KATHMANDU: Scientists have uncovered the fossil of a tiny mouse-sized mammal, Yeutherium pressor, in Chilean Patagonia, dating back about 74 million years to the Upper Cretaceous period — the era of the dinosaurs.
Weighing just 30 to 40 grams (around one ounce), Yeutherium pressor is the smallest mammal ever found in this part of South America, which was then part of the ancient supercontinent Gondwana.
The fossil includes a small jaw fragment with one molar and parts of two other molars. Researchers from the University of Chile and Chile’s Millennium Nucleus research center made the discovery in the Rio de las Chinas Valley, located roughly 3,000 kilometers south of Santiago.
Despite resembling a small rodent, Yeutherium pressor likely laid eggs like a platypus or carried young in a pouch like kangaroos and opossums. Its teeth shape suggests a diet of relatively hard vegetables.
This tiny mammal, like the dinosaurs it lived alongside, abruptly became extinct around 66 million years ago at the end of the Cretaceous period.
The findings were published this month in the British journal Proceedings of the Royal Society B.
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