Paleontologists Identify Giant Prehistoric Rodent in Thailand

An international team of paleontologists has identified an ancient rodent of extraordinary size from fossils uncovered in a mine in southern Thailand, according to Sciencedaily.

Researchers recovered remarkably large fossilized teeth belonging to a previously unknown species named Yakamys sirindhornae from the Bang Mark Pit at the Krabi lignite mine in Thailand’s Krabi Province. The ancient animal lived approximately 34 million years ago during the middle of the Paleogene period.

To determine the animal’s size, scientists applied seven established methods that use tooth measurements to calculate body mass.

The name of the newly identified creature reflects both its impressive size and its connection to Thailand. The first part of the name combines yak, the Thai word for giant, with mys, the Greek word for mouse or rat. The second part of the scientific name honors an important supporter of scientific research in the country.

The species name, sirindhornae, honors Princess Maha Chakri Sirindhorn, in recognition of her longstanding support for science and paleontological research in Thailand.

Virginie Millien, a biology professor at McGill University and co-author of the study

These findings show that massive rodents emerged across a wider global range and earlier than previously thought. Scholars from McGill University, the Department of Mineral Resources of Thailand, and French institutions such as CNRS and Université de Poitiers make up this global study group.

While the capybara is the largest living rodent today, very large rodents are not restricted to modern ecosystems, according to Millien.

Giant rodents evolved repeatedly during the later history of the group, mostly in South America. This discovery suggests that Southeast Asia also played an important role in the early evolutionary history of large-bodied rodents.

Virginie Millien, a biology professor at McGill University and co-author of the study

The findings stem from an ongoing international collaboration investigating ancient mammals in Thailand’s Krabi Basin. Financial backing for the study came from CNRS, Université de Poitiers, Université de Montpellier, McGill University, and the Department of Mineral Resources of Thailand.