Beijing: A clutch of fossilized dinosaur eggs discovered in China has been precisely dated to around 86 million years ago, offering fresh insights into the age and reproductive behavior of dinosaurs during the Late Cretaceous period.

The eggs, unearthed at Qinglongshan in the Yunyang Basin, are remarkably well preserved, with 28 specimens found intact in three-dimensional form. For the first time, researchers used uranium-lead (U-Pb) isotopic dating directly on the carbonate material of the eggshells rather than relying on the surrounding rock layers. This approach yielded an age of about 85.9 million years, with a margin of error of 1.7 million years.

The porous nature of the eggshells suggests that these dinosaurs may have buried their nests or relied on humid environments to incubate their young.

Scientists believe the findings could shed light on how dinosaurs adapted their nesting strategies in response to environmental conditions, especially during a period when Earth was undergoing cooling after earlier hothouse climates.

While the species of the egg-layers remains uncertain, the fossils are thought to belong to the dendroolithid family, with some classified under the type Placoolithus tumiaolingensis.

Researchers say the study provides a critical benchmark for understanding reproduction and climate interaction in the Late Cretaceous.

Experts hailed the study as a breakthrough in paleontology, noting that direct dating of eggshells reduces uncertainties long associated with fossil age estimates. The discovery is expected to aid further research into dinosaur evolution, nesting behaviors, and the ecological conditions that shaped their survival.