Nov 4, 2022
Updated: Nov 21, 2022
Fossil Coast’s Geo Travel blog series explores the Chengjiang fossil site of Yunnan Province in China (24° 40' 08'' N 102° 58' 38'' E) dating back approximately 518 million years ago. This location is among the “First 100 Geological Heritage Sites” designated by the International Union of Geological Sciences (IUGS) in 2022.
Are you looking for some travel inspiration or a reason for your next adventure? Do you consider yourself a traveller who likes to go a bit further afield? maybe off the beaten track? or are you someone who enjoys visiting places for their geological and fossil heritage?
So, sit back with a glass of Fossil Coast Lime Stone London Dry Gin and enjoy this excursion to China.
Before the 1984 discovery by Hou Xianguang, a researcher from Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences of a Naraoia spinosa - a small marine arthropod from what is now known as the Chenjiang Fossil Site.
This location is now the oldest soft-bodied fauna and the earliest record of a complex marine ecosystem superseding the exposures of the Burgess Shale of Yoho National Park high up the Canadian Rocky Mountains of British Columbia.
Yunnan Province (云南, Yúnnán) is known for its landscapes, culture, historical sites, and iconic temples. This province enjoys a mild climate and can be visited all year round. So much so that the capital city of Kunming is known as the "City of Eternal Spring" (春城, Chūnchéng).
Modern-day Yunnan Province was once a state established by the ancient non-Han Dian people. The province has had many names over the centuries including Nanzhao, Dali, and Yunnan Xingzhong Administration during the Tang, Song, and Yuan Dynasties. Yunnan Province was formally proclaimed during the Qing Dynasty and remains unchanged to this day.
This part of China is reachable by train and plane via the Kunming Changshui International Airport (KMG) reportedly the sixth busiest airport in China. The Chenjiang fossil site and museum is approximately an hour south of Kunming.
Among the many other attractions near the city of Kunming is the city of Shilin (E103°16'47' N24°45'20'') inhabited by the Sani People of Yi.
Shilin or Stone Forest has since 2007 been a UNESCO Global Geopark covering an area of approximately 350 km2 of karst geology reflecting the regional geological evolution since the late Paleozoic spanning the Early Devonian to Middle Permian Period.
The geological landscape of Shilin’s shallow water Devonian, Carboniferous, Permian carbonate, and dolomite rock presents one of the most diverse forms of karst scenery anywhere in the world with tall pillar-like limestone, sword-shaped limestone, mushroom-shaped limestone, and tower-like limestone pillars rising up to 20-50 meters in height and resembling a ‘stone forest’.
The Chengjiang fossils are located on the Maotian Mountain to the southeast of Chengjiang County in Yuxi situated near Lake Dianchi and Lake Fuxian, the largest lakes in Yunnan. The Chengjiang fossil fauna is found within the Maotianshan Shales and is an exceptionally well-preserved Lagerstätte.
A Lagerstätte is a German term describing a sedimentary deposit that exhibits extraordinary and exceptional preservation of especially soft-bodied fossils.
In this case, the soft body fossils are held within a 50-meter layer of mudstone sediment mudstone, not the siltstone interbeds, dated 525 million years ago.
This layer lies just above the Precambrian-Cambrian boundary that dates at 544 million years ago. Known as the lower part of the Lower Cambrian Eoredlichia-Wutingaspis Biozone of the Lower Cambrian Heilinpu (formerly Qiongzhusi) Formation. This is the youngest biozone defined by the first appearance of the trilobite genus Wutingaspis and by the last appearance of the trilobite genus Eoredlichi.
The soft-bodied and early sclerotized or hardened fossils found in the finely laminated mudstone are believed to have been deposited quickly under low oxygen or no oxygen conditions.
The rapid burial may have prevented the destruction of the organisms body forms by bioturbation, scavengers, carnivores, and water current activity and also has protected them against bacterial decay.
The extraordinary level of detailed preservation of the Chengjiang fossils includes complete carapaces, arthropod limbs showing setae or hairs and bristles; and the soft tissues of valves such as the pedicle of the brachiopod known as a lingulid. Another example of this fine-scale detailed preservation is that of the alimentary systems of animals such as Naraoia, and the delicate gills of the enigmatic Yunnanozoon.
The 520-million-year-old Chengjiang fossil record is over 300 species representing more than 20 phyla and several enigmas plus the oldest known fossil chordates to which all vertebrates belong.
Among this fossil record are also algae, sponges, ctenophorans ("comb jellyfish"), cnidarians ("coral animals, true jellyfish, sea anemones, sea pens"), nematomorphs ("Horsehair worms"), priapulids ("unsegmented worms"), anomalocaridids, brachiopods, hyoliths ("invertebrates with conical calcareous shells"), lobopods ("panarthropods with stubby legs"), bradoriid arthropods ("bivalved marine arthropod) and a broad variety of non-trilobite and non-bradoriid arthropods, discoidal fossils (echinoderms) and some problematical taxa.
Chengjiang Fossils - © Chengjiang Fossil National Geopark Management Committee
The Chengjiang fossil community shares several similarities with the Burgess Shale community by having species of Choia, Leptomitus, Naraoia, Leanchoilia, Canadaspis, Hallucigenia, Anomalocaris, Eldonia, and Dinomischus, but there are some notable differences in their species and in the composition of species within each ecosystem.
Unlike the Burgess Shale where trilobites made up 40% of the arthropod species, the Chengjiang fossil record has a single dominant species of up to 80% of small bivalved bradoriid arthropod called Kunmingella douvillei.
The differences between these two ecosystems and communities of organisms are believed to point to the Chengjiang fossil record having the earliest evidence of rapid diversification during the "Cambrian Explosion" of a shallow marine community of hard and soft tissues of invertebrate and vertebrate organisms. Whereas the Burgess Shale community is thought to be a more advanced community.
More recently a new Lagerstätte from the Cambrian Stage 3 Yuxiansi and Jiulaodong Formations in Sichuan Province, South West China has shown closer similarities with the fossil record of Chengjiang than the Burgess Shale. Known as the Fandian biota this includes euarthropods (radiodonts, bivalved forms, acercostracans, trolobites, non-biomineralized trilobitomorphs), armoured lobopodians, palaeoscolecids, pedunculate brachiopods, hyoliths, chancelloriids, sponges, and filamentous algae. Benthic dwellers dominate the fossil community (e.g. trilobitomorphs, brachiopods, sponges), with rare instances of nektonic (radiodonts, bivalved euarthropods) and infaunal (palaeoscolecids) organisms. It would appear that the northern Yangtze Platform during the Cambrian Period had a substantially greater distribution of life than just Yunnan Province.
If you’re planning to travel to China, find out what you need to know about the current entry restrictions and requirements. These may change with little warning. Monitor this advice for the latest updates and stay in contact with your travel provider. The Chinese authorities continue to impose various control and quarantine measures across the country. This includes restrictions on movement, reduced transport, entry and exit controls for cities, towns, and villages, and isolation requirements for travel between different parts of the country. Lockdowns can be implemented with little warning.