Editing Placozoa (section)

==== Cnidaria-sister hypothesis ====
DNA comparisons suggest that placozoans are related to [[Cnidaria]], derived from [[planula]] larva (as seen in some Cnidaria).<ref name=Laumer2019>{{cite journal |last1=Laumer |first1=C.E. |last2=Fernández |first2=R. |last3=Lemer |first3=S. |last4=Combosch |first4=D. |last5=Kocot |first5=K.M. |last6=Riesgo |first6=A. |last7=Andrade |first7=S.C.S. |last8=Sterrer |first8=W. |last9=Sørensen |first9=M.V. |last10=Giribet |first10=G. |display-authors=6 |year=2019 |title=Revisiting metazoan phylogeny with genomic sampling of all phyla |journal=Proc. Biol. Sci. |volume=286 |issue=1906 |page=20190831 |doi=10.1098/rspb.2019.0831 |pmc=6650721 |pmid=31288696}}</ref> The [[Bilateria]] also are thought to be derived from planuloids.<ref name=Aleshin2002>{{cite journal |last1=Aleshin |first1=V.V. |last2=Petrov |first2=N.B. |year=2002 |title=Molecular evidence of regression in evolution of metazoa |journal=Zh. Obshch. Biol. |volume=63 |issue=3 |pages=195–208|pmid=12070939 }}</ref><ref>{{cite journal |last1=Laumer |first1=Christopher E. |last2=Gruber-Vodicka |first2=Harald |last3=Hadfield |first3=Michael G. |last4=Pearse |first4=Vicki B. |last5=Riesgo |first5=Ana |last6=Marioni |first6=John C. |last7=Giribet |first7=Gonzalo |date=2018-10-30 |df=dmy-all |title=Support for a clade of Placozoa and Cnidaria in genes with minimal compositional bias |journal=eLife |lang=en |volume=7 |doi=10.7554/elife.36278 |pmid=30373720 |pmc=6277202 |issn=2050-084X |doi-access=free }}</ref><ref>{{cite journal |last1=Syed |first1=Tareq |last2=Schierwater |first2=Bernd |date=June 2002 |title=The evolution of the placozoa: A new morphological model |journal=Senckenbergiana Lethaea |lang=en |volume=82 |issue=1 |pages=315–324 |doi=10.1007/bf03043791 |s2cid=16870420 |issn=0037-2110}}</ref><ref>{{cite journal |last1=Hejnol |first1=Andreas |last2=Martindale |first2=Mark Q. |date=2008-04-27 |df=dmy-all |title=Acoel development supports a simple planula-like urbilaterian |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |lang=en |volume=363 |issue=1496 |pages=1493–1501 |doi=10.1098/rstb.2007.2239 |issn=0962-8436 |pmc=2614228 |pmid=18192185}}</ref><ref>{{cite journal |last1=Alzugaray |first1=María Eugenia |last2=Bruno |first2=María Cecilia |last3=Villalobos Sambucaro |first3=María José |last4=Ronderos |first4=Jorge Rafael |year=2019 |title=The evolutionary history of the orexin / allatotropin GPCR family: From Placozoa and Cnidaria to Vertebrata |journal=Scientific Reports |volume=9 |issue=1 |page=10217 |biorxiv=10.1101/403709 |doi=10.1038/s41598-019-46712-9 |pmid=31308431 |pmc=6629687 |bibcode=2019NatSR...910217A |s2cid=256990037 }}</ref><ref>{{cite journal |last1=da&nbsp;Silva |first1=Fernanda Britto |last2=Muschner |first2=Valéria C. |last3=Bonatto |first3=Sandro L. |year=2007 |title=Phylogenetic position of Placozoa based on large subunit (LSU) and small subunit (SSU) rRNA genes |journal=Genetics and Molecular Biology |volume=30 |issue=1 |pages=127–132 |doi=10.1590/S1415-47572007000100022 |doi-access=free |issn=1415-4757 }}</ref><ref>{{cite journal |last1=Adl |first1=Sina M. |last2=Bass |first2=David |last3=Lane |first3=Christopher E. |last4=Lukeš |first4=Julius |last5=Schoch |first5=Conrad L. |last6=Smirnov |first6=Alexey |last7=Agatha |first7=Sabine |last8=Berney |first8=Cedric |last9=Brown |first9=Matthew W. |display-authors=6 |date=2018-09-26 |df=dmy-all |title=Revisions to the classification, nomenclature, and diversity of eukaryotes |journal=Journal of Eukaryotic Microbiology |volume=66 |issue=1 |pages=4–119 |lang=en |doi=10.1111/jeu.12691 |pmid=30257078 |pmc=6492006 |issn=1066-5234}}</ref><ref>{{cite book |last1=Giribet |first1=Gonzalo |last2=Edgecombe |first2=Gregory D. |date=2020-03-03 |df=dmy-all |title=The Invertebrate Tree of Life |publisher=Princeton University Press |isbn=978-0-691-19706-7 |lang=en |url=https://books.google.com/books?id=anetDwAAQBAJ&q=cnidaria+placozoa&pg=PP7 }}</ref> The Cnidaria and Placozoa body axis are overtly similar, and placozoan and cnidarian cells are responsive to the same [[neuropeptide]] [[Antibody|antibodies]] despite extant placozoans not developing any neurons.<ref>{{Cite journal |last1=duBuc |first1=Timothy Q. |last2=Ryan |first2=Joseph |last3=Martindale |first3=Mark Q. |date=2019-02-06 |df=dmy-all <!-- |editor-last=True |editor-first=John --> |title="Dorsal-ventral" genes are part of an ancient axial patterning system: Evidence from ''Trichoplax adhaerens'' (Placozoa) |journal=Molecular Biology and Evolution |volume=36 |issue=5 |pages=966–973 |lang=en |doi=10.1093/molbev/msz025 |pmid=30726986 |pmc=6501881 |issn=0737-4038}}</ref><ref>{{cite journal |last=Schuchert |first=Peter |date=1993-03-01 |df=dmy-all |title=''Trichoplax adhaerens'' (phylum Placozoa) has cells that react with antibodies against the neuropeptide RFamide |journal=Acta Zoologica |lang=en |volume=74 |issue=2 |pages=115–117 |doi=10.1111/j.1463-6395.1993.tb01227.x |issn=1463-6395 }}</ref>

{{clade
<!-- |style=font-size:80%; line-height:80% -->
 |label1= [[Choanozoa]] 
 |sublabel1=950 mya
 |1={{clade
    |1=[[Choanoflagellate|Choanoflagellata]] [[File:Desmarella moniliformis.jpg|60 px]]
    |label2= [[Animalia]] 
    |sublabel2=760 mya<br/> 
    |2={{clade
       |1=[[Porifera]] [[File:Reef3859 - Flickr - NOAA Photo Library.jpg|60 px]]
       |label2= [[Eumetazoa]] 
       |2={{clade
          |1=[[Ctenophora]] [[File:Comb jelly.jpg|60 px]]
          |label2= [[ParaHoxozoa]] 
          |sublabel2=680 mya
          |2={{clade
             |label1=  
             |1={{clade
                |label1=  
                |1=[[Placozoa]] [[File:Trichoplax adhaerens photograph.png|60 px]]
                |2=[[Cnidaria]] [[File:Cauliflour Jellyfish, Cephea cephea at Marsa Shouna, Red Sea, Egypt SCUBA.jpg|60 px]]
                }}
             |2=[[Bilateria]] / [[Triploblasts]] [[File:Sorocelis reticulosa.jpg|60 px]]
          }}
       }}
     }}
  }}
}}