How was the fossilized city of 'Chinese Pompeii' formed?
About 12-13 million years ago, northeastern China had green forests, lakes, and an active ecosystem, home to large assemblages of dinosaurs, birds, mammals, insects, and other animals.
That ancient site is now known as the 'Yixian Formation', which is considered one of the world's fossil mines. In the 1980s, the villagers of the area began to look for these preserved fossils, which was referred to as the 'gold rush of fossils', according to the scientific site Norridge.
The search was so extensive that the extent of its excavations could be seen from space. In the 1990s, scientists were convinced that the area has a wealth of fossils that are not found anywhere else.
Many of these fossils are almost complete, with various animal internal organs, feathers, fur, striped spots and even various abdominal organs found.
The incredible find has unearthed a fossil showing a small dinosaur and a cat-sized mammal fighting. And they froze to death in the middle of this fist fight.
The discovery includes the world's first feathered dinosaur. This proves that feathers evolved in dinosaurs long before birds.
These fossils show the potential to revolutionize the conventional understanding of dinosaur evolution. Also, it has been confirmed that modern birds are direct descendants of feathered dinosaurs.
For years, scientists believed that fossils were preserved by eruptions, much like the city of Pompeii, which was buried underground in 79 BC.
This theory suggests that hot ash waves suddenly buried the animals underground, saving them instantly. And that is why Yixian Formation is nicknamed 'Chinese Pompeii'.
But a new study published in the Proceedings of the National Academy of Sciences challenges this theory.
The study, led by Scott McLennan, a researcher at the University of the Witwatersrand in South Africa, indicated that these fossils did not result from a dramatic eruption, but from simple processes such as crater collapse and seasonal rainfall. And with the passage of time there is a pile of soil.
The researchers used new techniques to date these fossils, where the duration of that particular era was less than 93,000 years, ending about 125 million years ago.
This relatively short period of time suggests that this process of fossilization did not occur suddenly in a series of eruptions, as previously thought. Instead, the research team believes that regular rainfall and deposition of sediments played a larger role in preserving these fossils.
McLennan's research team used a method called 'CA-ID-TIMS (Chemical Abrasion Isotope Dilution Thermal Ionization Mass Spectroscopy)' to measure tiny zircon particles in the fossils, according to Norridge's report.
