Some specimens of Acosmia maotiania have been found like this one
tightly curved, suggesting it may have lived in a U shaped burrow.
This is a monospecfic genus, only known from the Chengjiang Biota.
This Cambrian priapulid worm preserved here in exquisite detail
is a unique specimen of life from 525 million years ago.
in 1984, the Chengjiang Biota now ranks as the most diverse faunal
fossil assemblage of all the Burgess
deposits. It is also some 10 million years older than the Burgess
Shale. Like the Burgess Shale, non-mineralized soft tissue parts
are often extraordinarily well preserved with high resolution as
aluminosilicate films, sometimes with oxidized iron content. Various
taphonomic processes leading extensive preservation of soft tissue
have been proposed, including rapid death by asphyxia followed
by rapid burial in anoxic sediment undisturbed by turbidity. The
Chengjiang biota is dominated by phyla Arthropoda and Porifera.
There are seven lobopodians, more than any other Lagerstätte
that some scientists elevate to phylum rank, and seven members
of the extinct phylum Vetulicolia. Members or potential members
of phyla Priapulida, Nematomorpha, Hyolitha, Hemichordata, Echinodermata,
Ctenophora, Chordata, Cnidaria, Chaetognatha, and Brachiopoda are
found. A large number of enigmatic animals of uncertain affinity
are found as well, some of which may represent failed evolutionary
experiments, or even new phyla that did not persist for long in
the early Cambrian, or were rapidly replaced by more derived forms.
Among the diverse Maotianshan Shales fauna, of utmost important
are the putative early chordates, particularly Haikouella, potentially
an ancestor to or the earliest craniate chordate. Myllokunmingia
and Haikouichthys are interpreted as early Craniata, and possibly
very primitive agnathids, the progenitor of the fishes and all
see: Chengjiang Biota Chengjiang