Everybody likes a good soak in a hot bath from time to time. But new research suggests that some dinosaurs took it to the extreme, laying their eggs in the steaming hot soils near hot springs and Old Faithful-like geysers in what is now northwestern Argentina.

In the Cretaceous period over a hundred million years ago, Argentina's Sanagasta Valley was alive with hydrothermal activity, much like Yellowstone National Park or Iceland are today. Tunnels of near-boiling, mineral-rich water crisscrossed the subsurface (figures below, from the paper), and explosive geysers pockmarked the landscape. Doesn't seem like a very inviting place to raise a family.

But researchers found some 80 clutches of fossilized eggs in the area, many of them containing a dozen or more eggs each. Even more strange, the nests were almost exclusively found within 10 feet of a geyser or hot spring. It seems that far from avoiding the hydrothermal features, dinosaurs were purposefully laying eggs near them as a way to keep them incubated during their 1-2 month long gestation.

Gerald Grellet-Tinner of the Field Museum in Chicago and Lucas Fiorelli of CRILAR in Argentina published their findings in the journal Nature Communications....