Fossil crown surface, cheek side and tongue side of the "diptych" fossil. Photo courtesy of Institute of Paleovertebrate Vertebrate, Chinese Academy of Sciences
Beijing, November 12 (China News Network) -- As the most diverse ungulate group among living terrestrial mammals, the number of ungulates is large and closely related to human life, and the study of its origin has long attracted the attention of the academic community.
According to the news from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (Institute of Paleovertebrates of the Chinese Academy of Sciences), Researcher Li Qian and others found a class of primitive even ungulate fossils in the Mesocene strata of the Erlian Basin of Inner Mongolia about 45 million years ago.
Phylological location of "Diptychy". Photo courtesy of Institute of Paleovertebrate Vertebrate, Chinese Academy of Sciences
Li Qian said that the newly discovered fossil material in the Erlian Basin has a very simple tooth structure, which is a typical mound-shaped tooth, and the ridge between the main tip is weakly developed. Through detailed morphological studies, the fossil material is not the same as the various genera known in the even ungulates, and the tooth structure and some skull features show that they are closer to some of the even ungulates found in the middle and late Eocene strata in Myanmar and Thailand, but have obviously more primitive features than them, so the new genus "diptych" of the even ungulates is established.
Further phylogenetic analysis showed that the "dipterocarp" was located in a relatively basal position in the early ungulates. Based on the characteristics of the fully mound-shaped teeth of the "diptyched pig", it is inferred that this class of animals is likely to feed on more tender plants to avoid food competition with the odd-ungulates that dominate the fauna.
Strata in the Erlian Basin of Inner Mongolia are exposed in the Ilding Manha area. Photo courtesy of Institute of Paleovertebrate Vertebrate, Chinese Academy of Sciences
Li Qian pointed out that a large number of fossil materials such as odd-ungulates, rodents and rabbits have been found in the Erlian Basin of Inner Mongolia, and the appearance of the Mesocene mammal group in the basin has been basically formed, but the proportion of even ungulates in this animal group is very small, and the discovery and research of the "Erlian Pig" not only enriches the composition of this fossil fauna, but also provides new clues for understanding the evolution of early even ungulates in Asia, as well as exploring the phylogenetic relationship between different phyla in early even ungulates.
According to the Institute of Paleovertebrates of the Chinese Academy of Sciences, different types of primitive ungulates appeared in North America, Europe and the Asian continent almost simultaneously in the early Eocene, which makes the origin of even ungulates appear confusing and there is no consensus so far. Therefore, the study of early ungulate fossil materials, including "diptychlus", is of great significance for continuously improving the cognition of even-ungulate taxa and understanding its specific evolutionary process. (End)
Source: China News Network