Twelve things scientists never expected to surface from Siberia’s frozen ground are now forcing a dramatic rethink. As the permafrost thaws, it’s yielding more than ancient bones—it’s releasing ancient viruses and massive craters that have researchers deeply concerned.

High-resolution imaging has revealed some of the oldest tattoos ever found, preserved on a naturally mummified woman who died about 2,500 years ago in the Altai Mountains of Siberia. The discovery occurred during excavations of burial mounds on the Ukok Plateau in 1993, led by archaeologist Natalia Polosmak. The site sits near the meeting point of Russia, China, Mongolia, and Kazakhstan.Most ancie…