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 the same Dimetrodon base of neural spine in frontal view. From Ryan Sandstone, Wellington Formation, near Waurika - Jefferson Co. Oklahoma. Lower Permian.