PUBLICATIONS OF THE MUSEUM TEXAS TECH UNIVERSITY Two publications of The Museum of Texas Tech Uni¬ versity are issued under the auspices of the Dean of The Graduate School and Director of Academic Publications, and in cooperation with the International Center for Arid and Semi-Arid Land Studies. Shorter research papers are published as Occasional Papers, whereas longer contri¬ butions appear as Special Publications. Both are num¬ bered separately and published on an irregular basis. Institutional libraries interested in exchanging publi¬ cations may obtain the Occasional Papers and Special Publications by addressing the Exchange Librarian, Texas Tech University, Lubbock, Texas 79409. Individuals may purchase separate numbers of the Occasional Papers for 50 cents each through the Exchange Librarian. Remit¬ tance must be enclosed with request. OCCASIONAL PAPERS comp ZOOL. LIBRARY THE MUSEUM DEC 2 4 TEXAS TECH UNIVERSITaYva™ LINIVERSi f y NUMBER 18 19 DECEMBER 1973 A NEW SPECIES OF LEOPARD FROG (RANA PIPIENS COM¬ PLEX) FROM THE PLAINS OF THE CENTRAL UNITED STATES John S. Mecham, Murray J. Littlejohn, Robert S. Oldham, Lauren E. Brown, and Jill R. Brown Sufficient evidence has accumulated over the last six years to show that the leopard frogs ( Rana pipiens, sensu lato) of North America actually include several forms that merit recognition as distinct species. Littlejohn and Oldham (1968) showed that four essentially allopatric forms, recognizable on the basis of mating call structure and morphology of adult males, occur in the central United States. These were referred to informally as the northern, western, eastern, and southern call types. Narrow zones of sympatry were located be¬ tween western and eastern, western and southern, and between eastern and southern call types in Texas. The zone of overlap between west¬ ern and southern call types was found to be about 16 kilometers wide in north-central Texas, and that between southern and eastern call types was estimated to be about eight kilometers wide in central Texas. Also, Post and Pettus (1967) found an overlap zone only eight kilometers wide between so-called CF (continuous dorsolateral folds) and DF (displaced dorsolateral folds) complexes (corresponding to the northern and western call types, respectively) in Colorado, and Flury (1972) collected both northern and western call types together in northern Nebraska. Brown and Brown (1972) found the western call type in sympatry with both eastern and northern call types in Illinois, and overlap between western and southern call types in Texas has been confirmed by Purcell (1968), Mecham (1969), Cuellar (1971), and Platz (1972). Platz (1972) found the overlap zone between west- 2 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY ern and southern call types in western Texas to be about 56 kilo¬ meters wide. Crossing experiments (Mecham, 1969; Cuellar, 1971) have demonstrated genetic differences between certain of the forms, as have the studies on heart muscle lactate dehydrogenase by Salthe (1969). Other taxa apparently occur in the southwestern United States. Mecham (1968a, 1968 b) demonstrated sympatry between so- called northern and southern forms in Arizona. The northern form probably corresponds to the northern call type of Littlejohn and Old¬ ham (Mecham, 1968 b), but the southern form apparently is distinct from call types in the central United States (Mecham, 1968a, 1968 b, 1971). Platz and Platz (in press) recently identified a third type (the lowland form) in Arizona; sympatry between this third form and the southern form (Arizona), as well as between the northern and southern forms (Arizona), were detected through analysis of hemoglobins. Three of the call types identified by Littlejohn and Oldham (1968) correspond closely in their distributions to formally recognized sub¬ species (Mecham, 1969; Platz, 1972). The northern call type repre¬ sents R. p. pipiens Schreber; the eastern call type, R. p. sphenocephala Cope; and the southern call type, R. p. berlandieri Baird. The western call type, included largely within the range of R. p. berlandieri by Conant (1958), apparently represents an undescribed taxon. Three taxa, the western call type, R. p. berlandieri , and R. p. sphenocephala , contact one another and retain their distinctness in sympatry; thus, they clearly fulfill the requirements for recognition as separate species. The same is true of the western call type and R. p. pipiens. As R. p. pipiens and R. p. berlandieri are disjunctly allopatric, their relative specific status cannot be subjected to the ultimate taxonomic test. Also, sympatry has yet to be demonstrated between R. p. pipiens and R. p. sphenocephala , although the two taxa presumably come into contact. In both cases, however, the differentiation in mating call structure and other characters is comparable to those of taxa known to maintain their distinctness in sympatry, and it is reasonable to assume that the taxa involved would act as biological species. Sanders and Smith (1971) have proposed specific rank for R. p. berlandieri. We propose that all four taxa be treated as species. As no name is available for the western call type ( = plains or southern plains type of Mecham, 1969, 1971, Cuellar, 1971, and Platz, 1972, = the DF com¬ plex of Post and Pettus, 1 966, 1 967), a formal description is presented below. A detailed study of the systematic biology of the Rana pipiens complex in the United States has been made by Pace (in press). A nomenclatorial problem may have been created with the restric¬ tion of the type locality of Rana pipiens to White Plains, New York, MECHAM ET AL. — NEW LEOPARD FROG 3 by Schmidt (1953). Several lines of evidence (oviducts, head measure¬ ments, Moore, 1944; Snout shape, Ruibal, 1957; HLDH enzymes, Salthe, 1969) suggest that Rana sphenocephala extends into this area. See Pace (in press) for a detailed discussion of nomenclature. Rana blairi, new species Plains Leopard Frog (Figs. 1-2) Holotype. — Adult male, University of Michigan Museum of Zool¬ ogy Collection, no. 131690, from 1.6 km. W New Deal, Lubbock Co., Texas, collected by Charles Everett on 6 August 1971. Paratypes. — UMMZ 131691-131693, collected with the holotype, and UMMZ 1 3 1 694-13 1 697 from 1 .6 km. E New Deal, Lubbock Co., Texas, also collected on 6 August 1971 by Charles Everett. Diagnoisis. — A frog of the Rana pipiens complex distinguished by a combination of characters including: dorsolateral folds that are usu¬ ally interrupted posteriorly and deflected medially; absence of ovi¬ ducts in males; usually a complete pale line on the upper lip; and a mating call ( sensu Littlejohn and Oldham, 1968) with a uniquely low pulse rate (average of less than six pulses per second below 24 °C) and low pulse number (average of less than six pulses per call). Description of holotype. — Adult male with a snout-vent length of 91.3 millimeters; tibia length, 55.0; head width, 31.4; head length 31.5 nostril to edge of upper lip, 7.5; orbit to nostril, 6.6; diameter of tympanum, 8.9. Dorsolateral folds broken posteriorly just anterior to thigh and slightly inset medially, terminating midway above thigh; no vestigial oviducts; webbing on hind foot extending to the base of apical phalanx of fourth toe. External vocal sacs moderately de¬ veloped; skin smooth on venter, finely granular on posterior surface of thigh, moderately rugose or pustulate on sides, and with low longi¬ tudinally oriented plicae on the back. Color (in alcohol) pale cream below and pale brown above, tinged with gray on sides. Venter im¬ maculate except for sparse dark stippling on the throat and upper chest; a pale narrow stripe extending along the upper lip from a point below the posterior margin of the tympanum to a point beyond the naris; dorsolateral folds very pale brown; tympanum with an obscure, pale spot. Dorsum with 1 8 dark brown, rounded spots with traces of pale, very narrow, borders; spots on sides smaller; transverse dark bars' on upper surface of the hind limbs; posterior surface of thighs mottled with dark brown, diffuse spots. Variation within the type series. — Paratypes (three males, four females) agree closely with the holotype in most characters including 4 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSE! Y I 2 Fig. 1. — Holotype of Rana blairi. Fig. 2. — Paratype of Rana blairi , a female (UMMZ 131694) from 1.6 km. E New Deal, Texas. dorsolateral folds, oviducts, skin texture, extent of webbing, and gen¬ eral coloration. The supralabial stripe varies from well defined to obscure, but can be traced nearly to the tip of the snout in all speci¬ mens. A pale tympanic spot is present in all specimens, and varies from obscure to distinct. Pale borders to the spots are very narrow or absent. Dark markings on the posterior surface of the thigh vary from pale, diffuse spotting to heavy mottling. Some fine dark stippling or mottling is present on the throat, particularly to the sides, on all but MECHAM ET AL. — NEW LEOPARD FROG 5 two specimens. Coloration in life for all specimens of the type series was pale brown above, paler on the sides, with dark brown spots. Dorsolateral folds, tympanic spots, and supralabial stripes varied from pale brown to pale yellow-brown. The venter was pale white in all specimens except for yellow groin color and a tinge of yellow on the lower abdomen and proximal part of the thigh. Mean values with ranges for the type series are: snout-vent, males 81.90 (74.6-91.3) millimeters, females 88.07 (84.1-98.7); tibia/ snout-vent, males 0.58 (0.55-0.59), females 0.56 (0.53-0.60); head width/head length, males 1.01 (0.99-1.03), females 1.03 (1.00-1.05); head length/snout-vent, males 0.35 (0.33-0.35), females 0.33 (0.32- 0.34); nostril-lip/eye-nostril, males 1.11 (1.08-1.14), females 1.08 (1.03-1.11); dorsal spot number, males 19.50 (18-21), females 18.75 (14-22). Mean values for males and females together are: snout-vent, 87.50 ± 3.02; tibia/snout-vent, 0.57 ±0.01; head width/head length, 1.02 ± 0.01; head length/snout-vent, 0.34 ±0.01; nostril-lip/eye- nostril, 1.09 ±0.01 ; dorsal spot number, 19.10 ±0.92. Distribution. — Distribution is centered in the Great Plains, and includes northwestern Texas and eastern New Mexico, the western two-thirds of Oklahoma, all of Kansas with the possible exception of the southeastern corner, eastern Colorado, most of Nebraska, southern Iowa, apparently large parts of Missouri, and much of Illinois. Dis¬ tribution in Texas, Oklahoma, and Kansas is shown by the map of Littlejohn and Oldham (1968). Western limits of the range in New Mexico are not positively known, but one of us (Mecham) has identi¬ fied specimens from the Sacramento Mountains (Lincoln County) in the southern part of that state. Post and Pettus (1966) recorded R. blairi (as the DF complex) as far west as western Las Animas and Pueblo counties in southern Colorado. Distribution of males lacking vestigial oviducts (Moore, 1944) indicates that R. blairi extends as far north as northern Nebraska; Flury (1972) collected it with R. pipiens at Valentine, Nebraska. Distribution in Illinois appears to be largely associated with the prairie peninsula; Brown and Brown (1972) found R. blairi as far south as Jackson County and as far north as LaSalle County in that state. Pace (in press) has provided distri¬ bution maps and details of localities for leopard frog taxa, including R. blairi , in the United States. Comparisons. — Mating call structure. Characteristics of mating calls of R. blairi including those of a series recorded at the type lo¬ cality are given in Table 1. Also included for comparison are char¬ acteristics of mating calls of some other members of the R. pipiens complex. The initial calls of a series and single calls tend to be longest 6 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY and were chosen as the basis for call duration figures in the table. A sound spectrogram of two mating calls recorded at the type locality is given in Fig. 3. A sound spectrogram of a call sequence (including mating call or mating trill, low trills, grunts and grinds) as well as oscillograms of individual pulses of the mating call and low trill have been furnished by Mecham (1971); Littlejohn and Oldham (1968) provided an oscillogram of mating call pulses. The most distinctive characteristic of the mating call of R. blairi is the uniquely low pulse rate, which averages less than six pulses per second below 24 °C. In other taxa of the complex pulse rates are al¬ ways higher and never overlap those of R. blairi at comparable tem¬ peratures (Table 1). The number of pulses per call (which can be ex¬ tracted from Table 1 as pulse rate X call duration +1) is also un¬ usually low. Mean pulse number at the type locality for single calls and first calls in a series was only 4.76 (range 3 to 7) and subsequent calls in a series usually contained only three or four pulses. Mating calls of R. blairi resemble more closely those of the lowland form ( sensu Platz and Platz, in press) than those of other taxa examined, but pulse rates are well below those of the lowland form at comparable temperatures. Morphology and pattern. Some of the more diagnostic morphologi¬ cal and pattern characteristics of R. blairi are compared with those of other taxa of the R. pipiens complex in Table 2. The broken and dis¬ placed dorsolateral folds of R. blairi , as noted by Littlejohn and Old¬ ham (1968), have a diagnostic value of about 95 per cent in separating that form from R. pipiens and R. sphenocephala , both of which have continuous folds. Vestigial oviducts appear to be consistently absent in males of R. blairi , whereas they are almost always present in R. pipiens (Moore, 1944, examined one sample from Maine that lacked them). Oviducts also are present in males of R. berlandieri over most of Texas, although males from trans-Pecos Texas may lack them (Mc¬ Allister, 1 962), and the same is true for presumed R. berlandieri from some areas in Mexico (Cuellar, 1971). Specimens of R. blairi possess a usually well-defined labial stripe that extends from the posterior angle of the upper jaw to a point near the tip of the snout. It is always distinct in young animals, but occasionally becomes obscure in adults. A similar stripe appears to be present generally in R. pipiens and R. sphenocephala (Wright, 1949; Cuellar, 1971). In R. berlandieri (Cuellar, 1971; Platz, 1972) and in southern and lowland forms in Arizona (Mecham, 1968a, 1968/?; Platz and Platz, in press) a labial stripe is indicated posteriorly, but is less well defined, and becomes indistinct and diffuse anterior to the eye. Some yellow pigment may MECHAM ET AL. — NEW LEOPARD FROG 7 Table 1. — Comparison of some characteristics of mating calls of Rana blairi and some other members of the Rana pipiens complex. Mean values are given above ranges that are in parentheses. Locality Indi¬ viduals (No.) Tem¬ perature (°C) Call duration (sec) Pulse rate (No. /sec) Pulse duration (msec) Pulse rise time (msec) Rana blairi Texas, New Deal 10 22.0-24.0 0.70 5.3 28.6 9.7 (type locality) (0.36-1.00) (4.8-6. 1) (24-34) (7-16) Texas1 7 20-25 0.66 5.6 27.0 9.1 (0.48-0.89) (4.6-6. 8) (23-35) (7-11) Illinois2 5 21.8-22.5 0.68 5.1 24.0 — (0.57-0.77) (4.9-5. 3) (19.8-29.0) Rana pipiens Colorado1 4 12-16 3.75 13.7 17.8 2.0 (3.30-4.73) (12.9-14.6) (16-20) (2) Illinois2 5 17.6-18.2 2.90 19.4 7.3 — (2.48-3.39) (17.0-21.2) (6.9-7. 5) Rana sphenocephala Texas1 7 20-25 0.41 14.8 39.4 24.3 (0.31-0.52) (14.3-15.3) (33-50) (20-30) Illinois2 2 21.5-21.8 0.46 12.0 42.1 — (0.39-0.53) (11.8-12.3) (41.9-42.3) Rana berlandieri Texas1 7 20-25 0.64 28.2 19.1 9.7 (0.47-0.83) (26.0-31.3) (16-22) (9-11) Texas, McAllen3 4 22.9-23.1 0.54 22.3 18.3 4.3 (0.41-0.62) (20.4-25.8) (17.0-19.5) (3.5-5. 5) Lowland form (of Platz and Platz, in press) Arizona, Wikieup3 6 20.0-22.5 0.58 9.6 30.3 12.1 (0.44-0.74) (8.6-11.1) (25-33) (11-15) Southern form (of Mecham, 1 968a, 1968 b. 1971; Platz and Platz, in press) Mexico, Chihuahua, 2 21.0-23.6 1.36 34.6 14.7 0.9 Casas Grandes3 (0.84-1.75) (31.0-38.7) (10.0-18.0 (0.8-1. 0) ’Data of Littlejohn and Oldham (1968). ^Data of Brown and Brown (1972). 3Data of Mecham (unpublished). occur also on the lower abdomen and ventral thigh of mature R. blairi of both sexes, at least on the southern high plains (see description), but such coloration is very limited when present, and is not to be com¬ pared with the pronounced ventral yellow or yellow-brown of Arizona southern and lowland forms (Mecham, 1968u, 1968/?; Platz and Platz, in press). Ventral yellow appears to be absent generally in R. pipiens , R. sphenocephala , and Texas specimens of R. berlandieri (Wright and Wright, 1949; our observations). However, some presumed R. 8 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY N X SECONDS Fig. 3. — A sound spectrogram (Kay 6061 -A Sona-Graph, narrow filter band) of two mating calls (trills) of Rana blairi, recorded at the type locality on 22 May 1971 at a temperature of23.0°C. berlandieri in Mexico may be yellow-legged (Sanders and Smith, 1971). Protein variation. Salthe (1969), in an extensive study of lactate dehydrogenases in North American leopard frogs, found a number of electrophoretic variants of heart muscle lactate dehydrogenase (HLDH). The distribution of these variants conforms in part to the distribution of the various call types. Rana blairi and R. pipiens both Table 2. — Summary of certain morphological and pattern characteristics of Rana blairi and some other members of the Rana pipiens complex as indicated by information presented by Brown and Brown (1972), Cuellar (1971), Little¬ john and Oldham (1968), McAllister (1962), Mecham (1968a, 1968b), Moore (1944), Platz (1972), Platz and Platz (in press), Post and Pettus (1966), and Wright and Wright (1949), unless otherwise documented in the text. Species or form Dorsolateral folds Oviducts in males Labial stripe Yellow pigment (abdomen, thigh) R. blairi displaced absent complete occasional, slight R. pipiens continuous present complete absent R. sphenocephala continuous absent, except in peninsular Florida complete absent R. berlandieri (United States) displaced present, except in trans-Pecos Texas incomplete absent Southern form (of Mecham, 1968, 1971) displaced variable incomplete well developed Lowland form (of Platz and Platz, in press) displaced absent incomplete well developed MECHAM ET AL.— NEW LEOPARD FROG 9 possess a single HLDH variant (PIP I). PIP I, however, does not occur in either R. berlandieri or R. sphenocephala , although both of these taxa are highly polymorphic for HLDH. On the basis of HLDH, R. blairi is readily distinguishable from both R. berlandieri and R. sphenocephala , but not from R. pipiens. Platz (1972) compared serum proteins in the plains leopard frog and R. berlandieri , which was found to have a single fast migrating albumin band; the plains type has a slower double band. A slight dif¬ ference in relative frequency of slow and fast migrating transferrins also was found. Etymology. — The species is named in honor of W. Frank Blair because of his early suggestion that there were cryptic “ Rana pipiens' species in the southwestern United States (a suggestion which lead directly to the discovery of R. blairi in Texas in 1963), and more generally in recognition of his contributions to our knowledge of the systematics and evolutionary biology of anurans. Remarks. — Although some natural hybridization may occur within areas of contact between R. blairi and certain of the other taxa of the R. pipiens complex, reproductive isolation always appears to be com¬ plete enough to preserve the essential integrity of each form. Platz (1972) considered that only 12 of a sample of 138 frogs from the con¬ tact zone between R. blairi and R. berlandieri could be hybrids on the basis of electrophoretic analysis. Littlejohn and Oldham (1968) de¬ tected only three presumed hybrid mating calls in recorded samples of R. blairi and R. berlandieri that included at least 25 males of each taxon, and found no evidence of hybridization where R. blairi , R. berlandieri , and R. sphenocephala come together in Johnson County, Texas. Brown and Brown (1972) found no evidence of hybridization between sympatric R. blairi and R. sphenocephala in Mason County, Illinois. Brown and Brown (1972) recorded no hybrids between sympatric R. blairi and R. pipiens in La Salle County, Illinois, and Post and Pettus (1967) found no evidence of hybridization between the taxon described herein and R. pipiens where their ranges contact in southeastern Colorado. Experimental crosses by Mecham (1971) and Oldham (un¬ published) between R. blairi and R. sphenocephala produced only slight variations from normal development, as did crosses by Purcell (1968) between the new taxon and presumed R. pipiens from Arizona. Crosses with R. berlandieri (Mecham, 1969; Oldham, unpublished; Purrpll 1968) however, gave much more pronounced abnormalities, particularly using females of R. blairi and males of R berlandieri. In two such crosses with specimens from the contact zone, abnormali- 10 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY ties were so severe as to block development in all embryos (Purcell, 1968) . Hybrid males produced from both reciprocal crosses between R. blairi and R. berlandieri, however, proved to be fertile (Mecham, 1969) . These results indicate that developmental incompatibility, and perhaps hybrid sterility, are not highly effective as isolating mech¬ anisms between R. blairi and other members of the complex, although developmental incompatibility, at least, may contribute to reproduc¬ tive isolation from R. berlandieri. Reproductive isolation of R. blairi , therefore, must depend largely upon premating factors, although adaptive inferiority of hybrids could also play a role. Acknowledgments Much of the research on which this paper is based was supported by grants from the National Science Foundation. Support was received by Mecham under grants GB-6031 and GB-13791, by Littlejohn under grant GB-4659, and by Oldham under grant GB-133. Research support was also received by Brown and Brown under a grant (No. 722, 71-2) from Illinois State University. Literature Cited Brown, L. E., and J. R. Brown. 1972. Call types of the Rana pipiens com¬ plex in Illinois. Science, 176:928-929. Conant, R. 1958. A field guide to reptiles and amphibians of the United States and Canada east of the 100th meridian. Houghton Mifflin Co., Boston, 366 pp. Cuellar, H. S. 1971. Levels of genetic compatibility of Rana areolata with southwestern members of the Rana pipiens complex (Anura: Ranidae). Evolution, 25:399-409. Flury, A. G. 1972. Embryonic temperature adaptations of some mid- western members of the Rana pipiens complex. Unpublished Ph.D. dissertation, Texas Tech University, Lubbock, 64 pp. Littlejohn, M. J., and R. S. Oldham. 1968. Rana pipiens complex: mating call structure and taxonomy. Science, 162:1003-1005. McAllister, W. H. 1962. Variation in Rana pipiens Schreber in Texas. Amer. Midland Nat., 67:334-363. Mecham, J. S. 1968«. Studies on evolutionary effects of isolation in the Rana pipiens complex. Year Book Amer. Phil. Soc., pp. 314-316. - . 1968 b. Evidence of reproductive isolation between two populations of the frog, Rana pipiens , in Arizona. Southwestern Nat., 1 3:35-44. - . 1969. New information from experimental crosses on genetic relationships within the Rana pipiens species group. J. Exp. Zool., 170:169-180. - . 1971. Vocalizations of the leopard frog, Rana pipiens , and three related Mexican species. Copeia, 1971:505-516. Moore, J. A. 1944. Geographic variation in Rana pipiens Schreber of eastern North America. Bull. Amer. Mus. Nat. Hist., 82:345-370. M EC HAM ET AL. — NEW LEOPARD FROG 1 1 Pace, A. E. In press. Systematic and biological studies of the leopard frogs ( Rana pipiens complex) of the United States. Misc. Publ. Mus. Zool., Univ. Michigan. Platz, J. E. 1972. Sympatric interactions between two forms of leopard frog {Rana pipiens complex) in Texas. Copeia, 1972:232-240. Platz, J. E., and A. L. Platz. In press. Rana pipiens complex: hemoglobin phenotypes of sympatric and allopatric populations in Arizona. Science. Post, D. D., and D. Pettus. 1966. Variation in Rana pipiens (Anura: Rani- dae) of eastern Colorado. Southwestern Nat., 1 1:476-482. - . 1967. Sympatry of two members of the Rana pipiens complex in Colorado. Herpetologica, 23:323. Purcell, J. W. 1968. Embryonic temperature adaptations in southwestern populations of Rana pipiens. Unpublished MS thesis, Texas Tech University, Lubbock, 46 pp. Ruibal, R. 1957. An altitudinal and latitudinal cline in Rana pipiens. Copeia, 1957:212-221. Salthe, S. N. 1969. Geographic variation of the lactate dehydrogenases of Rana pipiens and Rana palustris. Biochem. Genet., 2:271-303. Sanders, O., and H. M. Smith. 1971. Skin tags and ventral melanism in the Rio Grande leopard frog. J. Herpetol. 5:31-38. Schmidt, K. P. 1953. A check list of North American amphibians and reptiles, 6th Ed., Amer. Soc. Ichthyol. Herpetol., Chicago, 280 pp. Wright, A. H., and A. A. Wright. 1949. Handbook of frogs and toads of the United States and Canada. Comstock Publ. Co., Ithaca, 640 pp. Addresses of authors: John S. Mecham. The Museum and Department of Biological Sciences, Texas Tech University, Lubbock 79409; Murray J. Littlejohn, Department of Zoology, University of Melbourne, Parkville, Vic¬ toria 3052, Australia; Robert S. Oldham, Department of Zoology, University of Ibadan, Nigeria; Lauren E. Brown and Jill R. Brown, Department of Bio¬ logical Sciences, Illinois State University, Normal 61761 . PUBLICATIONS OF THE MUSEUM TEXAS TECH UNIVERSITY Two publications of The Museum of Texas Tech Uni¬ versity are issued under the auspices of the Dean of The Graduate School and Director of Academic Publications, and in cooperation with the International Center for Arid and Semi-Arid Land Studies. Shorter research papers are published as Occasional Papers, whereas longer contri¬ butions appear as Special Publications. Both are num¬ bered separately and published on an irregular basis. Institutional libraries interested in exchanging publi¬ cations may obtain the Occasional Papers and Special Publications by addressing the Exchange Librarian, Texas Tech University, Lubbock, Texas 79409. Individuals may purchase separate numbers of the Occasional Papers for 50 cents each through the Exchange Librarian. Remit¬ tance must be enclosed with request. ~ L[y lo Idoc/c | OCCASIONAL PAPERS THE MUSEUM TEXAS TECH UNIVERSITY COMP. ZOOli library NUMBER 19 FEB 1 q W74 8 FEBRUARY 1974 Harvard STRATIGRAPHIC OF THE SHAFER LIMESTONE, SAN JUAN COUNTY, UTAH Richard B. Mattox and John P. Brand The Cutler Formation, or Group, has been the subject for strati¬ graphic controversies since it was named by Cross and Howe for ex¬ posures of redbeds along Cutler Creek at sites near Ouray, Colorado. This sedimentary unit is composed primarily of arkosic debris derived from the Precambrian metamorphic and igneous provenance of the Uncompahgre Plateau. It parallels the western margin of the plateau, is thickest near its source area, and its arkosic and redbed phases ex¬ tend approximately 50 miles southwest from the source area. The manner in which the Cutler Formation was deposited, by streams flowing westward from the Uncompahgre Plateau, leads to the inevitable conclusion that the basal beds on the eastern margin of the basin are distinctly older than the basal beds near the western limit of deposition. The formation crosses time planes and includes the boundary between the Pennsylvanian and Permian Systems. To add additional complexity to the problem, salt anticlines were developing at the time the formation was being deposited. A thickness of 8000 feet of Cutler beds exists near Gateway, Colorado, but on a nearby salt anticline less than 2000 feet of arkosic material are present. The trend of the salt anticlines is normal to the general direction of flow that streams transporting the Cutler sediments must have followed (Fig. 1). These salt structures appear to have been a significant con¬ trolling factor in the distribution of the Cutler sediments. A western source area may have provided sediments for units deposited west and south of the area in which the coarse, arkosic con¬ glomerates and redbeds were developed. The combination of many factors produced the multiple facies changes that exist within the Cut-