A fossil with a trial of five footprints from a small-sized dinosaur was discovered in the Linxia Global GeoPark in northwest China's Gansu Province, shedding lights on scientific research on how dinosaurs shrank in size and evolved to birds.
With the length of 1 to 3 centimeters, it is one of the smallest dinosaur footprint fossils in the world. The footprints on the fossil belong to the small-sized dinosaur from the early Cretaceous period dating back to nearly 120 million years ago, said experts based on field observations.
"This is the first time for the footprints of small-sized dinosaurs to be discovered in Gansu Province and the rest of northwest China. These footprints will play important roles in strata comparison, dinosaurs scientific research and relative education. With these footprints, we can learn how dinosaurs' body size gradually decreased and how they evolved to birds, which bears huge significance in the evolutionary history of dinosaurs," said Xing Lida, an associate professor at China University of Geosciences (Beijing).
Fossils with small-sized dinosaurs' footprints were initially discovered in Sichuan Basin, followed by Shandong Province in eastern China and the Republic of Korea. Yet the new discovery in Gansu Province suggests the broader presence of small-sized dinosaurs' footprints in the early Cretaceous period, giving more insights into the biostratigraphy, geologic age and dinosaur diversity study in the region, according to Xing.
"The trail of footprints on the fossil indicates the speed of small-sized dinosaur is not very fast. The obvious water-shaped cracks on the fossil layer suggests the dinosaur once came close to water and there were many waterfowl alongside them. They formed a typical pack, and this aligns with what we found in other regions," said Xing.
A fossil assemblage of more than 2,000 fossils with dinosaurs' footprints have been discovered in Yongjing County of Linxia Hui Autonomous Prefecture since the end of 1990s. These differentiated and well-reserved fossils were discovered at multiple rock layers.