Researchers in southern Thailand have identified the fossil remains of a massive rodent that inhabited the region approximately 33 to 38 million years ago, with an estimated body weight of around 30 kilograms. The significant discovery was made by an international scientific team following a detailed morphological analysis of two fossilized teeth.
Key Takeaways: Scientists analyzed lower jaw teeth found in a coal mine in Krabi province, revealing a previously unknown species named Yakamys sirindhornae. Weighing up to 47 kilograms, this ancient creature stands out as the largest known rodent of the Paleogene period.
The large molar and incisor belonging to the enigmatic rodent were originally unearthed back in 2004 in a coal mining site located on the southwestern coast of Thailand. At the time of discovery, the scientific community lacked sufficient comparative data and analytical technology to accurately classify the specimen. It took researchers from Thailand, France, and Canada over two decades to definitively categorize the findings. A formal description of the new species has now been published in the journal Scientific Reports.
Detailed analytical procedures demonstrated that the animal belonged to the extinct family Ischyromyidae, which flourished during the Paleogene period roughly 66 to 23 million years ago and was widely distributed across North America, Asia, and Europe. In honor of her royal highness Princess Sirindhorn of Thailand, who is well known for her patronage of scientific and paleontological research, the species was officially named Yakamys sirindhornae.
Specialist estimates indicate that the body mass of the rodent ranged between 21.4 and 47.3 kilograms, averaging around 30 kilograms—comparable in size to a modern beaver. The discovery conclusively proves that exceptionally large rodents existed in Southeast Asia as early as the late Eocene, long before the widespread diversification of caviomorph rodents in South America.
Source: kun.uz