Yimaia

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.

Yimaia Temporal range: Middle Jurassic PreꞒ Ꞓ O S D C P T J K Pg N
Restoration of Yimaia recurva from the Jurassic of China
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
Yimaia capituliformis Zhou, Zheng and Zhang, 2006 Yimaia qinghaiensis Wu, Yang and Zhou, 2006 Yimaia recurva (type) Zhou et Zhang, 1988

Species

• 

  Ginkgoites-type leaf associated with Yimaia capituliformis

  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