Description:
This unusual arthropod is known as Leanchoilia. The taxon is known
from a number of locations within the Chengjiang region. 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
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 a truly exceptional
specimen, showing a portion of the flagellate antennae believed
to have performed a sensory function (seen here tucked under the
body pointed anteriorly), and as such is quite uncommon. I have
included a reconstruction of the taxon showing what they looked
like in life.
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