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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Cycas Fushunensis sp. nov. (Cycadaceae) From the Eocene of Northeast China

Su, Kui, Quan, Cheng, Liu, Yu Sheng (Christopher) 01 January 2014 (has links)
A new cycad species, Cycas fushunensis sp. nov., is described from the Lutetian Jijuntun Formation at Fushun Coalmine, Liaoning Province, northeast China, based on a well-preserved partial frond containing about 15 leaflets. The fossil is characterized by a single strong vein per leaflet, decurrent leaflet base and haplocheilic stomata, suggesting that the fossil is attributed to the genus Cycas of Cycadaceae. Epidermal anatomical comparisons between the fossil and 17 selected modern Cycas species further indicate that C. fushunensis sp. nov. closely resembles Cycas panzhihuaensis Zhou et Yang, an endemic cycad to southwest China, due to characters shared, such as the straight anticlinal walls of both adaxial and abaxial epidermal cells and granular to striate cuticular characters on the internal surface of guard cell periclinal walls. The occurrence of close-to-modern Cycas from the early Cenozoic largely casts doubt on a hypothesis of the late Miocene differentiation of modern cycads, suggested by a recent molecular phylogenetic study.

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