Rediscovered Dinosaur Footprints in Northern Mongolia Redraw Early Cretaceous Ecosystem

In a landmark study published in Cretaceous Research in April 2026, an international team has rediscovered and fully documented a long-lost dinosaur tracksite in Mongolia’s Saijrakh region, proving that giant sauropods and large theropods roamed far northern laтιтudes during the Early Cretaceous (~120 million years ago).

First briefly noted by a Mongolian geographer in the 1950s, the site vanished from scientific records for seven decades. A 2024 joint expedition by the Insтιтute of Paleontology and Geology (Mongolian Academy of Sciences) and Okayama University of Science relocated and mapped the surface, revealing 31 well-preserved footprints forming trackways of at least two mᴀssive sauropods (exceeding 15 meters long) and five large theropods (over 8 meters).

The footprints occur on the same bedding plane, directly demonstrating that giant herbivores and apex carnivores coexisted in this northern ecosystem. Previously, Early Cretaceous body fossils from northern Mongolia were scarce, leaving a major gap in understanding faunal connections between East Asia, Far Eastern Russia, and North America during a time of global warming and angiosperm diversification.

“This site shows that large dinosaurs were not restricted to southern laтιтudes,” said lead researcher Dr. Shinobu Ishigaki. “It fills a critical biogeographic gap and supports models of dinosaur dispersal across the Beringian land bridge.”

The discovery transforms reconstructions of Early Cretaceous ecosystems: northern Mongolia hosted diverse, large-bodied dinosaur communities alongside flowering-plant-dominated forests. It also strengthens correlations with coeval track sites in China, Korea, and Japan.

After 70 years in obscurity, the Saijrakh tracks have delivered one of the most significant new windows into dinosaur distribution and paleoecology in Asia—proving the northern reaches of the continent were far more vibrant than previously imagined.