Over 400-mln-yr-old fossil of fish found in China

CHONGQING, March 4 (Xinhua) -- A fossil of an ancient fish species living about 436 million years ago has been uncovered in Xiushan Tujia and Miao Autonomous County, southwest China's Chongqing Municipality.

The ancient fish named "Binhai Yongdong fish," or Yongdongaspis littoralis, is a type of Galeaspida. Only 4 to 5 cm long, the fish was endemic to East Asia and mainly lived in shallow sea and coastal environments, said the municipal planning and natural resources bureau on Friday.

The uncovered fossil shows a layer of hard bone on the fish's head, making the ancient fish look like it is wearing a semicircular helmet. A paper on the relevant study has been published online in the journal Acta Geologica Sinica (English Edition).

The discovery of the new ancient species can help exhibit some transitional states during the evolution of Galeaspida, said Chen Yang, first author of the paper and senior engineer of the Chongqing Institute of Geology and Mineral Resources.

The Silurian period in which the fish existed was a critical period of the earth's evolution. During the period, the planet underwent violent geological tectonic movements which formed marine red beds. Due to the lack of sufficient fossils found, the exact geological age of the red beds remains an unsolved mystery.

The fossil found in Chongqing is expected to provide new evidence of the subdivision and correlation of the Upper Red Beds in southern China, according to Zhu Min, professor of the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences.