Panlongia
tetranudosa
Phylum Arthropoda,
Family Helmetidae
Geological
Time: Early Cambrian (~525 million years ago)
Size: 9 mm
long
Fossil
Site: Chengjiang Maotianshan Shale, Guanshan Fauna, Lower most part
of Wulongqing Formation, Caijiachong Valley, Yieyatoung, Gangtoucun Village,
Xiamacun Town, Kunming City, Yunnan
This
unusual arthropod is known as Panlongia tetranudosa. The genus was
described in mid- 2006, and comes from what has been termed the
“Guanshan Fauna”,
found in the Wulongqing Formation. The Guanshan Fauna shares many
genera with the slightly older Chengjiang Biota, but differs at
the species level.
With
the discovery of the Chengjiang Biota in 1984 a window on the Cambrain
Explosion in China was opened. 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 areknown as well, some
of which may have represented failed attempts at diversity that
did not persist to the present day.
The
taxon some resemblance to the younger Burgess Shale genus Hemetia,
which has led some to place them in the Helmetidae along with several
other similar arthropods, such as Kuamaia and Rhombicalvaria. The
body shape suggests that these helmetids were benthic animals which
were possibly carnivorous. There are two species described to date:
Panlongia tertranodusa and Panlongia spinosa. The fauna has only
been studied for some 6 years, so more unusual taxa are almost certainly
awaiting discovery.
Also
see: Chengjiang Biota
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