1000 Fossilized Eggs from China Hint Lack of Diversity in Dinosaurs, Decline Before Extinction

1000 fossilized eggs were discovered in China, providing evidence to support theories that the dinosaurs' lack of diversity may have contributed to their decline and eventual extinction.

A sizable asteroid that struck Earth nearly 66 million years ago played a part in the worldwide dinosaur extinction, leaving only birds as their living descendants.

Scientists are aware that a variety of dinosaurs, including many different species, coexisted on Earth in the late Cretaceous period, just before they went extinct.

Scientists disagreed as to whether the dinos were at their peak or already in decline when they died out.

Lack of Diversity

The Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) researchers and their associates have discovered the solution.

The concept that dinosaurs were not at all diverse before they went extinct and had generally declined during the late Cretaceous Period has been supported by evidence found.

North America provides the majority of the scientific information on the demise of the dinosaurs.

While some published studies contend that the dinosaur populations in the area were thriving before their mass extinction, other, more thorough studies contend that the dinosaurs were actually in decline, which prepared the way for their eventual mass extinction.

1000 Fossil Eggs

The Chinese researchers sought to ascertain whether this declining trend persisted throughout Asia by looking at the dinosaur record in China.

More than 1,000 fossilized dinosaur eggs as well as the eggshells from the Shanyang Basin located in central China were studied by the researchers.

These fossils were found in rock layers that were about 150 meters thick overall.

Through the examination of more than 5,500 geological samples and the use of computer modeling, the researchers were able to determine the precise ages of the rock layers.

As a result, the researchers were able to construct a timeline at the end of the Cretaceous that covered almost 2 million years and had a resolution of 100,000 years, representing the time just before extinction.

Direct comparisons against data from different corners of the world are possible using this timeline.

Based on the data from the Shanyang Basin, the scientists found a decline in the diversity of dinosaur species.

For instance, only three different species of dinosaurs- Elongatoolithus elongatus, Macroolithus yaotunensis, and Stromatoolithus pinglingensis-are represented among the 1,000 dinosaur egg fossils discovered in the basin.

Additionally, two of the three dinosaur eggs belong to a group of toothless dinosaurs, also known as oviraptors, and the third is from the hadrosaurid group, also known as duck-billed dinosaurs, which consumed plants.

Dinosaur Decline

According to several more additional dinosaur bones discovered in the area, sauropod and tyrannosaurus dinosaurs lived in the region between roughly 66.4 and 68.2 million years ago.

Before the mass extinction, central China had a low diversity when it comes to dinosaur species for the previous 2 million years.

The sparse dinosaur population in central China and the Shanyang Basin is very different from the setting of Jurassic Park.

Together with data from North America, these findings implied that dinosaur populations were likely declining globally before their extinction.

These known global climate fluctuations and the large volcanic eruptions from the Deccan Traps in India may have contributed to the long-term decline in dinosaur diversity that occurred through the end of the Cretaceous Period and the chronic low dinosaur lineage numbers for the last few million years.

These elements might have caused ecosystem-wide instability, leaving non-bird dinosaurs defenseless against a mass extinction that occurred at the same time as the asteroid impact, Phys Org reported.