China News Service, Beijing, July 27th (Reporter Sun Zifa) The Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (Institute of Paleontology, Chinese Academy of Sciences) announced on the 27th that the early vertebrate research team of the Institute and the University of Science and Technology of China and Tongji University Experts from the State Key Laboratory of Marine Geology have jointly completed the latest research results, claiming that the differentiation of airacantha-fanfin and lungfish-tetrapod should occur between 427 million and 416 million years ago.
The phylogeny and geographic history of the branch of sarcophagous fishes (including existing hollow spines, lungfish and tetrapods).
Photo courtesy of Zhao Wenjin
Chinese scientists in the South China Silurian-Devonian Boundary (SDB) research field. This is a new progress paper on "the minimum time constraint between the Silurian-Devonian boundary and the divergence point of lungfish-tetrapod in eastern Yunnan" , Has been published online by the Chinese and English editions of "Science China: Earth Sciences" recently.
Researcher Zhao Wenjin from the Institute of Paleospine, Chinese Academy of Sciences, Associate Professor Zhang Xiaolin from the School of Earth and Space Sciences, University of Science and Technology of China, are the co-first authors of the paper, and researcher Zhu Min from the Institute of Paleospine, Chinese Academy of Sciences is the corresponding author.
According to the early vertebrate research team of the Institute of Paleospine, Chinese Academy of Sciences, the latest research results mainly focus on the continuous Silurian-Devonian boundary sequence in the Yiliang Dahe area of eastern Yunnan. Reliable geochemical indicators were used to determine the location of the Silurian-Devonian boundary in Dahe area.
The phylogeny and geohistorical distribution of jaws during the Silurian-Devonian period.
Photo courtesy of Zhao Wenjin
The diversity of early sarcophagus fossils is very high in southern China, especially in eastern Yunnan. The fossil record shows that the earliest representatives of important sarcophagus branches also appeared in Yunnan.
The determination of the Silurian-Devonian boundary in Dahe area and the establishment of paleontological data and biostratigraphic fossil belts in eastern Yunnan have provided key data for clarifying the geological age of the fish-bearing strata in eastern Yunnan, which is very helpful for more information. Accurately calibrate the minimum and maximum estimated time of the divergence point of the airacanthus-fanfin and lungfish-tetrapod.
According to the research team, the lungfish-shaped Yang's fish from the Dongxishan Village and Xitun Formations in Yunnan are generally considered to be the oldest representatives of the crown group of fanfin fish and the crown group of sarcophagous fish. The fan-fin fish crown group excluded mainly includes lungfish and tetrapods.
Sister groups of the oldest known sarcophagous crest group, such as spotfish and ghost fish, have been reported in the Silurian Rodriguez Ludfordian.
Therefore, the differentiation of airacanthus-fanfin and lungfish-tetrapod should occur within the Rodros-Lochkoff interval, which means that the minimum estimated time of the two divergence points should be at least It is 416 million years ago and the maximum estimated time is about 427 million years ago. That is, the differentiation of airacantho-fanfin and lungfish-tetrapod should occur between 427 million and 416 million years ago.
Experts pointed out that the Silurian-Devonian boundary was the first to use modern stratigraphic methods and procedures for systematic research.
The determination of the accurate position of the Silurian-Devonian boundary in eastern Yunnan not only has the significance of global stratigraphic correlation, but also directly affects the estimation of the minimum and maximum time constraints of the lungfish-tetrapod divergence point.
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