Dinosaur incubators.

Cold-blooded? Maybe. Warm-hearted? Definitely. Discover has the latest on how dinosaur moms used hot springs to keep the babies warm:

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… 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.

Even more intriguing is evidence that over time, eggshells grew thicker to resist the acidity of the spring water. The dinosaurs actually adapted to living and breeding around the hydrothermal vents. Hearth… home… hydrothermal vent.