Paleontologists in the Orog Nuur Basin of Mongolia have identified a new species of prehistoric rodent that lived during the Miocene epoch. The fossils belong to a giant ground squirrel, estimated to have reached the size of a modern-day beaver, making it one of the largest sciurids ever discovered in Asia. The specimen, named Marmota mongoliensis, was found in a high-altitude sedimentary layer that has preserved nearly 80% of the skeletal structure, including a robust set of incisors adapted for grinding tough desert vegetation.
The discovery is significant because it provides data on the environmental shift toward more arid, open-plain conditions in Central Asia 12 million years ago. Analysis of the specimen's limb bones suggests a highly specialized digging morphology, indicating the species lived in complex underground burrow systems to avoid apex predators. This find fills a major gap in the evolutionary history of rodents in the region and highlights Mongolia's importance as a reservoir for mammalian evolution.