Canadaspis
4325458
222114935
2008-06-27T17:03:33Z
Rudolf Pohl
5573831
The Chengjiang fauna is older - see article "Maotianshan Shale"
{{Taxobox | status=Fossil
| name = ''Canadaspis''
| fossil_range = [[Cambrian]]
| image = Canadaspis_perfecta.JPG
| image_caption = ''Canadaspis perfecta'' & ''[[Waptia]] fieldensis''
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| subphylum = [[Crustacea]]
| classis = ?[[Malacostraca]]
| ordo = [[Canadaspidida]]
| familia = [[Canadaspididae]]
| genus = '''''Canadaspis'''''
| genus_authority = [[Derek Briggs|Briggs]], 1978
| subdivision_ranks = Species
| subdivision =
* ''C. perfecta''
* ''C. laevigata''
| type_species = ''C. perfecta''
}}
'''''Canadaspis''''' ("Shield of Canada") was a [[Cambrian]] [[genus]] of [[crustacean]] or [[euarthropod]], a benthic feeder that moved mainly by walking and possibly used its [[biramous]] [[appendage]]s to stir mud in search of food. The genus is placed within subclass [[Phyllocarida]] in class [[Malacostraca]] that includes shrimps and lobsters.
Once the food was obtained, ''Canadaspis'' used its [[Mandible (arthropod)|mandibles]] to grind larger particles. It is possible that its gill flaps were used for locomotion. ''Canadapsis perfecta'', the type species, comes from the Cambrian-age [[Burgess Shale]] in [[British Columbia]], [[Canada]]. ''Canadaspis'' are also found in different formations of the [[House Range]] of western [[Utah]] as well as the [[Pioche Shale]] of [[Nevada]]. ''Canadaspis laevigata'', coming from the [[Chengjiang biota]] and thus some 10 million years older than ''Canadapsis perfecta'', is an equivocal member of the genus. Some scientists believe ''Canadaspis laevigata'' to be a more primitive [[Crustaceomorpha]] antecedent of ''Canadaspis'', and others consider it a bi-valved [[arthropod]] of uncertain affinity.
The [[phylogeny]] of ''Canadaspis'', like many Cambrian [[arthropods]] is in a state of flux.
==References==
*{{cite web |url=http://www.nmnh.si.edu/paleo/shale/pcanadap.htm |publisher=[[National Museum of Natural History]] |accessdate=11 May |accessyear= 2006 |title=''Canadapsis perfecta'' (a crustacean)}}
*{{cite journal |quotes=no |author=[[Derek Briggs|Briggs, D.]] |year=1978 |title=The morphology, mode of life, and affinities of ''Canadaspis perfecta'' (Crustacea: Phyllocarida), Middle Cambrian, Burgess Shale, British Columbia |journal=[[Philosophical Transactions of the Royal Society|Phil. Trans. R. Soc. Lond. B]] |volume=281 |issue=984 |pages=439–487 |doi=10.1098/rstb.1978.0005}}
*{{cite web |url=http://www.fossilmuseum.net/ |publisher=The Virtual Fossil Museum |title=''Canadaspis'' from Chengjiang and Utah |accessdate=28 September |accessyear=2006}}
*{{cite journal |quotes=no |url=http://jpaleontol.geoscienceworld.org/cgi/content/abstract/77/4/674 |author=Lieberman, A. |year=2003 |title=New Soft-Bodied Fauana: The Pioche Formation of Nevada |journal=Journal of Paleontology |volume=77 |issue=4 |pages=674–690 |doi=10.1666/0022-3360(2003)077<0674:ANSFTP>2.0.CO;2 |doilabel=10.1666/0022-3360(2003)077<0674:ANSFTP>2.0.CO;2}}
[[Category:Prehistoric arthropods]]
[[Category:Burgess Shale fossils]]
[[Category:Maotianshan shales fossils]]
{{crustacean-stub}}
[[ca:Canadaspis]]
[[es:Canadaspis]]
[[ja:カナダスピス]]