The Wiwaxia (
Wiwaxia corrugata) was one of the species produced in the
Cambrian explosion 530 million years ago. The first fossil of Wiwaxia was found in
1899 and it consisted of a single spine. Found in the Middle Cambrian bed on
Mount Stephen across from the massive Cambrian fossil beds of the
Burgess Shale. Named after "Wiwaxy" a local
indian word for "windy".
Wiwaxia fossils range in size from 1/8" to 2" in size, looking much like an armored slug, with double row of spines on top.
The fossils recovered have been detailed enough that diffraction gratings on the spines and armored plates of Wiwaxia were detectable, thus Wiwaxia is one of the few fossils for which we have some idea of their color, an iridescent blue, green and yellow.
Sources:
http://www.amonline.net.au/invertebrates/parker/paper1.htm#16
http://www.nmnh.si.edu/paleo/shale/pwiwax.htm