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
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.
is one of the most striking, and quite rare; as of 2004, only
some 15 examples were known. The maximum length is 70 mm. It
possesses a sclerotized head shield with 10 paired sclerotic
plates, each 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. This one is very detailed,
with several of the legs preserved.
Biota List Chengjiang