Giant Rat of Krabi Unearthed: Two Teeth Reveal Rodent the Size of a Capybara

KRABI PROVINCE, THAILAND — Scientists have announced the identification of a previously unknown giant that once roamed southern Thailand, according to a report by The Debrief. The creature, it turns out, was a rodent, and a remarkably large one, said to have weighed close to 30 kilograms.

The evidence consists of two fossil teeth, a molar and an incisor, taken from a coal mine in Krabi province more than two decades ago. Pannipa Tian, a geologist with Thailand's Department of Mineral Resources and one of the discoverers, told AFP that she first mistook the incisor for a bone. Her supervisor, she said, identified it as a giant rat's tooth. The molar was recovered later the same day, the report states.

The site had already yielded fossils of other mammals, including ancient primates. It took more than twenty years, however, for the teeth to be formally identified. The animal is described as comparable in size to the capybara of South America, the largest living rodent, though it belongs to an entirely different family, the Ischyromyidae.

Much about the beast remains unknown, the report notes, including its appearance and diet, although the two teeth may offer some clues. The species has been named Yakamys sirindhornae, in tribute to Princess Sirindhorn, described as a notable advocate for paleontological research.

The findings appear in a study in Scientific Reports titled "A giant Eocene ischyromyid from Southeast Asia reveals the early evolution of rodent gigantism." The animal is now counted among the largest of its kind from the Paleogene period, and it raises fresh questions about how the ancestors of modern rodents grew to such sizes.