NANJING, March 10 (Xinhua) -- Chinese scientists have discovered a 600 million-year-old sponge-like fossil, predating existing findings of primitive animals by 60 million years.

The Nanjing Institute of Geology and Paleontology at the Chinese Academy of Sciences on Monday said that the tiny fossil, which only measures two to three cubic millimeters, was discovered in the Weng'an biota in the southwest province of Guizhou.

Yin Zongjun, from the institute, said that the fossil featured multiple characteristics of modern sponges, including three tubular chambers and a highly porous surface, which would have allowed water to flow in and out of the animal.

The discovery indicates that primitive sponge- and Eumetazoa-like animals lived before the Cambrian period, which is between 541 million and 485 million years ago, much earlier than previously assumed.

"Previous discoveries of Precambrian sponges have not approved as they lacked the distinguishing cell structure and pore system," Yin said.

This significant discovery will inform evolution research, he added.

The discovery was published on Tuesday in the Proceedings of the National Academy of the Sciences of the United States of America (PNAS).

Weng'an biota is a phosphorus-rich geological formation known for its well preserved fossils.