Chinese scientists have found that the "mixed element beast" rewrites the origin history of marsupial mammals

Beijing, June 14 (Xinhua) -- Chinese scientists named a fossil of a mammal found in Inner Mongolia about 126 million years ago as a mixed element beast, and believed that the mixed element beast was the early ancestor of placental mammals such as humans, and the Chinese bag beast, which was previously considered to be the ancestor of marsupial mammals such as kangaroos, belonged to the same branch as the mixed element mammal. The new study shakes the conclusion that marsupials originated in Asia, and the internationally renowned academic journal Nature published the results online on the 14th Beijing time.

The reporter learned from the Center for Excellence and Innovation in Biological Evolution and Environment of the Chinese Academy of Sciences that the research team of the center cooperated with Professor Bi Shundong of Yunnan University to study the most complete fossil of the early Cretaceous mammal that has been preserved so far, and found that the mixed element beast is an early type of eumorphic mammals (placenta and their ancestors), and at the same time developed mixed characteristics of euphrases and post-mammals (marsupials and their ancestors).

Placentals and marsupials make up 99% of mammalian species, and where and when they originate is a key scientific question in mammalian evolutionary research. Researchers said that the results of this study are of great scientific significance, and the new conclusion that Chinese possums belong to the true mammals suggests that Asia may not be the origin center of marsupials. The earliest known fossil record of marsupials is that of a triangular toothed beast found in North America 110 million years ago.

The hybrid specimen was found in the lower strata of the Ningcheng Yixian Formation in Inner Mongolia and is a mammal in the Rehe biota dating back 126 million years. In the past 20 years, more than 120 vertebrate fossils of more than 120 genera and species have been found in the Rehe biota of Northeast China. The newly discovered hybrid beast is well preserved and beautifully structured, and the researchers used high-precision CT scanning technology to digitally reconstruct the fossil bones buried in the rock in three dimensions, basically restoring the morphological characteristics of each bone. On this basis, the research team spent 3 years and constructed a large data matrix with 56 early mammal taxonomic units and more than 400 morphological characteristics, establishing an early mammalian genealogy tree.

According to reports, the genus name of the mixed element beast means "Yuan qi is not divided, chaos is one, and the beginning of yuan qi is also", indicating that the creature has special attributes of the mixed characteristics of real beasts and post-beasts.