A new sphenacodontid pelycosaur (Synapsida) from the Wichita Group, Lower Permian of north-central Texas Hook, Robert W. ; Hotton, Nicholas, III Abstract Publication: Journal of Vertebrate Paleontology Pub Date: March 1991 DOI: 10.1080/02724634.1991.10011374 Bibcode: 1991JVPal..11...37H