Chengjiang Biota

Early Paleozoic 542 - 416 million years ago

Chengjiang Biota

Testimony to the "Cambrian Explosion of Life"

The Chengjiang biota from eastern Yunnan in China are one of the most significant Lower Cambrian fossil assemblages in the world. The sediments containing the Chengjiang fossils were deposited in a shallow marine setting on the Yangtze Platform, which, during this period, was situated near the equator.

This diverse range of organisms provides clues to rapid evolution during the Cambrian Explosion and reveals information on modes of life in a complex ancient ecological system. Diversification meant that animals were already developing new ecological niches and strategies such as active swimming and hunting, pelagic as well as benthic lifestyles, and crawling on the seabed or burrowing deeply into sediments.

A window into diverse ancient life

The Cambrian Chengjiang Biota of east Yunnan is one of the most exciting 20th Century discoveries in paleontology. The rare, exceptionally well-preserved soft-part anatomy of a wide variety of species found within the same locality offers unparalleled insight into biodiversity and the true nature of a sophisticated ecosystem during a crucial period in the early history of life.

Algae

Photosynthesized in water and were probably the major food source for primary consumers.

Algae
Lower Cambrian
Chengjiang, Yunnan, China
Size: 10x7cm

Anomalocaris

Isolated grasping appendage of the largest high-end consumer in the Chengjiang ecosystem, the fearsome looking largest predator in the Cambrian Seas

Anomalocaris
Lower Cambrian
Chengjiang, Yunnan, China
Size: 15 cm

Eldonia (stellostomites) eumorpha

Flat impression of Eldonia (stellostomites) eumorpha, probably a pelagic animal.
The jellyfish-like shape suggests a pelagic lifestyle

Eldonia
Lower Cambrian
Chengjiang, Yunnan, China
Size: 9 x 8 cm

Brachiopoda

Primary consumer and filter feeder from suspended organic matter in the water.

Heliomedusa orienta
Lower Cambrian
Chengjiang, Yunnan, China
Size: 1.5cm

Priapulida

Deposit-feeding worms that were buried live in marine mud.

Maotianshania cylindrica
(Sun & Hou, 1987)
Priapulida
Infaunal deposit-feeding worm with a long, straight intestine preserved as a dark film
Lower Cambrian
Chengjiang, Yunnan, China
Size: 10x7cm

Circocosmia jinningensis
(Hou & Sun, 1988)
Priapulida
Lower Cambrian
Chengjiang, Yunnan, China
Size: 4.5x3.5cm

Isoxys

An active swimmer high in the water column

Isoxys
Arthropoda
Lower Cambrian
Chengjiang, Yunnan, China
Sample Size: 5 cm

Microdyctyon

Remains of an "Armoured worm" coated with pairs of dot-like scleritic scales

Microdictyon sinicum (Chen, Hou & Lu, 1989)
Lobopodia
Lower Cambrian
Chengjiang, Yunnan, China
Sample Size: 6cm

Arthropods

Arthropods were the most diverse group of animals comprising over 60% of all discovered specimens. They are characterized by their multiple body segments, jointed feet and exoskeleton.

Kunmingella

A small bivalved bradorii arthropod in its typical “butterfly” orientation, a food source for larger predators

Kunmingella
Lower Cambrian
Chengjiang, Yunnan, China
Sample Size: 7.5x6 cm