MOSCOW — Thousands of years after their brief lives ended in the frozen reaches of Siberia, the remarkably well-preserved carcasses of two cave lion cubs have been shown to the public.

They were unveiled on Tuesday at the Kingdom of Permafrost museum in Yakutsk, 4,900 kilometers (3,000 miles) east of Moscow.

Cave lions are believed to have become extinct about 10,000 years ago. The carcasses of the cubs, probably about a month old when they perished, were discovered in permafrost this year.

Valery Plotnikov, a researcher at the regional Academy of Sciences, said “it’s the first time in history that a cave lion, although it is a cub and not a grown-up animal, was found with all the fur, internal organs and soft parts of the body so well-preserved.”