Dinosaurs Had Rotten Strategy for Nesting in the Cold

Scientists say some of the heftiest dinosaurs on record weren't just roaming chilly high-altitude lands—they were raising babies there, too. A new Royal Society Open Science study of 255 fossilized titanosaur egg fragments from Argentina's southern tip, far from the equator, suggests the giants nested in a climate similar to present-day New York City roughly 68 million years ago. Titanosaurs, long-necked plant eaters that could tip the scales at 75 tons, were known to live at high latitudes, but where they laid their volleyball-sized eggs had been unclear, per Smithsonian.

The massive dinosaurs didn't sit on their eggs, as doing so "would have turned the nest into one giant omelet," study co-author Darla Zelenitsky of the University of Calgary tells CNN. Microscopic analysis revealed unusually porous shells that would have dried out if left exposed, indicating the dinosaurs instead buried the eggs in sand, soil, or mounds of rotting plants—much like modern crocodiles do—to trap heat and moisture. The work points to a flexible reproductive strategy that let these dinosaurs thrive in cooler, "more challenging" environments than many realized, Zelenitsky tells the CBC. (One titanosaur bone surfaced in Antarctica.)