|  Description:
The exact taxonomic status of this arthropod is in dispute. It has
been termed a “trilobitomorph” by some researchers,
showing their beliefs in its close affinity with the trilobites.
While the Trilobitoorpha was listed in the Treatise, most now consider
that this subphylum is invalid, a catchall much like some of the
dustbin terms used by Walcott for a number of the Burgess Shale
fauna. Whittington termed Naraioa a “soft-bodied trilobite”’
but that belief is not supported at present. Their similarity in
appearance to the Agnoistida is purely a result of convergence.
Two large groupings of the Paleozoic arthropods are currently in
favor: the Crustaceomorpha (which includes Waptia) and the Arachnomorpha,
dominated by the trilobites. The Naraoiidae are arachnomorphs and
include Misszhouia and Naraoia. The species is one found in several
locations within Yunnan Province.  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.
Even
if it is not a true trilobite, it is sure to be a coveted addition
to any collection, one found only as a member of the Chengjiang
Biota. This one has some of the cephalic region obscured, so is
being offered at a very reasonable price.
Also
see: Chengjiang
Biota Fauna List Chengjiang
Fossils |
