Researchers discover 1st amphibian footprints in Asia from Middle Jurassic period

A China-led team has discovered amphibian track fossils in Middle Jurassic strata in Beijing, marking the first such find in Asia, China's state-run Xinhua news agency reported Monday.

The discovery fills a major gap in Asia's Jurassic amphibian record and sheds light on northern China's paleogeography, ecology and biodiversity around 160 million years ago, according to a study published online in the journal Ichnos.

The fossils are two linked footprints on a single slab found on a roadside slope in the town of Longquan in Mentougou district. Based on their size, spacing and alignment, researchers concluded they were made by the same animal while moving.

One well-preserved print is a left forefoot with four slender, pointed toes measuring just 1.5 centimeters by 1.3 centimeters (0.59 inches by 0.51 inches).

Using photogrammetric 3D modeling, the research team captured fine surface details for precise analysis. Comparative morphology and skeletal-track correlation indicate the trackmaker was likely a salamander.

"This is the first time that amphibian track fossils have been discovered and scientifically described in Jurassic strata in China and across Asia," said Xing Lida, a dinosaur specialist and associate professor at the School of Earth Sciences and Resources at the China University of Geosciences.

Previously, Beijing's Jurassic track record included mainly dinosaurs and turtles.

The find suggests that small, land-adapted amphibians lived in Middle Jurassic lake-swamp environments around Beijing alongside ferns, ginkgos and cycads, forming a diverse ecosystem.