Yimaia
Extinct genus of seed-bearing plants
| Yimaia Temporal range: Middle Jurassic PreꞒ Ꞓ O S D C P T J K Pg N | |
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| Y. capituliformis specimen (CNU-PLA-NN-2009-085C), National Museum of Natural History | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Ginkgophyta |
| Class: | Ginkgoopsida |
| Order: | Ginkgoales |
| Family: | †Yimaiaceae Zhou, 1997 |
| Genus: | †Yimaia Zhou et Zhang, 1988 |
| Species | |
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Yimaia is an extinct genus of Ginkgoalean tree, and the only member of the family Yimaiaceae. In botanical form classification, its a form taxon for ginkgoalean ovulate organs. Yimaia species are distinguished from other Ginkgoales by the presence of "Ovulate organs consisting of a peduncle and up to eight or nine terminal, sessile, contiguous and orthotropous (straight, upright and with a micropyle at apex) ovules." The ovules are associated with leaves of either Baiera or Ginkgoites leaf morphospecies.[1] Fossils have been found in Middle Jurassic deposits in China.
Species
- Yimaia capituliformis Zhou, Zheng and Zhang, 2006 Daohugou Bed, China, Callovian[2] Associated with leaves of Ginkgoites type
- Yimaia qinghaiensis Wu, Yang and Zhou, 2006 Shimengou Formation, Qinghai, China, Middle Jurassic[3] Associated with leaves of Baiera furcata type.
- Yimaia recurva (type) Zhou et Zhang, 1988 Yima Formation, Henan, China, Middle Jurassic
References
- ^ Zhou, Zhi-Yan (March 2009). "An overview of fossil Ginkgoales". Palaeoworld. 18 (1): 1–22. doi:10.1016/j.palwor.2009.01.001.
- ^ Zhou, Zhiyan; Zheng, Shaolin; Zhang, Lijun (April 2007). "Morphology and age of Yimaia (Ginkgoales) from Daohugou Village, Ningcheng, Inner Mongolia, China". Cretaceous Research. 28 (2): 348–362. doi:10.1016/j.cretres.2006.05.004.
- ^ Wu, Xiangwu; Yang, Xiaoju; Zhou, Zhiyan (April 2006). "Ginkgoalean ovulate organs and seeds associated with Baiera furcata-type leaves from the Middle Jurassic of Qinghai Province, China". Review of Palaeobotany and Palynology. 138 (3–4): 209–225. doi:10.1016/j.revpalbo.2006.01.009.
