Category of Site: Natural site
Located in Chengjiang county in Yunnan province, Chengjiang’s fossils present the most complete record of an early Cambrian marine community. The exceptionally well-preserved specimens display the anatomy of hard and soft tissue in a wide variety of organisms, invertebrate and vertebrate. They record the early establishment of a complex marine ecosystem. The site documents at least 16 phyla and a variety of enigmatic groups, as well as about 196 species, presenting significant evidence of the diversification of life on Earth 530 million years ago when almost all of today’s major animal groups emerged. It opens a palaeo-biological window to scholarship.
The area was added to the World Natural Heritage List in 2012.
The property contains high quality fossils including soft and hard tissue of animals with hard skeletons, along with a wide array of organisms that were entirely soft-bodied, and, therefore, relatively unrepresented in the fossil record. Almost all the soft-bodied species are unknown elsewhere. The earliest known specimens of several phyla such as cnidarians, ctenophores, priapulids, and vertebrates occur here. Fine-scale detailed preservation includes features such as the alimentary systems of animals like the arthropod Naraoia and the delicate gills of the enigmatic Yunnan ozoon. The sediments of Chengjiang provide what are currently the oldest known fossil chordates, the phylum to which all vertebrates belong.
Together, the fossils and rocks of the Chengjiang Fossil Site, present a complete record of an early Cambrian marine community. It is one of the earliest records of a complex marine ecosystem with food chains topped by sophisticated predators. Moreover, it demonstrates that complex community structures had developed very early in the Cambrian diversification of animal life and provides evidence of a wide range of ecological niches. The area, therefore, provides a unique window of understanding into the structure of early Cambrian communities.
A museum has been built at Miaotanshan over the site of the first Chengjiang fauna fossil discovery.