Northeast China Fossils Buried Beneath Massive Volcanic Eruption and Hot Ash

The Jehol Biota, a trove of fossils located in northeast China, is home to one of the world's richest fossil beds. Now, new data has shown that the formation of these fossils occurred due to a volcanic eruption.

The fossil site was excavated over a century ago and contains a variety of detailed imprints: birds, dinosaurs, mammals, lizards and other animal life from over 100 million years ago. Since there are so many fossils located in one area, scientists have often asked themselves: How did so many creatures die at once?

The answer, evidence suggests, lies in the geographic location. It's possible that a series of avalanches caused by volcanic eruptions claimed the lives of these animal. Researchers discovered this by examining fossils from five different locations at the Jehol site, which is 180 miles long and 60 miles wide. The fossils showed signs of being roasted in a pyroclastic flow, which is a river of volcanic gas and bits of rock that travel 50 miles per hour or faster.

The details of the fossils - dark coating, cracks, charred surfaces - are similar to those found near Pompeii following the eruption of Mount Vesuvius in 79 A.D.  Similarly, both types of fossils appeared to be killed and preserved in a protective mold of hot and dry ash. Both also have alarming qualities of dark coating, which is a result of carbonized skin and muscle. But what's even more revealing is that the Jehol fossils were found with bent limbs, an indication of being trampled by a pyroclastic flow.

"All the evidence supports this hypothesis," says study co-author Jin Meng, a paleontologist at the American Museum of Natural History in New York, in this USA Today article. "Many or most of the vertebrate fossils were preserved this way."

To read more about the discovery of these fossils and other viewpoints on the subject, take a look at this USA Today article.