On September 13, 2009, the Institute of Geology of the Chinese Academy of Geological Sciences and the People's Government of Qaraqin Left-Wing Mongol Autonomous County officially released that the world's largest fossil of the earliest Cretaceous Tyrannosaurus rex was found in Kazuo, Liaoning. This is a species that two generations of paleontological scientists in China have been looking for more than 40 years throughout the country, with high scientific research value and scientific value, and experts have initially named it "Kazuo Chinese Tyrannosaurus rex".
Tyrannosaurus rexes are a special class of carnivorous dinosaurs, evolved from the osteolepticosaurs, their early body size was small, fossils found in China, North America and Europe in the Late Jurassic to Early Cretaceous strata, while the Late Cretaceous individuals of the huge Tyrannosaurus family fossils are mainly distributed in East Asia and North America, their skulls are large, their hind limbs are thick, and their forelimbs are extremely degenerated. Found in the Early Cretaceous Nine Buddhas Tang Group in Kazuo County, Liaoning Province, the Kazuo Chinese Tyrannosaurus rex represents a late individual larger Tyrannosaurus rex with a body length of 10 meters. The characteristics of the fossil bone and intestinal bone are different from other tyrannosaurs, so they represent a new genus species, and the species name "Kazuo" indicates that the fossil is produced in Kazuo, Liaoning.
Unearthed Kazuo Chinese tyrannosaur dragon head bone (photo by the author)
Tyrannosaurus rex was a ferocious carnivorous dinosaur. It lived in the late Cretaceous period. It is one of the largest known terrestrial carnivores, with a body length of 11-12 meters, a head of 1.35-1.45, a maximum skull of 1.58 meters long, and a height of 4 meters. The skull is heavy, high and flattened, with two large anterior foramen and oval orbits. Teeth are extremely developed. There are coarse moving ligament fixation marks between the dental bone, the hip bone, and the anterior joint bone, and the neck bone is short, with 9 to 10 cervical vertebrae, and its structure is characterized by a short and wide type. The shoulder straps are degenerate, the shoulder blades are slender, and the humerus is short, only half as long as the shoulder blades. The forefoot is degenerated and weak, with only two fingers, and may also have a third finger.
The Tyrannosaurus rex belt is very developed and extremely compact, not only the intestinal bone and the recommended vertebrae are closely healed, but the ischia and the distal end of the pubic bone are also attached to each other; The distal pubic bone is enlarged in the form of a foot-like process, while the distal ischial is rod-shaped. Such a thick belt structure indicates that its hind limbs are strongly moved. Tyrannosaurus rex lived mainly in hilly areas, with plant-feeding reptiles as the main prey. Due to changes in the surrounding living environment, Tyrannosaurus rex was extinct in the late Late Cretaceous. The earliest excavated fossils were found in the United States from 1902 to 1905, and such dinosaur fossils were also found in Xinjiang and Henan in China in the 1960s and 1970s.
It is reported that the discovery of this Tyrannosaurus rex fossil is purely accidental. On March 23, 2009, Cui Yan, a student at Liaoning University, went for a walk on Huaguo Mountain in Xiaochengzi Village, Dachengzi Town, and inadvertently found bone fossils in the quarry, which was immediately reported to the county Land and Resources Bureau. The staff of the county land and resources bureau rushed to the scene at the first time, implemented the protection, and immediately reported it to the higher authorities. According to experience, the person in charge of the competent department determined that this was a very important fossil specimen. On March 24, after on-site investigation, a large number of fossil specimens slipped off the cliff were found. On March 25, the head of the Kazuo authority reported to Sun Yongshan, then director of the Liaoning Provincial Fossil Resources Conservation Administration. Sun led the experts of the Fossil Bureau and Dr. Zhou Changfu of Shenyang Normal University to the scene of the dinosaur production area. After identification, it was believed that it must be a carnivorous dinosaur, but it was difficult for experts to judge what kind of dinosaur it was at that time. So on March 26, they reported the discovery to the Institute of Geology of the Chinese Academy of Geological Sciences. In the afternoon of the same day, Ji Qiang and Ji Shu'an, two paleontological experts, rushed to Kazuo. After on-site investigation and identification, researcher Ji Qiang said with great excitement: This is the "Tyrannosaurus Rex fossil" that his teacher and he have been searching for for half a century, which is the dream of two generations of paleontologists in China, and finally found it in Kazuo, Liaoning!
Skeleton of Kazuo Chinese Tyrannosaurus (photo by the author)
After half a year of meticulous excavation, 85% of the parts of the dinosaur were basically excavated. After careful restoration, the bones of the dinosaur are all presented, which is a very rare and complete fossil specimen. On September 13th, Chaoyang City held the first International Stone Festival. The county government took advantage of this once-in-a-lifetime opportunity to hold a press conference of the highest scale since the establishment of the county at the People's Hall of Kazuo County. This major discovery was released to more than 10 radio stations such as the world's top paleontologists from the United States, britain, Japan and Canada, more than 40 well-known paleontologists in China, reporters from major news media in China, and more than 10 radio stations such as Japan's Asia News Center and Hong Kong Phoenix Radio. In the evening, CCTV spent up to 7 minutes in the news broadcast to the world to report this scientific achievement that shocked the paleontological community.
Kazuo (right) Restoration of the Chinese Tyrannosaurus LiaoxiJialong (left) (drawn by Jiang Yansong)
Experts have confirmed that the "Kazuo Chinese Tyrannosaurus Rex" has a rare complete posture, not only the largest early Cretaceous Tyrannosaurus rex that has been found in the world, but also 50-60 million years earlier than the dinosaur "Su" (Su, number FMNH PR2081, which is the second surviving and most complete preserved Rex Tyrannosaurus rex fossil in the world) unearthed in the United States. Its discovery ended the era of dominance of the dinosaur "Su" and confirmed the "name of The Dragon Town" in Kazuo. It further proves that China is one of the most important evolutionary sites of Tyrannosaurus rex in the world, and that the T. rex family may have originated in Asia, and narrowed the difference in individual size between the Early Cretaceous Tyrannosaurus rex and the Late Cretaceous T. rex. This is of great value for in-depth discussion of the composition and ecological environment of the Rehe biota in western Liaoning, as well as its paleogeography, paleoenvironment and paleoclimate distribution.
At present, the 6.3 square kilometers of the "Kazuo Chinese Tyrannosaurus Rex" production area has been included in the national key fossil protection concentrated production area; the "Kazuo Chinese Tyrannosaurus" National Geopark is preparing to declare a world-class geopark. Kazoan Chinese Tyrannosaurus rex provides valuable material for studying the origins of the Tyrannosaurus rex family, a new genus that has shown the characteristics of the Tyrannosaurus rex family, further demonstrating that China is one of the most important evolutionary sites of the Tyrannosaurus rex in the world. "Tyrannosaurus rex is at the top of the biological chain, and the number is very small, and even fewer can be fossilized, so it is very difficult to find and very precious." Dong Zhiming, a famous paleontologist, said that tyrannosaurs belong to the "ancestral" category of dinosaurs. Experts believe that the tyrannosaurus rex found in Kazuo is the direct ancestor type of T. rex, and the reign of T. rex began at least 120 million years ago in the Early Cretaceous, and western Liaoning in China may be the true origin of T. rex.
The discovery of the Chinese Tyrannosaurus rex is of great scientific significance. First of all, it further improves our understanding of the early evolution of tyrannosaurs and provides valuable materials for the study of the resources of the family Tyrannosaurus, a new genus to show the characteristics of the family Tyrannosaurus, further proving that in Chinese history, one of the most important evolution sites of tyrannosaurs in the world. Tyrannosaurus rex may have originated in Asia; second, tyrannosaurs had developed into giants during the Early Cretaceous, further narrowing the differences in individual size between the Early Cretaceous Tyrannosaurus and the Late Cretaceous Tyrannosaurus rex family; third, the Kazuo Chinese Tyrannosaurus was the largest known theropod dinosaur in the Rehe biota of Western Liaoning, and its discovery was of great value for in-depth discussion of the composition of the Rehe biota, the ecological environment and its paleogeographic distribution. Fourth, it provides a possible ancestor of the famous Zhucheng Tyrannosaurus rex found in Shandong, China. (Wen Ge Lecture Hall)