Choia

Choia
Temporal range: Sirius Passet–Lower Ordovician[1]
Choia carteri
Scientific classification
Kingdom: Animalia
Subkingdom: Parazoa
Phylum: Porifera
Class: Demospongiae
Order: Monaxonida
Family: Choiidae
Genus: Choia
Species
  • Choia carteri Walcott 1920
  • Choia xiaolantianensis
  • Choia utahensis

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Choia is a fossil demosponge dating to the Cambrian and Lower Ordovician periods. It was unusual because it was not attached to the sea bed, and radiated spines from the edge of its flattish, conical body, producing an appearance not unlike that of the peak of a big top, with guy lines. Water entered the sponge parallel to the spines, being expelled, presumbaly, from a central opening.[2] It reached 28 mm in diameter.[2] 127 specimens of Choia are known from the Greater Phyllopod bed, where they comprise 0.2% of the community.[3]

Fossils of Choia have been found in the Burgess Shale in British Columbia; the Maotianshan shales of China; the Wheeler Shale in Utah; and the Lower Ordovician Fezouata formation.[4]

External links

References

  1. ^ Botting, J. (2007). "‘Cambrian’ demosponges in the Ordovician of Morocco: Insights into the early evolutionary history of sponges". Geobios 40 (6): 737–748. doi:10.1016/j.geobios.2007.02.006.  edit
  2. ^ Briggs, D.E.G.; Erwin, D.H.; Collier, F.J. (1995), Fossils of the Burgess Shale, Washington: Smithsonian Inst Press, ISBN 156098659x, OCLC 231793738 
  3. ^ Caron, J. -B.; Jackson, D. A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS 21 (5): 451–465. doi:10.2110/palo.2003.P05-070R.  edit
  4. ^ Van Roy, P.; Orr, P. J.; Botting, J. P.; Muir, L. A.; Vinther, J.; Lefebvre, B.; Hariri, K. E.; Briggs, D. E. G. (2010). "Ordovician faunas of Burgess Shale type". Nature 465 (7295): 215. Bibcode 2010Natur.465..215V. doi:10.1038/nature09038. PMID 20463737.  edit