A raptor, genus Zhenyuanlong. STEVE BRUSATTE AND JUNCHANG LU.
AtlasObscura has an interesting story about the "Chinese Pompeii". The Jehol Biota has long been known for its amazing preservation.
WHEN SOMETHING DIES, NATURE ENSURES that its remains won’t stay intact. Microbes eat away at the soft tissue, and wind, rain, rivers, oceans, and scavengers shuffle around the hard segments of the corpse. As eons pass by, these skeletal segments may become fossilized, but they remain broken jigsaw pieces of a puzzle that often cannot be entirely pieced back together.
But around 130 to 120 million years ago, in what is now northeastern China, nature behaved rather differently. It was then, during the early Cretaceous, that a series of cataclysmic events took place, ensuring that a vast collection of plants and animals, including plenty of dinosaurs, were left in much the same state they were in when they were alive.
These often fully or at least partly joined-up fossilized skeletons looked like they had been frozen in time. Many of them still retained soft tissues, from muscles to skin. The remarkable state of preservation at this location, officially known as the Jehol Biota, led to some researchers and journalists to dub the site the “Chinese Pompeii.”