Chengjiang trilobites

Trilobites of Chengjiang, China
Locality: Maotianshan and other localities near Chengjiang, eastern Yunnan Province, South China
Stratigraphy: Heilinpu (Qiongzhusi) Formation, Yu'anshan Member
Age: Early Cambrian. 525 mya

Maotian Hill (Maotianshan), near Chengjiang, Yunnan Province, China. Image courtesy this Chinese website.


Location of the Chengjiang lagerstatte today	Locality of Chengjiang during the Early Cambrian

The Chengjiang biota, first discovered by Hou Xianguang in 1984, is reknowned as a window on the diversity of the early Cambrian. As in the Burgess Shale lagerstatte, soft-bodied animals are preserved at Chengjiang, in fine mudstones, revealing a great diversity of early arthropods, as well as such curiosities as anomalocaridids and Hallucigenia. In fact, trilobites make up only about 0.5% of the Chengjiang fauna. There are four species recorded:


Eoredlichia intermedia (Lu 1940) REDLICHIIDA Redlichiidae	Kuanyangia pustulosa (Lu 1941) REDLICHIIDA Redlichiidae	Yunnanocephalus yunnanensis (Mansuy 1912) PTYCHOPARIIDA Yunnanocephalidae	Wutingaspis tingi (Kobayashi 1944) REDLICHIIDA Redlichiidae

Even the trilobite specimens from Chengjiang often have their soft parts preserved, such as antennae and limbs, as is apparent in the remarkable Yunnanocephalus specimen above. In addition to trilobites, there were many other species of arachnomorph (trilobite-like clade) arthropods such as Xandarella, Cinderella, Squamacula, Sinoburius, Kuamaia, Rhombicalvaria, Saperion, Retifacies, Naraoia, and Misszhouia. These trilobite-like arthropods demonstrate that the group from which trilobites arose was itself successful and diverse, though being uncalcified, are only preserved at exceptional lagerstatten such as Chengjiang.

Some Chengjiang literature:

Hou, Xian-Guang, R.J. Aldridge, J. Bergstrom, D.L. Siveter, D.J. Siveter, X.H. Feng. 2004. The Cambrian Fossils of Chengjiang China: The Flowering of Early Animal Life. 233 pp. Blackwell Publishing.

Chen, Junyuan and Guiqing Zhou. 1997. Biology of the Chengjiang fauna. in: The Cambrian Explosion and the Fossil Record. Bulletin of the National Museum of Natural Science 10:11-106.

Related localities: Burgess Shale