Accelerated evolution of early angiosperms： Evidence from ranunculalean phylogeny by integrating living and fossil data  

作　　者：Wei wang David L. Dilcher Ge Sun Hong-Shan Wang Zhi-Duan Chen 

机构地区：[1]State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China [2]Paleontological Institute of Shenyang Normal University, Shenyang 110034, China [3]Research Center of Paleontology, Jilin University, Changchun 130026, China [4]Department of Geology/Biology, Indiana University, Bloomington, IN 47405, USA [5]Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, USA

出　　处：《Journal of Systematics and Evolution》2016年第4期336-341,共6页植物分类学报（英文版）

基　　金：We sincerely thank Dr. Sheng-Xiang YU for permission to use the photographs of extant plants. This research was partially funded by the National Basic Research Program of China （Grant No. 2014CB954101）, the National Natural Science Foundation of China （Grant Nos. 31270269 and 31270268）, and the Youth Innovation Promotion Association Foundation of CAS.

摘　　要：The new discovery of angiosperm remains in the Jehol Biota of northeastern China contributes to our understanding of the origin and early evolution of flowering plants. The earliest eudicot genus with reproductive organs, Leefructus, was recently documented from the Lower Cretaceous Yixian Formation at 125.8-123.o Ma, and was reconsidered to be close to the extant family Ranunculaceae based on gross morphology. However, this hypothesis has not been tested using a cladistic approach. To determine the possible allies of Leefructus within extant eudicots, we constructed a 66 morphological data matrix. Molecular and morphological analyses of extant Ranunculales combined with the fossil suggest that it has an affinity with the Ranunculaceae. The earliest fossil record of the eudicots is 127-125 Ma based on tricolpate pollen grains. Thus, we suggest a hypothesis that the basal eudicots might have experienced an accelerated evolution and diversification during the latest Barremian and earliest Aptian, leading to the stem groups of at least six extant families or lineages, 10-15 Myr earlier than currently documented. Angiosperms have undergone multiple uneven pulses of radiation since their origin. Many key character innovations occurred in different stages that could have triggered those radiations in concert with various biotic and abiotic factors.The new discovery of angiosperm remains in the Jehol Biota of northeastern China contributes to our understanding of the origin and early evolution of flowering plants. The earliest eudicot genus with reproductive organs, Leefructus, was recently documented from the Lower Cretaceous Yixian Formation at 125.8-123.o Ma, and was reconsidered to be close to the extant family Ranunculaceae based on gross morphology. However, this hypothesis has not been tested using a cladistic approach. To determine the possible allies of Leefructus within extant eudicots, we constructed a 66 morphological data matrix. Molecular and morphological analyses of extant Ranunculales combined with the fossil suggest that it has an affinity with the Ranunculaceae. The earliest fossil record of the eudicots is 127-125 Ma based on tricolpate pollen grains. Thus, we suggest a hypothesis that the basal eudicots might have experienced an accelerated evolution and diversification during the latest Barremian and earliest Aptian, leading to the stem groups of at least six extant families or lineages, 10-15 Myr earlier than currently documented. Angiosperms have undergone multiple uneven pulses of radiation since their origin. Many key character innovations occurred in different stages that could have triggered those radiations in concert with various biotic and abiotic factors.

关 键 词：ANGIOSPERMS CRETACEOUS DIVERSIFICATION PALEOBOTANY PHYLOGENY Ranunculales. 

分 类 号：Q949[生物学—植物学]