Choia

{{Short description|Genus of sponges}}

{{Automatic taxobox

| fossil_range = {{Geological range|Cambrian Stage 3|Arenig}}{{Cite journal| pages = 737–748| year = 2007| doi = 10.1016/j.geobios.2007.02.006| first1 = J.| volume = 40| title = 'Cambrian' demosponges in the Ordovician of Morocco: Insights into the early evolutionary history of sponges| journal = Geobios| last1 = Botting| issue = 6| bibcode = 2007Geobi..40..737B}}

| image = USNM PAL 66482 Choia carteri Image 05.jpg

| image_caption = Fossil of Choia carteri from the Burgess Shale

| taxon = Choia

| authority = Walcott, 1920

| type_species = †Choia carteri

| type_species_authority = Walcott, 1920

| subdivision_ranks = Species

| subdivision =

  • C. carteri Walcott, 1920
  • C. hindei (Dawson, 1896)
  • C. utahensis Walcott, 1920
  • C. ridleyi Walcott, 1920
  • ?C. striata Xiao et al., 2005
  • C. xiaolantianensis Hou et al. 1999

}}

Choia is a genus of extinct demosponge ranging from the Cambrian until the Lower Ordovician periods. Fossils of Choia have been found in the Burgess Shale in British Columbia; the Maotianshan shales of China; the Wheeler Shale in Utah; the Itajaí Basin in Brazil; and the Lower Ordovician Fezouata formation.{{Cite journal| doi = 10.1038/nature09038| title = Ordovician faunas of Burgess Shale type| year = 2010| last1 = Van Roy | first1 = P.| last2 = Orr | first2 = P. J.| last3 = Botting | first3 = J. P.| last4 = Muir | first4 = L. A.| last5 = Vinther | first5 = J.| last6 = Lefebvre | first6 = B.| last7 = Hariri | first7 = K. E.| last8 = Briggs | first8 = D. E. G.| journal = Nature| volume = 465| pages = 215–8| pmid = 20463737| issue = 7295|bibcode = 2010Natur.465..215V | s2cid = 4313285}}{{Cite web |last=Zucatti |first=Ana |date=2005 |title=EVIDÊNCIAS DE VIDA NO EDIACARANO INFERIOR DA BACIA DO ITAJAÍ, SC |url=https://www.researchgate.net/publication/280078417_EVIDENCIAS_DE_VIDA_NO_EDIACARANO_INFERIOR_DA_BACIA_DO_ITAJAI_SC |access-date= |website=ResearchGate}} It was first described in 1920 by Charles Doolittle Walcott.{{cite journal | last1 = Walcott | first1 = C. D. | year = 1920 | title = Cambrian geology and paleontology IV:6—Middle Cambrian Spongiae | url = https://biodiversitylibrary.org/page/29838882 | journal = Smithsonian Miscellaneous Collections | volume = 67 | pages = 261–364 }}

Life habit

File:Choia carteri reconstruction.JPG specimens]]

Choia was originally thought to be not attached to the sea bed: the living animal was originally thought to rest directly on the substrate, with the radiating spines from the edge of its flattish, conical body, giving an appearance not unlike that of the peak of a big top, with guy lines. Recently discovered fossils from Lower Ordovician Morocco show that the living animal was actually suspended high above the seafloor, attached via stalk-like spines derived from spicules.{{cite book|last=Van Roy|first=Peter|title=Non-trilobite arthropods from the Ordovician of Morocco|year=2006|publisher=Ghent University|location=Ghent|pages=38–39}} Water is assumed to have entered the sponge parallel to the spines, being expelled, presumably, from a central opening.{{fotbs}} Species reached up to an average of 28 mm in diameter.{{fotbs}}

Distribution

127 specimens of Choia are known from the Greater Phyllopod bed, where they comprise 0.2% of the community.{{cite journal|last1=Caron |first1=Jean-Bernard|last2=Jackson |first2=Donald A.|title=Taphonomy of the Greater Phyllopod Bed community, Burgess Shale|journal=PALAIOS |volume=21 |issue=5 |pages=451–65|date=October 2006|doi=10.2110/palo.2003.P05-070R|jstor=20173022|bibcode=2006Palai..21..451C |s2cid=53646959 }}

USNM PAL 66487 Choia ridleyi Image 04.jpg|Fossils of C. ridleyi from the Burgess Shale

Choia xiaolantianensis, Chengjiang biota.jpg|Fossil of C. xiaolantianensis from the Maotianshan Shales

Choia sp. YPM IP 226567 2.jpg|Fossil of C. sp from the Fezouata biota

Choia utahensis KUMIP 563095.jpg|Fossil of C. utahensis from the Wheeler Shale

References

{{Reflist}}