China News Service, Beijing, May 12 (Reporter Sun Zifa) The reporter learned from the Institute of Paleontology and Paleontology of the Chinese Academy of Sciences (Institute of Ancient Spine, Chinese Academy of Sciences) on the 12th that the researchers of the Institute, Dong Liping, Wang Yuanqing, Wang Yuan, etc., and Japan and Britain In cooperation with colleagues, a new fossil of Lilongs was discovered in the coal bed of the Lower Cretaceous Shahai Formation in Heishan County, Liaoning (approximately 120 million to 100 million years ago), named after the fossil origin and its small size. Dwarf Black Mountain Dragon ".
This important fossil discovery and research achievements paper in the field of paleontology and lizards has recently been published by the International Professional Academic Journal "Journal of Systematic Paleontology". The Sino-foreign cooperative scientific research team claims that the formation of the Shahai Formation is considered to be integrated above the Jiufotang Formation, and has produced a large number of vertebrate fossils, including mammals rich in tumor-bearing mammals, tridents Beasts, etc. If the stratigraphic relationship between the Shahai Formation and the Jiufotang Formation is determined, then the pygmy Heishan Dragon is currently the latest Lilong-like fossil material in China.
Only one tooth bone and one cheek bone were exposed on the surface of the pygmy Heishan dragon fossil specimens discovered from the Shahai Formation. Researchers discovered more bone fragments inside the rock through high-precision CT scans, including a small half of the skull and some scattered bone fragments. Afterwards, the scanned data was modeled, enlarged, and mirrored for 3D printing, and most of the skull structure of the pygmy black mountain dragon was finally restored.
The results show that the pygmy black mountain dragon is similar to the Jurassic Ctenopharyngodon crocodile and the green dragon, with short kisses and inferior temporal foramen not closed. According to the length of the lower jaw, the body length of the pygmy black mountain dragon is about 30 cm, which is equivalent to the size of the crocodile and the dragon.
Lateral view of the skeletal temporal skeleton of the pygmy Black Mountain Dragon (left) and Jurassic Green Dragon (right). (Photo courtesy of Dong Liping)
The Science of the Ancient Spine Institute of the Chinese Academy of Sciences said that the Lilongs are an extinct aquatic / semi-aquatic reptile, which first appeared in the Middle Jurassic (approximately 174 million to 163 million years ago) to the Miocene (present) (About 23 million to 16 million years) disappeared. Although there are not many reported Lilong species in the world, only 12 genera and 25 species, but this group exhibits diverse morphological characteristics, such as the new Lilongs are large in size, the kiss is long and the neck is short, and the inferior temporal hole is not closed. "Non-New Lilongs" are small in size, short in kisses, and closed inferior temporal foramen. There are two types of long necks and short necks.
Asia, especially East Asia, is considered to be a key area for the evolution of the Lilongs during the Early Cretaceous. The vast majority of Lilongs in China were members of the Early Cretaceous Jehol Biota in western Liaoning, and were outside the Jehol Biota Fossil records of Lilongs are scarce. On the phylogenetic tree of Lilongs, the "non-new Lilongs" Manchurian crocodile, Qianlong, water dragon, resurrection dragon, etc. constitute the branch of the detached dragon; the crocodile, crocodile, and the black mountain dragon are located in Xinli Except for the branches composed of dragons and detached dragons, the individuals are relatively small and primitive in morphological characteristics. Among them, the pygmy black mountain dragon is the latest in the age distribution. (Finish)