Ground-penetrating radar and trenching studies of a barrier spit on the north shore of Huangqihai Lake were made,that reveal important implications for the coastal washover barrier boundary hierarchy and interpretatio...Ground-penetrating radar and trenching studies of a barrier spit on the north shore of Huangqihai Lake were made,that reveal important implications for the coastal washover barrier boundary hierarchy and interpretations of this depositional record.A four-fold hierarchy bounding-surface model,representing different levels of impact and genesis,is defined.Each level of the hierarchy is enclosed by a distinct kind of surface characterized by different ground-penetrating radar reflection features,sedimentary characteristics(color,grain size,sorting,rounding and sedimentary structures) and origin.We suggest that this hierarchical model can be applied to any coastal washover barrier deposits.展开更多
Documenting the origins of megadiverse(sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology.Nonetheless,the geological and ecological establishment of the modern Yangtze River rema...Documenting the origins of megadiverse(sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology.Nonetheless,the geological and ecological establishment of the modern Yangtze River remains poorly understood.Here,we reconstruct the geographic and ecological history of an endemic clade of East Asian fishes based on the mitochondrial phylogenomics analysis of Cyprinidae using 15 fossil calibrations.We estimate an ancestral condition of benthic spawning with demersal or adhesive eggs in southern East Asia before23 Ma and a derived condition of riverine spawning with semibuoyant eggs in the Yangtze by18 Ma.These results imply the formation of Yangtze riverine ecosystems around the Oligocene-Miocene boundary in response to plateau uplift and monsoon strengthening.Some of these cyprinids reverted to benthic spawning with adhesive eggs by15 Ma,a time of rising to peak net diversification rates,indicating the formation of potamo-lacustrine ecosystems by the mid-Miocene during a strong East Asian summer monsoon.Our study provides increased spatiotemporal resolution for the co-evolutionary histories of the Yangtze River and its biodiversity and highlights biological evidence concerning the geomorphological dynamics of the Yangtze River.展开更多
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120022130002)the State Scholarship Fund from the China Scholarship Council(No.201406400030)
文摘Ground-penetrating radar and trenching studies of a barrier spit on the north shore of Huangqihai Lake were made,that reveal important implications for the coastal washover barrier boundary hierarchy and interpretations of this depositional record.A four-fold hierarchy bounding-surface model,representing different levels of impact and genesis,is defined.Each level of the hierarchy is enclosed by a distinct kind of surface characterized by different ground-penetrating radar reflection features,sedimentary characteristics(color,grain size,sorting,rounding and sedimentary structures) and origin.We suggest that this hierarchical model can be applied to any coastal washover barrier deposits.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB31000000).
文摘Documenting the origins of megadiverse(sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology.Nonetheless,the geological and ecological establishment of the modern Yangtze River remains poorly understood.Here,we reconstruct the geographic and ecological history of an endemic clade of East Asian fishes based on the mitochondrial phylogenomics analysis of Cyprinidae using 15 fossil calibrations.We estimate an ancestral condition of benthic spawning with demersal or adhesive eggs in southern East Asia before23 Ma and a derived condition of riverine spawning with semibuoyant eggs in the Yangtze by18 Ma.These results imply the formation of Yangtze riverine ecosystems around the Oligocene-Miocene boundary in response to plateau uplift and monsoon strengthening.Some of these cyprinids reverted to benthic spawning with adhesive eggs by15 Ma,a time of rising to peak net diversification rates,indicating the formation of potamo-lacustrine ecosystems by the mid-Miocene during a strong East Asian summer monsoon.Our study provides increased spatiotemporal resolution for the co-evolutionary histories of the Yangtze River and its biodiversity and highlights biological evidence concerning the geomorphological dynamics of the Yangtze River.
