The Permian is a geologic period and system that extends from 299 The genus diversified and spread throughout Laurasia during the middle Jurassic and Cretaceous, but became much rarer thereafter. Laurasia (lɔˈreɪʃiə lɔˈreɪʒə was a Supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of By the Paleocene, Ginkgo adiantoides was the only Ginkgo species extant in the Northern Hemisphere with a markedly different (but not well-documented) form persisting in the Southern Hemisphere. The Paleocene or Palaeocene, "early dawn of the recent" is a geologic epoch that lasted from 65 Northern Hemisphere is the half of a Planet that is North of the Equator —the word hemisphere literally means 'half ball' Southern Hemisphere is the half of a Planet that is South of the Equator —the word hemisphere literally means 'half ball' At the end of the Pliocene, Ginkgo fossils disappeared from the fossil record everywhere apart from a small area of central China where the modern species survived. The Pliocene epoch (spelled Pleiocene in some older texts is the period in the Geologic timescale that extends It is in fact doubtful whether the Northern Hemisphere fossil species of Ginkgo can be reliably distinguished; given the slow pace of evolution in the genus, there may have been only 2 in total; what is today called G. biloba (including G. adiantoides), and G. gardneri from the Paleocene of Scotland. The Paleocene or Palaeocene, "early dawn of the recent" is a geologic epoch that lasted from 65 Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain.

Fossil Ginkgo leaves from the Jurassic of England

At least morphologically, G. gardneri and the Southern Hemisphere species are the only known post-Jurassic taxa that can be unequivocally recognised, the remainder may just as well have simply been ecotypes or subspecies. Within a Species, an ecotype is a genetically unique Population that is adapted to its local environment In Zoology, as in other branches of Biology, subspecies is the Taxonomic rank immediately subordinate to a Species. The implications would be that G. biloba had occurred over an extremely wide range, had remarkable genetic flexibility and though evolving genetically never showed much speciation. eVolution is the third Album by eLDee, it was due to be released in 2008 Speciation is the Evolutionary process by which new biological Species arise The occurrence of G. gardneri, seemingly a Caledonian mountain endemic, and the somewhat greater diversity on the Southern Hemisphere, suggests that old mountain ranges on the Northern Hemisphere could hold other, presently undiscovered, fossil Ginkgo species. Caledonia is the Latin name given by the Roman Empire to a northern area of the island of Great Britain. Since the distribution of Ginkgo was already relictual in late prehistoric times, the chances that ancient DNA from subfossils can shed any light on this problem seem remote. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known While it may seem improbable that a species may exist as a contiguous entity for many millions of years, many of the Ginkgo's life-history parameters fit. These are: extreme longevity; slow reproduction rate; (in Cenozoic and later times) a wide, apparently contiguous, but steadily contracting distribution coupled with, as far as can be demonstrated from the fossil record, extreme ecological conservatism (being restricted to light soils around rivers); and a low population density.

Ginkgo has been used for classifying plants with leaves that have more than four veins per segment, while Baiera for those with less than four veins per segment. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. Sphenobaiera has been used to classify plants with a broadly wedge-shaped leaf that lacks a distinct leaf stem. Trichopitys is distinguished by having multiple-forked leaves with cylindrical (not flattened) thread-like ultimate divisions; it is one of the earliest fossils ascribed to the Ginkgophyta.

References