![A student from the Department of Geology carries out research on a fossil from the Qingjiang biota in Northwest University in Xi\'an, capital of northwest China\'s Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)](http://www.ecns.cn/hd/2019/04/15/b36688d684ce4aa6aebd9438cbc04eb2.jpg)
A student from the Department of Geology carries out research on a fossil from the Qingjiang biota in Northwest University in Xi'an, capital of northwest China's Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)
![Undated file photo shows a fossil of branched alga from the Qingjiang biota. (Xinhua/Northwest University)](http://www.ecns.cn/hd/2019/04/15/733763d067ab46e3aa6c03543795657c.jpg)
Undated file photo shows a fossil of branched alga from the Qingjiang biota. (Xinhua/Northwest University)
![Undated file photo shows a fossil of new species from the Qingjiang biota. (Xinhua/Northwest University)](http://www.ecns.cn/hd/2019/04/15/31242a1e362a47fcbc65015de791ab44.jpg)
Undated file photo shows a fossil of new species from the Qingjiang biota. (Xinhua/Northwest University)
![Undated file photo shows a fossil of jellyfish from the Qingjiang biota. (Xinhua/Northwest University)](http://www.ecns.cn/hd/2019/04/15/a0a7ea92866247c0b95928a392ae10db.jpg)
Undated file photo shows a fossil of jellyfish from the Qingjiang biota. (Xinhua/Northwest University)
![Undated file photo shows a fossil of Leanchoilia arthropod from the Qingjiang biota. (Xinhua/Northwest University)](http://www.ecns.cn/hd/2019/04/15/70ca037799c5456c8ac3ff6d531af7ba.jpg)
Undated file photo shows a fossil of Leanchoilia arthropod from the Qingjiang biota. (Xinhua/Northwest University)
![A student from the Department of Geology carries out research on a fossil from the Qingjiang biota in Northwest University in Xi\'an, capital of northwest China\'s Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)](http://www.ecns.cn/hd/2019/04/15/e04dbde1b6b5486e99c42dd2e0456c4b.jpg)
A student from the Department of Geology carries out research on a fossil from the Qingjiang biota in Northwest University in Xi'an, capital of northwest China's Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)
![Photo taken on April 8, 2019 shows numbered fossils from the Qingjiang biota in Northwest University in Xi\'an, capital of northwest China\'s Shaanxi Province. (Xinhua/Liu Xiao)](http://www.ecns.cn/hd/2019/04/15/0994bfc2a11f4ccf9e36787870681c93.jpg)
Photo taken on April 8, 2019 shows numbered fossils from the Qingjiang biota in Northwest University in Xi'an, capital of northwest China's Shaanxi Province. (Xinhua/Liu Xiao)
![A student from the Department of Geology observes a fossil from the Qingjiang biota through a microscope in Northwest University in Xi\'an, capital of northwest China\'s Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)](http://www.ecns.cn/hd/2019/04/15/8effc524d96849eea357200b7e95616e.jpg)
A student from the Department of Geology observes a fossil from the Qingjiang biota through a microscope in Northwest University in Xi'an, capital of northwest China's Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)
![A student from the Department of Geology arranges fossils from the Qingjiang biota in Northwest University in Xi\'an, capital of northwest China\'s Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)](http://www.ecns.cn/hd/2019/04/15/9c6543d3b89a4dc6b75f4d8864af8ca1.jpg)
A student from the Department of Geology arranges fossils from the Qingjiang biota in Northwest University in Xi'an, capital of northwest China's Shaanxi Province, April 8, 2019. (Xinhua/Liu Xiao)