PALEONTOLOGY ARTICLE
Orthrozanclus: the armored Cambrian slug
compiled by MIKE BALDWIN
03.10.2007 -- Paleontologists have identified a
500-million-year-old slug-like creature species from 11
complete fossils found in the Burgess Shale fossil beds of
British Columbia. Cambrian period (543 to 490 million years
ago) fossils are prolific in this mountainous region, but
complete fossils of this prickly-armor coated marine
invertebrate have not been found until now. For decades
paleontologists have been wondering to what creature the tiny
little spines and shell-like parts belonged.
This new animal, named Orthrozanclus reburrus, is about half
the size of a potato bug, with a hard front shell, long spines
covering its entire body, and shorter spines along the edges.
Some of the spines are went, but not broken. Lacking eyes and
limbs, this creature most-likely lived at the bottom of the
sea, and scooted along the ocean floor searching for
bacteria-sized food.
The Orthrozanclus shares features with two invertebrate groups
called the halkieriids and the wiwaxiids. The halkieriids and
wiwaxiids are members of a large group of animals called the
lophotrochozoa, which includes mollusks, worms, and
brachiopods. A span of about 30 million years during the
Cambrian period is manifested in the fossil record with the
sudden appearance of many groups of animals which gave rise to
many present day animals. Before the Cambrian period, the
fossil record shows no precursors of today's animal groups
other than microbes. Rather than being classified in the same
group as the mollusks, worms, and brachiopods, scientists are
now suggesting that the Orthrozanclus, the halkieriids and the
wiwaxiids should be in a unique group of their own.
Works Cited:
1. S Perkins. Ancient slowpoke. Science News This Week.
Science News. March 3, 2007. Vol. 171., No. 9. Science
Service. Washington DC. pg 134.
2. Jeanna Bryner. Ancient pricky bugs discovered. Live Science
Animal Domain.
http://www.livescience.com/animalworld/070301_hairy_bugs.html.
01 March 2007. Accessed 10 March 2007
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