Scientific name Sphenacodontoidea | Phylum Chordata Clade Sphenacodontoidea | |
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Lower classifications Therapsid, Mammal, Sphenacodontidae, Dimetrodon, Bear | ||
Sphenacodontoidea is a node-based clade that defined to include the most recent common ancestor of the Sphenacodontidae and the Therapsida and their descendants (including mammals). They are defined according to a number of specialised characteristics concerning 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, unspecialised pelycosaurs.
Classification
The following taxonomy follows Fröbisch et al. (2011) and Benson (2012) unless otherwise noted.
Class Synapsida
References
Sphenacodontoidea Wikipedia(Text) CC BY-SA