LIST OF THE RICHARDS SPUR (FORT SILL) TETRAPOD PALEOFAUNA
Stratigraphic chart of the lower Permian (partial)
Content updated April 10, 2006
DIMETRODON
Synapsida-Eupelycosauria-Sphenacodontidae
Above: picture of a Dimetrodon base of neural spine in lateral view, on the top is visible the change in morphology from a normal blade like to an elongate structure . From Ryan Sandstone, Wellington Formation, near Waurika - Jefferson Co. Oklahoma. Lower Permian.