 Description:
The discovery of the Chengjiang Biota by Hou Xian-guang in 1984
resulted in a clear window on what is known as the Cambrian Explosion.
The diversity of soft-tissue fossils is astonishing: algae, medusiforms,
sponges, priapulids, annelid-like worms, echinoderms, arthropods
(including trilobites), hemichordates, chordates, and the first
agnathan fish make up just a  small
fraction of the total. Numerous problematic forms are known as well,
some of which may have represented failed attempts at diversity
that did not persist to the present day.
 The
Lobopodians are small marine and terrestrial animals termed colloquially
“velvet worms” or “worms with legs”. While
all Recent forms are terrestrial, most fossil Lobopodians are marine,
and are known primarily from the Cambrian. Six named genera, each
with a single species, are known from the Chengjiang Biota, making
it the richest source of fossils of the type on Earth. This is one
of the most striking, and quite rare; as of 2004, well less than
100 examples were known. A large specimen was thought to be 20 mm,
so this one is abnormally large. A complete example possesses 23
– 25 angular sclerotized paired sclerites, each pair of which
is associated with a pair of legs. Each leg bears curved claws which
are thought to have served the creature as an adaptation to crawling
on other organisms. It is most closely related to Aysheaia from
the younger Burgess Shale, and is unknown outside of Yunnan Province.
This
fine example has incredible detail, with the “myriapod”-
like legs in clear evidence.on the anterior portion which shows
the head. Note too the examples of the priapulid Selkirkia, and
a section of the putative nematomorph Paleoscolex. This is an exceptional
death assemblage that would serve as the cornerstone of any public
or private collection of fossils of the Cambrian Explosion.
|
