{{Short description|Extinct genus of aquatic animals}} {{Speciesbox | fossil_range = {{Geo range|Late Cambrian}} | image = Pywackia bailey pennetta.png | image_caption = Artist's restoration | genus = Pywackia | species = baileyi | authority = Landing in Landing et al., 2010 }}
'''''Pywackia''''' is a contentious Cambrian fossil that has been interpreted as the earliest (total group) bryozoan, and the only representative of that phylum in the Cambrian period.<ref>{{Cite journal| doi = 10.1130/G30870.1| title = Cambrian origin of all skeletalized metazoan phyla--Discovery of Earth's oldest bryozoans (Upper Cambrian, southern Mexico)| year = 2010| last1 = Landing | first1 = E.| last2 = English | first2 = A.| last3 = Keppie | first3 = J. D.| journal = Geology| volume = 38| issue = 6| page = 547| bibcode = 2010Geo....38..547L}}</ref> Its bryozoan credentials have been called into question,<ref>{{Cite journal | doi = 10.1666/13-029| title = Reinterpretation of the Cambrian 'Bryozoan' Pywackia as an Octocoral| journal = Journal of Paleontology| volume = 87| issue = 6| page = 984| year = 2013| last1 = Taylor | first1 = P. D. | last2 = Berning | first2 = B. R. | last3 = Wilson | first3 = M. A. | bibcode = 2013JPal...87..984T| s2cid = 129113026| url = https://zenodo.org/record/907861}}</ref> but the octocoral alternative is equally unconvincing, and there are reasons to suggest a position in the Stenolaemata stem lineage.<ref>{{cite journal|journal=Journal of Paleontology |volume=89|issue=2|pages=292–317|date=2015 |title=Distinguishing Earth's oldest known bryozoan (Pywackia, late Cambrian) from pennatulacean octocorals (Mesozoic—Recent) |author=Ed Landing |author2=Jonathan B. Antcliffe |author3=Martin D. Brasier |author4=Adam B. English |doi=10.1017/jpa.2014.26|bibcode=2015JPal...89..292L |s2cid=131609198 }}</ref> Finally, the skeletal microstructure is consistent with a cnidarian affinity, but insufficient to support a close affinity with any modern subgroup.<ref>{{cite journal | doi = 10.1017/jpa.2023.35| title = Late Cambrian Pywackia is a cnidarian, not a bryozoan: Insights from skeletal microstructure| year = 2023| last1 = Hageman| first1 = Steven J.| last2 = Vinn| first2 = Olev| journal = Journal of Paleontology| volume = 97| issue = 5| pages = 1–12| doi-access = free| bibcode = 2023JPal...97..990H}}</ref>
== References == {{Reflist}}
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Category:Fossils of Mexico Category:Enigmatic prehistoric animal genera Category:Cambrian invertebrates Category:Cambrian fossil record Category:Fossil taxa described in 2010 Category:Cambrian genus extinctions Category:Monotypic prehistoric animal genera