[Rockhounds] Scientists Solve Riddle Of World’s Best-Preserved Dinosaurs

[Kreigh Tomaszewski]

The Yixian Formation <https://www.idunn.no/doi/10.1111/let.12315>, a 120 to
130 million-year-old geological formation outcropping in the Liaoning
Province in northeast China, for more than 20 years has produced
exceptionally preserved fossils of insects, plants, shells, fish and
several hundred skeletons of feathered dinosaurs
<https://www.forbes.com/sites/shaenamontanari/2015/07/16/spectacularly-preserved-feathered-dinosaur-from-china-is-relative-of-velociraptor/#1539931241e5>
.

How did these fossils come to be so perfect? The leading hypothesis up to
now has been sudden burial by volcanism
<https://www.atlasobscura.com/articles/fossil-preservation-at-jehol-biota-in-china>,
perhaps like the waves of hot ash from Vesuvius that entombed many citizens
of Pompeii over 2,000 years ago
<https://pompeiisites.org/en/pompeii-map/analysis/the-casts/>, and the
Yixian deposits have been popularly dubbed the “Chinese Pompeii.”

Earlier studies have suggested that multiple volcanic events took place in
pulses over about a million years, repeatedly burying animals and
preserving their remains. But a new study completely refutes this theory,
showing that the fossils date to a period of less than 93,000 years when
there was no volcanic activity at all. The creatures were preserved by more
mundane events including collapses of burrows during rainy periods.

“These are probably the most important dinosaur discoveries of the last 120
years,” says study coauthor Paul Olsen
<https://people.climate.columbia.edu/users/profile/paul-olsen>, a
paleontologist at the Columbia Climate School’s Lamont-Doherty Earth
Observatory <https://lamont.columbia.edu/>.

“But what was said about their method of preservation highlights an
important human bias. That is, to ascribe extraordinary causes, i.e.
miracles, to ordinary events when we don’t understand their origins. These
fossils are just a snapshot of everyday deaths in normal conditions over a
relatively brief time.”

https://www.forbes.com/sites/davidbressan/2024/11/10/scientists-solve-riddle-of-worlds-best-preserved-dinosaurs/