Tuesday 7 November 2017

Ginkgo hamiensis: A new species of Ginkgoalean from the Middle Jurassic of eastern Xinjiang, China.

Ginkgoes, Ginkgoales, are Gymnospermous Plants (plants which produce seeds without coverings), with distinctive bilobed leaves. They first appeared in the Permian, but did not become an important group until the Middle Jurassic, when they became a dominant group in many parts of the world, before being replaced in most areas by Flowering Plants in the Middle Cretaceous. Only a single genus, Ginkgo (which first appeared in the Triassic) survived the End of the Cretaceous, with a single species Ginkgo biloba, surviving today.

In a paper published in the journal Acta Geologica Sinica in February 2017, Wang Zixi, Sun Fankai, Jin Peihong, Chen Yingquan, Chen Jingwei, Deng Peng, and Yang Guolin of the School of Earth Sciences & Key Laboratory of Mineral Resources in Western China at Lanzhou University, and Sun Bainian, also of the School of Earth Sciences & Key Laboratory of Mineral Resources in Western China at Lanzhou University, and of the Key Laboratory of Petroleum Resources of the Chinese Academy of Sciences, describe a new species of Ginkgo from the Xishanyao Formation of the Turpan–Hami Basin in eastern Xinjiang, China.

The new species is named Ginkgo hamiensis, meaning 'from Hami' in reference to the location where it was found, the Sandaoling Coal Mine in Hami.The species is described from a single specimen, comprising two pollen (male) cones and a number of leaves. Male cones are extremely rare in the fossil record, with only three previously described specimens assigned to the genus Ginkgo. These cones are long and cylindrical in shape, and provide an insight into the genus at an important time in its evolutionary history.

Pollen cones of Ginkgo hamiensis (arrows). Scale bar is 1 cm. Wang et al. (2017).

See also...

http://sciencythoughts.blogspot.co.uk/2017/10/cycas-dharmrajii-new-species-of-cycad.htmlhttp://sciencythoughts.blogspot.co.uk/2017/02/isaberrysaura-mollensis-neornithischian.html
http://sciencythoughts.blogspot.co.uk/2016/04/juraherba-bodae-herbaceous-angiosperm.htmlhttp://sciencythoughts.blogspot.co.uk/2016/02/butterflies-of-jurassic-convergent.html
http://sciencythoughts.blogspot.co.uk/2015/08/glenrosa-carentonensis-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2015/05/northern-mozambiques-critically.html
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