An international team of paleontologists including researchers from Canada's McGill University has described a new species of prehistoric giant rodent that lived in what is now Thailand about 34 million years ago, during the middle of the Paleogene period. The findings from the study of the fossils were published in the scientific journal Scientific Reports, infohub.kz reports.
The animal was given the scientific name Yakamys sirindhornae: the genus name combines the Thai word "yak" (giant) and the Greek "mys" (mouse), while the species name honors Princess Maha Chakri Sirindhorn of Thailand for her long-standing support of science.
The fossil remains, consisting of a lower second molar and a lower incisor, were recovered from the Bang Mark pit at a coal mine in Krabi province in southern Thailand. According to the researchers' calculations, using seven methods for estimating body mass from tooth size, the ancient animal weighed about 30 kilograms (approximately 66 pounds).
That makes it roughly twice as heavy as any other known rodent of that era, including the fossil Hulgana. Before this discovery, it was believed that the evolution of giant rodents occurred much later and mainly in South America.
As noted by study co-author Virginie Millien, a professor of biology at McGill University, the capybara is the largest rodent on the planet today, but the process of evolutionary gigantism began back in the Paleogene. The new find proves that Southeast Asia played a notable role in the emergence of large mammal forms.
Specialists from Thailand's Department of Mineral Resources, the French National Centre for Scientific Research (CNRS), the University of Poitiers and the University of Montpellier also took part in the international research project.