- Sphenacodontoidea
Taxobox
name = Sphenacodontoidea
fossil_range = LatestCarboniferous - MiddlePermian (non-therapsid)
image_caption = "Ctenospondylus "
regnum =Animal ia
phylum = Chordata
classis =Synapsid a
ordo =Pelycosaur ia
unranked_familia = Sphenacodontoidea
subdivision_ranks = Genera and Clades
subdivision =See TaxonomySphenacodontoidea is the name given to the
clade that includes themost recent common ancestor of theSphenacodontidae and theTherapsid a and their descendants (including mammals). They are defined according to a number of specialised characteristics concerning [http://tolweb.org/notes/?note_id=466 proportions of the bones of the skull and the teeth] .The Sphenacodontoidea evolved from earlier
Sphenacodontia such as "Haptodus " via a number of transitional stages of small, unspecialisedpelycosaur s.Taxonomy and Phylogeny
* Suborder
Eupelycosauria
**Sphenacodontia
*** Sphenacodontoidea
**** FamilySphenacodontidae
***** "Ctenospondylus "
***** "Dimetrodon "
***** "Secodontosaurus "
***** "Sphenacodon "
**** "Tetraceratops "
***** "'ORDER THERAPSIDA
****** "'ClassMammalia References
* Laurin, M. and Reisz, R. R., 1997, [http://tolweb.org/accessory/Synapsid_Classification_&_Apomorphies?acc_id=466 Autapomorphies of the main clades of synapsids] -
Tree of Life Web Project ee also
*
Evolution of mammals
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