Chinese scientists recently discovered a fossil of a primitive sponge animal believed to be 600 million years old, the oldest animal fossil in the world. The finding proves that sponges made their evolutionary debut 60 million years earlier than in the previously confirmed Cambrian Period (541-485.4 million years ago).
The discovery was published on Tuesday by Zhu Maoyan, a research fellow at the Nanjing Institute of Geology and Paleontology, a branch of the Chinese Academy of Sciences known as NIGPAS. The report says that the Weng'an Biota in southwest China's Guizhou Province was the location of the discovery, which would end the academic debate on whether there are in fact animal fossils in the Weng'an Biota.
The fossil's discovery is the fruit of years of effort -- researchers from NIGPAS have been going to the Weng'an Biota to collect samples since 2008. They found a rice-grain-sized fossil of an adult animal in phosphate ore and confirmed that it was 600 million years old, the first fossil of a so-called "adult animal" unearthed from the region. Zhu added that the fossil's age was determined by radiometric dating.
"The fossil measures 2.5 cubic millimeters, almost the size of a grain of rice, and it looks like a chalice," said Dr. Yin Zongjuin of the NIGPAS. "All signs confirmed that it is a fossil of a primitive sponge," he said, adding that the location of the discovery is noted in the fossil's name, "Guizhou Shibei ['first cup'] Sponge."
Read more »
