Beijing, September 9 (Zhongxin Net) -- After more than 6 days of field excavation and a year-long restoration and analysis research, Chinese scientists confirmed that a nearly intact dinosaur fossil found in the late Jurassic strata of Zhenghe County, Fujian Province about 200 million years ago belonged to a new species of bird-winged dinosaurs, and named it "strange Fujian dragon". This is the world's latest-Jurassic and southernmost ornithotera dinosaur, and it is also the first dinosaur fossil found in Fujian Province.
A fossil specimen of the bird-winged dinosaur "Exotic Fujian Dragon" about 1 million years ago. Photo by China News Network reporter Sun Zifa
At the same time, a large number of well-preserved reptile fossils were also found in the late Jurassic formation, including aquatic/semi-aquatic fish, amphibians, turtles and turtles, dragons and other vertebrate fossils. Based on its high fossil abundance and diversity, combined with chronostratigraphic and biostratigraphic work, the researchers established a Jurassic terrestrial biota dating back 1 million to 48 million years and named it "political and fauna".
This important discovery and research results of dinosaurs and paleontology were jointly completed by Wang Min's team from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences and Xu Liming of Fujian Institute of Geological Survey, and the research paper was published online in the internationally renowned academic journal Nature on the night of September 9, Beijing time. Among them, the comprehensive geological investigation and isotope dating work led by Xu Liming limited the time of the life of the strange Fujian dragon to the late Jurassic period (6 million to 1 million years ago); Through the restoration of paleogeographical location, Wang Min's team determined that the strange Fujian dragon was the southernmost known geographically southern Jurassic ornitteric dinosaur.
Researcher Wang Min presented the fossil discovery of "Exotic Fujian Dragon" and related research results. Photo by China News Network reporter Sun Zifa
Researcher Wang Min, the corresponding author and co-first author of the paper, said that the origin and evolution of birds has long been the focus of evolutionary biology discussions, and birds have diverged from non-avian theropods since at least the Late Jurassic. Academics define "the broadest taxon that includes all birds, but excludes dinosaurs" as ornithopterosaurs, while birds refer to modern birds and their close relatives. Therefore, the Jurassic ornithopterosis are crucial for studying the origin, key morphology and evolution of biological characteristics of birds, while the known Jurassic ornithopterosis are only close to Ornithischian and its similar species, not only the number of species is scarce, but also the geographical distribution is single (mostly Yanliao biota in northeast China, 1 million to 66 million years ago), which is 1 million years old with a large number of birds that appeared in the early Cretaceous.
Odd Fujian Dragon is a pheasant-sized bird-winged dinosaur with a lower leg (tibia) twice the length of the thigh (femur), which has not been seen in previous non-avian dinosaurs or Mesozoic bird wings, indicating that Exotic Fujian Dragon is either a fast runner or a long-legged "wading bird". The finding contrasts with the ecological habits of other Jurassic ornitteropods, which were thought to be more arboreal in other early ornithopteros.
About 1 million years ago, the bird-winged dinosaur "Exotic Fujian Dragon" and the ecological restoration of "Zhenghe Fauna". Zhao Chuang draws
Wang Min pointed out that the discovery of Exotic Fujian Dragon made up for part of the gap in time and space in the origin of birds, and showed the morphological characteristics of highly mosaic evolution: the forelimbs were similar to Archaeopteryx, and the pubic and ischial bones of the belt had the typical characteristics of Archaeopteryx and Ornithosaurus, respectively, and the hind limbs were even more so, indicating that mosaic evolution profoundly affected the evolution of characteristics at the beginning of the origin of birds.
Phylogenetic analysis showed that Fujian Dragon singularis and ornithosaurus formed a monophyletic group, which was the earliest differentiated group of ornithopteros. The most special thing about Fujian dragon is its hind limb structure: short femur, elongated tibia and homophyll. Combined with the analysis of comparative cladistics, the research team found that the body structure of Fujian Dragon was similar to that of other birdwing species, and it was between dinosaurs and birds in terms of body size and space, and this similarity was more caused by relatively conservative forelimbs in evolution, because if only the hind limbs were compared, Miratyposaurus Fujianosaurus was clearly different from all known Mesozoic dinosaurs and birds.
Comparison of the size and running ability of "Exotic Fujian Dragon" with other Mesozoic dinosaurs. Photo courtesy of Wang Min
In quadrupeds, relatively longer distal limb bones can increase step length, so it is more common in animals that are good at running, and it is also common in some wading birds, and researchers believe that Fujian Dragon miraculous is a small non-avian theropod dinosaur that is good at running or lives near water. Such living habits are completely different from the academic understanding of the evolution of ecological habits at the beginning of the origin of birds, most of them believe that adaptation to arboreal is the "main key", and the discovery of exotic Fujian dragon has increased the ecological diversity of primitive birdwing species.
Wang Min said that in addition to the strange Fujian dragon, the "political and fauna" established by this new discovery is also the world's most known late Jurassic and southernmost preserved bird wing fauna. This fauna and Yanliao biota form the trend of "Southern Zhenghe, Northern Yanliao", and the two have similar tectonic backgrounds but different biota performance.
From late Jura to early chalk, subduction by the Paleopacific Plate, the lithosphere in southwest China is strongly extended, forming widely distributed fault basins and large-scale volcanic activity, and this tectonic background is similar to that of North China during the A-stage period of the Yanshan Movement (about 1 million years ago), which is related to the formation of Yanliao biota.
A group photo after the joint expedition team of the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences and the Fujian Institute of Geological Survey and Survey found the fossil specimen of "Exotic Fujian Dragon". Photo courtesy of Wang Min
Wang Min believes that although the field investigation of the Zhenghe fauna has just begun, it has already shown differences from the Yanliao biota, and the Zhenghe fauna has preserved a large number of true bone fish, dragons and turtles and turtles, which are rarely found in the Yanliao biota. Most of the political and fauna fossils are preserved in black carbonaceous mudstone or shale, and combined with field area investigations, the researchers speculate that the political and fauna are a swamp-facing-like environment, which is also different from the Yanliao biota. (End)