jaw-dropping example of Ice Age architecture has been unearthed on Russia’s forest steppe: a huge, circular structure built with the bones of at least 60 woolly mammoths. But exactly why hunter-gatherers enduring the frigid realities of life 25,000 years ago would construct the 40-foot diameter building is a fascinating question. “Clearly a lot of time and effort went into building this structure so it was obviously important to the people that made it for some reason,” says Alexander Pryor, an archaeologist at the University of Exeter (U.K.). He is the lead author of a new study published this week in...