Yimaia
| Yimaia | ||||||||||||
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| Temporal occurrence | ||||||||||||
| Lower Jura to Upper Jura | ||||||||||||
| Locations | ||||||||||||
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Eurasia |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Yimaiaceae | ||||||||||||
| Zhou | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Yimaia | ||||||||||||
| Zhou & Zhang | ||||||||||||
Yimaia is an extinct relative of the ginkgo and the only genus in the Yimaiaceae family.
features
Of the representatives of the other Ginkgoales the genus is distinguished by the following features: The seed-forming organs consisting of a stem and up to eight or nine terminally standing, sitting and orthotropic standing ovules . Morphologically similar seed organs from Greenland and Sweden are placed in the genus Allicospermum .
The seed organs appear together with leaves of the Baiera or Ginkgoites type and with sprouts of Ginkgoitocladus . Pollen grains of the Tyus Ginkgocycadophytus were found in the seed organs .
distribution
The genus Yimaia occurs from the lower to middle Jurassic Eurasian. There are sites in England and China. Young seed organs from the Lower Lower Jurassic ( Hettangium ) from Franconia may also be classified in the genus Yimaia .
supporting documents
- Zhi-Yan Zhou: An overview of fossil Ginkgoales. In: Palaeoworld. Volume 18, No. 1, 2009, pp. 1–22, doi: 10.1016 / j.palwor.2009.01.001 .
- Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants. 2nd Edition. Academic Press, Amsterdam et al. 2009, ISBN 978-0-12-373972-8 . P. 752f.