Jiefang Daily Shangguan News reporter learned that on December 6, 2019, Scientists from China, the United States and Australia announced that their research team completed the study of dinosaur footprints in the Chengde area of Hebei Province. Amazingly, most of the footprints are distributed in the Chengde Mountain Resort, the ground of the world-famous Chinese royal garden, which is a rare case of the world's rare fossil paleontological relics combined with human history. The large number and preservation of these dinosaur footprints are of great value to the study of the evolution of dinosaurs, and are of great significance for further exploring the behavior habits and living environment of dinosaurs to restore the paleoenvironment of the region and its geological climate change.
The study was led by Associate Professor Xing Lida of China University of Geosciences (Beijing), Professor Martin Lockley, Director of the Footprint Museum of the University of Colorado (Denver), and Anthony Romerio Bo of the University of Queensland, Australia, and the paper was published in the internationally renowned paleontological journal Cretaceous Research.
Represented by hairy dinosaurs, primitive mammals and angiosperms, the Yanliao biota in northeastern China is world-famous, with the former dating back about 167 million years and the latter about 135 million years old, and there is a huge gap in the fossil record of vertebrates between these two biota. From the Yanliao biota to the Rehe biota, this long change was recorded in the Tucheng subgroup, and only skeletal fossils of Chaoyang Dragon, Xuanhua Horned Dragon and Brachiosaurus were found so far. A large number of dinosaur footprints have been found in the Tucheng subgroup, which is an important supplement to the evolution of the fauna. Among them, There are a large number of records in Chengde, Hebei. Chengde, Hebei is located in the northeast of Hebei Province, bordering Beijing and Tianjin to the southwest, and Tangshan and Qinhuangdao to the southeast. There is a thicker set of strata distributed in this area, called the Tucheng Sub-Group. Fossil footprints from the Tucheng subgroup were first reported in 1992. On April 5, 1992, ecologist Forman of Harvard University and Huang Runhua, director of the Geography Department of Peking University, found more than 20 dinosaur and bird footprints on thick plates on the hot side and southeast side of the Rehe Spring at the Chengde Mountain Resort during a tour in Chengde. Later, more than 40 dinosaur and bird footprints between 6 cm and 20 cm in length were found on the thick slabs of the main entrance and archway of Meru Fushou Temple. On April 21, 1992, Guo Jianwei and You Hailu of the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences surveyed the Chengde area and found a single footprint fossil on the surface of the paved stone slab near Rehe Spring. Since then, news of the discovery of dinosaur footprints in the area has often appeared in the media. In 2006, scholars such as Professor Martin Lockley of the University of Colorado (Denver) described four bird footprints on a thick slab found in the area, classified as aquatic bird footprints. However, apart from these four bird footprints, dinosaur footprints in the Chengde area are almost blank.
Since 2007, the team of Xing Lida of China University of Geosciences (Beijing) has successively conducted detailed research on a large number of dinosaur footprint fossils in Madigou, Summer Resort, Xumi Fushou Temple and Putuo Zongcheng Temple (Little Potala Palace), which not only enriched the fossil record of Dinosaur footprints in China, but also provided further strong evidence for the dinosaur activities of the late Jurassic period in Chengde, judging from the large number of invertebrate remains on the ground of the summer resort. The world, 150 million years ago, was supposed to be a relatively calm and shallow lakeshore with flat sand. This is also a prerequisite for various insects and dinosaurs to leave footprints. Xing Lida's team focused on the Mapigou footprint site that produced paving stone slabs, which was about 800 meters above sea level, and there were residential distributions on the western and northern slopes, many of which were built of local stones. Between 1979 and the early 1980s, stone slabs from these areas were used in the construction of the Chengde Mountain Resort and eight surrounding temples. In the spring of 2001, the Chengde County government announced that Madigou would be designated as a county-level cultural relics protection unit. At present, there are not many footprints left in Ma di Gou, and a large number of footprints are preserved on the ground of the summer resort.
After a detailed investigation, the area has preserved at least the following types of dinosaur footprints:
First, dinosaur footprints. Native to the Madigou footprint site, with an average length of 8.7 cm, the footprint has two toe marks (theiith and iv toes) and a rounded heel, which indicates its affinity with dinosaurs and is classified as velociraptorichnus. Dinosaur footprints are found less in the world, and at present, only the footprints of Chilong in Shandong, Sichuan, and Haman Chilong in South Korea. These footprints were found in the early Cretaceous period, and the Tucheng subgroup has previously found raptor footprints, one of the oldest members of the family. Dinosaurs include both leptosaurs and plesiosaurs, and what they have in common is that they all have large, spring-bladed ii toes, which is the "killer weapon" for their hunting. Interestingly, the second toe did not come into contact with the ground when the dinosaurs usually walked, so they left two-toed footprints, which are collectively known as dinosaur footprints.
Second, the eubrontes and grallators. Distributed at various footprint points in Chengde, these three-toed footprints have at least 140 footprints, of which 130 are complete footprints. These footprints are 13.4 cm long on average and vary in length between 4.1 cm and 23.4 cm, with footprints less than 10 cm long classified as small footprints, footprints with a length of 10 cm to 20 cm classified as medium footprints, and those with a length greater than 20 cm classified as large footprints. Of all the footprints, the main one is medium-sized. These footprints are divided into two types, morphological type a, the middle toe is relatively short, belonging to the theropod dinosaur footprint of the eubrontes, morphological type b, the middle toe is relatively long, belonging to the stilt-footed dragon footprint (grallator). These footprints belong to bipedal walking small and medium-sized carnivorous theropods, because the sediment is relatively soft and moist, so the foot pads are not very clear, the claw marks at the end are obvious, the functional toes are second, third and fourth toes, and only a few footprints leave thumb marks.
Third, Korean bird footprints (koreanaornis), distributed in the Madigou footprint point. This footprint point preserves at least four consecutive three-toed trails. The average maximum length of these footprints is 3.4 cm, the minimum length is 2.5 cm, and the maximum length is 4.6 cm. Morphologically, these bird footprints are classified as the Korean bird footprint type. Korean bird footprints were first found in Haman County, South Korea, and are a very typical class of Mesozoic bird footprints. Korean bird footprints belong to the partridge footprints, the plover is called shorebirds in English, literally translated as coastal birds, the largest of these birds is only 70 cm long and weighs more than 400 grams, so it is also called small waders. They share a common feature: They inhabit a variety of wetlands most of the time, feed mainly on molluscs and arthropods, and most species have migratory habits.
Fourth, possible thunder dragon footprints (brontopodus). The footprints of Chengde Mountain Resort produce some oval traces, measuring 28.9 centimeters in length and 22.6 centimeters in width. Morphologically similar to the trailing footprints of sauropods, such as the most famous sauropod footprint of the Cretaceous: the footprints of the rhyosaurus (brontopodus). However, due to poor preservation and no traces, it is not yet possible to fully confirm.
Xing Lida introduced that during this expedition, they found a diversified tuchengzi dinosaur fauna. The fauna is obviously composed of sauropods (including theropods and sauropods), of which theropods, birds account for the vast majority. These rich footprint records in the Chengde area show that the dinosaur evolution record in North China is basically continuous, starting from the Yanliao biota, to the Tuchengzi footprint fauna, and then to the Rehe biota. At present, the Xing Lida team is in close communication with the relevant departments of Chengde to discuss the next step of protection and utilization plans to promote the development and landing of tourism and scientific popularization.
Column Editor-in-Chief: Huang Haihua Text Editor: Huang Haihua Photo Editor: Zi Xi