Xinhua News Agency, Nanjing, March 3 (Reporter Wang Jueping) The reporter learned from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences on the 3rd that Chinese, German, and British paleontologists recently discovered a 110 million-year-old primitive insect in Yumen, Gansu, my country. -Yumen sheath cockroach.

Further research has shown that the cockroach, praying mantis, and termites are taxonomically related to Cockroaches, Cockroaches Yumeni, and can be called "ancient relatives" of these insects.

  There are 3 newly discovered fossils, each of which contains a specimen of Coleoptera japonicus insect.

From the morphological point of view, the head of the cockroach is cylindrical, the chest is approximately square, and the legs are stout, much like a "mini-version" cockroach.

However, there are dense small pits on the surface of its body. These pits greatly strengthen the hardness of the wings. Therefore, although the cockroach looks like a cockroach, the cockroach has hard wings like a beetle.

  The research team also selected 72 typical characteristics of Coleoptera yumeni and made a taxonomic comparison with 36 insect taxa.

The results showed that the cockroach, praying mantis, and termites are closely related to the current cockroaches, mantises, and termites, and they can be regarded as "ancient relatives" of these insects.

  "In the early Cretaceous period 110 million years ago, sheath cockroaches of Yumen had spread all over the world and prospered for a while. However, in the following 20 million years, they quickly became extinct and disappeared. We speculate that sheath cockroaches of Yumen have turned from prosperity to decline. It is related to the changes in the global biological environment at that time. During this period, the gymnosperms that can be eaten by them were greatly reduced, while the'rival' insects such as scarabs and fireflies prospered. The survival needs of the cockroach were gradually unable to meet and eventually evolved It is eliminated.” said Wang Bo, a researcher at the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences, who led the research.

  Relevant research results have been published recently in the international journal "Ancient World" in the field of paleontology.