Ancient dinosaur eggs discovered in China hold key clues to Earth’s past. New dating techniques reveal surprising details about life and climate 85 million years ago
Egg cluster used for age dating analysis.
These eggs from this family might have developed special pore patterns to adapt to cooler temperatures. One batch of 28 egg-filled calcite was chosen to research, giving the ideal sample for accurate dating.
How were the eggs dated so precisely?
For the first time, researchers applied carbonate uranium-lead (U-Pb) dating directly to the eggshells. A micro-laser vaporised carbonate minerals into aerosol, which a mass spectrometer analysed. Uranium naturally decays into lead at a fixed rate, acting as an “atomic clock” to calculate the age. The measurements indicated the eggs were laid about 85 million years ago, in the Late Cretaceous, with an error of 1.7 million years. The technique skips conventional indirect dating through volcanic units or nearby rocks, offering the first sound chronological constraints on Qinglongshan dinosaur eggs.
