Fossil seeds of Euryale(Nymphaeaceae) indicate a lake or swamp environment in the late Miocene Zhaotong Basin of southwestern China  

作　　者：Yongjiang Huang Xueping Ji Tao Su Li Wang Chenglong Deng Wenqi Li Hongfen Luo Zhekun Zhou 

机构地区：[1]Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences [2]Yunnan Institute of Cultural Relics and Archaeology and Research Center for Southeast Asian Archeology [3]Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences [4]State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences [5]Zhaotong Institute of Cultural Relics [6]Zhaoyang Museum

出　　处：《Science Bulletin》2015年第20期1768-1777,共10页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(31300187,31300188);the Natural Science Foundation of Yunnan Province(2010CC010)

摘　　要：Euryale （Nymphaeaceae） is a monotypic genus distributed in eastern Asia, but fossils in its native distribu- tion are sparse as compared to Europe where the genus has disappeared. Here, we describe a new fossil species, Euryale yunnanensis sp. nov., from the late Miocene Zhaotong Basin in southwestern China on the basis of seed remains. Char- acteristics including an ellipsoidal to almost spherical shape, a smooth surface, a germination cap that covers the micro- pyle, the separation of the hilum and germination cap （mi- cropyle）, elliptic testa surface cells with undulate margins and thickened cell walls collectively indicate a close affinity with the genus Euryale in Nymphaeaceae. Comparisons of seed morphology and anatomy demonstrate that the newly described fossil species differs from modem and other fossil species of Euryale and thus verify the assignment to a new fossil species. As the modem Euryale is an aquatic plant, preferably living in swamps and lakes with shallow and stable water, we hypothesize that a lake and/or swamp environment with shallow water was present near Shui- tangba in the Zhaotong Basin, where the Shuitangba homi- noid lived during the late Miocene. This inference is generally consistent with paleoenvironmental data extracted from avian, fish, frog, turtle and crocodile fossils, as well as from aquatic pollen. The fossil history suggests a compara- tively recent （Miocene） emergence of Euryale, which is roughly in agreement with the divergence time inferred from the molecular information.Euryale(Nymphaeaceae) is a monotypic genus distributed in eastern Asia, but fossils in its native distribution are sparse as compared to Europe where the genus has disappeared. Here, we describe a new fossil species, Euryale yunnanensis sp. nov., from the late Miocene Zhaotong Basin in southwestern China on the basis of seed remains. Characteristics including an ellipsoidal to almost spherical shape,a smooth surface, a germination cap that covers the micropyle, the separation of the hilum and germination cap(micropyle), elliptic testa surface cells with undulate margins and thickened cell walls collectively indicate a close affinity with the genus Euryale in Nymphaeaceae. Comparisons ofseed morphology and anatomy demonstrate that the newly described fossil species differs from modern and other fossil species of Euryale and thus verify the assignment to a new fossil species. As the modern Euryale is an aquatic plant,preferably living in swamps and lakes with shallow and stable water, we hypothesize that a lake and/or swamp environment with shallow water was present near Shuitangba in the Zhaotong Basin, where the Shuitangba hominoid lived during the late Miocene. This inference is generally consistent with paleoenvironmental data extracted from avian, fish, frog, turtle and crocodile fossils, as well as from aquatic pollen. The fossil history suggests a comparatively recent(Miocene) emergence of Euryale, which is roughly in agreement with the divergence time inferred from the molecular information.

关 键 词：Euryale NYMPHAEACEAE AQUATIC Late Miocene Zhaotong Basin Southwestern China 

分 类 号：Q914.2[天文地球—古生物学与地层学]