NANJING, Feb. 12 -- Research jointly conducted by Chinese and American scientists has found that a volcanic eruption in the Cretaceous Era may have caused the mass death of dinosaurs in northeast China.

Jiang Baoyu, associate professor with the School of Earth Sciences and Engineering at Nanjing University, said well-preserved fossils from the region indicated the dinosaurs had been killed more than 120 million years ago by volcanic ash flow that was about 200 to 300 degrees Celsius in temperature.

The flow was hot enough to kill the animals instantly but not hot enough to melt the remains, leaving exquisite fossils after the ash-covered remains were later submerged in lakes, Jiang told Xinhua on Wednesday.

The fossil formations were similar to remains uncovered from the Roman city of Pompeii, which was buried instantly following the eruption of Mount Vesuvius in 79 AD.

The fossils were found at the Jehol Biota located in northeast China, which covers the northern part of Hebei, eastern part of Liaoning and southeast part of Inner Mongolia and is known for the diversity of its plant and animal fossils.

Jiang, together with four scientists from Nanjing University, the American Museum of Natural History and the Los Alamos National Laboratory, began the research in 2011 and published their findings in the scientific journal "Nature Communications" on Feb. 4.

"Our findings have provided a pattern to explain mass deaths in the region back then. But it cannot explain the cause of the dinosaurs' extinction. The cause of their extinction is far more complex," he said.