Thai researchers, in collaboration with international experts, have discovered the fossil of a new genus and species of giant rodent in Krabi province, named Yakamys sirindhornae, Natural Resources and Environment Minister Suchart Chomklin announced today.
The 33-to-35-million-year-old fossil, weighing an estimated 30 kilogrammes, was uncovered in the late Eocene sediment layers of the Bang Mark coal basin.
It is the largest known rodent from the Paleogene period, providing crucial evidence that rodents evolved into large body sizes 15 to 20 million years earlier than previously understood.
Suchart said Her Royal Highness Princess Maha Chakri Sirindhorn graciously granted permission to use her royal name for the species, marking the fifth fossil named in her honour.
He added that the discovery reflects the potential of the Department of Mineral Resources and Thai researchers in generating paleontological knowledge in collaboration with international research networks. It also underscores the importance of Thailand, particularly the fossil site in Krabi province, as a natural heritage site of world-class scientific value.
“The Ministry of Natural Resources and Environment remains committed to supporting the department in advancing geological and paleontological research, conservation and knowledge dissemination, to raise awareness of Thailand's geo-heritage,” he stated.
The research was a joint effort between the Department of Mineral Resources and researchers from France and Canada, led by Dr. Yaowalak Chaimanee, a mammal fossil specialist from the French National Centre for Scientific Research (CNRS).
The findings were published today in the scientific journal Scientific Reports.









