The American science magazine Nature recently published an article written by Chinese scientist Chen Junyuan, "Phosphatized Polar Lobe-Forming Embryos from the Precambrian of Southwest China." In this article, the oldest animal fossil discovered in the world was dated back 50 million years earlier to 580 million years ago. The article helps explain the question which Darwin could not answer in his book The Theory of Evolution: how can some animals appear all of a sudden?

In Darwin's time, the oldest animal fossil discovered then belonged to the Cambrian period, and trilobite seemed to emerge on earth "overnight". No fossil was discovered that could show the evolution process of the animal, and scientists called it a "Cambrian outburst". Without fossils, human beings may have to attribute the emergence of animals to a "supernatural force".

In the 1980s, many mollusc animal fossils were excavated in Chengjiang, Yunnan province, from a stratum dating back to 530 million years from now. The discovery shifted the ancestors of modern animals, including the vertebrate, to an even earlier pre-Cambrian period. However, it still could explain why some animals emerged all of a sudden.

On February, 5, 1998, Chen Junyuan, research fellow from the Nanjing Institute of Geology and Paleontology, and his colleagues published their findings on the Science magazine, which said that some multicellular organic fossils dating back to 580 million years from now had been discovered in Weng'an, Guizhou province. The newly-discovered fossils representing animals that lived 40 million years earlier than the Cambrian period, 50 million years earlier than the animals discovered in Chengjiang County. The Weng'an animal fossils were regarded by evolution scientists as an important discovery in the 20th century. The Science magazine commented that the fossil discovery in China might present a clearer picture of the animal history at its "dawn" era.

In 2003, Chen and his colleagues went to Weng'an again to excavate fossils. They finally found ten well-preserved fossils of a symmetrical-shaped animal. Chen later named this animal "little Guizhou spring bug", to commemorate the time when living things began to emerge after the Earth experienced a long, dark, lifeless period. The "little spring bug" is the oldest animal fossils discovered so far.
 
Editor: Yan