Dinosaurs were not very diverse and had declined overall even before their extinction nearly 66 million years ago, a study of fossilised eggs in China suggests.
The long-term decline in global dinosaur diversity and sustained low number of their lineages for the last few million years may have resulted from climate fluctuations and massive volcanic eruptions from the Deccan Traps in India, the researchers said.
These factors may have led to ecosystem-wide instability, thus making non-bird dinosaurs vulnerable to mass extinction coincident with the asteroid impact, they said.
