Cambrian (~525 million years ago)
mm long on a 30 mm by 26 mm matrix pair
Site: Chengjiang Maotianshan Shale,
Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation, Jiansghan,
Anning, Kunming Yunnan Province, China
This unusual arthropod is known as Leanchoilia. The taxon is known
from a number of locations 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.
specimen is a member of the “great appendage arthropods”
known as the opabinids after Opabinia from the Burgess Shale Fauna.
Other members from Chengjiang are Jianfengia and Alalcomenaeus (see
my other offerings for examples). The exceptional detail of the
appendages are readily apparent in this fine specimen, and are indicative
of the fact that this was a strong swimmer. This is an exceptional
juvenile specimen, preserved here as a part/counterpart pair.