Editing Synapsida (section)

==Relationships==
Below is a [[cladogram]] of the most commonly accepted [[phylogeny]] of synapsids, showing a long stem lineage including Mammalia and successively more basal clades such as Theriodontia, Therapsida and Sphenacodontia:<ref name=TOL>{{cite web |url=http://tolweb.org/Synapsida/14845 |title=Synapsida. Mammals and their extinct relatives |last=Laurin |first=M. |author2=Reisz, R.R. |year=2011 |work=The Tree of Life Web Project |access-date=26 April 2012}}</ref><ref name=KTS11>{{cite book |last=Kemp |first=T.S. |year=2011 |chapter=The origin and radiation of therapsids |title=Forerunners of Mammals |editor=Chinsamy-Turan, A. |publisher=Indiana University Press |location=Bloomington |isbn=978-0-253-35697-0 |pages=3–30 |chapter-url=https://books.google.com/books?id=cp26-CA2CDUC&q=forerunners%20of%20the%20mammals&pg=PA3}}</ref>
{{clade| style=font-size:100%;line-height:100%
|label1='''Synapsida'''
|1={{clade
   |1=†[[Caseasauria]] [[File:Ennatosaurus BW.jpg|50px]]
   |label2=[[Eupelycosauria]]
   |2={{clade
    |1=†[[Varanopidae]] [[File:Varanops brevirostris.jpg|50px]]
     |2={{clade
      |1=†[[Ophiacodontidae]] [[File:Archaeothyris BW.jpg|50px]]
      |2={{clade
      |1=†[[Edaphosauridae]] [[File:Ianthasaurus BW.jpg|50px]]
           |label2=[[Sphenacodontia]]
            |2={{clade
             |1=†[[Sphenacodontidae]] [[File:Palaeohatteria DB.jpg|50px]]
               |label2=[[Therapsida]]
               |2={{clade
                  |1=†[[Biarmosuchia]] [[File:Biarmosuchus.jpg|50px]]
                  |label2=[[Eutherapsida]]
                  |2={{clade
                     |1=†[[Dinocephalia]] [[File:Struthiocephalus DB.jpg|50px]]
                     |label2=[[Neotherapsida]]
                     |2={{clade
                        |1=†[[Anomodontia]] [[File:Eodicynodon BW.jpg|50px]]
                        |label2=[[Theriodontia]]
                        |2={{clade
                          |1=†[[Gorgonopsia]] [[File:Gorgonops whaitsii1.jpg|50px]]
                           |label2=[[Eutheriodontia]]
                           |2={{clade
                             |1=†[[Therocephalia]] [[File:Moschorhinus DB.jpg|50px]]
                              |label2=[[Cynodontia]]
                              |2={{clade
                              |1=† [[Cynognathia]] [[File:Cynognathus BW.jpg|50px]]
                               |label2=[[Probainognathia]]
                              |2={{clade
                                    |1='''[[Mammalia]]'''[[File:Ruskea rotta.png|50 px]]
}} }} }} }} }} }} }} }} }} }} }} }} }}

Most uncertainty in the phylogeny of synapsids lies among the earliest members of the group, including forms traditionally placed within Pelycosauria. As one of the earliest phylogenetic analyses, Brinkman & Eberth (1983) placed the family [[Varanopidae]] with [[Caseasauria]] as the most basal offshoot of the synapsid lineage. Reisz (1986) removed Varanopidae from Caseasauria, placing it in a more derived position on the stem. While most analyses find Caseasauria to be the most basal synapsid clade, Benson's analysis (2012) placed a clade containing [[Ophiacodontidae]] and Varanopidae as the most basal synapsids, with Caseasauria occupying a more derived position. Benson attributed this revised phylogeny to the inclusion of postcranial characteristics, or features of the skeleton other than the skull, in his analysis. When only cranial or skull features were included, Caseasauria remained the most basal synapsid clade. Below is a [[cladogram]] modified from Benson's analysis (2012):<ref name=BRJ12>{{cite journal |last=Benson |first=R.J. |year=2012 |title=Interrelationships of basal synapsids: cranial and postcranial morphological partitions suggest different topologies |journal=[[Journal of Systematic Palaeontology]] |volume= 10|doi=10.1080/14772019.2011.631042 |issue=4 |pages=601–624|bibcode=2012JSPal..10..601B |s2cid=84706899 }}</ref>

{{clade| style=font-size:100%;line-height:100%
|1={{clade
   |1=''[[Tseajaia campi]]''
   |2=''[[Limnoscelis paludis]]''
   |label3=[[Amniota]]
   |3={{clade
      |1={{clade
         |1=''[[Captorhinus]]'' spp.
         |2=''[[Protorothyris archeri]]''}}
      |label2='''Synapsida'''
      |2={{clade
         |1={{clade
            |label1=[[Ophiacodontidae]]
            |1={{clade
               |1=''[[Archaeothyris florensis]]''
               |2={{clade
                  |1=''[[Varanosaurus acutirostris]]''
                  |2={{clade
                     |1=''[[Ophiacodon]]'' spp.
                     |2=''[[Stereophallodon ciscoensis]]''}} }} }}
            |label2=[[Varanopidae]]
            |2={{clade
               |1=''[[Archaeovenator hamiltonensis]]''
               |2={{clade
                  |1=''[[Pyozia mesenensis]]''
                  |2={{clade
                     |1={{clade
                        |1=''[[Mycterosaurus longiceps]]''
                        |2={{clade
                           |1=?''[[Elliotsmithia longiceps]]'' (BP/1/5678)
                           |2=''[[Heleosaurus scholtzi]]''
                           |3=''[[Mesenosaurus romeri]]''}} }}
                     |2={{clade
                        |1={{clade
                           |1=''[[Varanops brevirostris]]''
                           |2={{clade
                              |1=''[[Watongia meieri]]''
                              |2=''[[Varanodon agilis]]''}} }}
                        |2={{clade
                           |1=''[[Ruthiromia elcobriensis]]''
                           |2={{clade
                              |1=''[[Aerosaurus wellesi]]''
                              |2=''[[Aerosaurus greenleorum]]''}} }} }} }} }} }} }}
         |2={{clade
            |label1=[[Caseasauria]]
            |1={{clade
               |label1=[[Eothyrididae]]
               |1={{clade
                  |1=''[[Eothyris parkeyi]]''
                  |2=''[[Oedaleops campi]]''}}
               |label2=[[Caseidae]]
               |2={{clade
                  |1=''[[Oromycter dolesorum]]''
                  |2={{clade
                     |1=''[[Casea broilii]]''
                     |2={{clade
                        |1=''[[Trichasaurus texensis]]''
                        |2={{clade
                           |1=''[[Euromycter rutenus]]'' (=''"Casea" rutena'')
                           |2={{clade
                              |1=''[[Ennatosaurus tecton]]''
                              |2={{clade
                                 |1=''[[Angelosaurus romeri]]''
                                 |2={{clade
                                    |1=''[[Cotylorhynchus romeri]]''
                                    |2={{clade
                                       |1=''[[Cotylorhynchus bransoni]]''
                                       |2=''[[Cotylorhynchus hancocki]]''}} }} }} }} }} }} }} }} }}
            |2={{clade
               |1=''[[Ianthodon schultzei]]''
               |2={{clade
                  |label1=[[Edaphosauridae]]
                  |1={{clade
                     |1=''[[Ianthasaurus hardestiorum]]''
                     |2={{clade
                        |1=''[[Glaucosaurus megalops]]''
                        |2=''[[Lupeosaurus kayi]]''
                        |3={{clade
                           |1=''[[Edaphosaurus boanerges]]''
                           |2=''[[Edaphosaurus novomexicanus]]''}} }} }}
                  |label2=[[Sphenacodontia]]
                  |2={{clade
                     |1=''[[Haptodus garnettensis]]''
                     |2={{clade
                        |1=''[[Pantelosaurus saxonicus]]''
                        |2={{clade
                           |label1='''[[Therapsida]]'''
                           |1={{clade
                              |1=''[[Raranimus dashankouensis]]''
                              |2={{clade
                                 |1=''[[Biarmosuchus tener]]''
                                 |2={{clade
                                    |1=''[[Biseridens qilianicus]]''
                                    |2=''[[Titanophoneus potens]]''}} }} }}
                           |label2=[[Sphenacodontidae]]
                           |2={{clade
                              |1=''[[Cutleria wilmarthi]]''
                              |2={{clade
                                 |1=''[[Secodontosaurus obtusidens]]''
                                 |2={{clade
                                    |1=''[[Cryptovenator hirschbergeri]]''
                                    |2={{clade
                                       |1=''[[Dimetrodon]]'' spp.
                                       |2=''[[Sphenacodon]]'' spp. }} }} }} }} }} }} }} }} }} }} }} }} }} }}

However, more recent examination of the phylogeny of basal synapsids, incorporating newly described basal caseids and eothyridids,<ref name="ReferenceA">{{cite journal |author1=Neil Brocklehurst |author2=Robert Reisz |author3=Vincent Fernandez |author4=Jörg Fröbisch |year=2016 |title=A Re-Description of 'Mycterosaurus' smithae, an Early Permian Eothyridid, and Its Impact on the Phylogeny of Pelycosaurian-Grade Synapsids |journal=PLOS ONE |volume=11 |issue=6 |pages=e0156810 |doi=10.1371/journal.pone.0156810 |pmid=27333277 |bibcode=2016PLoSO..1156810B |pmc=4917111 |doi-access=free }}</ref> returned Caseasauria to its position as the sister to all other synapsids. Brocklehurst et al. (2016)<ref name="ReferenceA"/> demonstrated that many of the postcranial characters used by Benson (2012) to unite Caseasauria with [[Sphenacodontidae]] and [[Edaphosauridae]] were absent in the newly discovered postcranial material of eothyridids, and were therefore acquired convergently.