,,university ,,of ,,kansas ,,publications ,,museum ,,of ,,natural ,,history ,volume #ab1 ,no4 #f1 pp4 #big-cjg1 #f figs4 ,may #ba1 #aifb ,two ,new ,pelycosaurs from the ,lower ,permian of ,oklahoma ,,by ,,richard ,c4 ,,fox ,,university ,,of ,,kansas ,,lawrence #aifb ,,university ,,of ,,kansas ,,publications1 ,,museum ,,of ,,natural ,,history ,editors3 ,e4 ,raymond ,hall1 ,chairman1 ,henry ,s4 ,fitch1 ,theodore ,h4 ,eaton1 ,jr4 ,volume #ab1 ,no4 #f1 pp4 #big-cjg1 #f figs4 ,published ,may #ba1 #aifb ,,university ,,of ,,kansas ,lawrence1 ,kansas ,,printed ,,by ,,jean ,m4 ,,neibarger1 ,,state ,,printer ,,topeka1 ,,kansas #aifb #bi-cjja ,two ,new ,pelycosaurs from the ,lower ,permian of ,oklahoma ,,by ,,richard ,c4 ,,fox ,in the course of examining material from fissure deposits of early ,permian age collected from a limestone quarry near ,fort ,sill1 ,oklahoma1 the author recovered several tooth-bearing fragments of small pelycosaurs4 ,the fragments were examined1 compared with descriptions of known kinds appearing in the literature1 and determined to be new genera within the ,nitosauridae 7,edaphosauria7 and ,sphenacodontidae 7,sphenacodontia74 ,appreciation is expressed to ,prof4 ,theodore ,h4 ,eaton1 ,jr41 for permission to examine the collections of the ,university of ,kansas from ,fort ,sill1 and for the financial assistance furnished by his ,national ,science ,foundation grant 7,,nsf-,g#hfbd74 ,i am grateful both to ,prof4 ,eaton and ,mr4 ,dale ,l4 ,hoyt for their suggestions regarding this manuscript4 ,the accompanying figures have been drawn by the author4 ,family ,,nitosauridae ,delorhynchus priscus new genus and new species 7delos1 ,gr41 evident2 rhynchos1 ,gr41 neuter1 nostril2 priscus1 ,l41 ancient4 ,delorhynchus is masculine because of the ending that it acquires when transliterated into ,latin47 ,type specimen4--,fragmentary left maxilla1 bearing four teeth1 ,,ku #aaaag4 ,referred specimens4--,fragmentary right maxilla having four teeth1 ,,ku #aaaah2 fragmentary left maxilla having four teeth1 the most posterior of which has been broken1 ,,ku #aaaai4 ,horizon and locality4--,a fissure deposit in the ,arbuckle limestone at the ,dolese ,brothers ,limestone ,quarry1 approximately six miles north of ,fort ,sill1 in sec4 #ca1 ,t4 #d ,n1 ,r4 #aa ,w1 ,comanche ,county1 ,oklahoma4 ,these sediments are of early ,permian age1 possibly equivalent to the ,arroyo formation1 ,lower ,clear ,fork ,group of ,texas 7,vaughn1 #aieh3 #iha74 ,diagnosis4--,small2 marginal teeth conical1 slender and recurved at tips2 marginal tooth-row without caniniform enlargement2 narial opening enlarged and bordered dorsally1 posteriorly and ventrally by maxilla2 maxilla with foramen opening laterally at posteroventral corner of naris4 ,description 7based on #c maxillary fragments1 see ,table #a74--;,each of the maxillary fragments bears four thecodont teeth4 ,these are conical1 slender and sharply pointed2 in their distal third they are slightly recurved1 laterally compressed1 and have anterior and posterior non-serrated cutting edges4 ,in medial aspect at their bases1 the teeth are longitudinally striated4 ,the bases of the teeth are circular in cross-section and are slightly bulbous4 ,there is no caniniform enlargement of any of the teeth1 the longest tooth of each fragment being differently placed in the series of teeth and little longer than the others4 ,there is no swelling on either the internal or external surfaces of the maxillae4 ,the teeth are in a continuous series2 no diastema or maxillary step is evident4 ,illustration3 ,,figures #a-c4 ,delorhynchus priscus1 lower ,permian1 #f miles north of ,fort ,sill1 ,comanche ,county1 ,oklahoma4 ,all #c4 ,,fig4 #a4 ,,ku #aaaag 7type specimen71 lateral view of left maxilla4 ,,fig4 #b4 ,,ku #aaaah1 lateral view of right maxilla4 ,,fig4 #c4 ,,ku #aaaai1 lateral view of left maxilla4 ,the fragments have been broken along similar lines of fracture1 and each is approximately rhomboidal in shape4 ,the maxilla encircles the posterior border of the naris and extends dorsally above the naris to an extent sufficient to indicate the probable exclusion of the lacrimal bone from the narial border4 ,at the posteroventral corner of the naris a foramen opens onto the lateral surface of the maxilla4 ,the opening is the entrance to a canal that runs posteriorly above the tooth-row throughout the length of each specimen4 ,beneath the naris the maxilla extends as a broad tapering shelf1 the ventral surface of which articulates with the premaxilla4 ,the narial rim is wide1 but wider ventrally than dorsally4 ,the plane of the narial rim is oblique to the lateral surface of the maxilla4 ,the external surface of each fragment is grooved and pitted4 ,the ossification of each fragment appears to have been complete4 ,,table #a4--;,,dimensions1 ,,in ,,millimeters1 ,,of ,,three ,,maxillary ,,fragments ,,of ,,delorhynchus ,,priscus ,key3 ,a4 ,anterior height of fragment ,b4 ,posterior height of fragment ,c4 ,length of fragment at tooth-row ,d4 ,dorsal length of fragment ,e4 ,mean length of teeth ,f4 ,anterior width of naris ,,catalogue ,,number ,a4 ,b4 ,c4 ,d4 ,e4 ,f4 ,,and ,,mean ---------------------------------------- ------------- ,,ku #aaaag #f4j #h4j #f4j #h4j #c4j #c4j ,,ku #aaaah #f4j #f4j #i4j #h4j #b4j #c4j ,,ku #aaaai #f4f #h4j #aj4j #aa4j 8 #d4f ---------------------------------------- ------------- ,mean #f4b #g4c #h4c #i4j #b4e #d4e ---------------------------------------- ------------- ,discussion4--,the ,nitosauridae are small primitive edaphosaurs with a moderately elongate face1 sharp subisodont teeth1 little development of canines and few specializations4 ,the jaw is of a primitive type and articulates on a level with the tooth-row4 ,the palatal dentition is primitive 7,romer1 #aief3bhj74 ,the nitosaurids are thought to be related to the later ,caseidae1 and the most obvious structural similarities are found in the postcranial skeleton 7,vaughn1 #aieh3ihi74 ,cranial resemblances between the families are fewer1 but nevertheless indicate that a nitosaurid-caseid relationship exists4 ,vaughn 7#aieh7 described a small pelycosaur1 ,colobomycter pholeter 7,eothyrididae1 ,ophiacodontia7 that structurally resembles the ,caseidae4 ,this individual also was obtained from the ,fort ,sill locality4 ,in ,vaughn's opinion the features of ,colobomycter indicate a close relationship between eothyridids and caseids and the possibility that the caseids may well have been of eothyridid rather than nitosaurid derivation4 ,in view of this historical uncertainty of the relationships between the ,nitosauridae1 the ,eothyrididae and the ,caseidae1 it is well to consider how the maxillary fragments described above differ from and resemble representatives of each of these three families as reported in the literature4 ,delorhynchus resembles ,colobomycter in size4 ,the mean extra-maxillary length of the undamaged teeth of the three fragments is #b4e mm41 equal to that reported by ,vaughn 7#aieh3ihe7 for teeth about midway in the postcanine series of ,colobomycter4 ,none of the teeth of ,delorhynchus extends beyond the maxillary rim as far as does the canine of ,colobomycter 7#c4e mm474 ,the teeth in both genera are conical and sharply pointed4 ,the naris in each is enlarged1 and the lacrimal is excluded from the narial margin in each 7by inference in ,delorhynchus47 ,the differences between the maxillae of ,colobomycter and ,delorhynchus are most striking in the lack of canines in the latter and the correlated absence of modifications of the maxillary for support of canines4 ,additionally1 ,delorhynchus bears an infraorbital canal in contrast to the groove in similar position in ,colobomycter4 ,the recurvature of the four teeth present in the fragments of ,delorhynchus differs from that in the teeth of ,colobomycter in which only the canine and precanine are recurved4 ,vaughn implies that anterior and posterior cutting edges extend the length of the teeth in ,colobomycter2 these are restricted to the distal third of the teeth in ,delorhynchus4 ,the external surfaces of the maxillae of ,delorhynchus are pitted and ridged2 ,vaughn was unable to discern sculpturing of the corresponding surfaces in ,colobomycter4 ,delorhynchus resembles the nitosaurids in size1 the shape and sharpness of the teeth1 their recurvature and the slight enlargement of their bases1 the exclusion of the lacrimal bone from the narial margin 7in ,mycterosaurus7 and the apparent lack of a special canine pair of teeth4 ,resemblances to the caseids are to be noted in the enlargement of the naris 7#d4e mm4 in height as opposed to #a4g mm4 in ,colobomycter71 lack of development of canines1 presence of an infraorbital canal 7in ,cotylorhynchus7 and absence of many replacement gaps in the marginal row of teeth4 ,the absence of caniniform enlargement and the extension of the maxilla dorsad of the naris exclude ,delorhynchus from the ,eothyrididae 7,ophiacodontia7 but are no bar to its inclusion in the ,nitosauridae 7,edaphosauria74 ,the marginal teeth of ,delorhynchus are simple and primitive1 being much like those of the nitosaurids that are described in the literature4 ,the large narial opening and its posterior1 dorsal and ventral enclosure by the maxilla1 the infraorbital canal1 and the sculptured external surfaces of the maxillary fragments indicate that ,delorhynchus1 in these features at least1 is close to achieving the caseid grade4 ,family ,,sphenacodontidae ,thrausmosaurus serratidens new genus and new species 7,thrausmosaurus is formed from the neuter ,greek noun1 thrausma1 meaning fragment1 and the masculine ,greek noun1 sauros1 meaning reptile4 ,the specific name1 serratidens1 is formed from the ,latin serratus1 meaning serrate1 and the masculine ,latin noun1 dens1 meaning tooth4 ,the specific name is used as a substantive in apposition with the generic name47 ,type specimen4--,fragmentary left dentary1 bearing five teeth1 the most posterior of which is broken at the base1 ,,ku #aaabj4 ,referred specimens4--,fragmentary 8left maxilla1 having two teeth1 ,,ku #aaaba2 fragmentary left dentary having two teeth1 ,,ku #aaabb4 ,horizon and locality4--,from the early ,permian fissure deposits in the ,arbuckle limestone of the ,dolese ,brothers ,limestone ,quarry1 approximately #f miles north of ,fort ,sill1 in sec4 #ca1 ,t4 #d,n1 ,r4 #aa ,w1 ,comanche ,county1 ,oklahoma4 ,diagnosis4--,small2 teeth thecodont1 compressed laterally1 recurved distally1 and bearing anterior and posterior cutting edges2 anterior serrations limited to recurved portions of teeth1 posterior serrations extending nearly entire length of teeth2 lateral compression of teeth more pronounced medially than laterally2 bases of teeth expanded4 ,description4--,the type specimen is #af mm4 long4 ,it bears five teeth that are implanted in a straight row4 ,empty sockets are present between the first and second teeth1 and the third and fourth teeth4 ,the first tooth is #c4j mm4 long1 the middle two are each #b4e mm4 long1 and the fourth tooth is #b4j mm4 long4 ,the fifth tooth is broken off at its base4 ,the empty sockets are large4 ,the mouth of each is circular and approximately #b4j mm4 in diameter4 ,both sockets are #a4be mm4 deep4 ,the bases of the teeth are expanded to fill the sockets1 although the blades of the teeth arise from only the lateral portions of the bases4 ,the edge of the dentary rises above the bases of the teeth medially1 thereby producing a small depression at the junction of each base with the dentary bone4 ,the lateral compression of the teeth is pronounced but asymmetrical1 in that the lateral surface of each blade is more convex than the medial surface4 ,illustration3 ,,figures #d-f4 ,thrausmosaurus serratidens1 lower ,permian1 #f miles north of ,fort ,sill1 ,comanche ,county1 ,oklahoma4 ,all #c4 ,,fig4 #d4 ,,ku #aaabj 7type specimen71 lateral view of left dentary4 ,,fig4 #e4 ,,ku #aaaba1 lateral view of 8left maxilla4 ,,fig4 #f4 ,,ku #aaabb1 lateral view of left dentary4 ,the recurvature of the anterior cutting edges is much more severe than that of the posterior edges1 but the recurvature of both is limited to the distal half of each tooth4 ,the serrations of the cutting edges are not visible to the naked eye and are limited on the anterior edges of the teeth to those portions of the blades that are recurved4 ,the posterior serrations extend nearly to the junction of the blade of each tooth with its base4 ,the serrations tend to be more nearly crenulate than cuspidate4 ,a portion of the lateral wall of the dentary surrounding the ,meckelian canal is present4 ,the external surface of the wall is gently convex and smooth1 without sculpturing4 ,the internal surfaces of the canal are unmarked either by muscle scars or foramina4 ,the fragment is a piece from the posterior portion of the dentary1 since the decrease in height from the first tooth to the fourth is pronounced4 ,,ku #aaabb1 a fragment of the left dentary bearing two teeth1 is #g4e mm4 long4 ,the anterior tooth is #c4j mm4 long2 the posterior tooth is #c4e mm4 long4 ,the shape of the teeth and their implantation conform to the description of the type specimen4 ,the lateral surface of the fragment is smooth and gently convex4 ,what little is present of the surface bordering the ,meckelian canal is unmarked4 ,the 8maxillary fragment bears two teeth which are #c4j mm4 long1 and which conform in their characters to the type4 ,the lateral1 medial and ventral surfaces of the fragment have been sheared off1 so that an exact identification of the bone is impossible4 ,presumably the fragment is too deep dorsoventrally to be a piece of the dentary1 and no sign of the ,meckelian canal is present4 ,discussion4--,the implantation1 lateral compression1 recurvature and cutting edges of the teeth borne by these fragments make clear their sphenacodontid nature4 ,the characters of the fragments are too few to determine subfamilial affinities1 however4 ,that the fragments are the remains of adult animals can be only surmised from the lack of bones or teeth of large pelycosaurs in the extensive collections of the ,university of ,kansas from the ,fort ,sill locality4 ,if ,thrausmosaurus is1 in fact1 adult1 the genus is an unusually small sphenacodontid1 and of significance both on that account and because of the resemblance of the teeth presently known to those of its far larger relatives4 ,the ,fort ,sill ,locality4--,peabody 7#aifa7 suggested that the fissures of ,fort ,sill had been used as dens by predatory animals in the early ,permian1 and that the unusually abundant bones in the fissures were the remains of animals eaten there by these occupants4 ,evidence now known to me affords an alternative explanation that is presented here as a preliminary to a more complete study of the fauna and paleoecology of these deposits currently being undertaken4 ,the suggestion that the skeletal material found in the fissures is the remnant of the prey of other animals is questionable because of3 #a4 ,the absence of tooth marks on the fossils4 #b4 ,the recovery from the matrix of skulls and portions of articulated skeletons that are undamaged or damaged only by pressure after burial4 #c4 ,the rarity in the deposits of animals of larger body size than ,captorhinus1 the exceptions being a few limb fragments and skull fragments of labyrinthodont or pelycosaurian nature4 #d4 ,the absence of coprolites in the matrix4 ,if the fissures were the dens of predators1 at least some and probably many of the bones would show tooth marks4 ,a predator feeding on other animals would be expected to leave some evidence of its habits on the bones of its prey4 ,no such evidence is known to me1 either from my own examination of several thousand bones or from the reports in the literature by others who have studied aspects of the early ,permian fauna of ,fort ,sill4 ,if the predators were larger than ,captorhinus and occupied the fissures for a long enough time to account for the accumulation of the tremendous numbers of individuals that are represented1 a considerable amount of the skeletal material of the larger animals would be present in the fissure deposits4 ,even if for some reason the predators died in areas other than within the fissures1 thereby accounting for the absence of large bones1 coprolites should appear in the deposits if1 in fact1 the fissures were feeding places4 ,in view of the nearly undamaged condition of many of the bones recovered from the fissures1 it is reasonable to expect that fecal material would be preserved4 ,the character of the matrix of the deposits varies from a homogeneous clay to clay interrupted by layers of soft1 limey1 conglomeratic rock1 to a hard1 well-cemented1 calcareous conglomerate4 ,in general the bone in each kind of matrix is colored characteristically and exhibits a characteristic degree of wear4 ,the bones entrapped in the homogeneous clay are relatively few1 black1 usually disarticulated1 little worn and not unduly fragmented2 consequently the discovery of undamaged limb bones1 for example1 from this kind of matrix is not unusual4 ,the bones found in the stratified portion of the matrix are more numerous within the layers of conglomerate than between4 ,the bones are black1 brown or white1 highly fragmented and waterworn to a variable degree4 ,the fragments recovered from the hard1 calcareous matrix are numerous1 range in color from white through various shades of brown1 to black1 are highly fragmented1 and are usually worn by water4 ,these categories for bone and matrix1 however1 are not mutually exclusive1 since bones of any of these colors and exhibiting any degree of wear and fragmentation are found in any of the kinds of matrix described above4 ,that water was the agent of wear is suggested by the highly polished appearance of the worn bones and pebbles that are found in the matrix4 ,the variability of the matrix and of the color and condition of the bones indicates that the agencies of burial and fossilization differed from time to time and that the agency of transportation of the bones from the site of burial to the fissures was running water4 ,one can easily visualize a stream coursing the early ,permian landscape that was subject to periodic flooding and droughts4 ,along the banks of the stream and in its pools lived a variety of microsaurs1 captorhinids1 small labyrinthodonts and small pelycosaurs4 ,some of the animals1 after they died1 were either buried near the site of their death or were swept along and buried in sediments further downstream4 ,burial was for a length of time sufficient to impart a color to the bones characteristic of the site in which they were buried4 ,later floods reexposed the sites of burial1 picked up the bones and carried them to the openings into the fissures4 ,presumably1 too1 a proportion of the bones was carried to the fissures without previous burial4 ,the differences in wear exhibited by different bones within the same block of matrix is attributable to differences in distance that the bones were transported before final deposition4 ,the final sites of deposition1 the fissures1 were inundated occasionally by floods alone1 or because of changes in location of the channel of the stream at the time of flooding4 ,the periodicity of deposition of the sediments within portions of the fissures is indicated by the stratification of the bone conglomerate mentioned earlier4 ,in summary1 it seems that there is little or no evidence beyond the numbers of bones involved to support the hypothesis that the concentration of bones in the fissures of ,fort ,sill represents the remains of food of predators1 and that the fissures were used as dens by their predatory occupants4 ,on the contrary1 the evidence indicates that the deposition of the bones in the fissures was secondary and that the agency of transportation1 deposition and accumulation of the bones was an early ,permian stream characterized by periodic flooding4 ,,literature ,,cited ,,peabody1 ,f4 ,e4 #aifa4 ,annual growth zones in living and fossil vertebrates4 ,jour4 ,morph4 #ajh 7#a73 #aa-fb1 #fi figs41 ,january4 ,,romer1 ,a4 ,s4 #aief4 ,osteology of the reptiles4 ,the ,university of ,chicago ,press1 ,chicago1 xxi #ggb pp41 #bdh figs4 ,,romer1 ,a4 ,s41 and ,,price1 ,l4 ,i4 #aidj4 ,review of the ,pelycosauria4 ,geol4 ,soc4 ,america1 ,spec4 ,pap41 #bh3 x #ech pp41 #ga figs41 #df pls41 #h tables1 ,december #f4 ,,vaughn1 ,p4 ,p4 #aieh4 ,on a new pelycosaur from the lower ,permian of ,oklahoma1 and the origin of the family ,caseidae4 ,jour4 ,paleont41 #cb3iha-iia1 #a fig41 ,september4 ,transmitted ,march #ae1 #aifb4