Stratigraphic chart of the lower Permian (partial)
Content updated October 16, 2005
OPHIACODON
Synapsida-Eupelycosauria-Ophiacodontidae
Above: picture of Ophiacodon transverse flange of pterygoid showing the edentulous area in front of the tooth row ( the teeth are broken, but is visible the base). From Ryan Sandstone, Wellington Formation, near Waurika - Jefferson Co. Oklahoma. Lower Permian.