Reported by CGTN, On Wednesday (9/21/22), the study was published on Monday (9/19/2022) as a cover story for the journal Proceedings of National Academy of Sciences (PNAS).
Researchers from the Chinese Academy of Sciences (CAS) Institute of Vertebrate Paleontology and Paleoanthropology, together with their collaborators, evaluated 1,000 dinosaur egg and shell fossils from the Shanyang Basin in central China, identifying a decline in the diversity of dinosaurs based on the data.
The 1,000 dinosaur egg fossils collected from the basin represent only three distinct species: Macroolithus yaotunensis, Elongatoolithus elongatus, and Stromatoolithus pinglingensis.
Two species belong to a group of toothless dinosaurs known as oviraptors, while the other belongs to a group of plant-eating hadrosaurids (also known as duck-billed dinosaurs).
The study found that this low dinosaur species diversity was maintained in central China for the past 2 million years before the mass extinction.
The long-term decline in world dinosaur diversity until the end of the Cretaceous period and the low number of dinosaur lineages over the past million years could be due to known global climate fluctuations and massive volcanic eruptions.
These factors may have caused instability throughout the ecosystem, leaving non-avian dinosaurs vulnerable to a mass extinction coinciding with the asteroid impact, CAS wrote.