Produced by Chris Curnow, Woodie4, Joseph Cooper and the Online Distributed Proofreading Team at https://www.pgdp.net UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 12, No. 6, pp. 297-307, 6 figs. May 21, 1962 Two New Pelycosaurs from the Lower Permian of Oklahoma BY RICHARD C. FOX UNIVERSITY OF KANSAS LAWRENCE 1962 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 12, No. 6, pp. 297-307, 6 figs. Published May 21, 1962 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS 1962 29-3001 Two New Pelycosaurs from the Lower Permian of Oklahoma BY RICHARD C. FOX In the course of examining material from fissure deposits of early Permian age collected from a limestone quarry near Fort Sill, Oklahoma, the author recovered several tooth-bearing fragments of small pelycosaurs. The fragments were examined, compared with descriptions of known kinds appearing in the literature, and determined to be new genera within the Nitosauridae (Edaphosauria) and Sphenacodontidae (Sphenacodontia). Appreciation is expressed to Prof. Theodore H. Eaton, Jr., for permission to examine the collections of the University of Kansas from Fort Sill, and for the financial assistance furnished by his National Science Foundation grant (NSF-G8624). I am grateful both to Prof. Eaton and Mr. Dale L. Hoyt for their suggestions regarding this manuscript. The accompanying figures have been drawn by the author. Family NITOSAURIDAE =Delorhynchus priscus= new genus and new species (_delos_, Gr., evident; _rhynchos_, Gr., neuter, nostril; _priscus_, L., ancient. _Delorhynchus_ is masculine because of the ending that it acquires when transliterated into Latin.) _Type specimen._--Fragmentary left maxilla, bearing four teeth, KU 11117. _Referred specimens._--Fragmentary right maxilla having four teeth, KU 11118; fragmentary left maxilla having four teeth, the most posterior of which has been broken, KU 11119. _Horizon and locality._--A fissure deposit in the Arbuckle limestone at the Dolese Brothers Limestone Quarry, approximately six miles north of Fort Sill, in sec. 31, T. 4 N, R. 11 W, Comanche County, Oklahoma. These sediments are of early Permian age, possibly equivalent to the Arroyo formation, Lower Clear Fork Group of Texas (Vaughn, 1958: 981). _Diagnosis._--Small; marginal teeth conical, slender and recurved at tips; marginal tooth-row without caniniform enlargement; narial opening enlarged and bordered dorsally, posteriorly and ventrally by maxilla; maxilla with foramen opening laterally at posteroventral corner of naris.