Pyroclastic flow caused mass death of dinosaurs: expert  

南京大学科学家发现恐龙死亡之谜:火山爆发所致

南京大学副教授姜宝玉等科学家团队在东北地区热河生物群动物化石遗址中，发现保存完好的恐龙、哺乳动物和鸟类化石：这些古生物的遗骸，都有被烧焦过的痕迹——这跟庞贝城所见的人类遗骸很相似，发现地也因此被称为中国古生物的“庞贝城”。 [查看全文]

(ECNS) -- A new study has found that pyroclastic flow 100 million years ago was the main reason behind the mass mortality of dinosaurs and other animals in northeastern China, the Modern Express observed on Tuesday.

The discovery was published in "Nature Communications" by a research team under the leadership of Jiang Baoyu, an associate professor at Nanjing University.

In the 1990s a series of well-preserved fossils were discovered in the Jehol Biota (an ecosystem in northeast China between 133 and 120 million years ago), and those discoveries have changed people's understanding of the lives of early birds and mammals, as well as the dinosaurs they shared an ecosystem with.

To figure out why so many well-preserved fossils were found in that region, Jiang and four other scientists launched a research project in 2011.

After three years of study, researchers discovered that this remarkable preservation has been the result of a Pompeii-like event, where hot ash from a volcanic eruption entombed the animals.

Using six different fossils discovered in the region, Jiang found marks of fast-moving ash and hot gas that can only result from a nearby volcanic eruption. The bones showed black streaks, which suggest that charring had occurred.

"We are shocked when we find bones of animals kept in volcanic ash, rather than mudstones," said Jiang.

The reason the bones were not burned up is that the ash gradually cooled down during its flow. The temperature of the pyroclastic flow was too low to burn up skeletons of animals, Jiang added.