There are only 8 genera and 10 species of early angiosperm fossils that meet the strict definition so far in the world, and 7 genera and 9 species have been found in western Liaoning and surrounding areas of China, named Liang's Chaoyangxu and Liaoning ancient fruit , Chinese ancient fruit, Chinese cross fruit, Shihua ancient fruit, Chinese Shi's fruit, Dilali flower, Chinese astrology flower, Daohugou sun flower. These early angiosperm fossils from the Early Cretaceous to the Jurassic period provided key evidence for revealing the origin of angiosperms.
Wang Xin, an associate researcher at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, pointed out in the recently published English monograph "The Dawn of Angiosperms" that people have put forward many hypotheses about the origin of angiosperms, and the only thing that can distinguish these doctrines is true. The way is to find the corresponding fossils to test. In this sense, a group of large fossils of early angiosperms found in western Liaoning and its surrounding areas in the past decade or so can be said to be intriguing.
For example, Wang Xin said that the discovery of Chinese Shi's fruit has brought the study of the origin and evolution of angiosperms to a new stage. For a long time, mainstream paleobotanists believed that the history of angiosperms would not be earlier than the Cretaceous. This concept has caused unfair treatment for paleobotanists who advocated the earlier origin of angiosperms at home and abroad, and the corresponding research has almost stagnated.
In 2007, Wang Xin and others first recognized the angiosperm properties of Chinese Shi's fruit. Although Chinese Shi's fruit was only found in the Middle Jurassic in China, it appeared in the Early Jurassic in Germany and Poland. The recent re-examination of the German Shi's fruit specimens has made people not only realize the branches, leaves, flowers, inflorescences, fruits, inflorescences, seeds of this earliest angiosperm, but also the various developmental stages of the plant's reproductive organ . Without the discovery of Chinese Shi's fruit in western Liaoning, the corresponding research results would not be possible.
Wang Xin also said that the discovery of the Chinese astral flower provided key evidence for the origin of the new angiosperm theory. Carpel is the most characteristic feature of angiosperms distinguished from all gymnosperms. For a long time, there have been two diametrically opposed views on the nature of angiosperm carpels in the botanical community: one thought that carpel was equivalent to a leaf, and one thought that carpel was equivalent to a branch. Although the former theory has long dominated, the latter theory is not entirely without a market, and the debate between the two continues.
The Chinese astral flower discovered in the Middle Jurassic strata in western Liaoning early this year has a unique central placenta. According to the theory recently proposed by Wang Xin, this finding shows that the traditional carpel should be composed of two parts, namely the placenta equivalent to a branch of a long ovule and the lamellar structure equivalent to a leaf. This bipartite division of the carpel in the traditional sense not only solves the long-standing dispute between the two schools of thought, but also provides a favorable clue for finding the carpel's homologous organs in gymnosperms.
Following this clue, people can not only find the ancestral group of angiosperms, but also provide necessary and solid evidence to straighten out the relationship between angiosperms and gymnosperms. So far this conclusion has been supported by plant anatomy, morphology, developmental genetics and branch taxonomy. In this important research progress, the Chinese astrology has played a vital role.
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