Rare fossilized feathers reveal the secrets of the epicenter of Cretaceous paleontology

The Jehol Biota site in China is famous for the amazing fossils that preserved soft tissues – skin, organs, feathers, and fur. These fossils provide rare insights into the evolution of characteristics such as flight, but they need careful interpretation to fully understand the shape and behavior of life’s soft tissues, and how decomposition affected them.

Study published in Frontiers in Earth Sciences They analyzed five fossils of an early Cretaceous bird, Sapeornis chaoyangensis, in order to study how the environment in which they were buried altered the preservation of their soft tissues.

“Jehol Biota provides the most useful resource for understanding the Mesozoic ecology,” said corresponding author Dr. Yan Zhao, based at the Institute of Geology and Paleontology of Linyi University. “A better understanding of the diversified pecking biology of Jehol’s terrestrial vertebrates can help us understand more about the past and future of biological evolution.”

Why does sedimentation matter?

Even at the Jehol Biota, not all fossils are equally well preserved—and understanding the paleoenvironment is crucial to understanding the differences. Without this information, it is difficult for scientists to gauge the extent of soft tissue preservation, which limits interpretation of the evidence. But at Jehol Biota, because of the range of excavated specimens, individuals of the same species can be compared to understand the taphonomic effects—the effects of the processes that occurred between death and excavation—of the environment on soft tissues.

“An exceptionally well-preserved collection of soft tissues of countless taxa has been reported from Jehol Biota, containing information irreplaceable for understanding early development Of the biological and ecological characteristics, Zhao said, “we would like to examine the factors that influence their conservation.”

The samples used by the scientists were selected from the archives of the Shandong Tianyu Museum of Natural History and matched with sediment samples for analysis. They were all fully articulated – ossified with all joints still connected – but the soft tissue preservation was varied. The STM 15-36 was the best, retaining a full featherweight finish with amazing detail.

Preserved Swift Lake burial feathers

The team analyzed the sediment to determine what kind of organic material the birds were surrounded by when they were buried and how the sediment was deposited. STM 15-36 was associated with coarse sediment grains as well as the best preservation, and the ambient organic material came mainly from terrestrial plants rather than lake algae like the other four avians. The climate when STM 15-36 was deposited was much warmer and wetter, and the environment in which it was deposited was more anoxic, which prevented the feathers from rotting before they fossilized.

There were two possible options to explain the rapid burial of STM 15-36: volcanic activity Or a strong rainstorm washes it away and buries it under other debris. Since excavations in lava flows Do not maintain softness tissues Well, the most likely explanation is that the bird was swept away by a rainstorm and quickly buried at the bottom of the lake, where the restricted burial environment ensured it would not be disturbed. This combination of circumstances means that after millions of years, their beautiful plumage will still be preserved in stone.

“This discovery provides a valuable case study on tabonomy in Jehol terrestrial vertebrates Zhao said she looks forward to future studies that focus on the chemical features and fine structure of the feathers themselves, expanding scientists’ understanding of the way these birds live and die.