[6] Although fossils from the region have been known from the early part of the 10th century, Chengjiang was first recognized for its exquisite states of preservation with the 1984 discovery of the naraoiid Misszhouia, a soft-bodied relative of trilobites.

The preservation of an extremely diverse faunal assemblage renders the Maotianshan shale the world's most important for understanding the evolution of early multi-cellular life, particularly the members of phylum Chordata, which includes all vertebrates.

[11] In respect of 'the Chengjiang fossils represent[ing] an uparalleled record of the fundamentally important rapid diversification of metazoan life in the early Cambrian', the International Union of Geological Sciences (IUGS) included the 'Cambrian Chengjiang fossil site and lagerstätte' in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022.

The Yuanshan Member is extensive, covering multiple 10,000 square kilometres (3,900 sq mi) of eastern Yunnan Province, where there are many scattered outcrops yielding fossils.

The preserved fauna is primarily benthic and was likely buried by periodic turbidity currents, since most fossils do not show evidence of post-mortem transport.

The soft parts are preserved as aluminosilicate films, often with high oxidized iron content and often exhibiting exquisite details.

Most of those are the trilobites (of which there are five species), all of which have been found with traces of legs, antennae, and other soft body parts, an exceedingly rare occurrence in the fossil record.

[15][16] About one in eight animals are problematic forms of uncertain affinity, some of which may have been evolutionary experiments that survived for only a brief period as benthic environments rapidly changed in the Cambrian.

Chengjiang is the richest source of the Lobopodia, a group including many early panarthropods,[17] with six genera represented: Luolishania, Paucipodia, Cardiodictyon, Hallucigenia (also known from the Burgess Shale), Microdictyon, and Onychodictyon.

[18] Specimens initially identified as Haikouella (a genus later deemed a junior synonym of Yunnanozoon)[19] display has several chordate features, including a discernible heart, dorsal and ventral aorta, gill filaments, and a notochord (neural chord).

Shu (2006) recently described Stromatoveris psygmoglena as a possible bilateran missing link between Ediacaran fronds and Cambrian ctenophores.

[26] The Chengjiang biota is believed to have inhabited a delta front environment rich in oxygen, with high sedimentation rates and major fluctuations in salinity being the main environmental stressors.

Other species belong to sponges, chancelloriids, cnidarians, ctenophores, priapulids, lobopodians, arthropods, anomalocaridids, hyoliths, molluscs, brachiopods, echinoderms, algae and vetulicolians.