The smallest dinosaur footprint in China found in Zigong, Sichuan

Collection of footprints from Zigong Dinosaur Museum

Beijing, Zigong, June 26 (Liu Gang, Jiangshan, Li Yi) - on June 26, the Zigong Dinosaur Museum in Sichuan Province announced to the public that recently, a research team composed of Peng Guangzhao, ye Yong, research librarian of Zigong Dinosaur Museum, Jiang Shan, deputy research librarian, Xing Lida, associate professor of China University of Geosciences (Beijing) and other Chinese and foreign paleontologists, A number of well preserved dinosaur footprints were found in Fushun County, Zigong City. Among them, a tiny dinosaur footprint only 10.2 mm long may reveal the early or very early developmental strategy of theropod dinosaurs.

Specimen of footprints provided by Zigong Dinosaur Museum

It is understood that the units participating in the research include Zigong Dinosaur Museum, China University of Geosciences (Beijing), Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, University of Colorado, German Museum of ancient reptiles and amphibians, Charleston college, etc. relevant papers will be published in this issue of Journal of historical biology.

According to reports, in July 1998, the brothers Ding Yongfu and Ding Yongjian, villagers of Wuli Village, Yongnian Town, Fushun County, decided to use the open space next to their houses to excavate a pond to store water in order to solve the problem of daily washing vegetables and laundry. As a result, the Ding brothers spread the strip-shaped stones around the pond as stepping stones to facilitate walking. Although people sometimes notice that some rocks are covered with "chicken feet" like shapes during walking, they don't think much about it. In recent years, with the discovery of dinosaur footprints, the deepening of dinosaur footprints research and the increase of publicity reports, more and more people have a better understanding of dinosaur footprints.

The smallest dinosaur footprints from Zigong Dinosaur Museum

In April 2017, Ding Li, Ding Yongfu's daughter, posted several photos of stepping stones beside the pond in her hometown on the Internet and asked whether the "chicken feet" in the photos were dinosaur tracks. Zigong Dinosaur Museum immediately contacted Ding Li after learning the news. In early May of the same year, the Zigong Dinosaur Museum first went to the field to check, and confirmed that it was the dinosaur footprints. In mid May, after negotiation with the other party, Zigong Dinosaur Museum collected these dinosaur footprints and fossils back to Zigong Dinosaur Museum for collection, protection and research.

There are eight footprints collected by Zigong Dinosaur Museum. In order to accurately outline the footprints, the research group used three-dimensional image reconstruction, data analysis visualization and three-dimensional point cloud processing software to make three-dimensional images. In this process, a very small footprint on the No. 5 rock plate attracted scholars' attention. There are at least 44 three toed footprints on the No. 5 rock slab with a footprint density of about 120 footprints per square meter. One of the footprints is very small. It is 10.2 mm long and 9.6 mm wide. It has three obvious toes. The third toe is the most prominent. There is no clear toe pad. There is a relatively blunt claw mark on each toe. This footprint is also the smallest dinosaur footprint recorded in China at present.

Specimen of footprints provided by Zigong Dinosaur Museum

"As a typical trace fossil, the dinosaur footprints contain rich information, which is the epitome of the dynamic behavior of dinosaurs at that time. An important function of dinosaur footprints is to effectively identify the composition of the local fauna at that time, and this information can make up for the limitations of bone fossils to a great extent. " According to relevant scholars, if Fushun's tiny footprints do record the footprints left by juvenile theropod dinosaurs at a very early stage of life, it may indicate an early or ultra early development strategy. Early or super early formation is one of the ancient characteristics of the main dinosaurs, which has been found in some dinosaurs (such as gnathodonts, antibirds) and other vertebrates (such as pterosaurs). At the same time, according to the dinosaur footprints, we can judge the movement state of dinosaurs at that time, such as walking, running and even swimming.

It is reported that the footprints found in Fushun, Zigong City have expanded the dinosaur fossil record of the lower Jurassic strata in the area. This is also the first time to record the footprints of microminiature theropod dinosaurs in the Jurassic period in Zigong City, revealing the early or very early formation of theropod dinosaurs, and the possibility of microminiature adult creators. A large number of footprints, such as the footprints of stilopods, indicate the high abundance of theropod dinosaurs in the area at that time. These theropod dinosaurs are confirmed to be widely distributed in the early Jurassic Sichuan Basin. The discovery is of great significance to the restoration of paleoecology, paleogeography and Paleoenvironment in the area.