Giant fossil rodent species identified in Thailand

Scientists have identified a previously unknown giant rodent species from two fossilised teeth found in southern Thailand, saying the animal weighed about 30 kilograms and lived 33 to 35 million years ago.

The findings, published Wednesday in Scientific Reports, were based on a molar and an incisor discovered in 2004 at a coal mine in Krabi province. Researchers from Thailand, France and Canada later identified the animal through detailed analysis of the teeth.

Pannipa Tian, a geologist with Thailand's Department of Mineral Resources who found the incisor, said she first mistook it for bone because of its size. She said a supervisor told her it was a "giant rat's tooth".

The animal, named Yakamys sirindhornae in honour of Thailand's Princess Sirindhorn, belonged to the extinct Ischyromyidae family, one of the earliest major groups of rodents. Scientists said it was among the largest known rodents from the Paleogene period.

Because only two teeth have been recovered, the animal's appearance, diet and behaviour remain unknown.