German researchers trace the origin time of angiosperms with ancient pollen.

　　Xinhua News Agency, Berlin, May 22 (Reporter Chu Yi) With the help of ancient pollen sealed in fossils, a research team composed of Leibniz University in Hanover, Germany and Bonn University traced the origin of angiosperms back to 123 million years ago, 2 million years earlier than previously recognized. Related results were recently published in the Journal of the National Academy of Sciences.
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　　The research team found pollen fossils in coastal sediments of Lusitania basin in Portugal. Through the analysis of the test samples, the researchers identified a typical three-furrow structure from four kinds of microfossils, that is, there are three small furrows on the pollen shell. The researchers said that 72% of the existing angiosperms still retain this morphological feature, which is the key basis for identifying this group.

　　In order to accurately date, the research team used relevant isotope dating techniques and biostratigraphic analysis to study mussel fossils in sedimentary layers. The analysis results not only advance the origin time of angiosperms by 2 million years, but also provide the most accurate and reliable evidence of the first appearance of dicotyledonous angiosperms so far. The study also shows that the geographical location of Lusitania basin shows that the early morphology of angiosperms was originally thought to have evolved only in the tropics, but in fact it may be more common in the middle latitudes than previously thought.

　　Despite the above breakthrough, the origin mechanism of angiosperms is still an unsolved mystery in the scientific community. You Liya Glavin Dick, a professor at Bonn University, who is in charge of the study, said: "Since Darwin’s time, when and where the development (of angiosperms) began is still a big mystery in biology." In addition, the specific impact of plate movement and large-scale climate change on angiosperm development is still unknown.