Everything about Sphenacodontia totally explained
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See taxonomy}}
Sphenacodontia is the name given to the
clade that includes the
Sphenacodontidae and all their descendants (including mammals). They first appear during the
Late Pennsylvanian epoch. The
defining characteristics include a thickening of the
maxilla visible on its internal surface, above the large front (caniniform) teeth; and the
premaxillary teeth being set in deep sockets. All other (sister group and more primitive) synapsid clades have teeth that are set in shallow sockets.
Basal Sphenacodontia constitute a
transitional evolutionary series from early
pelycosaurs to ancestral
therapsids (which in turn were the ancestors of more advanced forms and finally the
mammals). One might say that the Sphenacodontians are proto-therapsids.
Taxonomy and Phylogeny
