BEIJING, Feb. 3 (Xinhua) — A Chinese-led study reported the discovery of fossilized amphibian footprints in the Middle Jurassic strata of Beijing, the first record in Asia. The study was published online in the journal Ichnos.
Experts say the discovery not only fills a gap in the study of Jurassic amphibian trace fossils across Asia, but also provides important evidence for understanding the paleogeography, paleoecology and biodiversity of northern China around 160 million years ago.
The fossil consists of two footprints preserved in one slab. They were found on a slope beside a road in Longquan Town, Mendougou District, Beijing, and formed a pair with their front and hind legs connected, said Lida Xin, a dinosaur expert and associate professor at the School of Earth Science and Resources at the China University of Geosciences in Beijing.
Based on the relative size, spacing, and roughly aligned orientation of the two impressions, the researchers determined that the impressions were likely made by the same animal over the course of continuous movement.
One well-preserved impression was identified as the left front footprint of a small animal, showing a distinct fan-shaped morphology with four slender, pointed toes. The entire palm print is only 1.5 cm long and 1.3 cm wide.
To extract maximum information from these small impressions, researchers employed the latest digital techniques. Photogrammetric 3D modeling was used to generate a high-precision 3D digital model that visually revealed the most subtle surface features of the impression and provided a solid data foundation for morphological analysis.
Through detailed morphological comparisons and quantitative skeletal trace correlation analysis, the researchers concluded that the trace creator most likely belonged to the suborder Salamandera.
“This is the first time that fossil amphibian footprints have been discovered and scientifically explained in Jurassic geological formations in China and across Asia,” Singh said. Until now, records of Jurassic vertebrate footprints in the Beijing area have been dominated by dinosaurs and turtles, with no amphibian footprints reported.
This discovery indicates that a group of small terrestrial-adapted amphibians existed in the lacustrine environment of the Beijing area during the deposition of the Yaopo Formation during the Middle Jurassic. They coexisted with abundant ferns, ginkgos, and cycads, forming a complex ecosystem.
It is worth noting that this important fossil was first discovered by Beijing elementary school student and fossil enthusiast Nie Jingchen, who discovered it on the rocky slopes of Mentougou during an expedition in early 2025.
“This is a vivid example of public participation in paleontological discoveries, a reminder that profound chapters of Earth’s history are sometimes preserved within the most subtle traces of surrounding rocks, waiting to be discovered and interpreted by those with keen eyes,” Singh said. ■