Metaconid, and Each Lophid Shows a Complicated Separate the Cones Of

86 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

TABLE 23.—Measurements (in mm.) of Perchoerus nr. P. minor, Perchoerus nr. P. norms, and Perchoerus norms

P. nr. P. minor P. or. P. nanus P. nanus No. No. No. No. No. 8237 9000 8236 19873. 11784"

P4 , antero-posterior length 8.6 134 , transverse width 10.8 MI, antero-posterior length 10.2 • • • • MI, transverse width 10.6 Crown length of Pi-M3 Crown length of P3-M3 62.6 . . Crown length of MI - M3 43.1 P3, antero-posterior length 8.6 9.5 P3, transverse width 4.5 antero-posterior length •10.5 10.7 11.0 P4, transverse width 5.6 7.0 MI, antero-posterior length 10.5 10.2 11.3 MI, transverse width 7.9 7.6 7.6 M2, antero-posterior length 11.3 12.1 12.2 M2, transverse width 8.6 9.3 M3, antero-posterior length 18.3 15.2 M3, transverse width 9.5 Depth of ramus at P2 25.0 Depth of ramus at M3 32.0 a. University of Colorado Museum. b. Dr. JOSEPH T. GREGORY kindly supplied the measurements of the type specimen of Perchoerus nanus (Yale Univ., Peabody Mus. Nat. Hist. No. 11784). Scarfs ( 1940, p. 503) measurements of the teeth of the type specimen were based on MARSH ' S illustration ( 1894, p. 271, fig. 28) of the specimen. c. Estimated. d. Damaged. damaged, and most of the enamel has been weath- especially M,. The M, and M 2 of P. socialis ered away. Enough of the tooth remains to show ( MARSH) from the John Day beds of Oregon are that it was bilophodont and that there was some also similar in size to this Whitneyan specimen, but complicated folding of the enamel about the cusps. other comparisons are not possible. M, is larger than M, and equally worn and weathered ; it has a cingulum on the anterior face of the FAMILY ANTHRACOTHERIIDAE GILL, 1872 metaconid, and each lophid shows a complicated folding of the enamel on the anterior face. M, is Heptacodon sp. weathered but not greatly worn. The metaconid Referred specimen.—Cedar Creek member (middle): No. has an anterior cingulum. Practically no valleys 8235; left jaw with P4-M3; NM sec. 5, T. 11 N., R. 54 W., separate the cones of the metalophid and hypo- Logan County. lophid, but the transverse valley between the two This is the first known occurrence of the genus lophids is easily seen. in This transverse valley is northeastern Colorado and seemingly only the sec- divided by a faint crest which unites two the lophids ond record of a lower jaw. The types for all species and runs from the hypoconid to internal side the of of Heptacodon are based on upper teeth and skulls, third the protoconid. The lobe is united to the and none have lower jaws. The only other lower hypoconid by a similar crest. third is The lobe jaw known, AMNH No. 1360, was referred to seems to consist large and of one cusp. A small H. occidentalis by Scum. tubercle Scorr (1940, p. 484) be- lies between the third lobe and the ento- cause of geological age ( lower conid on the internal Brule), but he makes border of the tooth, thus en- it plain that the jaw could equally well be assigned closing a basin. On the external border, two small to H. curtus MARSH of the upper Brule. No. 8235 tubercles lie between the third hypo- lobe and the agrees with the description of AMNH No. conid. Although the rest of the teeth size 1360 in are the pattern and size, the dimensions of the teeth being, of those of Perchoerus naafis, or smaller, M, is equal in all cases, within 1 mm. of those given by Scorr in size to P. M, of probus. The symphysis is long (1940, p. 485). and seems to reach back to 132 ; the ramus is thick and sturdy. Anthracotheriid sp. The most unusual features of No. 19873 are the shortness of P, and the unusual length of M, in Referred specimen.—Horsetail Creek member: No. 9788; fragment of upper molar; W3 sec. 16, T. 10 N., R. 51 W., relation to P -1\4 2 , when compared with specimens Logan County. of P. probus, P. nantis, and P. minor ( Table 23). The specimen may be P. probus, rather than P. This fragment of tooth is similar to the M 2 of nanus, or it may be an unnamed species—a pos- Bothriodon but is insufficient to assign it, unequivo- sibility enhanced by the relative sizes of the teeth, cally, to this genus. TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 87

FAMILY AGRIOCHOERIDAE LEIDY, 1869 No. 112 has the first molar relatively reduced. Otherwise the teeth do not differ in any respect Agriochoerus antiquus LEIDY from those of Agriochoerus ryderanus. The dimen- 4955, Agriochoerus antiquus LEIDY, 1850a, p. 122. sions ( Table 24) of the upper molars of No. a skull and associated right ramus of A. ryderanus Referred specimen.—No. 5029; anterior part of skull with from the John Day formation of Oregon, are given cheek dentition; according to catalogue data this specimen was collected by H. T. MARTIN in northeastern Colorado. for comparative purposes. Although the matrix and type of preservation is FAMILY MERYCOIDODONTIDAE THORPE, 1923 that seen in northeastern Colorado specimens, the reference of this particular specimen to a Colorado The use of cranial dimensions and proportions locality must remain in doubt because it was not for discriminating the various species and sub- Merycoidodon, as utilized by BUMP 81 catalogued by MARTIN personally and was not species of listed in his field notes. This, in itself, would not LOOMIS ( 1930 ), THORPE ( 1937 ), and Scorr ( 1940 ), be of importance were it not that a second speci- was found to be unsatisfactory in studying the specimen, No. 206, is listed in the Museum records as mens from northeastern Colorado. coming from northeastern Colorado, but its pres- Using the criteria of size of skull and shape of ervation and matrix resembles material from South nasals suggested by COPE ( 1884, p. 511), the mery- Colorado. coidodont skulls from northeastern Colorado fall Dakota much more than from the 5029 agrees into two groups — those of smaller size with In size and other characters No. Merycoidodon gracilis; closely with descriptions of Agriochoerus antiquus. nasals acute posteriorly, large and those of larger size with the nasals obtuse pos- No. 206 deserves mention because of its teriorly, Mer ycoidodon culbertsonii. However, the size. Although the dentition is the size of that in specimens of each species show variation that does Agriochoerus antiquus, the skull has a length from not permit further separation into subspecies ( or the premaxillary to the occipital condyle that must additional species ) as was done by COPE and others. have exceeded 235 mm. The sagittal crest is well The groups established by them seemingly repre- developed; it has a relatively deep depression be- sent selected variants of the total population. tween the bifurcated anterior ends. The orbital Because the exact stratigraphie position is not region was probably wide, but the muzzle is narrow known, the series of skulls and jaws of Mery- A. antiquus. as in coidodon from northeastern Colorado collected by H. T. MARTIN for the University of Kansas is not Agriochoerus cf. A. ryderanus ( CopE ) listed under the referred specimens. Referred specimen. — ?Cedar Creek member: No. 112; fragment of left maxillary with MI-M 3 ( M3 damaged); Merycoidodon culbertsonii LEIDY western Logan County. Merycoidodon culbertsonii LEMY, 1848, p. 47. Our catalogue states that this specimen was col- Referred specimens.—Horsetail Creek member: No. 8496; MAR- lected by H. T. MARTIN from "Cedar Creek." left M3 ; SE41 sec. 1, T. 11 N., R. 54 W., Logan County. No. TIN'S field notes, and the associated fossils collected 9108; lower jaws; W3i sec. 29, E3i sec. 30, T. 11 N., R. 53 W., on the same day, indicate that the specimen came Logan County. No. 9128; lower jaws; NE X sec. 31, T. 11 N., 11 R. 56 W., Weld County. from the Cedar Creek member somewhere in T. Cedar Creek member: No. 9141; damaged skull; NW}i N., R. 55 W., Logan County. It is my opinion that sec. 3, T. 11 N., R. 54 W., Logan County. the reference to Cedar Creek by MARTIN did not mean the Cedar Creek member, inasmuch as he With the materials at hand it is difficult to recog- generally used letters of the alphabet to indicate nize the subspecies of Merycoidodon culbertsonii horizons. Evidently MARTIN'S, and probably MAT- by the criterion established by COPE, which does no THEw's, concept of Cedar Creek was that of the more than differentiate the specimens with larger stream draining this area and not the Cedar Creek teeth [M. c. culbertsonii ( CopE ) ] from those with of today, which lies to the south. smaller teeth [M. c. periculorum ( COPE ) ]. Speci- mens from the Horsetail and Cedar Creek members TABLE 24.—Measurements ( in mm. ) of Agriochoerus cf. show, seemingly, the same vertical range for both A. ryderanus size groups, which suggests that selected variants make up the two subspecies. On the other hand, No. 112 No. 4955 lack of material prevents a final answer to the Crown length of MI-M3 • 35.8 problem of vertical range, and because it is un- MI, antero-posterior length 9.6 10.9 settled there yet remains the possibility that the MI, transverse width 10.5 11.7 M 2 , antero-posterior length 12.8 12.4 mean size of M. culbertsonii was increasing, with M2,transverse width 14.1 13.7 M. c. periculorum representing the earlier stage and M3, antero-posterior length 14.0' 14.3 M. c. culbertsonii the later stage. This is not indi- M 3 , transverse width 16.0' 17.0 cated by the limited evidence at hand, but the idea a. Estimate based on badly damaged tooth. warrants further investigation. 88 UNIVERSTTY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

THORPE ( 1937 ) thought M. c. periculorum to be FAMILY CAMELIDAE GRAY, 1821 a small geographic variant or mutant confined mainly to Colorado, and he pointed out that this Eotylopus sp. would not support the view that it could be the Referred specimens.—Horsetail Creek member: No. 8974; female of the more widespread M. c. culbertsonii. left MI. No. 9116; left M 1 -M 3 . Both specimens from W34 The contention of BUMP Sc Loomis ( 1930 ) that sec. 9, T. 10 N., R. 51 W., Logan County. M. periculorum is a distinct species is not sup- Dr. PAUL O. McGREw kindly compared the maxil- ported by present evidence. That M. c. periculorum lary fragment No. 9116 with the type specimen of represents the smaller individuals of the M. cul- Eotylopus reedi MATTHEW and assures me that the bertsonii population appears to be the best sup- specimen undoubtedly belongs to the genus. On ported possibility at present. the other hand, the strong internal cingula of the molars and the prominent internal pillar on M3 Merycoidodon gracilis (LEmy) lead Dr. McGREw to think that the specimen is Oreodon gracilis LEIDY, 1851a, p. 239. probably specifically different from Eotylo pus reedi. Merycoidodon gracilis, HAY, 1902, p. 666. Because of Dr. McGREw's interest in this group, the material is referred to him for further study. Referred specimens.—Horsetail Creek member: No. 9107; fragments of upper and lower jaws; W% sec. 29, E3'2 sec. 30, This discovery of Eotylo pus in late Chadronian T. 11 N., R. 53 W., Logan County. beds extends the range of this primitive genus up- Cedar Creek member: No. 9143; skull; SW% sec. 12, T. ward and firmly establishes its presence in the 11 N., R. 54 W., Logan County. No. 9144; damaged skull Oligocene. and jaws; SW% sec. 21, T. 11 N., R. 53 W., Logan County. No. 9145; left P4-M 2 ; SW% sec. 21, T. 11 N., R. 53 W., Logan County. No. 9147; skull; NE% sec. 28, T. 11 N., Poëbrotherium wilsoni LEIDY R. 53 W., Logan County. Pabrotherium wilsoni LEMY, 1847, p. 322. This species may be recognized by its posteriorly Referred specimens.—Cedar Creek member: Univ. Colo- acute nasals and small size of the skull. Some of rado Mus. No. 19123; skull and jaws; northwest of Sterling, the specimens have the broad frontals and length of Colorado. No. 9027; right jaw with P i , P3-M3; SW34 sec. 12, skull that are attributed to Merycoidodon affinis T. 11 N., R. 54 W., Logan County. No. 9028; right jaw with II, C-M3; sec. 28, T. 11 N., R. 53 W., Logan County. LEIDY, but the size of the teeth is within the range No. 9029; right jaw with Pi-M3; NW% sec. 3, T. 11 N., of large M. gracilis. Like specimens of Mery- R. 54 W., Logan County. No. 9030; left MI-M3; sec. 28, coidodon culbertsonii, these specimens indicate a T. 11 N., R. 53 W., Logan County. wide range of variation in size for the species. The species has been found throughout specimens from this area which This the Cedar THORPE ( 1937 ) ro. Creek member in numbers almost equal to those ferred to M. affinis may be the males of M. gracilis, of the oreodonts. Considerable variation exists in but it appears likely that they more are merely the depth of the jaws part of which is owing to age large variants of both sexes of M. gracilis. and perhaps part to sex. Some variation is seen in Eporeodon major (LEmY) the anterior teeth, but the cheek teeth seem remark- ably constant. Notable in this respect are Nos. Oreodon major LEIDY, 1854, p. 55. 9027, 9028, and 9029. These three specimens have Eporeodon major, MARSH, 1875, p. 250. light jaws, smaller diastemata, and trenchant ca- MArrxEw reported (1901, p. 396) Eporeodon nines and first premolars, while the cheek teeth are major as occurring in the Leptauchenia beds of indistinguishable from specimens with larger jaws northeastern Colorado. The specimens collected by and caniniform canines and first premolars. Some the American Museum were described as a variety, specimens suggest, and better material may demon- E. m. var. cedrensis MAT-rxEw, because of their strate, that the shallow jaws with trenchant canines consistently smaller size. and first premolars grade into the condition seen in No additional identifiable specimens have been the larger specimens of Poëbrotherium wilsoni. A found. possible conclusion is that these are small variants or females of P. wilsoni. Leptauchenia decora LEIDY Among the specimens collected by H. T. MARTIN Leptauchenia decora LEIDY, 1856, p. 88. in northeastern Colorado are two poorly preserved skulls, Nos. 1 and 190. These two skulls seem to Referred specimens.—Vista member: No. 8497; right 134- M 1 , right M 1 -M3 , left Pi-P2; NE% sec. 3, T. 11 N., R. 54 W., have no, or very small, lacrimal vacuities as com- Logan County. pared with other northeastern Colorado specimens, and the depth of the skull is perhaps less than in MATrxEw ( 1901, p. 357) referred specimens from other specimens. Colorado to this species. Our material is too incomplete to do more than make approximate meas- Pabrotherium labiatum COPE urements, but these measurements indicate that the specimens agree in size with those of typical Pabrotherium labiatum COPE, 1881, p. 271. Leptauchenia decora. Type.—AMNH No. 6520; Cedar Creek beds, head of TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN CoLoRADo 89

Cedar Creek, Logan County, Colorado (fide COPE & MAT- No. 9115 has molars smaller than those of Poebro- THEW, 1915). therium wilsoni, and the heel of M s relatively re- Referred specimen. - ?Cedar Creek member ( lower ): No. duced. However, P., is relatively large-almost as 9031; left jaw with C, R4-M3; sec. 28, T. 11 N., R. 53 W., Logan County. large as the P, of P. labiatum ( Table 25). MATTHEW ( 1901, p. 422) commented upon find- This species seems to be confined to the lowest ing a hind foot of Poebrotherium in the "Titano- Cedar Creek beds or upper part of the Horsetail therium Beds" that was somewhat longer and about Creek member, for nothing of comparable size has one-fourth heavier than "either" [P. wilsoni and been found in higher beds. Poebrotherium labiatum P. labiatun] of the known species. is distinctive in size ( Table 25), although of the same general relative proportions as P. wilsoni, and Protomeryx campester MATTHEW there does not seem to be any intergradation between the two species. Protomeryx campester MAI-rxEw, 1901, p. 422. The apparent restriction of Poebrotherium labia- Type.-AMNH No. 8969; Leptauchenia beds, Colorado. turn to the lowest part of the Cedar Creek member, Referred specimen. - ?Cedar Creek member: No. 133; whereas the remains of P. tvilsoni are found mandible; sec. 3, T. 11 N., R. 54 W., Logan County. throughout the silty phase of the Cedar Creek Our specimen was found in 1925 by Gums HESSE member, would argue against the possibility of and was recorded in the field notes as coming from P. labiatum being the male of P. tvilsoni. A ratio "high" in the Orellan beds. On the basis of geo- of about one specimen of P. labiatum to twenty graphic locality alone it is possible that the speci- specimens of P. wilsoni further suggests that the men came from the Vista member, which is some- two kinds are two species instead of different sexes what difficult to recognize at places in Chimney of the same species. Canyon. Of course, the same statement is equally to the age assignment given to the type Poëbrotherium sp. applicable specimen by MATTHEW. Our specimen is un- Referred specimens.-Horsetail Creek member: No. 8492; doubtedly later than the silty phase of the middle left M 1 -M3 ; SE3.i sec. 1, T. 10 N., R. 54 W., Logan County. part of the Cedar Creek member. No. 9026; right M 2 ; Ni sec. 31, T. 11 N., R. 56 W., Weld No. 133 is practically identical to the type in size County. No. 9115; left jaw with P4-M3; W3i sec. 9, T. 10 N., R. 51 W., Logan County. and proportions. One feature of Protomeryx cam pester, not men- Specimens Nos. 8492 and 9026 and specimens of tioned by MATTHEW, is the smaller P s-PIK-M s Poebrotherium wilsoni are closely similar except ratio as compared with species of Poebrotherium. that the former are smaller and have weaker styles. All the specimens of Poebrotherium from north-

TABLE 25. - Measurements ( in mm. ) of Poebrotherium wilsoni, Poëbrotherium labiatum, and Poebrotherium sp.

Poebrotherium sp. P. wilsoni P. labiatum No. No. No. No. No. No. 8492 9026 9115 9029 19123. 9031

Crown length of MI-M 3 32.4 P4 , antero-posterior length 7.4 b P4 , transverse width Ml, antero-posterior length 9.0 . . M', transverse width 10.4 M 2, antero-posterior length 11.3 11.5 M2,transverse width 11.4 9.8 M3, antero-posterior length 13.3 • • • • M 3, transverse width 12.1 • • • Crown length of P2-M3 60.0 66.6

Crown length of MI - M3 34.2 36.5 35.5 .43.5 P2, antero-posterior length 7.6 7.7 P2,transverse width 2.0 2.5 P3, antero-posterior length . . 8.1 8.9 P3, transverse width 2.8 3.4 P4, antero-posterior length 9.5 7.9 8.9 10.0+ P4, transverse width 3.8 3.1 4.0 4.7 MI, antero-posterior length 9.6 10.7 9.0 11.4 MI, transverse width 6.2 6.4 6.4 7.1 M2, antero-posterior length 10.5 11.5 11.1 13.4 Mo, transverse width 7.1 7.3 7.7 8.2 M3, antero-posterior length 13.8 14.7 15.9 19.5 M3, transverse width 7.0 6.4 7.7 8.3 Depth of ramus at M2 13.5 14.7 20.4 21.6 a. University of Colorado Museum. b. Damaged. 90 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS eastern Colorado have a 132 -P 4/M 1 -M 3 ratio that eastern Colorado. No. 9013 is slightly smaller, but falls between 0.66 and 0.68, whereas the referred otherwise similar to other specimens of this species. specimen and type of P. cam pester have a ratio of 0.57. Leptomeryx sp. (Small form) Attention is directed to a footnote by STOCK Referred specimen.—Cedar Creek member: No. 9035; ( 1935, p. 122) in which Protomeryx cedrensis MAT- left M 1 -M3 ; center sec. 3, T. 11 N., R. 54 W., Logan County. THEW ( 1901 ) is made a synonym of Protomeryx cam pester. No. 9035 has an M 1 -M3 length of 16 mm. as compared with a length of 20.7 mm. in the specimen FAMILY HYPERTRAGULIDAE COPE, 1879 ( No. 9034) referred to Leptomeryx evansi. In addition, this small specimen lacks the strong tubercle Hypertragulus calcaratus ( COPE ) that is seen at the base of the postero-internal lobe of the molars in L. evansi, and the M 1 is relatively Leptauchenia calcarata COPE, 1873b, p. 7. much smaller. Hypertragulus calcaratus, COPE, 1873d, p. 419. That there is a species of Leptomeryx smaller Type.—AMNH No. 6518; Oligocene of northeastern Colo- than L. evansi or L. esukatus in the Cedar Creek rado. member seems rather certain, but until enough ma- Referred specimens.—Cedar Creek member: No. 9036; terial is collected to allow upper and lower teeth of several individuals ( apparently positive correlation of representing one herd of animals ); at boundary lbetween differences in occlusal pattern and in premolar and secs. 17-18, T. 11 N., R. 55 W., Logan County. molar sizes, and to permit determination of the range of variation, this small species remain Hypertragulus calcaratus is confined to must the Cedar undescribed. Perhaps this small species was Creek member in northeastern the Colorado. No no- one MATTHEW (1902e, ticeable differences were found p. 314) had in mind when in the specimens he mentioned from the various levels. a small, undescribed form from the Leptauchenia beds of northeastern Colorado. Leptomeryx esulcatus COPE Hypisodus minimus ( COPE ) Leptomeryx esulcatus COPE, 1889a, p. 154. Leptauchenia minima COPE, 1873b, p. 8. Referred specimens.—H ors etail Creek member: No. 9104; Hypisodus minimus, COPE, 1873d, p. 419. left P2-M 2 and left P.-M 3 ; WY2 sec. 29, Eli sec. 30, T. 11 N., R. 53 W., Logan County. Type.—AMNH No. 6543; Oligocene, northeastern Colo- Cedar Creek member (middle ): No. 8998; right jaw with rado. P2-Ma; W3(: sec. 7, T. 11 N., R. 53 W., Logan County. Referred specimens.— Cedar Creek member (lower and middle): No. 8281; right and left P4-Ms; SE34 sec. 21, MArrirEw ( 1903, p. 223) and CLARK ( 1937, p. T. 11 N., R. 53 W., Logan County. No. 9040; associated 823) discussed p, of this species and pointed out upper and lower cheek teeth; locality same as No. 8281. that the internal ridge is connected with the heel in I have collected specimens of this species from this species opposed to as the condition in Lepto- all levels of the Cedar Creek member up to within meryx evansi where the external ridge connects with 100 feet of the top of the beds. No. 9130 from the the heel. This is the only constant character that upper distinguishes part of the Horsetail Creek member may be the two species. MATTHEW thought referable to this species. the average size of L. esulcatus was greater, which may be In dental pattern these specimens correspond in true, but the specimens from northeastern general with Colorado seen by the description given by SCOTT (1940, me have a size range similar to pp. 538-535), that of L. but the range in size includes speci- evansi, and it is doubtful if the average mens which are size is much different. smaller than those indicated by his measurements, although Specimens of Leptomeryx none are as small as com- are not rare in the parable teeth of Hypisodus alcer TROXELL. An- Chadronian beds of northeastern Colorado, but few other point of difference from SCOTT ' S have P, present, so that it cannot be determined description concerns P„. Judged by the presence of alveoli in whether L. esulcatus is the only member of the the Cedar Creek specimens, only one has diastema genus present in the Horsetail Creek beds. a between P. and P„ whereas three do not; P, is not Leptomeryx evansi LEIDY shed early in life, if at all, and was double rooted. Of great interest is the rate of growth seen in the Leptomeryx evansi LEIDY, 1853, p. 394. series of lower jaws and maxillaries. Apparently Referred specimens.—Cedar Creek member: No. 9034; the permanent dentition was erupted before the right P2-M3 , P3-M3, left P4-M 3, P3-M3 ( in occlusion ); at jaws and skull attained full development, and M, boundary between secs. 17-18, T. 11 N., R. 55 W., Logan County. was developing roots before the last deciduous tooth was shed. No upper or lower teeth were Vista member: No. 9013; left P4-M 2 ; NE34 sec. 17, T. 11 N., R. 53 W., Logan County. observed which did not have, at least, incipient roots—a statement also applicable to the Chad- No. 9034 is one of the largest of several hundred ronian and Whitneyan species from northeastern specimens of this species which I collected in north- Colorado. These observations are not wholly in TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 91

TABLE 26.—Measurements (in mm.) of Hypisodus sp. (Form A)•

No. 8271

Crown length of MI-M3 12.1 MI, antero-posterior length 4.0 M1, transverse width 2.9 M2, antero-posterior length 4.35 M2, transverse width 2.6 M3, antero-posterior length 4.5 M 3 , transverse width 2.3 Crown length of Mi-M3 12.8 Mi, antero-posterior length 3.6 3.7 3.5 3.4 MI, transverse width 2.1 2.2 2.1 M2, antero-posterior length 4.3 3.7 3.8 M2, transverse width 2.3 2.5 M3, antero-posterior length 5.9 5.8 M3, transverse width 2.3 2.15 a. The measurements are arranged so that the youngest specimen is at the left, and the oldest at the right of the table. All measurements were made at the occlusal surface. The transverse measurements of the upper molars were made from the antero-internal crescent to the external rib.

agreement with those of Scorr, who thought that These teeth are large like those described from roots were developed in the molars only in old age. the Chadronian beds, but they lack the strongly de- In my opinion, much could be gained by a study of veloped styles. In size, they approach Hypisodus the teeth of this genus with a view toward cor- sp. ( from the "Uppermost Brule" of E. Nebraska) relating growth of the skull, root development, tooth mentioned by Scorr (1940, p. 535). pattern, tooth size, and geological age. Compari- sons already made between specimens from the THE MIOCENE FAUNA Horsetail Creek and Cedar Creek members indicate possibilities in this study. Relatively little Miocene material was collected by me in northeastern Colorado and much of that Hypisodus sp. (Form A) which was collected adds nothing new to a knowl- Referred specimens.—Horsetail Creek member. No. 8271; edge of the species other than to clarify the strati- five partial lower jaws containing one to three molars, and a graphic position of some. 25 left maxillary with P4-M3 ; NE% sec. 31, T. 11 N., R. 56 W., Four species from the Marsh Collection at Yale Weld County. No. 8285; left M3; SE% sec. 1, T. 10 N., R. 54 W., Logan County. No. 8286; right M3; W% sec. 9, University—Proheteromys parvus, Nothocyon vul- T. 10 N., R. 51 W., Logan County. No. 8973; left P 4 -M 3 ; pinus, Mesocyon robustus, and Pseudaelurus marshi W34 sec. 9, T. 10 N., R. 51 W., Logan County. No. 9110; listed, it should be kept in mind that these, left M2-M3; W34 sec. 29, Eli sec. 30, T. 11 N., R. 53 W., —are but Logan County. specimens may not be from northeastern Colorado. ?Horsetail Creek member: No. 8269; right maxillary fragment with M 1 -M3 , and left lower M3 ( not associated); SE% CLASS OSTEICHTHYES sec. 17, T. 11 N., R. 65 W., Weld County. Teleostean, sp. indet. Although the occurrence of Hypisodus in Chad- ronian beds is surprising, it is not entirely unex- Referred specimen.—Pawnee Creek formation ( Eubanks pected. The discoveries of CLARK ( 1937 ), and the local fauna ): No. 9252; maxillary; NE% sec. 1, T. 10 N., stratigraphic position of some of the fossils in north- R. 59 W., Weld County. eastern Colorado have already indicated that a large This bone is damaged, but it is similar to the part of the fauna once thought to be restricted to maxillary of a carp. Orellan beds also lived in Chadronian times. Noteworthy characteristics of the teeth compared CLASS REPTILIA to those of Hypisodus minimus are: well-developed parastyle and rib on the antero-external crescent of ORDER TESTUDINES BATSCH, 1788 all the molars; equally well-developed metastyle on FAMILY TESTUD1NIDAE GRAY, 1825 the third molar; shorter crowns; and larger size ( Table 26). Testudo osborniana HAY Testudo osborniana HAY, 1904, p. 504. Hypisodus sp. (Form B) Type.—AMNH No. 5868; Pawnee Creek beds, north- Referred specimens.—Upper 40 feet of Cedar Creek mem- eastern Colorado. ber, and Vista member: No. 9037; right P4-M3; SW% sec. 2, T. 11 N., R. 54 W., Logan County. No. 9038; left M 3 ; 25. Subsequent to the writing of this paper, a considerable number of Miocene specimens were collected. These are being prepared for sec. 22, T. 11 N., R. 52 W., Logan County. No. 9039; left study and should answer some of the questions posed in the faunal dis- P4-M2; Eli sec. 12, T. 11 N., R. 54 W., Logan County. cussion and in the following pages. 92 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBTJTIONS

Gopherus pansa ( HAY) how much difference in pattern exists without comparison Testudo pansa HAY, 1908, p. 420. of the actual specimens. Differences between this tooth M 1 Gopherus pansa, WILLIAMS, 1950, p. 26. and in the type of Metechinus nevadensis MArrHEw are seen in the less concave Type.—AMNH No. 5869; Pawnee Creek beds, north- borders and more quadrate shape eastern Colorado. of the former. Because of these differences, the tooth was referred Specimens that approach the size of Testudo to Brachyerix rather than to Metechinus. osborniana or Gopherus pansa have been found by me in bed No. 5 of measured section XIV in the FAMILY SORICIDAE GRAY, 1821 Pawnee Creek at Martin formation Canyon. Smaller Soricid, ?n. gen. and sp. specimens of Testudo or Gopherus have been found in beds containing Ustatochoerus and Merychippus Referred specimens.—Pawnee Creek formation ( Martin west of Sand Canyon. Canyon local fauna ): No. 9280; right 1st, 2nd, and 3rd upper teeth in fragment of bone. No. 9281; left upper incisor. No. 9282; posterior part of right jaw. No. 9341; CLASS AYES fragment of left lower incisor. NE3.i sec. 27, T. 11 N., R. 53 W., Logan County. Passerine, sp. indet. These specimens were collected from Quarry A Referred specimen.—Pawnee Creek formation ( Martin Canyon local fauna ): No. 9831; distal end of left tarsometa- and are considered, tentatively, to be individuals of tarsus; Quarry A, Martin Canyon, NE sec. 27, T. 11 N., one species. If this be true, the soricid is an unusual R. 53 W., Logan County. and unnamed kind. It is left unnamed pending further exploration of the deposit. CLASS MAMMALIA The base of the first upper tooth overlaps the ORDER INSECTIVORA BOWDICH, 1821 bone and has a basal cuspule as in other soricids. The tooth broadens anteriorly where a cuspule on FAMILY ERINACEIDAE BONAPARTE, 1838 the inner edge forms a second and smaller prong alongside the pointed principal cusp, thus producing Brachyerix spp. a rather inefficient chisel-like cutting edge. The Referred specimens.—Pawnee Creek formation ( Martin root of this tooth is deeply grooved on the inner Canyon local fauna ): No. 9358; outer half of left M 1 ; NE%. surface, giving the impression of fused roots. sec. 27, T. 11 N., R. 53 W., Logan County. The second upper tooth is relatively broad, with Pawnee Creek formation ( Kennesaw local fauna ): No. 9175; left M 1 in fragment of maxillary; SW)i sec. 26, T. 12 the principal cusp close to the outer border. Two N., R. 55 W., Logan County. small cusps on the inner border form a "protocone" and a "hypocone," the first being united to the prin- These specimens have been referred to the genus cipal cusp by a ridge. Together these Brachyerix structures but because of their large size they and the encircling cingulum make an incipient probably basin are not referable to Brachyerix macrotis in the postero-internal part of the tooth. MATTHEW. The third upper tooth is relatively small but has Only the outer half of No. 9358 is preserved and a well-formed heel. it shows a low, rounded paracone and metacone The posterior part of the lower incisor does not with the cingulum and styles having about the same differ basically from the lower incisors of other degree of development as in Brachyerix macrotis. soricoids: the upper surface is flattend and bor- No. 9175 is less worn than the corresponding dered by ridges; the sides converge below to give tooth in Brachyerix macrotis and shows the four the tooth a roughly triangular shape; and the enamel principal cusps to be sharp pointed with the para- is thick and rugose. cone highest. The cingulum is absent except for None of the teeth fluoresce under ultraviolet the parastyle and metastyle which show greater light. development than in B. macrotis or No. 9358. The No. 9282, the lower jaw fragment, does not have zygomatic arch is lighter than the arch in B. ma- any part of the horizontal ramus preserved, but the crotis but occupies a position similar to that in broken edge of the fragment suggests that the Brachyerix; that is to say, the arch arises opposite missing part was shallow and weak. The coronoid M 1 and not farther back as in Erinaceus europaeus. process is narrow antero-posteriorly and rounded at Dimensions of No. 9175 are: length ( parastyle to the tip. No intertemporal fossa is present. The metastyle )-4.6 mm.; length ( protocone to hypo- angular process is damaged. The condyle is un- cone )-3.7 mm.; greatest width ( protocone to para- divided, and the supero-internal border is more style )-4.5 mm. concave than in similar structures of Crocidura. Comparison of No. 9175 with the M 1 of Erinaceus The neck of the condyle is short. shows the teeth to be similar in pattern and size Without question these fragments (if associated) except for the more reduced cingulum on No. 9175. represent a new genus and species but do not sug- The tooth is much larger than M 1 of Parvericus gest the affinities of the animal with other shrews. montanus KOERNER, and it is difficult to determine The undivided condyle and type of reduction seen TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 93 in the first three upper teeth suggest a crocidurine These specimens closely resemble Oreolagus ne- shrew, whereas the lack of an intertemporal fossa brascensis in the following characters: the size is is a character found only in Heterosorex delphi- about the same ( Table 27); the diastema is shorter nensis GAILLARD ( middle Miocene, Europe), con- than the cheek tooth row; the masseteric scar is sidered to be a soricine shrew. faint and extends to a point below the posterior pillar of 1n4 2 ; the anterior mental foramen is anterior FAMILY TALPIDAE GRAY, 1825 to Ps ; the posterior mental foramen is below M 2 ; and P„ M„ and M 2 are similar to those Talpid sp. in pattern described by McGaEw. Despite the absence of Ps , Referred specimen.—Pawnee Creek formation ( Martin the alveolus of No. 9287 shows that the tooth was Canyon local fauna ): No. 9359; left MI or M2; NEli sec. 27, approximately as long as it was wide. A small ridge T. 11 N., R. 53 W., Logan County. of bone on the antero-external corner of the alveolus This tooth, belonging to a large talpid, has well- suggests that Ps had only one fold like that seen in developed cingula on its anterior and posterior Oreolagus—a supposition supported by No. 9829, faces and between the protoconid and hypoconid. an isolated right Ps from Quarry A that has a single A small ectostylid is present, anterior to the ento- fold ( Fig. 23, B) and, presumably, belongs to this conid. The paraconid is compressed and close to species. The incisor is missing from the type of the metaconid. The antero-posterior length of the O. nebra,scensis, but McGaEw ( 1941a, p. 38), basing tooth is 3.2 mm., or 2.6 mm. exclusive of the anterior his judgment upon the alveolus, described the upper ana posterior cingula, and 2.4 mm. wide. surface of the incisor as evenly rounded. In No.

This - specimen, although larger and proportion- 9287, the incisor is flat on the internal surface ( Fig. ately wider, represents a species that could well be 23, G ), is roughly triangular in shape, and extends the structural ancestor of Hesperoscalops HIBBARD, back to a point below P„ which differs principally in having higher crowned In addition to the jaws found in Quarry A several teeth and more reduced anterior and posterior isolated first and second lower molars were col- cingula. lected, which are listed with the referred specimens. Cf. Condylura The occlusal patterns of these isolated molars and those of the teeth of Nos. 9287 and 9815 resemble Referred specimens.—Pawnee Creek formation ( Ken- nesaw local fauna): Nos. 9840-9841; left humerii; W3i sec. the patterns figured by McGriEw for the holotype 26, T. 12 N., R. 55 W., Logan County. No. 9842; right of Oreolagus nebrascensis, with the exception of humerus; SW3.i sec. 26, T. 12 N., R. 55 W., Logan County. their having a greater concavity to the antero- Pawnee Creek formation ( Vim-Peetz local fauna): No. external surface of the anterior pillar. In this one 9843; left humerus; NV% sec. 28, T. 12 N., R. 55 W., Logan County. feature the molars from Martin Canyon resemble the teeth of O. nevadensis ( KELLOGG). This may Nos. 9840 and 9841 compliment each other in re- well be an individual age character, however. At spect to missing parts. Both specimens represent no place along the axis of the teeth do the antero- the same species and differ from the humerus of posterior and transverse dimensions vary more than Condylura cri stata in having the shaft slightly wider 0.1 mm. The dimensions of these isolated teeth and heavier. The length of No. 9840 is 13.25 mm., reflect the one probably significant difference be- which is 0.5 mm. longer than the humerus of a tween these teeth and those of the type of O. ne- specimen of Condylura cristata from Michigan. brascensis — relatively greater antero-posterior Nos. 9842 and 9843 possibly represent a second length. species of the genus represented by Nos. 9840 and Assignment of the upper teeth found in Quarry A 9841. Although both specimens lack the proximal to the species represented by the lower jaws must articular surfaces, they seem to be shorter than the remain tentative, although the association appears humerus of Condylura cristata. The shaft is inter- valid. The upper incisor ( Fig. 23, F) has a groove mediate in width and thickness between the sizes similar to that seen in Ochotona. P3 has the antero- of the shaft of C. cristata and Nos. 9840 and 9841. external part of the tooth reduced, as in Ochotona, and the anterior arm of the crescent opens upon the ORDER LAGOMORPHA BRANDT, 1855 grooved antero-external surface. The hypostria is continuous to the bottom of the root FAMILY OCHOTONIDAE THOMAS, and is partly 1897 filled with cement. The permanent upper molar, Oreolagus nr. O. nebrascensis McGaEw No. 9286, is probably an W. The occlusal pattern of this tooth ( Fig. 23, E) Figure 23 shows the hypostria to be deep, partly filled with cement, and, like the ex- Referred specimens.—Pawnee Creek formation ( Martin ternal groove, continuous to Canyon local fauna ): Nos. 9285, 9335-9337; lower cheek the bottom of the tooth. teeth. Nos. 9338-9339; upper incisors. No. 9356; right P3 . A faint trace of a small, J-shaped, crescentic valley No. 9286; right ?MI. No. 9340; upper deciduous molar. is present which has its inner end posterior to the No. 9287; left jaw with I, P4-M1. No. 9815; right jaw with apex of the hypostria. Pa-Mi. No. 9829; right P3. All specimens from NE sec. The protocone and hypo- 27, T. 11 N., R. 53 W., Logan County. cone have sharp inner borders like those on the

94 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS teeth of Ochotona. No. 9286 is smaller but re- lagus. Presumably not enough of the ramus was sembles in pattern the specimen from the late Mio- preserved to assign unequivocally the specimen to cene of Oregon referred to Oreolagus(?), n. sp. by that genus. However, concerning these specimens WALLACE ( 1946, p. 125). The tooth is well ad- WILSON ( 1949a, p. 56) commented: "If the genus vanced in development over the upper teeth of Amphilagus antiquus POMEL, as figured by VIRET ( 1929, fig. 12), in that the hypostria is deeper and the tooth more hypsodont. The tooth is also well advanced beyond the condition seen in Desmato- lagus, which was suggested by McGREw (1941a) as an ancestor to Oreolagus, but nothing in the structure of this one tooth prevents it from being derived from the type of tooth seen in Desmato- lagus. The importance of these specimens is dependent upon their belonging to the same species. If the association is valid and the material belongs to Oreolagus, it gives us additional knowledge of the upper teeth and indicates the relationship of this genus to the ochotonids—a point of doubt. The type of groove in the upper incisor, and the sharp edges of the inner cusps of the upper molar resemble the corresponding structures in Ochotona. However, these are not strictly diagnostic characters that may be used to assign the material to the Ochotonidae, although the specimens do not resemble the known Miocene leporids. Probably of more importance in indicating the relationship of FIGURE 23.—Oreolagus nr. O. nebrascensis. (A) this genus is the comparison of the Martin Canyon Dorsal view of left ramus of No. 9287 showing alveolus material with the specimens reported by WALLACE of P3, occlusal pattern of P4-Mi, alveolus of M2, and mandibular foramen. (B) Occlusal pattern of right ( 1946 ). As will be recalled, prior to 1946 the genus P3 No. 9829. ( C ) Cross section of left lower I No. Oreolagus was known by lower jaws whose char- 9287 at alveolus. (D) Cross section of left upper I acteristics suggested ochotonid affinities. In 1946 No. 9338 at alveolus. (E) Occlusal pattern of right WALLACE reported the discovery of a maxillary with P No. 9356. (F) Occlusal pattern of right ?M 1 No. 9286 ( external border reconstructed). ( G ) External P3 -M 2 which had several features, and a ochotonid view of right jaw No. 9815 with P4-M1. A-F, approxi- ramus with M 1 -M 2 that resembled those of Oreo- mately X 6.8; G, approximately X 2.5.

TABLE 27.—Measurements ( in mm. ) of Oreolagus nr. O. nebrascensis

No. 9338 No. 9339 No. 9356 No. 9286 No. 9340 I, transverse width 1.56 1.30

133 , antero-posterior length 1.47 . • • • P, transverse width 2.20

?M 1 , antero-posterior length • • • • ?M 1 , transverse width 2.30 dM, antero-posterior length 1.30 dM, transverse width 2.40 No. No. No. No. No. No. No. 9287 9335 9336 9337 9285 9815 9829 Alveolar length of Pa-M2 7.85 I, transverse width at alveolus 1.59 P3, antero-posterior length of alveolus 1.50 P3, transverse width of alveolus 1.57 P3, antero-posterior length 1.07 P3, transverse width 1.30 P4, antero-posterior length 1.65 P41 transverse width 1.65 M1, antero-posterior length 1.80 1.86 Mi, transverse width 1.75 1.88 M2, antero-posterior length . . . • • • • 1.83 M2, transverse width 1.82 M1 or M2, antero-posterior length 1.89 1.90 1.80 1.115 Mi or M2, transverse width 2.00 1.80 1.70 1.72 Depth of ramus at M2 6.50 6.35

TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 95 represented at Beatty Buttes is properly assigned to Oreolagus, the question of ochotonid affinities for the latter may be solved." It seems that the upper and lower teeth from Martin Canyon are at least generically similar to those from Beatty Buttes. This would indicate that the teeth from Beatty Buttes belonged to Oreolagus and that the association of the upper and lower teeth from Martin Can- yon is valid—a conclusion not as circuitous as it seems when one considers that no other lagomorphs are known from either fauna, and that the chances of the association of the upper teeth of one genus with the lower teeth of a second genus in both faunas would be a coincidence that appears rather 9364 remote. This association is further substantiated by the Oreolagus material ( mentioned in the discussion of the Martin Canyon local fauna) from southeastern Fremont County, Wyoming, in beds equivalent to the "lower Snake Creek." These specimens consist of two upper third premolars like those from Martin Canyon and a lower third premolar referable to Oreo/actis. I think that the argument for assignment of Oreolagus to the Ochotonidae is strengthened to the point where Oreolagus may be referred to that family. The upper incisors and molars from Quarry A in Martin Canyon are similar to those of Ochotona and are the only lagomorph remains that have been found in the quarry along with the lower jaws of Oreolagus. The similarity of these specimens to FIGURE 24.—Mesogaulus paniensis (MArnizw). Oc- those from other faunas shows that the association clusal patterns of Nos. 9197, right P4 (reversed); 9292, is not fortuitous. left P 4 ; 9293, left P4; 9294, left M2; 9364, left P4; 9370, left P4 ; and internal view of No. 9197. The lower pre- Until the range of variation of Oreolagus ne- molars are arranged vertically with the youngest at the brascensis is known, it is thought best not to con- top, and the oldest at the bottom. Approximately x 4. sider the material from Martin Canyon as conspecific with the type. The fact that most of the lower Canyon local fauna ): No. 9197; right P4. No. 9292; left teeth are longer than wide, whereas O. nebrascensis 134 . No. 9293; left P4. No. 9294; left Mo. No. 9364; left P4. No. 9370; left P4. All specimens from NE% sec. 27, has teeth wider than long, may or may not be sig- T. 11 N., R. 53 W., Logan County. No. 160; anterior part nificant. This may be an individual variation, as of skull, and lower jaws; northeastern Colorado. is suggested by the one tooth from Martin Canyon Reference of these teeth and the skull to Meso- that is wider than long and by P4 of No. 9287 which has the length equal to the width. gaulus paniensis is based on size of the teeth and similarity of occlusal pattern. FAMILY LEPORIDAE GRAY, 1821 The crowns of all the teeth tend to be plump Hypolagus sp. and bulbous, and the roots are small. Some of the teeth have traces of cement, reported to be absent Referred specimen. —Pawnee Creek formation (Vim- on the type specimen. Peetz local fauna): No. 9805; proximal end of left femur; On the basis of occlusal NEL sec. 27, T. 11 N., R. 53 W., Logan County. pattern, antero-posterior length of occlusal surface, and depth of crown, the four lower premolars range ORDER RODENTIA BownicH, 1821 in individual age from No. 9197, the youngest, through Nos. 9364 and 9370 FAMILY MYLAGAULIDAE COPE, 1881 to No. 9293, the oldest. This series gives a good picture of the development Mesogaulus paniensis ( MArrifEw ) and loss of lakes in 134 (Fig. 24). Pt, No. 9292, be- Figure 24 longed to an old individual, as indicated by the Mylagaulus paniensis MATTHEW, 1902b, p. 299. occlusal pattern, yet there remains a considerable Mesogaulus paniensis, Cool( & GREGORY, 1941, p. 551. amount of crown—suggesting that the tooth was more hypsodont 4 Type.—AMNH No. 9381; base of Loup Fork beds (Paw- than P in Mesogaulus praecursor nee Creek beds), Courthouse Butte, near Pawnee Buttes, Coox & GREGORY. No. 9294 is considered to be an Colorado. M. on the basis of the angle of occlusal wear, size, Referred specimens.—Pawnee Creek formation (Martin presence of a pressure facet on the anterior face, 96 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

TABLE 28.—Measurements (in mm.) of Mesogaulus paniensis

PI, P4, P4, P., M„ No. No. No. No. No. No. 9197 9364 9370 9293 9292 9294 Antero-posterior occlusal length 5.1 5.1 5.9 8.2 6.5 3.2 Maximum antero-posterior length 8.6 7.0 8.3 8.2 6.7 3.6 Occlusal surface to notch between roots 9.9 8.2 8.1 6.0 Occlusal surface to tip of roots 11.7 10.7 10.7 8.8 10.3 Maximum transverse width 4.3 4.1 4.1 4.2 5.7 2.75 shape of tooth, and similarity to the M, in No. 160. Peetz local fauna): No. 9267; right P4; Eli sec. 28, T. 12 The measurements in Table 28 show the changes N., R. 55 W., Logan County. No. 9801; right and left P 4 ; Wii sec. 28, T. 12 N., R. 55 W., Logan County. in proportion of P, that take place with wear. Com- pared with a closely related species, Mesogaulus No. 9267 is a relatively unworn specimen and is praecursor, M. paniensis shows an increase in size larger than any of the teeth referred to Mylagaulus and hypsodonty and a simplification of the occlusal laevis ( Table 29). The occlusal pattern of this pattern in an earlier, or total, loss of some of the specimen is the same as that figured by GAZIN smaller lakes. ( 1932, pl. 6, fig. 5, upper right specimen), who No. 160 consists of the damaged anterior part of comments that the specimens from Skull Spring are the skull with left I, P3-P4 , and right P4 preserved. larger than the type of Mylagaulus laevis. No. 9267 In size and proportions this specimen resembles the seems to be approximately the same size as the skull of Mesogaulus vetus more than that of Myla- specimens from Skull Spring. gaulus laevis. The lower jaws lack the posterior parts, but the dentition is complete except for the TABLE 29.—Measurements (in mm.) of Mylagaulus sp. right M 2 . There is no definite record of the locality or level in northeastern Colorado from which this No. 9267 specimen was collected. The appearance of the P4, maximum antero-posterior length 11.2 matrix and the preservation of the bone is similar P4, antero-posterior length of occlusal surface 6.0 P4, maximum transverse width 5.4 to that of specimens of the Martin Canyon fauna P4, maximum crown depth 14.9 collected from the nodular silts ( horizon D of MArrHEw ) at Martin Canyon. T. M. STOUT, of the University of Nebraska, has completed a study FAMILY SCIURIDAE GRAY, 1821 of this specimen in conjunction with his work on the mylagaulids and will present a detailed descrip- Sciurus sp. tion and discussion of the material. Figure 25 Referred specimen.—Pawnee Creek formation ( Martin Ceratogaulus rhinocerus MATTHEW Canyon local fauna ): No. 9290; right jaw with P4, M2 - M3; NE34 sec. 27, T. 11 N., R. 53 W., Logan County. Ceratogaulus rhinocerus MATTHEW, 1902b, p. 299. Type.—AMNH No. 9456; Loup Fork (Pawnee Creek This specimen is referred to Sciurus (s. 1.) in beds) of Colorado. order to emphasize its similarity to the jaws of tree squirrels. The tooth pattern bears features com- Mylagaulus laevis MATTHEW mon to those of chipmunks, tree squirrels, and Mylagauius laevis MATTHEW, 1902b, p. 298. ground squirrels; but the brachyodont cheek teeth, narrow incisor, Type.—AMNH No. 9043; Loup Fork (Pawnee Creek deep and heavy ramus, short di- beds) Cedar Creek, Logan County, Colorado. astema, and large inferior pterygoid fossa suggest Referred specimens.—Pawnee Creek formation (Kenne- a closer relationship to the tree squirrels than to saw local fauna): No. 9154; left P 4 ; W3i sec. 27, T. 12 N., the other groups. R. 55 W., Logan County. No. 9155; right P4; W3 sec. 27, Figure 25 shows most of the features discernible T. 12 N., R. 55 W., Logan County. No. 9174; left P4-Mu; on SVV3.i sec. 26, T. 12 N., R. 55 W., Logan County. No. 9808; this specimen, and the reconstructed parts are damaged skull, lower jaws, and postcranial skeleton; SWIi added primarily to prevent any misinterpretation sec. 26, T. 12 N., R. 55 W., Logan County. No. 9807; of the figure. The masseteric fossa ends anteriorly skull without cheek teeth; WI sec. 27, T. anterior part of below 134 and is well defined ventrally by a sharp 12 N., R. 55 W., Logan County. ridge. However, the upper border is poorly de- No. 9807 is of more than usual interest because fined. The anterior tip of the fossa encloses a of the slight callosity appearing on the anterior roughened area, which is less depressed than the one-half of each nasal bone. remainder of the fossa. Table 30 gives the dimensions of this specimen. Mylagaulus sp. 13 4 has the protoconid and metaconid almost equal Referred specimens.—Pawnee Creek formation (Vim- in development, set close together, and only slichtly

TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLOFtADO 97

than the hypoconid of M 3 . The metalophulid H is weaker than the arm on M 2 . The ectolophid is weak, but the mesoconid is better developed on this tooth than on M 2 . The hypoconid is large and inflated, this swollen condition continuing along the posterolophid to the entoconid, which is not discernible as more than a swelling on the rim of the basin. The metastylid is poorly developed and separated from the metaconid and entoconid by notches of equal size. Sciurid sp. Referred specimens.—Pawnee Creek formation ( Martin Canyon local fauna ): No. 9291; fragments of right and left lower incisors (not associated); NE34 sec. 27, T. 11 N., R. 53 W., Logan County.

— The narrow and deep incisors ( Table 31) suggest sciurid, Sciurus niger FIGURE 25.—Sciurus sp. No. 9290. (A) Occlusal a larger than and more closely view of right P4, M2-M3. Approximately X 7.5. (B) related to the tree squirrels than to other sciurids. External view of right jaw with teeth. Approximately X 3.4. TABLE 31.—Measurements ( in mm.) of Sciurid sp. anteroconid is higher than the hypoconid. No No. 9291 present. The hypoconid is large and swollen, united Right Left to the protoconid by a weak ( practically divided) incisor incisor ectolophid, and united to the entoconid by a Antero-posterior length 4.35 4.20 posterolophid. A metastylid is present on the side Transverse width 2.10 2.00 of the metaconid and is separated from the entoconid by a notch. FAMILY HETEROMYIDAE ALLEN & CHAPMAN, M 2 is roughly quadrate in shape, with the entoconid angle more rounded and reduced than are 1893 the other corners. The metaconid is well developed Proheteromys parvus ( TnoxELL) and the highest of the cusps, and it has a strong Diplolophus parvus TuoxELL, 1923, p. 158. anterolophid extending across the face of the tooth. Proheteromys porous, WOOD, A. E., 1935, p. 170. The protoconid and hypoconid are of approximately Type.—Yale Univ., Peabody Mus. Nat. Hist. No. 10362; equal development and are connected by a weak ?Miocene of northeastern Colorado (fide WOOD, A. E., 1935). ectolophid bearing a small mesoconid. An incom- Unfortunately, the type of this species does not plete metalophulid II extends into the basin of the have a reliable locality or age record. WOOD ( 1935, tooth and fails to reach the metaconid. A postero- p. 171) discussed this problem and concluded that lophid unites with the weak, but distinct, entoconid. TROXELL'S age assignment of middle Oligocene was The metastylid is separated from the metaconid by incorrect. a notch deeper than that which separates the struc- Proheteromys spp. ture from the entoconid. Referred specimens.—Pawnee Creek M„ like M 2 , has the metaconid highest. The formation (Martin anterolophid is thick Canyon local fauna ): No. 9288; fragment of right jaw with and heavy. The protoconid is P4-M1. No. 9289; left ?M 2 . Both specimens from Quarry similar to the protoconid of M 2 in size, but smaller A, NE% sec. 27, T. 11 N., R. 53 W., Logan County. Pawnee Creek formation (Kennesaw local fauna ): No. TABLE 30.—Measurements (in mm.) of Sciurus sp. 9159; right jaw with I, 134-M1; W% sec. 27, T. 12 N., R. 55 W., Logan County. No. 9290 No. 9289 is an isolated tooth which is questionably Crown length of P4-M3 6.70 I, antero-posterior length at diastema 2.71 identified as an M 2 because of its size ( Table 32) I, transverse width at diastema 1.32 in relation to the lower jaw from the same site. P4, antero-posterior length 1.37 This tooth has two well-developed lophs, each com- P4, transverse width of anterior lophid 1.00 posed of two cusps, united at the lingual edge by a P4, transverse width of posterior lophid 1.37 single M2, antero-posterior length 1.65 cusp that blocks the transverse valley. Com- M2,transverse width 1.98 pared with the first or second upper molar of M3, antero-posterior length 2.40 Hcliscomys, this tooth shows a relative increase in M3, transverse width 1.95 width and Depth of ramus reduction in length, a loss of the anterior at P4 6.40 cingulum, and better-developed lophs. 7-3493

98 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

No. 9288, like No. 9289, was recovered from the cause of its weathered condition, the structural de- matrix of Quarry A at Martin Canyon. Whether or tails of this specimen are difficult to discern, but it not it represents the same species as No. 9289 is, of does show that a small heteromyid ( Table 32) was course, unknown; but the stage of development of present in the Kennesaw local fauna. both specimens, when compared with Heliscomys, appears to be about the same. P., has four equally Peridiomys sp. small anteroconid, developed conical cusps and a Referred specimen.—Pawnee Creek formation (Kennesaw which is more closely associated with the metaconid local fauna ): No. 9177; right P 4 -MI; SW% sec. 26, T. 12 N., than with the protoconid. Weak ridges unite the R. 55 W., Logan County. metaconid, entoconid, and hypoconid and also con- The teeth of this specimen are relatively unworn, nect the anteroconid to both the metaconid and the and the metaloph of P4 and both lophs of M 1 show protoconid. These ridges do not seem to form the their tricuspid origin. The lophs of M 1 are not found in the Perognathus line. A hypo- X pattern united. In pattern and size ( Table 33), the teeth conulid is present on the posterior margin of the are close to those of Peridiomys ore gonensis (GAzw) metaconid protoconid are not set tooth. The and if allowance is made for wear. MATTHEW described so closely together as in other specimens of Pro- P. rusticus, based on a lower jaw, from the "lower this is probably because of their heteromys, but Snake Creek" beds of Nebraska. No. 9177 may size development of the anteroconid, large and the represent the upper teeth of that species. which extends back as a ridge between them. M, has an occlusal pattern that does not differ greatly TABLE M.—Measurements ( in mm.) of Peridiomys sp. from that described for Proheteromys? ( Chicago Nat. Hist. Mus. No. PM381 ) from the Cedar Creek No. 9177 fauna, except as follows: the lophodont structure is Crown length of P4-M 3 at alveolus 5.30 better developed; the anterior cingulum is weaker; P 4, antero-posterior length 1.35 the notch between the protostylid and hypostylid is P4, transverse width 1.61 broader deeper; and the posterior cingulum is Ml, antero-posterior length 1.24 and M 1 , transverse width 1.58 absent. That P 4 of No. 9288 may be deciduous does not seem likely. These specimens from Quarry A are referred to FAMILY CASTORIDAE GRAY, 1821 Proheteromys in a broad sense—actually as a structural stage between the ancestor of Proheteromys Monosaulax curtus ( MArrnEw & CooK) and Heliscomys, and the later forms such as Peri- Dipoides curtus MATTHEW & Coox, 1909, p. 381. diomys. With the discovery of more material, it is Monosaulax curtis, STIRTON, 1935, p. 420. becoming increasingly difficult to fit the size, struc- Referred specimen.—Pawnee Creek formation (Eubanks tural pattern, and geological age of individual spe- local fauna): Univ. Colorado Mus. No. 19836; right lower cies and specimens now assigned to Proheteromys jaw with P4-M3; north of Pawnee Buttes in sec. 21, T. 10 N., into a simple evolutionary scheme that would main- R. 59 W., Weld County. tain Proheteromys as a taxonomic unit in the sense This specimen is identical to the type of Mono- in which it is used at present. saulax curtus. No. 9159 is weathered and the tooth pattern is poorly preserved, but the following details seem Monosaulax nr. M. curtus ( MATTHEW & COOK) evident. The incisor is asulcate. Both cheek teeth subhypsodont. P, Referred specimens.—Pawnee Creek formation ( Martin are has four prominent cusps. Canyon local fauna ): No. 9196; right P4 and part of incisor M, is composed of a well-developed metalophid ( not associated). No. 9283; right P4-M2. No. 9284; right and hypolophid united buccally and possibly also M3. All specimens from NE% sec. 27. T. 11 N., R. 53 W., at the center of the tooth. Both lophids retain Logan County. vestiges of the component cusps, the one on the These specimens represent a species as small as lingual end of the metalophid being especially Monosaulax curtus and similar to M. curtus in most prominent. In addition, an anterior cingulum com- respects. The occlusal pattern of the fourth pre- posed of several cusps seems to be present. Be- molars from Martin Canyon differs in having a crescent-shaped parafossettid resembling that of TABLE 32.—Measurements ( in mm. ) of Proheteromys spp. M. pansus ( CoPE). 134 of No. 9283 has, in addition, No. No. No. a small fossettid anterior to the parafossettid which 9289 9159 9288 is lost early in wear. In all of the teeth, except the ?M 2, antero-posterior length 0.74 well-worn M 3 the hypoflexid appears to be shorter ?M2 , transverse width 1.05 • • • • and wider than those of M. curt us. I, transverse width 0.60

P4, antero-posterior length . 0.65 0.64 Amblycastor? Sp. P4, transverse width 0.60 0.69 Mi, antero-posterior length 0.90 1.05 STIRTON ( 1935 p. 413) states that two beaver Mi, transverse width 1.00 0.95 teeth from the Pawnee Creek beds (those reported

TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 99 by MAITHEw, 1902b, p. 305, figs. 12-13) "appear to belong to this genus." The specimen designated as figure 12 ( AMNH No. 9364) came from 10 feet above the base of the Pawnee Creek formation, three miles west of Pawnee Buttes, Weld County. So far as can be determined, the other specimen came from the Pawnee Creek formation, Pawnee Buttes.

FAMILY ZAPODIDAE COUES, 1875 Plesiosminthus? clivosus, new species Figure 26 Holotype.—Left lower jaw with Mi-M3, No. 9279, Vert. Paleont. Coll., Univ. Kansas Mus. Nat. Hist. Geological age and locality.—Silts of Hemingfordian age in the Pawnee Creek formation, Quarry A, NE!, sec. 27, T. 11 N., R. 53 W., Logan County, Colorado. FIGURE 26.—Plesiosminthus? clivosus, n. sp. No. 9279. ( A ) Occlusal view of left Mi-M3. Approxi- Diagnosis.—The lower molars of this species are mately X 20. (B) External view of left jaw with characterized by small size ( Table 34); rounded teeth. Approximately x 12. principal cusps; and well-developed internal arm of the anterior cingulum, posterior protoconid arm, and extends no higher than the ridge that connects and metastylid. When more specimens of this spe- it to the metaconid. A well-developed mesolophid cies are known, it may be possible to emend this unites the mesostylid and mesoconid on M, and M 2 , diagnosis of the lower teeth and cite characters con- but it is present only as a faint wrinkle on the sur- fined to single teeth. face of the tooth in M,. The principal cusps are Description.—Only the body of the jaw, lacking round and have a rounded pattern of wear. Except the inferior border, and the three molars are pre- for the protoconid on M„ the protoconid and hypo- served. The scar for the masseter muscle extends conid on all teeth are slightly posterior to the meta- forward to the anterior root of M„ and the lower conid and entoconid. border is prominently marked by a ridge. The Grooved upper incisors, No. 9295, also from mental foramen lies anterior to M„ There seems Quarry A, are similar in cross section and enamel to be an inferior dental foramen on the damaged structure to the upper incisors of Plesiosminthus internal surface of the jaw above the angle of the schaubi VIRET (ScHAus, 1930, p. 621, fig. 4) but, jaw and below the root of the incisor. without association, cannot be assigned to Plesio- The molars are short crowned, and all the struc- sminthus? clivosus. tures comprising the occlusal surface are in one Discussion.—It seems unlikely that this North plane, except the protoconid, metaconid, and ento- American zapodid from the middle Miocene is con- conid on M 1 , and the metaconid and entoconid on generic with the lower Miocene zapodid of western M 2 and M„, which extend above this plane. An Europe. Yet, until the upper teeth are found or anteroconid is present on all three teeth. It is free enough material is collected to determine some- and small on M, but is united by ridges to both the thing of the range of variation of the structures on protoconid and metaconid on M, and M„. In both the lower teeth, it is advisable to refrain from M, and M, a strong crest forming the internal arm naming a new genus. The similarities between this of the anterior cingulum passes from the antero- specimen and the European specimens of Plesio- conid along the anterior face of the molar and unites sminthus are evident, but, of course, these similari- with the anterior face of the metaconid. On the ties may be those common to the plesiosminthid same two teeth a weak external arm extends down- group. The differences between the two, especially ward from the anteroconid to unite with the base those cited in the diagnosis, may be sufficient to dis- of the protoconid. A strong posterior protoconid arm unites the protoconid and metaconid in all TABLE 34.—Measurements ( in mm. ) of Plesiosminthus? three teeth, thus forming a deep pit on M 2 and M,. clivosus The mesoconid is large and roughly rhomboidal in shape on all the teeth and lacks a well-developed No. 9279 union with the protoconid. Posteriorly the meso- Crown length of Mi-M3 2.85 Mi, antero-posterior length 0.99 conid is connected to the crest that unites the hypo- Mi, transverse width 0.72 conid and entoconid, the union being closer to the M2, antero-posterior length 0.99 latter cusp. Well-developed mesostylids, united to M2, transverse width 0.76 the metaconids by low ridges, are present on M, M3, antero-posterior length 0.87 M3, transverse width 0.72 and M a. However, the mesostylid on M, is weak 100 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS tinguish the material generically; but with the range "horizon E" in Martin Canyon which may have been of variation recognized by SCHAUB in the species of the specimens MATTHEW had in mind. The speci- Plesiosminthus, it is difficult ( with one specimen) men ( No. 9220) listed below as Tomarctus sp. may to select characters with any assurance that they well belong to this species. will continue to be significant when more specimens are found. Tomarctus sp. Referred specimens.—Pawnee Creek formation ( Martin ORDER CARNIVORA BowDicH, 1821 Canyon local fauna): No. 9342; right Ml; NE % sec. 27, T. 11 N., R. 53 W., Logan County. FAMILY CANIDAE GRAY, 1821 Pawnee Creek formation (Vim-Peetz local fauna): No. 9220; left P 4 ; NO4 sec. 27, T. 11 N., R. 53 W., Logan Nothocyon vulpinus MATTHEW County. Nothocyon vulpinus MATTHEW, 1907, p. 183. No. 9342 is smaller than most specimens of To- THORPE ( 1922, p. 480) described and named as a marctus, being 13.9 mm. wide when measured along new mutant" Nothocyon vulpinus coloradoensis, a line through the hypocone and paracone. The which he based on a specimen ( Yale Univ., Peabody metacone is damaged and no maximum antero- Mus. Nat. Hist. No. 12812) from the "lower Miocene, posterior measurement can be obtained, but the Pawnee Buttes, Colorado." Concerning this speci- diameter at the conules is 7.95 mm. This indicates men, Dr. JOSEPH T. GREGORY has informed me that that the specimen had the proportions of T. con- it was part of a shipment of fossils from Pine Bluff, fertus MATTHEW, but it differs from this species, and Wyoming, received in 1873, which included some others, in having small and delicate cusps. Oligocene material from Gerry's Ranch ( see account No. 9220 has a maximum length of 17.1 mm. and of Phalacrocorax mediterraneus for locality of Ger- a width of 6.9 mm. The protocone is reduced and ry's Ranch) and Pawnee Buttes. Inasmuch as lies well forward on the side of the tooth, having a Arikareean beds are unrecognized in the Pawnee position similar to that seen in Tomarctus confertus Buttes area, but may be present in the Gerry Ranch or T. optatus MATTHEW. This tooth, like No. 9342, area, it is suggested that the locality record is in- although nearly the same size as P. in T. optatus, correct and that this specimen is from Gerry's Ranch appears more slender and delicate. —if in truth it is from Colorado. MATTHEW reported Tomarctus cf. T. temerarius from beds in Martin Canyon which he assigned to Mesocyon robustus MATTHEW DARTON'S horizon D and E. No. 9342 came from the surface of Quarry A which would place it in Mesocyon robustus MATTHEW, 1907, p. 185. horizon D as recognized by MATTHEW, and No. THORPE ( 1922, p. 429) referred a specimen from 9220 came from beds ( No. 5 of measured section Gerry's Ranch, Weld County, to this species. The XIV ) near the top of the section in horizon E. importance of this specimen, like Nothocyon, lies in its possible stratigraphic value in indicating the Leptocyon vafer ( LEmy ) presence of Arikareean beds in western Weld Canis vafer LEIDY, 1858, p. 21. county. It is as yet, so far as I know, the only Leptocyon va fer, MArrfiEw, 1918, p. 190. vertebrate fossil to support such a possibility. If Arikareean beds are present, they probably repre- Referred specimen.—Pawnee Creek formation (Kenne- sent an extension of the Arikareean beds known in TABLE 35.—Measurements (in mm.) of Leptocyon va fer southeastern Wyoming. No. 9157 left right Tomarctus brevirostris COPE Crown length of Pi-M3 45.4 Tomarctus brevirostris COPE, 1873b, p. 2. C, antero-posterior length at alveolus 4.8 C, transverse width at alveolus 3.5 Type.—AMNH No. 8302; Pawnee Creek beds of north- P1, antero-posterior length 2.9 eastern Colorado (fide MATTHEW, 1924). Pi, transverse width 1.4 P2, antero-posterior length 5.9 6.1 Tomarctus temerarius ( LEIDY ) P2, transverse width 2.4 2.1 P3, antero-posterior length 7.1 7.1 Canis temerarius LEIDY, 1858, p. 21. P3, transverse width 2.7 2.7 Tomarctus ternerarius, MATrxEw, 1924, p. 98. P4, antero-posterior length 7.9 8.1 P4, transverse width 3.2 3.3 This species was listed by MATTHEW ( 1901, p. MI, antero-posterior length 12.2 12.2 the Pawnee Creek fauna, MI, transverse width 5.0 5.0 358; 1924, p. 71) as part of M2, antero-posterior length 6.6 which, of course, at that time included material Mo, transverse width 4.3 from Martin Canyon. Although MATTHEW did not M3, antero-posterior length 2.5 . . . . refer to specimens by number, there is in the M3, transverse width 2.2 the Depth of ramus at Ml 11.0 .12.7 American Museum of Natural History material from

TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 101

saw local fauna ): No. 9157; left ramus with C-M3, and nearer to such primitive Dogs as Cynodictis than to part of right ramus with P2-Mi; W34 sec. 27, T. 12 N., R. 55 the modern Raccoons." HOUGH ( 1948a, p. 97) con- W., Logan County. firmed the close relationship of the specimen to the In size ( Table 35) and other characters this speci- canids, but she pointed out that the procyonid-like men agrees with the description of the type and characters could be the results of parallelism or the referred specimen of Leptocyon va fer from the convergence and would not necessarily indicate Merychippus paniensis zone of the lower Snake procyonid ancestry. Because of this and the simi- Creek fauna. larities of the auditory region, she placed the genus Euoplocyon sp. in the family Canidae and denied any relationship to the Procyonidae. MATTHEW ( 1924, P. 71) lists this genus as occur- On the other hand, McGREw (1987a, 1938a, 1941) ring in the Pawnee Creek fauna. has considered the Procyonidae, including Phlao- cyon, to be a highly diversified family held together Amphicyon sinapius MArrnEw by the fundamental similarities of the dental pat- Amphicyon sinapius MAT-rnEw, 1902a, p. 288. tern. Cynarctus saxatilis MATTHEW Type.-AMNH No. 9358; Loup Fork (Pawnee Creek beds), three miles northeast of Pawnee Buttes, Weld County, Cynarctus saxatilis MArrtiEw, 1902a, p. 281. Colorado. Amphicyon reinheimeri COOK Type.-AMNH No. 9453; Loup Fork (Pawnee Creek beds), Cedar Creek, Colorado. Amphicyon reinheimeri Coox, 1926, p. 29. FAMILY MUSTELIDAE SWAINSON, 1835 Type.-Denver Mus. Nat. Hist. No. 823; Pawnee Creek beds, E. C. Davis Ranch, six miles west of Pawnee Buttes, Plionictis ogygia ( MATTHEw ) Weld County, Colorado. The type locality of this species is in an area Mustela ogygia MATTHEW, 1901, p. 383. where there are exposures of the Pawnee Creek Plionictis ogygia, MAT-niEw, 1924, p. 135. formation carrying equivalents of the Kennesaw and Type.-AMNH No. 9042; Pawnee Creek beds, Cedar Martin Canyon local faunas. Creek, Logan County, Colorado. Referred specimens.-Pawnee Creek formation (Kenne- saw local fauna ): No. 9271; right Mi in fragment of jaw; FAMILY URSIDAE GRAY, 1825 E% sec. 27, T. 12 N., R. 55 W., Logan County. No. 9810; left and right C, P3 in fragments of jaws; SWN sec. (?)Ursavus pawniensis FrucK 26, T. 12 N., R. 55 W., Logan County. Pawnee Creek formation ( Vim-Peetz local fauna): No. (?)Ursavus pawniensis FRICK, 1926, p. 106. 9800; left 1 1 -P 1 , P4 -M 1 , right C-P 1 , M 1 , and left P3-M1, Type.-AMNH no. 20801; Pawnee Creek Miocene, Tapir right C, P2-Ri; WX sec. 28, T. 12 N., R. 55 W., Logan Hill, Pawnee Buttes, northeastern Colorado. County, Colorado. MATTHEW ( 1902a, p. 285) referred AMNH No. No. 9271 is an unworn tooth similar to the type in 9454, a carnassial and other fragments from north- structure but approximately 18 percent smaller in eastern Colorado, to ??Ursavus sp. but never specifi- size-being 6.15 mm. long and 2.9 mm. wide. The cally mentioned it again in faunal lists or discussions. first lower molars of the other two specimens are Neither did FRICK refer to the specimen when he intermediate in size between No. 9271 and the molar described (?)Ursavus patvniensis. I cannot de- of the type specimen. termine which specimen MATTHEW had in mind Plionictis parviloba (COPE) when he included the entry "?Ursavus ( Pawnee Creek)" in a chart ( 1929, p. 480) showing the Aelurodon mustelinus COPE, 1873, p. 1. phylogeny of the Ursidae. Mustela parviloba, COPE, in Scorr & OSBORN, 1890, p. 71. Plionictis parviloba, MArrimw, 1924, p. 135. FANfrix PROCYONIDAE BONAPARTE, 1850 The present location of the type specimen of this Phlaocyon leucosteus MATTHEW species is unknown. MATmEw ( 1924, p. 135) considered the specimen to have come from the Pawnee Phiaocyon leucosteus MATTHEW, 1899, p. 54. Creek beds. Type.-AMNH No. 8768; American Museum Meryco- choerus Quarry, Martin Canyon, Logan County, Colorado. Leptarctus primus LEIDY Concerning this specimen, WORTMAN & MATTHEW Leptarctus primus LEIDY, 1856e, p. 311. ( 1899, p. 131) wrote: "It represents a new and Referred specimen.-Pawnee Creek formation ( Kennesaw aberrant genus of Dogs, the characters pointing local fauna ): No. 9153; skull (lacking basicranial region) clearly in the direction of the Raccoons, so that if and lower jaws; W% sec. 27, T. 12 N., R. 55 W., Logan we adopt the genealogical conception of a family it County. must be placed in the Procyonidae, although it is This skull is the same size as the skull (AMNH 102 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

TABLE 36.—Measurements ( in mm.) of Leptarctus primus variation. It is possible also that the slope of the No. 9153. external face and the size of the protocone are related to transverse width. Crown length of C-M 1 28.7 C, antero-posterior length 5.1 Because of the similarity in tooth structure, length C, transverse width 4.1 of tooth row, and length of skull in No. 9153 and P2, antero-posterior length 3.1 Leptarctus primus, and despite the wider teeth of P2, transverse width 2.4 No. 9153, I think that it belongs to the species P3, antero-posterior length 4.0 L. primus. From the evidence P3 , transverse width 3.8 of the shorter tooth P4, antero-posterior length 7.7 row and wide teeth in the Coloradan specimen, it 134 , transverse width 7.7 may be concluded that L. progressus, with its wide M 1 , antero-posterior length 7.3 and short tooth, was closer to L. primus than to M 1 , transverse width 7.6 L. wortmani MATTHEW, which has Crown length of C-M2 33.6 longer teeth. C, antero-posterior length 4.5 Although some of the differences between L. primus C, transverse width 4.0 and L. progressus are probably the result of geo- P2, antero-posterior length 2.9 graphic variation and different geologic age, the P2, transverse width 2.1 P3, antero-posterior length 4.2 greater width of the teeth in L. pro gr essus and the P3, transverse width 3.8 differences associated with greater width may be P4, antero-posterior length 6.0 the result of secondary sexual or individual varia- P4, transverse width 4.1 tion. MI, antero-posterior length 9.8 FAMILY Mi, transverse width 5.2 FELIDAE GRAY, 1821 M2, antero-posterior length 4.4 M2, transverse width 4.0 Pseudaelurus intrepidus LEIDY Depth of ramus at rear of MI 13.0 Pseudaelurus intrepidus LEIDY, 1858, p. 22. a. Right tooth row. So far as can be determined, COPE collected material from northeastern Colorado referable to this No. 18241) from the "lower Snake Creek" beds re- species, which MATTHEW ( 1924, p. 72) referred to ferred to Leptarctus primus by MATTHEW (1924, the Pawnee Creek fauna. p. 139). However, the temporal crests are less divergent in No. 9153. Another difference is seen Pseudaelurus marshi THORPE in the greater length and width of P4 when compared with the teeth in LEIDY'S type and in the Pseudaelurus rnarshi THORPE, 1922, p. 446. Snake Creek skull. Compared with AMNH No. THORPE ( 1922, p. 446) referred a specimen from 18270, a lower jaw from the Snake Creek beds that the "middle or upper Miocene" of "northwest" Colo- has been referred to the species, the jaw of No. rado to this species. However, the correct locality, 9153 is heavier and has P4 and M, wider but not according to the Yale Peabody Museum records, is longer antero-posteriorly ( Table 36). Comparison Gerry's Ranch, Weld County, Colorado. of this specimen with Leptarctus progressus SIMP- SON from the Pliocene of Florida can be made only ORDER PROBOSCIDEA ILLIGER, 1811 on the basis of P4 . The only significant similarity of the Colorado specimen to SIMPSON'S figure and The list of proboscidean species from north- description ( 1930, p. 186, fig. 19) is seen in the eastern Colorado is presented using SIMPSON'S relatively greater width. The two teeth differ in ( 1945 ) generic and suprageneric taxonomy and that the specimen from Colorado lacks all traces OSBORN'S assignment of species. This appears to of a cingulum other than the prominent anterior be the best method of recording and keeping clear cuspule, which seems to be approximately twice as the pertinent data on the material from the area. wide as the cuspule on L. pro gr essus ; the external FRICK ( 1933 ) referred all the proboscidean material, surface is not so broad as that on L. progressus; except that mentioned under Serridentinus produc- and possibly the metacone was much better de- tus, to Serridentinus proavus ( CoPE ); but OSBORN ( 1936 ) considered veloped. The width of P4 in the skull from north- four species, Serridentinus pro- eastern Colorado equals its length; therefore, it is ductus COPE, Serridentinus proavus ( COPE ), Rhyn- intermediate in proportion between L. primus and chotherium rectidens OSBORN, and Mammut (Mio- L. progressus, but closer to the latter. From the mastodon) merriami OSBORN, to be present. evidence of the specimens of Leptarctus from the FAMILY Miocene and Pliocene, one would judge that the GOMPHOTHERIIDAE CABRERA, 1929 width of P4 was not a geographic nor an evolu- Serridentinus proavus ( COPE) tionary trend, unless in the latter case two separate lines of development are represented—a circum- Mastodon proavus COPE, 1873c, p. 10. stance certainly not reflected by any other struc- Serridentinus proavus, OSBORN, 1936, p. 403. tures in the skull. This suggests that the wider Type.—AMNH No. 8523; Pawnee Buttes, Weld County, teeth might be the result of sexual or individual Colorado ( fide OSBORN, 1936). TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 103

Concerning the age of this specimen OSBORN Miocene" age, which would be his Merychippus ( 1936, p. 403) wrote: sejunctus zone or lower Pawnee Creek beds. The typical (lower) Pawnee Creek beds (Merychippus Proboscidean, sp.? sejunctus zone) of the late Middle Miocene yield traces of mastodon, fragments of a humerus and tooth, and part of a Referred specimens. —Pawnee Creek formation (Ken- lower jaw found at the head of Two Mile Creek ( F. B. nesaw and Vim-Peetz local faunas): Nos. 9148-9152; frag- Loomis, letter of November 5, 1920). The ( upper ) Pawnee ments of teeth and bones; secs. 28 and 36, T. 12 N., R. 55 Creek beds (Protohippus zone), perhaps early Pliocene, also W., and sec. 31, T. 12 N., R. 54 W., Logan County. yield simple grinding teeth similar to the type of M. proavus Pawnee Creek formation ( ?Vim-Peetz local fauna): No. (F. B. Loomis, 1921). We cannot be certain whether the 9201; fragment of tooth; NE3•i sec. 27, T. 11 N., R. 53 W., type of "Mastodon" proavus comes from the lower "Mery- Logan County. chippus sejunctus" or from the upper "Protohippus" zone of the Pawnee Creek. One of the critical specimens from Martin Canyon is a fragment of proboscidean tooth, No. 9201. Al- However, it was OSBORN'S opinion that this spe- though recorded ( tentatively) as belonging to the cies was from the upper zone, which he stated to be fauna, this specimen was found by upper Miocene. This is the same level and age to Vim-Peetz local which he assigned Rhynchotherium rectidens OS- Dr. ROBERT WILSON and me on the surface of an exposure nodular silts at the same level as and BORN, and above the level assigned to Mammut of not far from the site of Quarry A. It seems un- merriami ( OSBORN ) . likely that this specimen was part of the Martin Serridentinus productus ( CoPE) Canyon local fauna. On the other hand, it seems rather coincidental that in two instances ( for a Mastodon productus COPE, 1874b, p. 221. similar occurrence see the discussion of Teleoceras Serridentinus productus, OSBORN, 1923, p. 2. sp. ) specimens of immigrant genera were found FRICK ( 1933, p. 609) listed several specimens under circumstances that would suggest that the from the Pawnee Buttes area of Weld County, arrival in North America of these genera had been which he doubtfully thought might represent set at too late a date, or that the age of the beds ( ?)Amebelodon paladentatus (Coox) collected containing the Martin Canyon local fauna had been from middle Pliocene deposits near Wray, Yuma seriously misjudged. County, Colorado. Most of the material is not ade- quate for purposes of identification, and no strati- ORDER PERISSODACTYLA OWEN, 1848 graphic is given. OSBORN (1938, p. 440), position FAMILY EQUIDAE GRAY, 1821 in some supplementary observations on the genus Serridentintts, referred one of these specimens (left Parahippus pawniensis GIDLEY M„ F:AM No. 23336) to Serridentinus productus. Subsequent summaries of the proboscidean species Parahippus pawniensis Grin.Ev, 1907, p. 932. in OssonN's monograph, however, fail to mention Type.—AMNH No. 9085; "horizon D" ( of MATTHEW this referred specimen. 1901), Martin Canyon, Cedar Creek, Logan County, Colo- rado (fide AMNH catalogue records ). Rhynchotherium rectidens OSBORN Referred specimens.—Pawnee Creek formation (Martin Canyon local fauna ): No. 7730; left P3-M2. No. 9198; Rhynchotherium rectidens OSBORN, 1923, p. 3. upper molar and fragments of lower teeth. No. 9375; two left upper molars. Univ. Colorado Mus. Nos. 19842 and Type.—AMNH No. 9366; upper Miocene, Pawnee Creek right upper molars. Above specimens from NE) sec. horizon, eight miles west of Pawnee Buttes on Davis Ranch, 19847; R. 53 W., Logan County. No. 9212; two Weld County, Colorado. 27, T. 11 N., upper and two lower cheek teeth; W34 sec. 22, T. 11 N., R. FRICK ( 1933, p. 612) placed this species in syn- 52 W., Logan County. onymy of Serridentinus proavus. OSBORN (1936, p. In pattern and size these teeth range from those 489) discussed such a possible synonymy without similar to the type of Parahip pus pawniensis to taking notice of FRICK'S action. specimens that approach P. coloradensis in pattern and equal it in size, especially No. 9212. AMNH FAMILY MAMMUTIDAE CABRERA, 1929 No. 8961a, the Parahip pus tooth found in the Amer- Mammut merriami ( OsEoEN) ican Museum Merycochoerus Quarry at Martin Canyon, is also similar to these teeth in size and Mastodon merriami OSBORN, 1921, p. 6. pattern. Mammut merriami, HAY, 1930, p. 630. Parahippus coloradensis GIDLEY OSBORN (1938, p. 156) referred to this species proboscidean material from northeastern Colorado Parahippus col oradensis CIDLEY, 1907, p. 932. which FRICK ( 1933, p. 612) assigned to Serri4 Type.—AMNH No. 9040; Pawnee Buttes, Weld County, dentinus proavus. Colorado ( fide AMNH catalogue records). The stratigraphie level for these specimens was referred to by OSBORN ( 1936, p. 403) as "the classic) Referred specimens indicate that earlier authors Pawnee Creek horizon of Colorado" of "middle considered Parahip pus pawniensis and Parahip pus 104 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBTJTIONS coloradensis to be unchanging morphological types These specimens consist of two damaged and that coexisted over a considerable span of time in worn teeth which are clearly referable to the genus the Miocene. However, the range of variation seen Hypohip pus. Reference to the species H. osborni in the Parahippus teeth from Martin Canyon sug- is based on size, the teeth being smaller than those gests that P. coloradensis might be only a part of of H. affinis LEIDY and larger than those of H. the Parahip pus pawniensis population. If No. 9210, equinus Scam discussed in this paper as ?Merychippus sp., is Both specimens were found as float in beds bear- referable to Parahip pus, then this view is consider- ing the Kennesaw local fauna, but under circum- ably strengthened. On the other hand, P. colo- stances that make it possible that they came from radensis has been described as more advanced than higher beds. P. pawniensis, so it would appear reasonable to think that P. pawniensis represents a population of On the Merychippine Specimens from horses that evolved into a population typified by Northeastern Colorado P. coloradensis, if they are not conspecific. When enough specimens of Parahippus pawniensis and The collection of merychippine material obtained P. coloradensis with stratigraphie records are known, by me in northeastern Colorado is highly unsatis- it may be possible to determine the relationship of factory. Less than 100 specimens were collected, these two species and the bearing of this relation- of which only two finds had associated upper and ship on the correlation of the beds in the Pawnee lower teeth, and in only nine instances were there Creek formation. more than two teeth preserved. Of the remaining Some features that point out possibilities con- specimens more than half were badly worn, weath- cerning the relationship and time span of these two ered, or incomplete. The collection of Merychippus species deserve comment. The "upper Rosebud" material made by H. T. MARTIN for the University and "upper Harrison" localities in South Dakota of Kansas Museum of Natural History contains and Nebraska, respectively, which OSBORN cites some excellent specimens but lacks stratigraphie ( 1918, p. 75) for occurrences of these species, are and locality data, which makes it useless for this probable equivalents of the Martin Canyon "hori- work. zon D." Nothing referable to either species has The difficulties encountered in attempting to been reported as coming from either the Sheep identify the specimens suggest that the range of Creek or Snake Creek faunas. Although OSBORN variation in the species is rather large—perhaps listed both species as coming from the "Ticholeptus- great enough to allow synonymizing of some forms. Merychippus zone" of Pawnee Buttes ( Ossomsr's Unfortunately, not enough material with accurate Classical Pawnee Creek level; M. paniensis zone; stratigraphie data is available to accomplish such a or Pawnee Creek A), the type of Parahip pus paw- study, especially in the manner that species of niensis came from "horizon D" at Martin Canyon. Merychippus from the West Coast have been stud- The association of P. coloradensis with M. paniensis ied. has not been demonstrated, and the parahippine Poor as this collection may be, it nevertheless teeth that have been found associated with M. does show features that seem significant. As a paniensis at Pawnee Buttes are not specifically whole, the milk teeth and occlusal patterns of the identifiable. Consequently, a parahippine younger permanent teeth of the merychippines in the Vim- than P. coloradensis possibly is present at Pawnee Peetz local fauna are more like those of the Pliocene, Buttes in the Eubanks local fauna. In brief the while the crown heights are distinctly shorter. most likely suggestions are: ( 1 ) the species are conspecific and limited to the early Hemingfordian; Meryehippus paniensis (CoPE) ( 2 ) the species are conspecific and range through Hippotherium paniense COPE, 1874, p. 12. the Hemingfordian and early Barstovian time span, Merychippus paniensis, GIDLEY, 1907, p. 890. but their presence or absence is controlled by facies differences or limited Type.—AMNH No. 8249; Pawnee Creek formation, Paw- distribution; or ( 3 ) one species nee Buttes, northeastern Colorado (fide OSBORN, 1918). evolved into the other, and their presence or ab- Referred specimens.—Pawnee Creek formation (Eubanks sence is due to time and facies differences or limited local fauna): No. 3125; skull and jaws; northeastern Colo- distribution. rado. Nos. 9233 and 9240; left P2 and left upper molar (possibly associated); Pawnee Buttes volcanic ash layer, Hypohippus osborni GIDLEY NE3.1 sec. 1, T. 10 N., R. 59 W., Weld County. No. 3125 was collected Hypohippus osborni GIDLEY, 1907, p. 930. by H. T. MARTIN, and its position in the Pawnee Creek section is unknown. Type.—AMNH No. 9407; Pawnee Creek beds, 8 miles west of Pawnee Buttes, northeastern Colorado. Merychippus sejunctus ( COPE) Referred specimens.—Pawnee Creek formation ( ?Kenne- saw local fauna): No. 9169; two upper cheek teeth; SWii Protohippus sejunctus COPE, 1874, p. 15. sec. 26, T. 12 N., R. 55 W., Logan County. Merychippus sejunctus, HAY, 1902, p. 618.

TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 105

Type.—AMNH No. 8291; Pawnee Creek formation, Paw- Type.—AMNH No. 9394; Pawnee Creek beds, Pawnee nee Buttes, northeastern Colorado (fide OSBORN, 1918). Buttes, northeastern Colorado. Referred specimens.—Pawnee Creek formation (Eubanks Merychippus eoplacidus OSBORN local fauna): No. 9238; right M 1 . No. 9811; left II-13, C, NE3 P2-M1 in fragment of jaw. Both specimens from sec. Merychippus eoplacidus OSBORN, 1918, p. 114. 1, T. 10 N., R. 59 W., Weld County. Type.—AMNH No. 9397; Pawnee Creek beds, Pawnee Merychippus sphenodus ( COPE) Buttes, northeastern Colorado.

Hippatherium sphenodus COPE, 1889, p. 449. Merychippus eobipparion OSBORN Merychippus sphenodus, CIDLEY, 1907, p. 908. Merychippus eohipparian OSBORN, 1918, p. 117. Type.—AMNH No. 8281; Pawnee Creek formation, Paw- Type.—AMNH No. 9402; Pawnee Creek beds, Pawnee nee Buttes, northeastern Colorado (fide OSBORN, 1918). Buttes, northeastern Colorado. Referred specimens.—Pawnee Creek formation (Kenne- saw local fauna): No. 9164; left P 2 ; WY: sec. 27, T. 12 N., Merychippus proplacidus ( OssonN ) R. 55 W., Logan County. No. 9173; right P2 ; SW11 sec. 26, T. 12 N., R. 55 W., Logan County. No. 3122; right P 2-M3 ; Protohippus proplacidus OSBORN, 1918, p. 139. northeastern Colorado. No. 9167; right P3-M2; IN% sec. 27, Merychip pus proplacidus, STniToN, 1940, p. 182. T. 12 N., R. 55 W., Logan County. No. 9178; left upper molar and right lower molar (associated); W% sec. 27, T. Type.—AMNH No. 9115b. 12 N., R. 55 W., Logan County. No. 9172; palate with all teeth except left molars; SVn sec. 26, T. 12 N., R. 55 W., This specimen is listed as having been collected Logan County. from the "Upper Pawnee Creek beds," Sand Can- yon, head of Pawnee Creek, Logan County, by 112) designated skull (Prince- Ossonil (1918, p. a BARNUM BROWN in 1898. The locality "head of ton Univ. Mus. No. 12291) as the neotype of this Pawnee Creek" was a lapsus on OSBORN ' S part and species. 26 The locality from which this Princeton should have been "head of Cedar Creek." STnrroN specimen was obtained seems to be approximately ( 1940, p. 182) tentatively considered that the speci- the same as that from which I collected the referred men might be a "lower Pawnee Creek" form. Pos- specimens listed above, with the exception of No. sibly this species is synonymous with one of the 3122 which was collected by H. T. MARTIN. species of Merychippus known by permanent teeth. No. 3122 is smaller than the type or neotype but has an occlusal pattern similar to that of the neo- Merychippus campestris GIDLEY type. Nos. 9164 and 9173 differ from the type in Merychippus campestris G1DLEY, 1907, p. 928. having the protocone united with the protoconule. Type.—AMNH No. 9096. Merychippus republicanus OSBORN GIDLEY gave the number of the type as 9069 and Merychip pus republicanus OSBORN, 1918, p. 125. the age and locality as middle Miocene, Pawnee Creek formation, Pawnee Buttes, Colorado. Os- Referred specimen. —Pawnee Creek formation ( Vim- BORN (1918, p. 114) repeated this information and Peetz local fauna): No. 9802; right P 2-M3 ; WY, sec. 27, T. 12 N., R. 55 W., Logan County. pointed out that the specimen was collected by W. D. MATTHEW in 1898 ( an error since MArrnEw No. 9802 is the best of several specimens collected did not collect at Pawnee Buttes in 1898). The from the level of the Vim-Peetz local fauna in the American Museum records, in MATTHEw's hand- exposures west of Sand Canyon. This specimen has writing, state that the type specimen of this species an occlusal pattern close to that of Neohipparion was collected by MATTHEW in 1898 from the Paw- coloradense, but the crowns of the teeth are short nee Creek beds, horizon D, at Martin Canyon, and curved. Cedar Creek, Colorado. The specimen number given by GIDLEY seems to be a typographical error Merychippus labrosus ( COPE) inasmuch as the records and the description of the material indicate that specimen No. 9096 is the Protohippus labrosus COPE, 1874, p. 13. type. Merychippus labrosus, HAY, 1902, p. 617. While there is no reason to doubt that this speci- Type.—AMNH No. 8266; Pawnee Creek formation, Paw- men came from the Martin Canyon area, MAT- nee Buttes, northeastern Colorado (fide OSBORN, 1918). THEW' S assignment to "horizon D" appears to have GIDLEY ( 1907, p. 891) considered this species to been an error. The type and referred specimens be "of rather uncertain standing." bear a resemblance to Pliohippus that suggests a horse greatly advanced over anything known from Merychippus proparvulus OSBORN beds of Hemingfordian age. In my opinion the level of occurrence probably was "horizon E" ( Vim- Merychippus proparvulus OSBORN, 1918, p. 117. Peetz local fauna of this paper). 26. Although OSBORN Wrote "Amer. Mus. 1291" for the neotype, MATTHEW ( 1901, p. 359) reported a specimen of reference to page 114 and the legend for plate 12 leaves no doubt as to 'she specimen he had in mind. "Pliohippus mirabilis" which would indicate the 106 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS presence of an advanced protohippine in the Logan position than the hypocone, and less so on the County area, but it is not known whether or not the others. Unlike M. westoni, the protocone is strongly specimen referred to by MATTHEW was the same united to the protoconule in every specimen. Pliohip pus ( AMNH No. 9093) which OSBORN men- The specimens also bear some similarity to tioned as being associated with Neohipparion colo- Calippus sp.? 27 of HESSE (1936, p. 65) from the radense. Another specimen that might fit into this Clarendonian Pliocene of Oklahoma but seem to be advanced protohippine group is AMNH No. 9459, more primitive and of a different species. referred to Merychip pus cam pestris by OSBORN ( 1918, p. 114) and recorded as coming from the FAMILY CHALICOTHERHDAE GILL, 1872 uppermost beds at Cedar Creek, 40 miles north of Sterling, Colorado. Possibly the "Phohippus" and ?Macrotherium matthewi ( HOLLAND & PETERSON) referred specimens of M. cam pestris are the same Moropus matthewi HOLLAND & PETERSON, 1913, p. 230. species. The general similarity of M. cam pestris to ?Macrotherium matthewi, MArrnEw, 1929, p. 519. Pliohippus ( Ossorm, 1918, pp. 114, 146), and the almost imperceptible intergradation Cotypes.—AMNH Nos. 9076, 9077, 9078, 9080; Pawnee of Pliohip pus Creek horizon, Martin Canyon, Cedar Creek, Colorado. with the protohippine species of Merychip pus, com- AMNH No. 9368; Loup Fork horizon, near Pawnee Buttes, mented upon by STIRTON (1940, p. 190), suggest that Weld County, Colorado. these specimens are transitional between typical Referred specimen. —Pawnee Creek formation ( Martin protohippine and pliohippine horses. Canyon local fauna): No. 9378; right ?P4 ( damaged); NE % sec. 27, T. 11 N., R. 53 W., Logan County. Merychippus sp. (Advanced protohippine) The stratigraphie position of the chalicothere re- Referred specimens. —Pawnee Creek formation ( Vim- mains collected by MATTHEW ( Nos. 9076-9080) Peetz local fauna): No. 9803; left P2; WM sec. 27, T. 12 N., cannot be exactly determined to my satisfaction. R. 55 W., Logan County. No. 9804; external wall of lower MATmEw stated ( 1901, p. 359), "It appeared prob- cheek tooth; NE) sec. 27, T. 11 N., R. 53 W., Logan County. able that the heavy beds of coarse gravel filling These teeth show little more than that the proto- erosion valleys are connected with these upper beds hippine horses at this level had not reached a stage [horizon E or bed No. 5 of measured section XV, of development typical of the horses of the lower Fig. 6] rather than with the finer concretionary Clarendonian. sandstones [bed No. 4 of measured section XV, shingle bed ?Merychippus sp. Fig. 6] and are continuous with the overlying the latter rather than the one [bed No. 3 Referred specimen. —Pawnee Creek formation ( Martin of measured section XV, Fig. 6] underneath it Canyon local fauna ): No. 9210; fragment of upper molar [italics mine, E. C. G.]. The Moropus and other preserving only the metaloph and part of the metacone; NE% species should therefore also be added to this list sec. 27, T. 11 N., R. 53 W., Logan County. [fauna of horizon E]." In the N% of sec. 27 the This specimen was collected at Quarry A in Mar- relationship of the channels are as MArniEw de- tin Canyon. The metaloph shows multiple plica- scribed them, but the American Museum records tions similar to those seen in Merychippus paniensis state that MATTHEW collected the chalicothere re- and M. sphenodus and better developed than those mains at the "gravel hill west of spring," which of M. primus and M. gunteri. The fragment indi- appears to have been one of the exposures near cates a tooth nearly the size of M. primus in antero- Sand Butte and west of Willow Spring ( the only posterior and transverse diameters. However, it spring in the immediate area, in N% sec. 34, and one seems to have been shorter crowned. with a long and well-known history). In this locality at least some, if not all, of the coarse gravel Calippus sp. beds are thought to be associated with the fine con- Referred specimens. —Pawnee Creek formation ( Ken- cretionary sandstones or the underlying rubble bed. nesaw local fauna ): No. 3131; right P3-M2 ; northeastern No. 9378 was found near the base of the fine con- Colorado. No. 7731; incomplete left M 2 ; NE% sec. 31, cretionary sandstones, and it must be kept in mind, T. 12 N., R. 54 W., Logan County. No. 9166; right M2> W32 sec. 27, T. 12 N., R. 55 W., Logan County. No. 9188; on the surface. Although it appears improbable, right M3; SW}i sec. 25, T. 12 N., R. 55 W., Logan County. the possibility of the specimen drifting down to this level cannot be overlooked, since MATTHEW These teeth, because of their pattern and small thought his specimens came from the higher level. size, are referred to Calip pus. However, they are There is much to suggest that the chalicotheres not referable to any known species of this genus, were part of the Martin Canyon local fauna found having less crown height and being more curved in the concretionary sandstones: the probability than in other species. 27. Ca/ippus sp.? was based on one of 17 specimens catalogued In antero-posterior and transverse diameters, under No. 3736 in the University of Kansas Museum of Natural His- tory. Some of the remaining 16 teeth in lot No. 3736 and part of a these specimens are similar to the teeth of Mery collection of much larger teeth catalogued under No. 3738 in this Museum were referred to Nannippus sp.? by HESSE (1936, p. 64). SIMPSON. Also, as in the teeth of-chip pus westoni Inasmuch as the remaining 16 teeth in /lo. 3738 are also referable to Ca/ippus sp.?, I think that at least part of the discussion of Nannippus M. westoni, the protocone of 133 is more internal in sp.? by HESSE refers to the species represented by Ca/ippus sp.?. TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 107 that MArrHEw collected his material near Willow considered the age of the specimen to be middle Spring where there are channel gravels older than Miocene, whereas MATTHEW gave the age as upper those to which he assigned the specimens; and the Miocene. The age may have influenced the think- mixed fauna of the gravels ( as given by MATTHEW, ing of each author. 1901, p. 858) which suggests that he had the channels confused. The level from which the Pawnee Aphelops profectus ( MAI-THEW ) Butte specimen was collected cannot be deter- Aceratherium pro fectum MArmEw, 1899, p. 71. mined. Aphelops profectus, MArrnzw, 1901, p. 358. Unfortunately, chalicotheres are much too rare as Fork of northeastern individuals to allow conclusions based on their Type.— AMNH No. 9082; Loup presence or absence in a fauna. However, the Colorado. absence of chalicotheres from the lower Snake American Museum records state that this speci- Creek fauna, which has many forms in common men was obtained from "horizon D," Martin Can- with the Pawnee Creek fauna, is suggestive that yon [NEri sec. 27, T. 11 N., R. 53 W., Logan they occur in the Martin Canyon fauna but not the County]. Pawnee Creek fauna in northeastern Colorado. Aphelops profectus is known only by the one lower jaw. Possibly our material from Martin Can- FAMILY TAPIRIDAE BURNETT, 1830 yon that is listed under Aphelops sp. belongs to this Tapiravus? sp. species. Aphelops megalodus (COPE) Referred specimen.—AMNH no. 9367; upper jaw fragment with two premolars. Aceratherium megalodus COPE, 1873, p. 1. Aphelops megalodus, COPE, 1873, p. 1. Mrs. RACHEL H. NIcHoLs brought this specimen to my attention and supplied the following data: Type.—AMNH No. 8292; Pawnee Buttes, Colorado (Me "A. M. no. 9367, labeled 'Tapir', . . . found at OSBORN, 1904). Davis' Ranch, Weld Co., Colo., in Pawnee Creek This specimen probably came from the Eubanks beds, by Loomis, 1901." Presumably it is the same local fauna in the Pawnee Creek formation, but the specimen referred to by MATTHEW ( 1901, p. 445) vertical range of the species is unknown. ST1RTON as Tapiravus(?). FRICK ( 1926, p. 106) reported (1936, p. 190) thought that possibly this species that a specimen of Tapirus had been collected in belonged to the "upper Pawnee Creek fauna" of 1922 from beds contain- the Pawnee Buttes area in northeastern Colorado. MATTHEW ( 1924, p. 150) ing Merycodus and Merychippus. This specimen tentatively listed it in the Sheep Creek fauna and seems to be lost, but these reports indicate that more certainly in the M. paniensis zone of the lower Miocene tapirids were present in northeastern Colo- considered Aphelops mega- rado. Snake Creek fauna. He iodas to be more primitive than the Pliocene species. FAMILY RHINOCEROTIDAE OWEN, 1845 More recently HENSHAW (1942, p. 95) stated that A. megalodus was more primitive than the late Diceratherium? persistens ( OSBORN) Miocene rhinoceroses of the Tonapah fauna. Al- Caenopus persistens OSBORN, 1904a, p. 318. though the species may have survived into the Diceratherium? persistens, WOOD, H. E., 1927, p. 72. latest Miocene or early Pliocene, an earlier age for the form seems more probable. Type.—AMNH No. 9081; middle ( p. 318), or upper ( p. 326) Miocene of northeastern Colorado ( OSBORN, 1904a). Aphelops spp. American Museum records state that the speci- Referred specimens.—Pawnee Creek formation ( Martin men was collected in 1898 from the Loup Fork Canyon local fauna ): No. 9376; right dM 3 ; NEX sec. 27, beds, Pawnee Creek, Colorado. However, the cata- T. 11 N., R. 53 W., Logan County. logue number and the year of collection indicate Pawnee Creek formation (Eubanks local fauna): No. 9250; left P3. No. 9812; paroccipital and exoccipital bone. that the locality would probably be either the Mar- No. 9813; astragalus. All three specimens from Pawnee tin Canyon or Sand Canyon area in Logan County. Buttes ash layer, NE% sec. 1, T. 10 N., R. 59 W., Weld This specimen has been discussed by WOOD County. ( 1927, p. 72) and MATTHEW (1932, p. 418), but Pawnee Creek formation (Vim-Peetz local fauna ): No. neither author offers 7734; damaged left tibia; NE34 sec. 27, T. 11 N., R. 53 W., a satisfactory taxonomic alloca- Logan County. No. 9799; cuneiform; W3: sec. 29, T. 12 N., tion of the type specimen. WOOD thought that the R. 55 W., Logan County. specimen was a female dicerathere, but specifically indeterminate. MATTHEW thought the skull char- No. 9376 agrees in size and shape with the cor- acters too primitive to fall into any of the genera responding milk tooth figured by MATTHEW (1918, Aphelops, Peraceras, or Teleoceras, but "might be p. 206, fig. 13) from the Snake Creek beds. This compared with `Diceratherium' palaeosinense of the specimen, and other rhinocerotid fragments from Chinese Pliocene, which is not Diceratherium but the Martin Canyon fauna, seem advanced in com- not readily referable to any described genus." Woon parison with Diceratherium. 108 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

The premolar from Pawnee Buttes is 49.5 mm. Colorado have been discussed recently by Scmuurz long and 27.7 mm. wide. & FALKENBACH ( 1940, 1941, 1947). These authors The tibia from the Vim-Peetz local fauna be- reidentified the material collected by earlier work- longed to an individual that perhaps exceeded ers with but little change other than to assign speci- Aphelops mutilus in size. mens regarded by MATTHEW ( 1901, p. 412) as pertaining to "Merycochoerus rusticus" to Ustato- Teleoceras medicornutus OSBORN choerus medius (LEIDY). Teleoceras medicornutus OSBORN, 1904a, p. 319. Ustatochoerus medius (LEmy ) Type.—AMNH No. 9832; OSBORN gave the locality of the type specimen as 25 miles north of Pawnee Buttes. Merychyus medius LEIDY, 1858, p. 26. There does not seem to be any evidence in the American Ustatochoerus medius, SCHULTZ & FALKENBACH, 1941, p. 23. Museum records for any locality other than 15 feet above the base of the Loup Fork, 15 miles northeast of Grover, Referred specimens.—Pawnee Creek formation (Kenne- Weld County, Colorado. saw local fauna ): No. 9809; palate and lower jaws; SW3•i sec. 26, T. 12 N., R. 55 W., Logan County. MATudEw (1982, p. 418) thought that Aphelops Pawnee Creek formation ( Vim-Peetz local fauna): No. planiceps OSBORN ( 1904a, p. 821), from northeastern 9186; skull, jaws, atlas, and axis; W Y2 sec. 28, T. 12 N., R. Colorado, probably was synonymous with this 55 W., Logan County. species. Isolated teeth and fragments of bone, probably Teleoceras spp. referable to this species, are not uncommon in the basal 50 feet of the Referred specimens. —Pawnee Creek formation (Vim- Pawnee Creek formation west Peetz local fauna ): No. 9795; right radius. No. 9796; left of Sand Canyon, Logan County, but good specimens humerus. No. 9797; left nasal bone. Above specimens are rare. from WX sec. 29, T. 12 N., R. 55 W., Logan County. No. 9389; nasal bones; NE% sec. 27, T. 11 N., R. 53 W., Logan Ustatochoerus? schrammi SCHULTZ & FALKENBACH County. Ustatochoerus? schramm: SCHULTZ & FALKENBACH, 1941, Except for their smaller size, Nos. 9795-9797 re- p. 49. semble the respective structures in Teleoceras fossiger. SCHULTZ & FALKENBACH (1941, p. 50) have re- No. 9389, consisting only of the blunt, fused nasal ferred specimens from the "basal part of the Ogal- bones with a well-developed callosity, most closely lala deposits (lower Valentine )," Pawnee Creek fits the nasals of Teleoceras medicornutus. The area, Weld County 29 to this species. assignment of this specimen to the Vim -Peetz local fauna must be tentative for the present. It was Ustatochoerus sp. found by Dr. ROBERT WILSON on the surface of Referred specimen.—Pawnee Creek formation (Eubanks "horizon D" beds a few feet above the University local fauna): No. 9814; left P2; NE% sec. 1, T. 10 N., R. of Kansas Quarry A. The topography of the area 59 W., Weld County. seemingly precludes deriving the specimen from younger beds by drifting; therefore, its presence on Merycochoerus proprius magnus (Loo/vris) "horizon D" beds cannot be explained unless it was Merycochoerus magnus Loomis, 1924, p. 28. carried in by human agency. 28 Merycochoerus proprius ma gnus, SCHULTZ 8c FALKENBACH, 1940, p. 286. ORDER ARTIODACTYLA OWEN, 1848 Referred specimens.—Pawnee Creek formation ( Martin Canyon local fauna ): No. 9206; right lower jaw with teeth. FAMILY TAYASSUIDAE PALMER, 1897 No. 9363; muzzle of skull with canines and anterior premolars. No. 9392; damaged skull and mandible. Specimens Tayassuid sp. from NE34 sec. 27, T. 11 N., R. 53 W., Logan County. No. Referred specimens.—Pawnee Creek formation (Martin 9213; left P2, 1n42 , M 3, and right M2. No. 9214; fragments Canyon local fauna ): No. 9325; canine. No. 9347; frag- of left M3. No. 9276; right P3 and M3. Last three speci- ment of upper molar. NE% sec. 27, T. 11 N., R. 53 W., mens from sec. 22, T. 11 N., R. 52 W., Logan County. Logan County. In addition to the well-known Merycochoerus These specimens and some unprepared material proprius magnus slab ( AMNH No. 8968) from the indicate that a peccary as small as Perchoerus was lowest Miocene exposures at Martin Canyon, there present in Quarry A. are several specimens ( AMNH Nos. 9051-9053, 9055, 9057-9058, and 9064) from the nodular silts FAMILY MERYCOIDODONTIDAE THORPE, 1923 (horizon D of MATTHEW) above the beds contain- The post-Oligocene oreodonts from northeastern ing No. 8968. These specimens were assigned by 28. All doubt concerning the age of this specimen was dispelled MATTHEW (1901, p. 401) to Merycochoerus pro- with the discovery of a nearly complete skull and some limb bones of prius. Later (1909, p. 115) he listed the Mery- a teleocerine in Quarry A in the summer of 1952. The nasal bones of the newly discovered skull are similar in all respects to the nasals found cochoerus of northeastern Colorado as M. cf. M. by WILSON. Therefore, Teleocerine sp. should be added to the Martin Canyon local fauna. 29. The authors state Logan County, but this is evidently a lapsus.

TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 109 proprius. To just which specimens ( or all?) MAT- Protolabis fissidens (COPE) THEW was referring at this time is unknown. SC:HULTZ Procamelus fissidens COPE, 1876, p. 145. & FALKENBACH referred AMNH No. 9052 to Mery- Protolabis fissidens, MArrnEw, 1924, p. 190. cochoerus p. magnus but did not commit themselves on the remaining specimens. From the same lo- Type.—AMNH No. 8297; Pawnee Creek beds, northeastern MATTHEW, cality and level as AMNH Nos. 9051-9064, several Colorado (fide 1901). specimens have been collected in recent years, of Protolabis heterodontus (CopE) which the three best are listed above. No. 9206, a Procamelus heterodontus COPE, lower jaw, was examined by Mr. CHARLES FAIKEN- 1873d, p. 420. Protolabis heterodontus, COPE, 1876, p. 145. BACH and considered to be close to Merycochoerus matthewi Loomis (personal communication). Mr. Type.—AMNH No. 8296; Pawnee Creek beds, near FALKENBAC:H pointed out, however, that the assign- Pawnee Buttes, Weld County, Colorado (fide COPE & MAT- ment of lower jaws to species of Mer ycochoerus was THEW, 1915). a precarious practice subject to error ( at this time Protolabis angustidens (COPE) the other specimens had not been prepared). No. 9363 also agrees in size and description with Mer y- Procamelus angustidens COPE, 1874, p. 20. cochoerus matthewi, but No. 9392 has the size and Protolabis angustidens, MATTHEW, 1899, p. 74. appearance of M. p. ma gnus. The specimens were Type.—AMNH No. 8294; Pawnee Creek beds near collected from the immediate vicinity of the Uni- Pawnee Buttes, Weld County, Colorado (fide COPE & MAT- versity of Kansas Quarry A and stratigraphically THEW, 1915). within a few feet of each other. It is questionable whether Nos. 9206 and 9363 represent anything Protolabis longiceps MATTHEW more than sexual or individual variants of Mery- Protolabis longiceps MArrnEw, 1909, p. 115. cochoerus p. ma gnus. Type.—AMNH No. 9108; Pawnee Creek beds ( horizon D), Cedar Creek, northeastern Colorado. Merychyus elegans LEIDY The record of occurrence of this type specimen in "horizon D" refers to MATTHEW'S "horizon D" at Sand Canyon, Logan Merychyus elegans LEIDY, 1858, p. 25. County, and indicates that the specimen is probably late Barstovian in age. Referred specimens.—Pawnee Creek formation ( Martin Canyon local fauna ): No. 9207; mandible. No. 9312; left Alticamelus leptocolon MATTHEW M 2, and right Mi-M3. No. 9313; left M 2 . All from NE34 sec. 27, T. 11 N., R. 53 W., Logan County. No. 9378; left Alticamelus leptocolon Mivr-rxEw, 1909, p. 115. P9i sec. 22, T. 11 N., R. 52 W., Logan County. Type.—AMNH No. 9116; brown Miocene sandstone, For the most part, the specimens collected by the Sand Canyon, Cedar Creek, Colorado. American Museum party of 1898 were subsequently In the designation of the type of this species discussed by MATTHEW ( 1901, p. 418), Looxris MATTHEW ( 1909, p. 115) referred to specimens dis- ( 1924, p. 34), COLBERT ( 1943, p. 303), and SC:HULTZ cussed ( 1901, pp. 427-428) as Procamelus robustus, & FALICENBACH ( 1947, p. 202). Insofar as I can and including AMNH Nos. 9112, 9112a, 9114, 9116, determine, the University of Kansas specimens from 9117. Later ( 1924, p. 187) MATTHEW stated that Martin Canyon came from the same beds as the the type was No. 9115. Dr. G. G. SIMPSON and specimens collected by the American Museum party. Mrs. RACHEL Maims kindly investigated this problem for me and found that MATTHEW (1924, p. 187) ScHuurz & FALKENBACH ( 1947, p. 202) referred had described the material numbered AMNH 9116, AMNH Nos. 9442-9444 from Pawnee Buttes, Weld but used the number 9115. The use of number County to Merychyus elegans. They also tenta- 9115 was a typographical error, and the correct tively referred a specimen from Weld County to number for the type is 9116. the subspecies M. elegans bluei. Alticamelus giraffinus MATTHEW FAMILY CAMELIDAE GRAY, 1821 Alticamelus giraffinus MATTHEW, in MATTHEW & COOIC, 1909, Camelid specimens were collected from most of p. 402. the Miocene localities in northeastern Colorado, but Type.—AMNH No. 9109; Pawnee Creek formation; SW31 none of the fragments were sufficiently complete to sec. 25, T. 12 N., R. 55 W., Sand Canyon, Logan County, permit specific identification or, with few excep- Colorado. Referred specimens. — Pawnee Creek formation ( Vim- tions, even generic identification. No. 9248, frag- Peetz local fauna): Nos. 9793-9794; ulna and distal end of ments of foot bones, from the Pawnee Buttes vol- radius; W% sec. 29, T. 12 N., R. 55 W., Logan County. canic ash layer in the NEli sec. 1, T. 10 N., R 59 W., Originally, MATTHEW ( 1901, p. 430) referred the Weld County, probably belongs either to Protolabis type specimen to Alticamelus altus. This specimen heterodontus or to Protolabis angustidens. was found by H. T. MARTIN. MARTIN later pointed 110 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

out the site to CURTIS HESSE, who subsequently gave species, has been found by any University of Kansas the locality information to Dr. ROBERT WILSON. party in beds of the Pawnee Creek formation. The referred material is assigned to this species because of its size. Merycodus furcatus ( LEIDY ) Cosoryx furcatus LEIDY, 1869, p. 173. FAMILY CERVIDAE GRAY, 1821 Merycodus furcatus, HAY, 1902, p. 683. Little identifiable cervid material was found in Meryceros warreni (LEIDY) the Pawnee Creek formation. Recovered teeth are generally comparable to specimens from the Sheep Cervus tvarreni LEIDY, 1858, p. 23. Meryceros warreni, FRICK, 1937, p. 354. Creek beds. Meryceros minor FIUCK Blastomeryx gemrnifer ( COPE) Meryceros minor FRICK, 1937, p. 403. Merycodus gemmifer COPE, 1874, p. 22. Blastomeryx gemmifer, COPE, 1877, p. 350. FRICK ( 1937 ) has reported the above three species from northeastern Colorado. He gives no indi- Type. — AMNH No. 8301; Pawnee Creek fauna (fide MATTHEw, 1924). cation of the age of the beds except to state that they were late Tertiary. Blastomeryx elegans MATTHEW & COOK cf. B. Ramoceros osborni ( MAYTHEw ) Referred specimen. —Pawnee Creek formation ( Martin Canyon local fauna ): Univ. Colorado Mus. No. 19837; right Merycodus osborni MATTHEW, 1904, p. 107. P4-M 3. Nos. 9209, 9318, 9319, 9346; isolated upper molars. Ramoceros osborni, FRICK, 1937, p. 328. All specimens from NO: sec. 27, T. 11 N., R. 53 W., Logan County. Type. — AMNH No. 9476; middle Miocene ( Pawnee Creek beds ), northeastern Colorado. Isolated teeth of this form and of Blastomeryx cf. Referred specimen. —Pawnee Creek formation ( Vim- B. medius were numerous in the University of Kan- Peetz local fauna): No. 9183; left horn; W31 sec. 28, T. 12 N., R. 55 W., Logan County. sas Quarry A at Martin Canyon. No. 9183 was removed from indurated, coarse, Blastomeryx cf. B. medius MATrilEw channel sandstone approximately 10 feet above the Referred specimen. —Pawnee Creek formation ( Martin base of the Pawnee Creek formation. Canyon local fauna ): No. 9316; left jaw with P4-M3; NE% sec. 27, T. 11 N., R. 53 W., Logan County. THE PLIOCENE FAUNA Barbouromeryx pawniensis Flom( One early Clarendonian species of mammal is known from northeastern Colorado. Possibly some Barbouromeryx pawniensis FRICK, 1937, p. 133. of the species assigned to the Barstovian faunas Type.—F: AM No. 31290; two miles west of Mastodon have a range in time extending into the Claren- Quarry, Pawnee Creek, Weld County, Colorado. donian, but until the Sand Canyon local fauna (i. e., Neohipparion coloradense) is associated with a Dromomeryx pawniensis FMCK definite set of beds, little can be done about this Dromorneryx pawniensis FRICK, 1937, p. 115. problem. The Kimball member of the Ogallala formation in Type.—F:AM No. 31297; near Pawnee Buttes, Pawnee northeastern Creek, Weld County, Colorado. Colorado has not yielded any fossil material. The Dromomeryx borealis of the Pawnee Creek CLASS MAMMALIA fauna (MATTHEW, 1924, p. 72) was referred to this ORDER PERISSODACTYLA OWEN, 1848 species by FRICK. FAMILY EQUIDAE GRAY, 1821 Cranioceras pavvniensis FRICK Neohipparion coloradense ( OsEom ) Cranioceras pawniensis FRICK, 1937, p. 93. Type.—F:AM No. 31294; middle horizon, west of Buttes, Hipparion coloradense OSBORN, 1918, p. 183. Pawnee Creek, Colorado. Neohipparion coloradense, HESSE, 1936, p. 62. Type. — AMNH No. 9094; upper Pawnee Creek beds, FAMILY GRAY, ANTILOCAPRIDAE 1866 Sand Canyon, Logan County, Colorado. No merycodonts other than Ramoceros osborni Attention has already been given to the problem were reported by MATTHEW from northeastern Colo- of the locality and level of this specimen in the dis- rado, and nothing identifiable, other than this same cussion of the Sand Canyon local fauna. TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 111 REFERENCES

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Rept., pt. 4, pp. V ertebrata of Nebraska and adjacent areas: Nebraska 719-785, pls. 74-118. Geol. Survey Paper 5, pp. 1-58, 1 unnumbered figure. & GREGORY, J. T. ( 1941) Mesogaulus praecursor, a (1905) Preliminary report on the geology and un- new rodent from the Miocene of Nebraska: jour. Paleont., derground water resources of the central Great Plains: vol. 15, pp. 549-552, figs. 1-2. U. S. Geol. Survey, Prof. Paper 32, pp. 1-433, pls. 1-72, figs. 1-18. COPE, E. D. ( 1873) On some new extinct Mammalia from the Tertiary of the Plains: Palaeont. Bull., no. 14, pp. 1-2. EL.I.As, M. K. ( 1942 ) Tertiary prairie grasses and other herbs from the High Plains: (1873a) Second notice of extinct Vertebrata from Geol. Soc. America, Spec. Papers, no. 41, pp. 1-176, pls. 1-17, the Tertiary of the Plains: Palaeont. Bull., no. 15, pp. 1-6. fig. 1. (1873b) Third notice of extinct Vertebrata from the FENNEMAN, N. M. ( 1931) Physiography of western United Tertiary of the Plains: Palaeont. Bull., no. 16, pp. 1-8. States: McGraw-Hill, New York, pp. i-xiii, 1-534, pl. 1, figs. 1-173. ( 1873c) Synopsis of new V ertebrata from the Ter- tiary of Colorado, obtained during the summer of 1873: Ficonsis, J. D. ( 1934) The generic status of ?Caenopus pre- Gov't. Printing Office, Washington, pp. 1-19. mitis: Colorado Mus. Nat. Hist., Proc., vol. 13, no. 1, p. 1. ( 1873d ) [On Menotherium /emurinum, Hypisodus ( 1934a) New material for the study of individual minimus, Hypertragulus calcaratus, H. tricostatus, Proto- variation, from the lower Oligocene of Colorado: Colo- hippus, and Procamelus occidentalis]: Acad. Nat. Sci. rado Mus. Nat. Hist., Proc., vol. 13, no. 3, pp. 7-14, pls. Philad., Proc., 1873, pp. 419-420. (1874) Report on the strati graphy and Pliocene ver- FRICK, C. ( 1926 ) The Hemicyoninae and an American Ter- tebrate palaeontology of northern Colorado: U. S. Geol. tiary bear: Am. Mus. Nat. Hist., Bull., vol. 56, art. 1, pp. and Geog. Survey Ten., Bull. 1, ser. 1, vol. 1, pp. 9-28. 1-119, frontispiece, figs. 1-63. (1874a) Report on the vertebrate palaeontology of (1933) New remains of trilophodont-tetrabelodont Colorado: U. S. Geol. and Geog. Survey Ten., Ann. Rept. mastodons: Am. Mus. Nat. Hist., Bull., vol. 59, art. 9, 1873, F. V. Hayden, U. S. Geologist, Washington, D. C., pp. 505-652, figs. 1-38, 7 tables. pp. 427-533, pls. 1-8. ( 1937 ) Horned ruminants of North America: Am. ( 1874b ) On a new mastodon and rodent: Acad. Mus. Nat. Hist., Bull., vol. 69, pp. i-xxviii, 1-669, frontis- Nat. Sci. Philad., Proc., 1874, pp. 221-223. piece, figs. 1-68, 17 tables. ( 1875) Systematic catalogue of Vertebrata of the GALBREATH, E. C. (1948) A new species of heterornyid ro- Eocene of New Mexico, collected in 1874: Rept. to Engi- dent from the middle Oligocene of northeastern Colorado neer Dept., U. S. Army, in charge of Lieut. Geo. M. with remarks on the skull: Univ. Kansas Mus. Nat. Hist. Wheeler, Washington, pp. 5-37, 1 unnumbered figure. Pub., vol. 1, no. 18, pp. 285-300, pls. 2-3. (1876) On a new genus of Camelidae: Acad. Nat. GAZIN, C. L. ( 1932) A Miocene mammalian fauna from Sci. Philad., Proc., 1876, pp. 144-147. southeastern Oregon: Carnegie Inst. Wash. Pub., no. 418, (1877) Report upon extinct V ertebrata obtained in pp. 37-86, pls. 1-6, figs. 1-20. New Mexico by parties of the expedition of 1874. Chap. GIDLEY, J. W. ( 1907 ) Revision of the Miocene and Pliocene 11-13: U. S. Geog. Surveys W. 100th Mend. ( Wheeler ), Equidae of North America: Am. Mus. Nat. Hist., Bull., Rept., vol. 4, pt. 2, pp. 1-370, pLs. 22-83. vol. 23, art. 35, pp. 865-934. 112 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

GILMORE, C. W. ( 1928 ) The fossil lizards of North America: ( 1850a ) Descriptions of Rhinoceros nebraskensis, Nat. Acad. Sci., Mem., vol. 22, pp. i-xxii, 1-201, pls. 1-27, Agriochoerus antiquus, Palaeotherium proutii, and P. figs. 1-106. bairdii: Acad. Nat. Sci. Philad., Proc., vol. 5, pp. 121- ( 1938 ) Fossil snakes of North America: Geol. Soc. 122. America, Spec. Papers, no. 9, pp. i-viii, 1-96, pls. 1-4, figs. (1851) [Description of Stylemys nebrascensis]: 1-38. Acad. Nat. Sci. Philad., Proc., vol. 5, pp. 172-173. GREEN, M. ( 1942 ) A study of the Oligocene Leporidae in ( 1851a) Descriptions of fossil ruminant ungulates the Kansas University Museum of Vertebrate Paleon- from Nebraska: Acad. Nat. Sci. Philad., Proc., vol. 5, pp. tology: Kansas Acad. Sci., Trans., vol. 45, pp. 229-247, 237-239. pls. 1-3. ( 185 lb) [Remarks on Oreodon priscus and Rhinoc- GREGORY, W. K. ( 1910 ) The orders of mammals: Am. Mus. eros occidentalis]: Acad. Nat. Sci. Philad., Proc., vol. 5, Nat. Hist., Bull., vol. 27, pp. 1-524, figs. 1-32. p. 276. & COOK, H. J. (1928) New material for the study of (1851e) [Descriptions of fossils from the Green- evolution. A series of primitive rhinoceros skulls (Tri- sand of New Jersey]: Acad. Nat. Sci. Philad., Proc., vol. gonias) from the lower Oligocene of Colorado: Colorado 5, pp. 329-330. Mus. Nat. Hist., Proc., vol. 8, no. 1, pp. 1-32, pls. 1-6, ( 1853) [Remarks on a collection of fossil Mammalia figs. 1-5, 1 graph, 8 tables. from Nebraska]: Acad. Nat. Sci. Philad., Proc., vol. 6, HAY, O. P. ( 1899 ) Notes on the nomenclature of some North pp. 392-394. American fossil vertebrates: Science, ser. 2, vol. 10, pp. ( 1854 ) The ancient fauna of Nebraska, or a descrip- 253-254. tion of remains of extinct Mammalia and Chelonia from ( 1902 ) Bibliography and catalogue of the fossil Ver- the Mauvais Terres of Nebraska: Smithson. Contrib. tebrata of North America: U. S. Geol. Survey, Bull., vol. Knowl., vol. 6, art. 7, pp. 1-126, pls. 1-24. 179, pp. 1-868. ( 1854a) [Remarks on a new species of mammal (1904) A new gigantic tortoise from the Miocene of from Nebraska, Dinictis feline]: Acad. Nat. Sci. Philad., Colorado: Science ( n. s.), vol. 19, pp. 503-504. Proc., vol. 7, p. 127. ( 1908 ) The fossil turtles of North America: Car- (1856) Notices of remains of extinct Mammalia, negie Inst. Wash. Pub., no. 75, pp. i-iv, 1-568, pls. 1-113, discovered by Dr. F. V. Hayden in Nebraska territory: figs. 1-704. Acad. Nat. Sci. Philad., Proc., vol. 8, pp. 88-90. ( 1930) Second bibliography and catalogue of the ( 1856a ) Notices of several genera of extinct Mam- fossil V ertebrata of North America: Carnegie Inst. Wash. malia, previously less perfectly characterized: Acad. Nat. Pub. no. 390, vol. 1 ( 1929 ), pp. i-viii, 1-916; vol. 2 Sel. Philad., Proc., vol. 8, pp. 91-92. ( 1930 ), pp. i-xiv, 1-1074. (1856b) Notice of some remains of extinct verte- brated animals: Acad. Nat. Sel. Philad., Proc., vol. 8, pp. HENSHAW, P. C. ( 1942) A Tertiary mammalian fauna from the San Antonio Mountains near Tonopah, Nevada: Car- 163-165. negie Inst. Wash. Pub., no. 530, pp. 77-168, pls. 1-11, ( 1856c ) Notices of extinct Vertebrata discovered by figs. 1-7. Dr. F. V. Hayden, during the expedition to the Sioux under the command of Lieut. G. K. Warren: lower Pliocene vertebrate fossils country HESSE, C. J. ( 1936) The Acad. Nat. Sci. Philad., Proc., vol. 8, pp. 311-312. from the Ogallala formation (Lavern zone) of Beaver County, Oklahoma: Carnegie Inst. Wash. Pub., no. 476, ( 1858 ) Notice of remains of extinct Vertebrata, pp. 47-72, figs. 1-10. from the valley of the Niobrara River, collected during the exploring expedition of 1857, in Nebraska, under the HOLLAND, W. J., & PETERSON, O. A. ( 1913) The osteology command of Lieut. G. K. Warren, U. S. Top. Eng., by of the Chalicotheroidea; with special reference to a Dr. F. V. Hayden, Geologist to the expedition: Acad. Nat. mounted skeleton of Moro pus elatus Marsh, now installed Sci. Philad., Proc., vol. 10, pp. 20-29. the Carnegie Museum: Carnegie Mus., Mem., vol. 3, in (1869) The extinct mammalian fauna of Dakota and pp. 189-406, pls. 48-77, figs. 1-115. Nebraska, including an account of some allied forms from HOUGH, J. R. ( 1948 ) A systematic revision of Daphoenus other localities, together with a synopsis of the mam- and some allied genera: Jour. Paleont., vol. 22, pp. 578- malian remains of North America: Acad. Nat. Sci. Philad., 600, pls. 84-87, figs. 1-3. Jour., ser. 2, vol. 7, pp. 1-472, pls. 1-30. ( 1948a) The auditory region in some members of Loomis, F. B. ( 1924 ) Miocene oreodonts in the American the Procyonidae, Canidae, and Ursidae: Am. Mus. Nat. Museum: Am. Mus. Nat. Hist., Bull., vol. 51, art. 1, pp. Hist., Bull., vol. 92, art. 2, pp. 67-118, pls. 9-15, figs. 1-11. 1-37, figs. 1-26. ( 1949 ) The subspecies of Hoplophoneus: a statis- LUCAS, F. A. ( 1900 ) A new rhinoceros, Trigonias osborni, tical study: Jour. Paleont., vol. 23, pp. 536-555, pls. 86- from the Miocene of South Dakota: U. S. Nat. Mus., 87, figs. 1-3. Proc., vol. 23, pp. 221-223, figs. 1-2. KOERNER, H. E. ( 1931) Fossil birds and mammals of Colo- LUGN, A. L. (1939) Classification of the Tertiary system in rado: Univ. Colorado Studies, vol. 18, no. 3, pp. 163-176. Nebraska: Geol. Soc. America, Bull., vol. 50, pp. 1245- LAMBE, L. M. (1908) The Vertebrata of the Oligocene of 1275, pl. 1. the Cypress Hills, Saskatchewan: Contrib. Canadian McGrtEw, P. 0. (1937) New marsupials from the Tertiary of Palaeont., vol. 3, pt. 4, pp. 1-65, pls. 1-8, figs. 1-13. Nebraska: Jour. Geol., vol. 45, no. 4, pp. 448-455, figs. LEIDY, J. ( 1847) On a new genus and species of fossil 1-4. Ruminantia: Poebrotherium wilsoni: Acad. Nat. Sci. (1937a) The genus Cynarctus: Jour. Paleont., vol. Philad., Proc., vol. 3, pp. 322-326. 11, pp. 444-449, figs. 1-2. 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( 1939 ) Nanodelphys, an Oligocene didelphine: ( 1929 ) Critical observations upon Siwalik mammals: Field Mus. Nat. Hist., Geol. Ser., vol. 6, no. 26, pp. 393- Am. Mus. Nat. Hist., Bull., vol. 56, art. 7, pp. 437-560, 400, fig. 114. figs. 1-55. ( 1941 ) A new procyonid from the Miocene of Ne- ( 1930) Range and limitations of species as seen in braska: Field Mus. Nat. Hist., Geol. Ser., vol. 8, no. 5, fossil mammal faunas: Geol. Soc. America, Bull., vol. 41, pp. 33-36, figs. 12-13. pp. 271-274. ( 1941a ) A new Miocene lagomorph: Field Mus. ( 1931 ) Critical observations on the phylogeny of the Nat. Hist., Geol. Ser., vol. 8, no. 6, pp. 37-41, fig. 14. rhinoceroses: Univ. Calif. Dept. Geol. Sci., Bull., vol. 20, ( 1941b) Heteroniyids from the Miocene and lower pp. 1-9, figs. 1-2, Oligocene: Field Mus. Nat. Hist., Geol. Ser., vol. 8, no. 9, ( 1932) A review of the rhinoceroses with a descrip- pp. 55-57, fig. 17. tion of Aphelops material from the Pliocene of Texas: ( 1941c) The Aplodontoidea: Field Mus. Nat. Hist., Univ. Calif. Dept. Geol. Sci., Bull., vol. 20, pp. 411-480, Geol. Ser., vol. 9, no. 1, pp. 1-30, figs. 1-13. pls. 61-79, figs. 1-12. MARSH, O. C. ( 1870 ) Discovery of the Mauvaises Terres (1937) Paleocene faunas of the San Juan Basin, formation in Colorado: Am. Jour. Sci., ser. 2, vol. 50, New Mexico: Am. Phil. Soc., Trans., n. s., vol. 30, pp. p. 292. i-viii, 1-510, pls. 1-65, figs. 1-85. ( 1873 ) Notice of new Tertiary mammals: Am. Jour. & Comc, H. J. ( 1909 ) A Pliocene fauna from western Sc., ser. 3, vol. 5, pp. 407-410, 485-488. Nebraska: Am. Mus. Nat. Hist., Bull., vol. 26, art. 27, ( 1875 ) Notice of new Tertiary mammals. IV: Am. pp. 361-414, figs. 1-27. Jour. Sci., ser. 3, vol. 9, pp. 239-250. MERRIAM, J. C. (1919) Tertiary mammalian faunas of the (1893) Description of Miocene Mammalia: Am. Mohave desert: Univ. Calif. Dept. Geol. Sci., Bull., vol. Jour. Sci., ser. 3, vol. 46, pp. 407-412, pls. 7-10. 11, pp. 437a-437e, 438-585, figs. 1-253. ( 1894 ) Description of Tertiary artiodactyles: Am. MILLER, A. H., & SIBLEY, C. G. ( 1942 ) An Oligocene hawk Jour. Sci., ser. 3, vol. 48, pp. 259-274, figs. 1-34. from Colorado: The Condor, vol. 44, pp. 39-40, fig. 12. MATTHEW, W. D. ( 1899 ) A provisional classification of the O'HARRA, C. C. ( 1930 ) A fossil mammal with unborn twins: fresh-water Tertiary of the West: Am. Mus. Nat. Hist., Science, n. s., vol. 71, pp. 341-342. Bull., vol. 12, art. 3, pp. 19-75. OSBORN, H. F. ( 1904 ) New Oligocene horses: Am. Mus. ( 1901 ) Fossil mammals of the Tertiary of north- Nat. Hist., Bull., vol. 20, art. 7, pp. 167-179, pls. 4-5, eastern Colorado: Am. Mus. Nat. Hist., Mem., vol. 1, figs. 1-8. pt. 7, pp. 355-447, pls. 37-39, figs. 1-34. ( 1904a ) New Miocene rhinoceroses with revision of ( 1902 ) On the skull of Bunaelurus, a musteline known species: Am. Mus. Nat. Hist., Bull., vol. 20, art. from the White River Oligocene: Am. Mus. Nat. Hist., 27, pp. 307-326, figs. 1-21. Bull., vol. 16, art. 10, pp. 137-140, figs. 1-3. ( 1909 ) Cenozoic mammal horizons of western North ( 1902a ) New Canidae from the Miocene of Colo- America: U. S. Geol. Survey, Bull., no. 361, pp. 1-90, rado: Am. Mus. Nat. Hist., Bull., vol. 16, art. 21, pp. pls. 1-3, figs. 1-15. 281-290, figs. 1-4. ( 1918 ) Equidae of the Oligocene, Miocene, and ( 1902b ) A horned rodent from the Colorado Mio- Pliocene, of North America; iconographic type revision: cene, with a revision of the Mylagauli, beavers, and hares Am. Mus. Nat. Hist., Mem., vol. 2, pp. 1-330, pls. 1-54, of the American Tertiary: Am. Mus. Nat. Hist., Bull., figs. 1-173. vol. 16, art. 22, pp. 291-310, figs. 1-17. ( 1921 ) First appearance of the true mastodon in ( 1902c ) The skull of Hypisodus, the smallest of the America: Am. Mus. Nov., no. 10, pp. 1-6, figs. 1-2. artiodactyla, with a revision of the Hypertragulidae: Am. ( 1923 ) New subfamily, generic, and specific stages Mus. Nat. Hist., Bull., vol. 16, art. 23, pp. 311-316, figs. in the evolution of the Proboscidea: Am. Mus. Nov., no. 1-4. 99, pp. 1-4. ( 1903 ) The fauna of the Titanotherium beds at ( 1929 ) The titanotheres of ancient Wyoming, Da- Pipestone Springs, Montana: Am. Mus. Nat. Hist., Bull., kota, and Nebraska: U. S. Geol. Survey, Mon. 55 ( 2 vol. 19, art. 7, pp. 197-226, figs. 1-19. vois.), pp. 1-953, frontispiece, pls. 1-236, figs. 1-797. ( 1904 ) A complete skeleton of Merycodus: Am. ( 1936 ) Proboscidea. A monograph of the discovery, Mus. Nat. Hist., Bull., vol. 20, art. 7, pp. 101-129, pl. 3, evolution, migration, and extinction of the mastodonts and figs. 1-21. elephants of the world. Vol. I: Moeritherioidea, Deino- ( 1907 ) A lower Miocene fauna from South Dakota: therioidea, Mastodontoidea: The American Museum Press, Am. Mus. Nat. Hist., Bull., vol. 23, art. 9, pp. 169-219, New York, pp. i-xl, 1-802, frontispiece, pls. 1-12, figs. figs. 1-26. 1-680. ( 1909 ) Faunal lists of the Tertiary Mammalia of ( 1942 ) Proboscidea. A monograph of the discovery, the West: U. S. Geol. Survey, Bull., no. 361, pp. 91-138. evolution, migration and extinction of the mastodonts and ( 1910 ) On the skull of Apternodus and the skeleton elephants of the world. Vol. II: Stegodontoidea, Elephan- of a new artiodactyl: Am. Mus. Nat. Hist., Bull., vol. 28, toidea: American Museum Press, New York, pp. i-XXVII, art. 5, pp. 33-42, pl. 6, figs. 1-5. 805-1676, frontispiece, pls. 13-30, figs. 681-1244. ( 1910a ) The phylogeny of the Felidae: Am. Mus. PATTEnsoN, B., & McGnEw, P. O. ( 1937 ) A soricid and two Nat. Hist., Bull., vol. 28, art. 27, pp. 289-316, figs. 1-15. erincaeids from the White River Oligocene: Field Mus. ( 1918 ) Contributions to the Snake Creek fauna; Nat. Hist., Geol. Ser., vol. 6, no. 18, pp. 245-272, figs. with notes upon the Pleistocene of western Nebraska; 60-74. American Museum Expedition of 1916: Am. Mus. Nat. RUSSELL, L. S. (1934) Revision of the lower Oligocene ver- Hist., Bull., vol. 38, art. 7, pp. 183-229, pls. 4-10, figs. tebrate fauna of the Cypress Hills, Saskatchewan: Roy. 1-20. Canadian Inst., Trans., vol. 20, pp. 49-67, pls. 7-10. ( 1924 ) Third contribution to the Snake Creek SCHARF, D. W. ( 1935 ) A Miocene mammalian fauna from fauna: Am. Mus. Nat. Hist., Bull., vol. 50, art. 2, pp. 59- Sucker Creek, southeastern Oregon: Carnegie Inst. Wash. 210, figs. 1-63. Pub., no. 453, pp. 97-118, pls. 1-2, figs. 1-11.

8-3493 114 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

SCHAUB, SAMUEL ( 1930) Fossile Sicistinae: Ed. geol. helv., (1945) The principles of classification and a classifi- Bd. 23, no. 2, pp. 616-637, figs. 1-17. cation of mammals: Am. Mus. Nat. Hist., Bull., vol. 85, SCHLAIKJER, E. M. (1933) A detailed study of the structure pp. i-xvi, 1-350. and relationships of a new zalambdodont insectivore from (1946) Palaeogale and allied early mustelids: Am. the middle Oligocene: Harvard College Mus. Comp. Zool., Mus. Nov., no. 1320, pp. 1-14, figs. 1-4, 1 table. Bull., vol. 76, pp. unnumbered 1-27, 1 plate, figs. 1-8. SINCLAIR, W. J. (1922) Hyracodons from the Big Badlands (1934) A new fossil zalambdodont insectivore: Am. of South Dakota: Am. Phil. Soc., Proc., vol. 61, pp. 65- Mus. Nov., no. 698, pp. 1-8, figs. 1-3. 79, figs. 1-8. SCHLOSSER, M. (1902) Beitriige zur Kenntniss der Siiuge- STIRTON, R. A. (1935) A review of the Tertiary beavers: thierreste ans den siiddeutschen Bohnerzen: Geol. pal4ont. Univ. Calif. Dept. Geol. Sci., Bull., vol. 23, pp. 391-458, Abh., Jena, n. s., vol. 5, pp. 1-144, pls. 1-5. figs. 1-142, 1 map, 2 charts. ScnuLTz, C. B. (1941) The pipy concretions of the Arikaree: (1936) Succession of North American continental Nebraska State Mus. Bull., vol. 2, no. 8, pp. 69-82, 1 un- Pliocene mammalian faunas: Am. Jour. Sci., ser. 5, vol. numbered plate, figs. 28-37. 32, pp. 161-206. & FALKENBACH, C. H. (1940) Merycochoerinae, a ( 1940) Phylogeny of North American Equidae: new subfamily of oreodonts: Am. Mus. Nat. Hist., Bull., Univ. Calif. Dept. Geol. Sci., Bull., vol. 25, pp. 165-198, vol. 77, art. 5, pp. 213-306, figs. 1-18, 4 tables. figs. 1-52, 1 chart. ( 1941) Ticholeptinae, a new subfamily STOCK, C. (1935) Artiodactyla of oreodonts: from the Sespe of the Las Am. Mus. Nat. Hist., Bull., vol. 79, art. 1, Posas Hills, California: pp. 1-105, Carnegie Inst. Wash. Pub., no. figs. 1-17, 9 tables. 453, pp. 119-125, pl. 1. ( 1947 ) Merychyinae, a subfamily of TAYLOR, E. H. oreodonts: Am. Mus. Nat. Hist., Bull., vol. 88, art. 4, pp. ( 1951) Concerning Oligocene amphisbaenid 157-286, figs. 1-17, 6 tables, 4 charts. reptiles: Univ. Kansas Sci. Bull., vol. 34, pt. 1, pp. 521- 578, pls. 63-67, figs. 1-8. ( 1949) Promerycochoerinae, a new subfamily of oreodonts: Am. Mus. Nat. Hist., Bull., vol. 93, THORPE, M. R. (1922) Some Tertiary Carnivore in the art. 3, pp. 69-198, figs. 1-26, 8 tables, 6 charts. Marsh collection, with descriptions of new forms: Am. Jour. Sci., ser. 5, vol. 3, pp. 423-455, figs. 1-12. & STOUT, T. M. (1938) Preliminary remarks on the Oligocene of Nebraska: Geol. Soc. America, Bull., vol. 49, ( 1937 ) The Merycoidodontidae. An extinct group no. 12, p. 1921. of ruminant mammals: Peabody Mus. Nat. Hist., Yale Scorr, W. B. ( 1894) A new Univ., Mem., vol. 3, pt. 4, pp. i-XXi, 1-428, pls. 1-50, figs. insectivore from the White 1-188, 12 River beds: Acad. Nat. Sci. Philad., Proc., 1894, pp. 446- tables. 448. TORDOFF, H. B. ( 1951) A quail from the Oligocene of Colo- ( 1894a ) The osteology of Hyaenodon: Acad. Nat. rado: The Condor, vol. 53, no. 4, pp. 203-204. Sci. Philad., Jour., vol. 9, pp. 499-535, figs. 1-10. TROXELL, E. L. (1920) Entelodonts in the Marsh collection: ( 1898 ) Notes on the Canidae of the White River Am. Jour. Sci., ser. 4, vol. 50, pp. 243-255, 361-386, 431- Oligocene: Am. Phil. Soc., Trans., n. s., vol. 19, pt. 3, art. 445, pl. 3, figs. 1-20. 8, pp. 325-415, pls. 19-20. (1922) Oligocene rodents of the genus Ischyromys: ( 1940) The mammalian fauna of the White River Am. Jour. Sci., ser. 5, vol. 3, pp. 123-130, figs. 1-7. Oligocene. Part IV. Artiodactyla: Am. Phil. Soc., Trans., (1923) Diplolophus, a new genus of rodents: Am. n. s., vol. 28, pt. 4, pp. 363-746, pls. 36-78, figs. 118-136. Jour. Sci., set. 5, vol. 5, pp. 157-159, figs. 1-5. ( 1941) The mammalian fauna of the White River VERET, J. (1929) Les faunes de mammifères de l'Oligocène Oligocene. Part V. Perissodactyla: Am. Phil. Soc., Trans., superieur de la Limagne Bourbonnaise: Univ. Lyon, n. s., vol. 28, pt. 5, pp. 747-980, pls. 79-100, figs. 137-157. Annales, n. s., fasc. 47, pp. 1-328, i-viii, pls. 1-31 and 1 & JEPSEN, G. L. (1936) The mammalian fauna of unnumbered plate, figs. 1-32. the White River Oligocene. Part I. Insectivore and WALKER, M. V. Notes on North Carnivore: Am. Phil. Soc., Trans., ( 1931) American fossil lago- n. s., vol. 28, pt. 1, pp. morphs: Aerend, vol. 2, no. 4, 1-153, pls. 1-22, figs. 1-7. pp. 227-240, pl. 1. WALLACE, R. E. (1946) A Miocene mammalian fauna from & Os BORN, H. F. (1890) Preliminary account of the fossil mammals from the White River and Loup Fork Beatty Buttes, Oregon: Carnegie Inst. Wash. Pub., no. formations contained in the Museum of Comparative 551, pp. 113-134, pls. 1-6, fig. 1. Zoology. Part II. Carnivore and Artiodactyla, by W. B. WETMORE, A. (1927) Fossil birds from the Oligocene of Scott. Perissodactyla, by Henry F. Osborn: Harvard Colorado: Colorado Mus. Nat. Hist., Proc., vol. 7, pp. College Mus. Comp. Zool., Bull., vol. 20, pp. 65-100, ph. 3-13, figs. 1-23. 1-3, figs. 1-18. ( 1940) A check-list of the fossil birds of North SHUFELDT, R. W. (1915) Fossil birds in the Marsh collection America: Smithson. Misc. Coll., vol. 99, no. 4, pp. 1-81. of Yale University: Connecticut Acad. Sci., Trans., vol. WILLIAMS, E. E. (1950) Testudo cubensis and the evolu- 19, pp. 1-110, pls. 1-15. tion of western hemisphere tortoises: Am. Mus. Nat. Hist., SIMPSON, G. G. (1930) Tertiary land mammals of Florida: Bull., vol. 95, art. 1, pp. 1-36, ph. 1-8, figs. 1-2. Am. Mus. Nat. Hist., Bull., vol. 59, art. 3, pp. 149-211, WILSON, R. W. (1949) On some White River fossil rodents: figs. 1-31. Carnegie Inst. Wash. Pub., no. 584, pp. 27-50, pls. 1-2, ( 1933 ) Glossary and correlation charts of North figs. 1-2. American Tertiary mammal-bearing formations: Am. Mus. (1949a) Rodents and lagomorphs of the upper Nat. Hist., Bull., vol. 67, art. 3, pp. 79-121, figs. 1-8. Sespe: Carnegie Inst. Wash. Pub., no. 584, pp. 51-65, ( 1941) The species of Hoplophoneus: Am. Mus. pl. 1, fig. 1. Nov., no. 1123, pp. 1-21. (1949b) Early Tertiary rodents of North America: ( 1941a ) A new Oligocene insectivore: Am. Mus. Carnegie Inst. Wash. Pub., no. 584, pp. 67-164, figs. 1-13. Nov., no. 1150, pp. 1-3, fig. 1. WOOD, A. E. (1985) Evolution and relationship of the hetero- (1948) Criteria for genera, species, and subspecies myid rodents with new forms from the Tertiary of western in zoology and paleozoology: New York Acad. Sc., North America: Carnegie Mus., Annals, vol. 24, pp. 73- Annals, vol. 44, pp. 145-178, 2 tables. 282, figs. 1-157, 5 tables. TERTIARY GEOLOGY AND PALEONTOLOGY OF NORTHEASTERN COLORADO 115

(1937) The mammalian fauna of the White River ( 1931) Lower Oligocene rhinoceroses of the genus Oligocene. Part H. Rodentia: Am. Phil. Soc., Trans., Trigonias: Jour. Mammal., vol. 12, no. 4, pp. 414-428, n. s., vol. 28, pt. 2, pp. 155-269, pls. 23-33, figs. 8-70. figs. 1-4. ( 1939 ) Additional specimens of the heteromyid ro- ( 1949 ) Oligocene faunas, facies, and formations: dent Heliscomys from the Oligocene of Nebraska: Am. Geol. Soc. America, Mem., no. 39, pp. 83-92, fig. 1. Jour. Sci., vol. 237, pp. 550-561, figs. 1-11, 1 table. & WOOD, A. E. (1937) Mid-Tertiary vertebrates ( 1940) The mammalian fauna of the White River from the Texas coastal plain: fact and fable: Am. Midi. Oligocene. Part III. Lagomorpha: Am. Phil. Soc., Nat., vol. 18, pp. 129-146, pl. 1, figs. 1-4. Trans., n. s., vol. 28, pt. 3, pp. 271-362, pls. 34-35, figs. et al. ( 1941) Nomenclature and correlation of the 71-116. North American continental Tertiary: Geol. Soc. America, WOOD, H. E. (1927) Some early Tertiary rhinoceroses and Bull., vol. 52, pp. 1-48, pl. 1. hyracodonts: Bull. Am. Paleont., vol. 13, no. 50, pp. WORTMAN, J. L., & MArrnEw, W. D. (1899) The ancestry 3-104, pls. 1-7, 8 tables. of certain members of the Canidae, the Viverridae and ( 1929) American Oligocene rhinoceroses - a post- Procyonidae: Am. Mus. Nat. Hist., Bull., vol. 12, art. 6, script: Jour. Mammal., vol. 10, no. 1, pp. 63-75. pp. 109-139, pl. 6, figs. 1-10.

INDEX Abstract, 7 Bathomithidae, 40 Cedar Creek member, 7, 10, 13, 14- Accipitridae, 40 Beatty Buttes ( Oregon), 34, 94, 95 17, 21, 22, 23, 24, 25, 26, 27, 30, 71 acer, Megaceratops, 81 Berthoud, E. L., 8 cedrensis, Eporeodon major var., 88 acer, Megacerops, 28, 81 Biggerstaff, A., 16 cedrensis, Protomeryx, 90 Aceratherium, 83, 107 Biorbia, 25 Cedromus, 29, 54, 55, 57, 59-83 Aciprion, 39 Blastomeryx, 33, 34, 110 Ceratogaulus, 34, 35, 96 Adjidaumo, 28, 29, 58 bluei, Merychyus elegans, 109 Cervidae, 110 Aelurodon, 101 Boidae, 39 Cerous, 110 affinis, Hypohipmss, 104 borealis, Dromomeryx, 110 Chadron formation, lower, 28 affinis, Merycoiclodon, 88 Bothriodon, 86 Chadron formation ( Montana), 48 Agnotocastor, 29, 66-69 Brachyerix, 7, 32, 34, 35, 92 Chadron formation ( South Dakota), Agriochoeridae, 87 brachyodus, Eumys, 31, 69-71, 73, 74 8, 12, 28, 83, 85 Agriochoerus, 7, 87 brevirost ris, Apternodus, 42, 43, 44 Chalicotheriidae, 106 alcer, Hypisodus, 90 brevirost ris, Tomarctus, 34, 35, 100 Chalk Bluffs, 8, 9, 27, 40 Alticamelus, 34, 35, 109 Brontops, 81 Cherry ( Cedar) Creek, 57, 58 altus, Alticamelus, 109 Brontotheriidae, 81 Cherry Creek (Wyoming), 58 Amblycastor, 34, 35, 98 Brown, B., 8, 105 Cheyenne, Wyoming, 58 amblyceps, Rhineura, 39 Brute formation, 14 Chicago Natural History Museum, 41, Amebelodon, 103 Brule formation ( Nebraska ), 51, 52, 45, 46, 49, 66, 84, 98 American Museum of Natural History, 70, 71, 91 Chimney Canyon, 13, 16, 17, 24 8, 36, 38, 42, 57, 82, 72, 88, 100, bullatus, Ictops, 44 Chimney Rock, 16, 17 105, 106, 109 Bump, B., 87, 88 Clark, J., 8, 12, 28, 45, 85, 90, 91 Amnodon, 85 Bunaelurus, 77 "clay fauna," 31 Amphibia, 38 Burge locality ( Nebraska), 36 Clear ( Cedar) Creek, 14 Amphicyon, 34, 35, 101 burkei, Palaeolagus, 29, 31, 50, 51 clivosus, Plesiosminthus, 7, 32, 99 Amphilagus, 94 Bute°, 40 Colbert, E. H., 31, 32, 109 Amphisbaenidae, 39 Butler, P. M., 45 Colinus, 40 amphithorax, Testudo, 38 Caenopus, 28, 82-83, 107 coloradense, Hipparion, 110 Anchisodon, 83 Calamagras, 39 coloradense, Neohipparion, 35, 36, Anguidae, 39 calcarata, Leptauchenia, 90 105, 106, 110 angulatus, Ca/amagras, 39 calcaratus, Hypertragu/us, 29, 90 coloradensis, Agnotocastor, 29, 66-69 angustidens, Procamelus, 109 California Institute of Technology, 63, coloradensis, Parahippus, 33, 34, 35, angustidens, Protolabis, 34, 35, 109 64, 65 103, 104 angustidens, Pseudocynodictis, 76 Ca/ippus, 7, 34, 35, 106 Colorado, 8, 9, 11, 13, 14, 15, 16, 18, Anky/odon, 7, 29, 42, 45-46 Camelid, 33 21, 23, 32, 36, 38, 40, 57, 58, 63, annectens, Ankylodon, 29, 45, 46 Camelidae, 88, 109 69, 72, 77, 80, 82, 87, 88, 100, Anthracotheriid, 28, 86 Camp, C. L., 38 102, 103, 105, 106, 107, 108 Anthraeotherfidae, 88 campester, Protomeryx, 29, 31, 89, 90 Colorado, northeastern, 7, 8, 10, 25, Antilocapridae, 110 campestris, Merychippus, 34, 35, 36, 27, 31, 36 antiquus, Agriochoerus, 87 105, 106 Colorado Piedmont, 9, 10, 14 coloradoensis, Nothoc yon vulpinus, antiquus, Amphi/agus, 94 caniculus, Isacus, 44 apertus, Hyracodon, 82 caniculus, Mesodectes, 44 100 Aphelophis, 39 coloradoensis, Platyrhachis, 39 Canidae, 75, 100, 101 39 Aphelops, 33, 34, 35, 107-108 Canis, 75, 76, 100 coloradoensis, Rhineura, Aplodontia, 53 Colotaxis, 58 carinicollis, Cremastosaurus, 39 7, 29, 46-48, 49 Apternodus, 7, 28, 42-44 Camivora, 74, 100 compressa, Domnina, aquaticus machrinoides, Scab pus, 49 Condylura, 34, 35, 93 carolinensis, Sciurus, 59 100 Archaeotherium, 28, 29, 85 Carr, Colorado, 40 confertus, Tomarctus, arcidens, Hyracodon, 82 Cook, H. J., 28, 32, 33, 82, 95 Casement, J., 8 Cook, M. C., 33 Arctoryctes, 7, 29, 49 Castle Rock, 50 Arikaree formation, 10, 18, 27 rooki, Trigonias, 82 Castoridae, 66, 98 Cope, E. D., 8, 10, 38, 42, 44, 48, 47, Arkansas River, 9, 10 Cathartidae, 40 Artiodactyla, 83, 108 48, 50, 58, 74, 76, 77, 80, 81, 82, caurina on genes, Martes, 77 83, 84, 85, 87, 89, 102, 109 Ayes, 40, 92 Cedar Creek, 14, 57, 58, 87 bairdii, Mesohippus, 80, 81 Cosoryx, 110 Barbour, E. H., 30, 57, 63 Cedar Creek beds, 14 Courthouse Butte, 95 Barbouromeryx, 34, 110 Cedar Creek facies, 14 Cranioceras, 34, 35, 110 Bathornis, 40 Cedar Creek fauna, 7, 26, 27, 28-30 crassigenis, Domnina, 47, 48

116 INDEX

crassigenis, Miothen, 48 Eubanks Ranch, 18, 20, 32 hatcheri, Heliscomys, 64, 65, 66 crassum, Archaeotherium, 28, 85 eulophus, Mesohip pus, 29, 80-81 hatcherii, Rhineura, 39 crassum, Elotherium, 85 Eumys, 28, 29, 31, 69-73, 74 Hawthorn fauna (Florida ), 36 crassus, Protosorex, 48 Euoplocyon, 34, 35, 101 Hawthorn formation (Florida), 33 Cremastosaurus, 39 europaeus, Erinaceus, 92 Hay, O. P., 38 Cretaceous deposits, 10, 11, 12, 13, Eutypomys, 66, 68, 69 haydeni, Leptictus, 44 14, 15, 21, 24, 25 evansi, Leptomeryx, 28, 29, 31, 90 haydeni, Palaeolagus, 29, 50, 51 Cricetidae, 69 exiguus, Eumys, 29, 71-72, 74 Heliscomys, 29, 59, 63-66, 97, 98 Cricetodon, 69, 70 exoletus, Mesohip pus, 80, 81 Heloderma, 39 cristata, Condylura, 93 Exostinus, 38 Helodermidae, 39 cristatus, Colotaxis, 58 Falconiformes, 40 Henshaw, P. C. 107 Crocidura, 92 Falkenbach, C. H., 19, 20, 27, 33, 34, Heptacodon, 7,'29, 86 Crotalidae, 39 36, 37, 108, 109 Herpetotheriuin, 40, 41 crucians, Hyaenodon, 29, 74, 75 faunas, northeastern Colorado, 26, 32 Hesperoscalops, 93 cruentus, Hyaenodon, 74 fax, Palaeocrex, 40 Hesse, C. J., 12, 18, 36, 83, 89, 106. Culbertsoni, Oreodon, 8 Felidae, 80, 102 110 culbertsonii, Merycoidodon, 28, 87, 88 felina, Dinictis, 80 heterodontus, Procamelus, 109 culbertsonii, Merycoidodon culbert- Fenneman, N. M., 10 heterodontus, Protolabis, 34, 35, 109 sonii, 87, 88 Figgins, J. D., 82 Heteromyidae, 63, 97 culbertsonii culbertsonii, Merycoido- fissidens, Procamelus, 109 Ileterosorex, 93 don, 87, 88 fissidens, Protolabis, 34, 109 Hibbard, C. W., 10, 16 culbertsonii periculorum, Merycoido- Flat Top Butte, 13, 16, 17 hibbardi, Rhineura, 39 don, 87, 88 Florida, 33, 102 High Plains, 10, 14 cultrata, Testudo, 38 floridanus, Proheteromys, 33, 66 Hipparion, 110 cultratus, Testudo, 38 fluviaticus, Buteo, 40 Hip potherium, 104, 105 cuneatus, Mesohip pus, 80 formosum, Aciprion, 38 Hoplophoneus, 80 curtis, Monosaulax, 98 Fort D. A. Russell, Wyoming, 58 "Horizon A," 27 curtus, Dipoides, 98 fossiger, Teleoceras, 108 "Horizon B," 27 curtus, Heptacodon, 86 fossilia, Biorbia, 25 "Horizon C," 19, 27, 28, 32 curtus, Monosaulax, 32, 33, 34, 35, 98 Fox Hills sandstone, 10, 12 "Horizon D," 27, 31-33 Custer County, South Dakota, 44 Fremont County, Wyoming, 33, 95 "Horizon E," 27, 31-32 Cynarctus, 34, 35, 101 Frick, C., 10, 32, 101, 102, 103, 107, horridu,s, Hyaenodon, 29, 74 Cynodictis, 75, 76, 77, 101 110 Horse Creek ( Wyoming), 58 Cynomys, 59 Frye, J. C., 8 Horsetail Creek, 14 Daimonelix tube, 16 fugax, Herpetotherium, 40 Horsetail Creek beds, 12 dakotensis, Ictops, 45 fugax, Peratherium, 28, 29, 31, 40, Horsetail Creek facies, 12 dakotensis, Parictis, 28, 76 41 Horsetail Creek fauna, 7, 26, 27, 28 Daphoenocyon, 7, 77 furcatus, Cosoryx, 110 Horsetail Creek member, 7, 10, 12-14, Daphoenus, 29, 76 furcatus, Merycodus, 34, 110 15, 21, 23, 24, 25, 26, 27 Daptophilus, 80 galbreathi, Hyporhina, 39 Hough, J. R., Darton, 75, 77, 80, 101 N. H., 20, 100 Galliaetatus, 49 huntii, Herpetotherium, 41 Davis Ranch, 101, 103, 107 Galliformes, 40 huntii, Peratherium, 29, 41, 42, 48 decora, Leptauchenia, 31, 88 Gazin, C. L., 96 Hyaenodon, 29, 74-75 delphinensis, Heterosorex, 93 gemmifer, Blastomeryx, 34, 110 Hyaenodontidae, 74 Denver Museum of Natural History, gemmifer, Merycodus, 110 Hypertragulidae, 90 10, 14, 40, 81, 82, 85, 101 Geolabis, 42, 50 Hypertragulus, 28, 29, 90 Department of Agriculture, United Geological Survey, State of Kansas, 22 Hypisodus, 28, 29, 31, 90-91 States, 13 Geological Survey, United States, 11 Hypohippus, 7, 34, 35, 104 Desmatolagus, 94 Geomyidae, 63 Hypola gus, 34, 35, 95 Diacium, 39 Gerry Ranch, 40, 100, 102 Hyporhina, 39 Diceratherium, 107 Gidley, J. W., 105 Hyporhinidae, 39 Didelphidae, 40 Gilmore, C. W., 38, 39, 40 hypostylus, Trigonias, Dinictis, 82 28, 29, 80 giraffinus, Alticamelus, 34, 35, 109 Hyracodon, 28, 29, 31, 81-82, 83 Diplolophus, 7, 29, 30, 31, 63, 97 Glaucomys, 52 Hyracodontidae, 81 Dipoides, 98 Glyptosaurus, 39 Ictops, 29, 42, 44, 45 dodgei, Daphoenocyon, 77 Gomphotheriidae, 102 Iguanidae, 38 Domnina, 7, 29, 42, 46-49, 50 Gopherus, 38, 92 Iliff, Colorado, 11, 42 dorsalis, Neurodromicus, 39 Goshen Hole ( Wyoming), 58 iliffensis, Apternodus, 7, Drassonax, 28, 42-44 7, 29, 77-79 gracile, Miothen, 48 incretus, Mionictis, 78 Dromomeryx, 34, 35, 110 gracilis, Merycoidodon, 28, 87, 88 Insectivora, 42, 92 elegans, Blastomeryx, 33, 110 gracilis, Oreodon, 88 insolens, Diplolophus, elegans, Eumys, 63 29, 69-71, 73, 74 gradata, Domnina, 29, 46, 47, 48, 49 intermedius, Palaeola gus, 28, 29, 31, elegans, Merychyus, 32, 33, 34, 109 Grand Island gravels, 20 50 elegans bluei, Merychyu,s, 109 granulosus, Peltosaurus, 39 intrepidus, Pseudaelurus, 34, 35, 102 Elias, M. K., 32 Green, M., 38, 50 Isacus, 44 Elotherium, 85 gregarius, Canis, 75 Ischyromyidae, 7, 51, 63 Elum Ranch, 40 gregarius, Pseudownodictis, 29, 75, Ischyromys, 28, 29, 30, 51, 53, 57-58, Emydidae, 38 76 59 Entelodontidae, 85 Gregory, J. T., 58, 86, 95, 100 jeffersoni, Prosciurus, 54 eohipparion, Merychippus, 34, 105 Gregory, W. K., 28. 49, 82 Jepsen, G. L., 44, 45, 50, 75 Eomyidae, 58 gregoryi, Apternod us, 42, 43, 44 John Day formation ( Oregon ), 41, eoplacidus, Merychippus, 34, 105 Grover, Colorado, 11, 36, 108 86, 87 Eotylopus, 7, 28, 88 Gruiformes, 40 Kansas, 9, 10, 26 Eporeodon, 31, 88 gunteri, Merychippus, 106 Kennesaw local fauna, 7, 26, 27, 32, Equidae, 80, 103, 110 Gymnoptychus, 58 34, 35, 36 equinus, Hypohippus, 104 Hall, E. R., 8 Kennesaw valley, 32 Erinaceidae, 7, 45, 92 harpagops, Drassonax, 7, 29, 77-79 Keota, Colorado, 11 Erinaceus, 92 Harrison, upper ( Nebraska ), 104 Keota ash, 22 esulcatus, Leptomeryx, 28, 29, 90 "Harrison beds" (Wyoming), 18 Kimball County, Nebraska, 20 Eubanks local fauna, 7, 26, 27, 32, hartshornianus, Canis, 76 Kimball member, 7, 20, 27, 32, 36, 33, 34, 35, 36 hartshornianus, Daphoenus, 76 110

INDEX 117

Koenig, J., 8 Marsland fauna (Nebraska), 33, 36 minor, Meryceros, 34, 35, 110 labiatum, Poébrotherium, 29, 88, 89 Marsland formation ( Nebraska), 33, minor, Perchoerus, 28, 85, 86 labrosus, Merychip pus, 34, 105 34 minutus, Adjidaumo, 29, 58 labrosus, Protohip pus, 105 marslandensis, Phlaocyon, 33 minutus, Gymnoptychus, 58 laevis, Mylagaulus, 34, 35, 96 Marsupialia, 40 minutus, Nanodelphys, 29, 41 Lagomorpha, 50, 93 Martes, 77, 78 miocaenus, Proscalops, 31, 42, 49 lagophaga, Palaeo gale, 29, 77 Martin, H. T., 12, 18, 76, 77, 81, 83, Miohippus, 7, 31, 81 lagophagus, Bunaelurus, 77 85, 87, 88, 104, 105, 109 ( Miomastodon) merriami, Mammut, Laramie- formation, 10 Martin Canyon, 13, 19, 26, 27, 33 102 Laramie sandstone, 12 Martin Canyon beds, 10, 18, 19, 27, Mionictis, 78 Laramie shales, 12 37 Miothen, 48 laticunea, Gopherus, 38 Martin Canyon beds, lower, 18, 19 mirabilis, Pliohip pus, 105 laticuneus, Testudo, 38 Martin Canyon beds, upper, 18, 19 mite, Aceratherium, 83 Laverne locality ( Oklahoma ), 36 Martin Canyon local fauna, 7, 26, 27, mitis, Caeno pus, 28, 82, 83 Leidy, J., 44, 80, 102 32-34, 108 Monosaulax, 7, 32, 33, 34, 35, 98 leidyanus, Hyracodon, 81, 82 Mascall fauna ( Oregon), 34 montanus, Parvericus, 92 Leidymys, 72, 74 Mastodon, 102, 103 montanus, Stibarus, 84 lemurinum, Menotherium, 83 Mastodon Quarry ( C. Frick ), 110 Moro pus, 106 kmurinus, Leptochoerus, 83, 84 Matthew, W. D., 8, 10, 12, 14, 16, niortoni, Archaeotherium, 28, 85 lemurinus, Stibarus, 28, 29, 83-84 18, 19, 20, 26, 27, 28, 31, 32, 33, murivorus, Calama gras, 39 Leonard, A. B., 8 34, 35, 36, 37, 42, 44, 49, 50, 74, Mustela, 101 Leporidae, 50, 95 76, 77, 79, 80, 82, 83, 84, 85, 88, Mustelidae, 7, 77, 101 Leptarctus, 34, 35, 101-102 89, 90, 96, 98, 99, 100, 101, 102, Mustelinae, 79 Leptauchenia, 31, 88, 90 105, 106, 107, 108, 109, 110 mustelinus, Aelurodon, 101 Leptauchenia beds, 28 matthewi, Heloderma, 39 mustelinus, Hyaenodon, 29, 75 Leptauchenia zone, 28 matthewi, Macrotherium, 32, 34, 108- mutilus, Aphelops, 108 Leptictidae, 44, 45 107 Mylagaulidae, 95 Leptictus, 44 matthewi, Merycochoerus, 109 Mylagatilus, 34, 35, 95, 96 Leptochoeridae, 83 matthewi, Aforopus, 106 Nannippus, 106 Leptochoerus, 29, 31, 83, 84 mediaevus, Apternodus, 43, 44 Nanodelphys, 7, 29, 41 leptocolon, Alticamelus, 34, 35, 109 medicornutus, Teleoceras, 34, 35, 108 nantis, Perchoerus, 29, 31, 85-86 Leptocyon, 7, 34, 35, 100-101 mediterraneus, Phalacrocorax, 40, 100 Nebraska, 7, 8, 9, 10, 12, 19, 20, 28, Leptomeryx, 28, 29, 31, 90 medius, Blastomeryx, 33, 110 30, 31, 33, 34, 41, 46, 51, 52, 59, leucosteus, Phlaocyon, 32, 33, 101 medius, Merychyus, 108 70, 71, 72, 82, 91, 98, 104 Lewis, G. E., 8, 10 medius, Ustatochoerus, 34, 35, 108 nebrascensis, Oreolagus, 32, 33, 93-95 Lewis Canyon, 33 Megaceratops, 81 nebrascensis, Stylemys, 38 ligonia, Testudo, 38 Megacerops, 28, 81 nebraskensis, Cricetodon, 69, 70 ligonius, Testudo, 38 Megalagus, 29, 51 nebraskensis, Hyracodon, 81-82 lippincottianus, Canis, 75 megalodus, Aceratherium, 107 nebraskensis, Proamphicyon, 76 lippincottianus, Pseudocynodictis, 29, megalodus, Aphelops, 33, 34, 35, 107 nebraskensis, Proheteromys, 66 75, 76 Mellinger, J., 63 nebraskensis, Rhinoceros, 81 Little Crow Creek, 8 Mellinger locality, 66 Neohipparion, 35, 36, 105, 106, 110 Lodge Pole Creek ( Nebraska ), 9 mellingert, Metacodon, 29, 45 Neurodromicus, 39 Lodge Pole Creek ( Wyoming ), 58 Menotherium, 83 nevadensis, Metechinus, 92 Logan County, Colorado, 7, 8, 9, 10, merriami, Mammut, 34, 102, 103 nevadensis, Oreola gus, 93 11, 12, 13, 14, 15, 16, 18, 19, 20, merriami, Mammut ( Miomastodon), Nichols, R. H., 8, 107, 109 21, 22, 23, 24, 25, 28, 27, 29, 30, 102 niger, Sciurus, 97 32, 36, 38, 39, 40, 45, 46, 47, 50, merriami, Mastodon, 103 Niobrara River local fauna ( Ne- 58, 63, 76, 77, 81, 83, 85, 87, 105, merriami, Peratherium, 41 braska ), 36 106, 107, 108, 109 Meryceros, 34, 35, 110 North Platte River ( Nebraska), 9 Lone Star School, 27 Merychippus, 20, 22, 32, 34, 35, 38, Norton County, Kansas, 26 longiceps, Protolabis, 34, 35, 109 92, 101, 103, 104-106, 107 Nothocyon, 18, 19, 91, 100 Longmont, Colorado, 63 Merychippus paniensis zone ( Ne- obliquidens, Eumys, 29, 69-71, 74 Loomis, F. B., 87, 88, 103, 107, 109 braska), 34, 101, 107 obtusilobus, Stibarus, 28, 83, 84 Lophortyx, 40 Merychippus sejunctus zone, 103 occidentale, Subhyracodon, 83 Loup Fork, 18 Merychyus, 32, 33, 34, 108, 109 occidentalis, Heptacodon, 86 Lugn, A. L., 20, 27, 36 Merycochoerus, 32, 33, 108-109 occidentalis, Rhinoceros, 83 McGrew, P. 0., 32, 33, 36, 41, 42, 45, Merycochoerus Quarry ( American occidentalis, Subhyracodon, 29, 83 46, 47, 48, 52, 65, 66, 88, 93, 94, Museum of Natural history), Ochotona, 93, 94, 95 101 19, 26, 32 Ochotonidae, 93, 94, 95 Machairodus, 80 Merycodus, 34, 107, 110 Odontophorinae, 40 machrinoides, Scab pus aquaticus, 49 Merycoidodon, 28, 29, 87-88 Ogallala formation, 7, 10, 11, 13, 14, Macrotherium, 32, 34, 106-107 Merycoidodontidae, 87, 108 15, 20, 21, 22, 23, 24, 25, 26, 27, macrotis, Brachyerix, 92 Alesocyon, 18, 19, 91, 100 31, 32, 33, 36, 110 ma gnus, Merycochoerus, 108 Mesodectes, 42 ogygia, Mustela, 101 ma gnus, Merycochoerus pro prius, 32, Mesogaulus, 32, 33, 34, 95-96 ogygia, Plionictis, 34, 35, 101 33, 108-109 Mesohippus, 28, 29, 80-81 Oklahoma, 106 magnus, Metacodon, 29, 45 Metacheriomys, 49 optatus, Tomarctus, 100 major, Eporeodon, 31, 88 Metacodon, 29, 42, 45 Oregon, 41, 86, 87, 94 major, Oreodon, 88 Metacodontidae, 45 oregonensis, Peridiomys, 98 major var. cedrensis, Eporeodon, 88 metalophus, Subhyracodon, 83 Orella member (Nebraska ), 14, 30 ma jus, Aciprion, 39 Metamynodon, 7, 28 Oreodon, 8, 88 Mammalia, 40, 92, 110 Metechinus, 92 Oreodon beds, 28 Mammut, 34, 102, 103 Meterix, 45 Oreodon zone, 28 Mammutidae, 103 meteulophus, Miohippus, 81 oreodontis, Hoplophoneus, 80 Mansfield, B., 8 Michigan, 93 Oreolagus, 7, 32, 33, 93-95 Marmota, 60 Minick, J. N., 32 on genes, Martes caurina, 77 Marsh, O. C., 8, 28, 58, 75, 85, 86 minima, Leptauchenia, 90 Osborn, H. F., 10, 14, 19, 27, 31, 32, marshalli, Plesiogulo, 78 minimus, Adjidaumo, 58 35, 36, 37, 80, 81, 102, 103, 104, mars/si, Pseudaelurus, 34, 91, 102 minimus, Hypisodus, 29, 90-91 105, 106, 107, 108 118 INDEX osborni, Hypohippus, 34, 35, 104 Perognathus, 98 Pseudaelurus, 34, 35, 91, 102 osborni, Merycodus, 110 persistens, Caeno pus, 107 Pseudocyondictis, 28, 29, 31, 75-76 osborni, Ramoceras, 34, 35, 110 persistens, Diceratherium, 107 quadrata, Testudo, 38 osbomi, Tri gonias, 28, 82 Phalacrocoracidae, 40 quadratus, Testudo, 38 osborni osborni, Tri gonias, 82 Phalacrocorax, 40, 100 quadriplicatum, Aceratherium, 83 osbomi precopei, Trigonias, 82 Phasianid, 40 quadriplicatus, Anchisodon, 83 osborni, Tri gonias osborni, 82 Phasianidae, 40 quadriplicatus, Hyracodon, 83 osborniana, Testudo, 91, 92 Phasmagyps, 40 Quarry A ( University of Kansas Osteichthyes, 91 Phlaocyon, 32, 33, 101 Museum), 26, 32 Owl Creek, 40 Pierre shale, 10, 12, 24 quinquepedale, Diacium, 39 paladentatus, Amebelodon, 103 Pine Bluffs, Wyoming, 100 quinquepedalis, Diacium, 39 Palaeocrex, 40 Pipestone Springs ( Montana), 57, 58 Raisz, E., 8 Palaeogale, 29, 77, 79 Pipestone Springs fauna ( Montana ), Rallidae, 40 Palaeogyps, 40 28 Ramoceras, 34, 35, 110 Palaeolagus, 28, 29, 30, 31, 50-51 placidus, Pelycomys, 7, 29, 54, 55-57 ramosum, Elotherium, 85 palaeosinense, Diceratherium, 107 Plains Oil Company, 8 ramassis, Archaeotherium, 28, 29, 85 paniense, Hip potherium, 104 planiceps, Aphelops, 108 rectidens, Rhynchotherium, 34, 102, paniensis, Merychip pus, 20, 22, 32, planidens, Eumys, 72-73, 74 103 34, 35, 36, 101, 104, 106, 107 Platyrhachis, 39 reedi, Eotylopus, 88 paniensis, Mesogaulus, 32, 33, 34, 95- Pleistocene deposits, 10, 14, 15, 20 reinheimeri, Amphicyon, 34, 35, 101 96 Plesiogulo, 77, 78, 79 relictus, Paramys, 51 paniensis, Mylagaulus, 95 Plesiosminthus, 7, 32, 33, 99-100 relictus, Prosciurus, 29, 51-54, 57, 60, pansa, Gopherus, 92 Plesiosorex, 45 61, 62 pansa, Testudo, 92 pliacus, Ischyromys, 30, 57 Reptilia, 38, 91 pansus, Monosaulax, 98 Pliohippus, 36, 105, 106 republicanus, Merychippus, 34, 35, Paradjidaumo, 28, 29, 58 Plionictis, 34, 35, 101 36, 105 Parahip pus, 32, 33, 34, 35, 103-104 Poebrotherium, 28, 29, 88-89 rhambastes, Cremastosaurus, 39 Paramyinae, 63 potens, Amnodon, 85 rhambastes, Platyrhachis, 39 Paramys, 51, 53 potens, Archaeotherium, 28, 85 Rhineura, 39 Pari ctis, 7, 28, 76, 78 praecursor, Mesogaulus, 95, 96 Rhinoceros, 81, 83 Parvericus, 92 praetereadens, Agnotocastor, 66, 68 Rhinocerotid, 35, 36, 83 parvidens, Eumys, 74 precopei, Tri gonias, 82 Rhinocerotidae, 82, 107 parviloba, Mustela, 101 precopei, Tri gonias osborni, 82 rhinocerus, Ceratogaulus, 34, 35, 96 parviloba, Plionictis, 34, 101 premitis, Caeno pus, 28, 82 rhynchaeus, Geolabis, 50 porous, Diplolophus, 97 preoccidentali,s, Trigonias, 82 Rhynchotherium, 34, 102, 103 porous, Proheteromys, 91, 97 primaevus, Hoplophoneus, 80 riggsi, Promylagaulus, 52 Passerine, 92 prirnaevus, Machairodus, 80 robustus, Hoplophoneus, 80 paterculus, Cynodictis, 75 primus, Leptarctus, 34, 35, 101-102 robustus, Mesocyon, 91, 100 paterculus, Pseudocynodictis, 28, 75 primus, Merychip pus, 106 robustus, Procamelus, 109 pointus, Phasmagyps, 40 Princeton University, 8 Rodentia, 51, 95 Patterson, B., 42, 45, 46, 47, 48, 66 Princeton University Museum, 39, 62, Roper, A. B., 8 Pawnee Buttes, 20, 27 105 Rosebud, upper (South Dakota), 104 Pawnee Buttes ash, 22 Proamphicyon, 7, 78 rugosus, Pelycomys, 7, 28, 54-55, 56, Pawnee Creek, 105 proavus, Mastodon, 102, 103 57 Pawnee Creek A, 27, 31, 104 proavus, Serridentinus, 34, 102, 103 rusticus, Merycochoerus, 108 Pawnee Creek B, 31, 35 Proboscidea, 35, 102 rusticus, Peridiomys, 98 Pawnee Creek beds, 27, 32, 33, 35, Proboscidean, 103 ryderanus, Agriochoerus, 87 37, 103 probus, Perchoerus, 88 sabrinus, Glaucomys, 52 Pawnee Creek beds, lower, 27 Procamelus, 109 Sand Butte, 13 Pawnee Creek beds, upper, 27, 35 Procyonidae, 101 Sand Canyon, 13, 18, 22, 27 Pawnee Creek fauna, 31, 32, 34, 36 prodromus, Palaeogyps, 40 Sand Canyon beds, 27 Pawnee Creek fauna, lower, 31 productus, Mastodon, 103 Sand Canyon local fauna, 7, 26, 27, Pawnee Creek fauna, upper, 32 productus, Serridentinus, 34, 102, 103 32, 34, 35-36 Pawnee Creek formation, 7, 11, 13, profactum, Aceratherium, 107 saskatchewaensis, Prosciurus, 57 14, 15, 16, 18-20, 21, 22, 23, 24, pro fectus, Aphelops, 33, 107 Sauria, 38 25, 26, 27, 31, 32, 33, 36, 37 progress-us, Ankylodon, 7, 29, 45-46 saxatilis, Cynarctus, 34, 35, 101 pawneensis, Xestops, 39 pro gressus, Leptarctus, 102 Scalopine, 49 pawniensis, Barbouromeryx, 34, 110 Proheteromys, 7, 29, 32, 33, 34, 35, Scalopus, 49, 50 pawniensis, Cranioceras, 34, 35, 110 65, 66, 91, 97, 98 Schaub, S. 99, 100 pawniensis, Dromomeryx, 34, 35, 110 Promylagaulus, 52 schaubi, Plesiosminthus, 99 pawniensis, Parahip pus, 32, 33, 103, proparvu/us, Merychip pus, 34, 105 Schlaikjer, E. M., 43, 49 104 proplacidus, Merychippus, 34, 35, 36, schrammi, Ustatochoerus, 34, 35, 108 pawniensis, Ursavus, 34, 101 105 Schultz, C. B., 14, 19, 20, 27, 30, 33, Pearlette ash, 20 proplacidus, Protohip pus, 105 34, 36, 37, 108, 109 Peetz, Colorado, 11, 32 proprius, Merycochoerus, 108 Sciurid, 32, 97 Pelecaniformes, 40 pro prius ma gnus, Merycochoerus, 32, Sciuridae, 59, 62, 96 "Pelonax," 85 33, 108-109 Sciurus, 7, 32, 59, 60, 96-97 Peltosaurus, 39 Proscalops, 29, 31, 42, 49 Scott, W. B., 40, 41, 44, 45, 48, 50, Pelycomys, 7, 28, 29, 54-57, 62, 63 Prosciurinae, 57, 62 75, 81, 82, 83, 84, 85, 86, 87, 90, pennanti, Mertes pennanti, 77 Prosciurus, 29, 51-54, 55, 56, 57, 60, 91 pennanti pennanti, Martes, 77 51, 62, 63 secundus, Proscalops, 49 Peraceras, 107 proteulophus, Mesohippus, 28, 80, 81 sejunctus, Merychip pus, 34, 35, 103, Peratherium, 28, 29, 31, 40-41, 42, 48 Protoceras, 7, 28, 31 104 Perchoerus, 7, 28, 29, 31, 85-86, 108 Protohip pus, 103, 104, 105 sejunctus, Protohippus, 104 perditus, Merychippus, 36 Protohippus zone, 103 selenidens, Hyracodon, 82 periculorum, Merycoidodon, 88 Protolabis, 34. 35, 109 Serpentes, 39 periculorum, Merycoidodon culbert- Protolabis beds, 18, 31 serratus, Exostinus, 38 sonii, 87, 88 Protolabis-Hipparion zone, 35 Serridentinus, 34, 36, 102, 103 Peridiomys, 7, 34, 35, 98 Protomeryx, 29, 31, 89, 90 Sespemys, 57 Perissodactyla, 80, 103, 110 Protosorex, 48 Sheep Creek ash (Nebraska), 22

INDEX 119

Sheep Creek beds ( Nebraska ), 110 Testudinidae, 38, 91 Vim-Peetz local fauna, 7, 26, 27, 32, Sheep Creek fauna ( Nebraska ), 33, Testudo, 38, 91, 92 34-35, 36 38, 104, 107 Thompson Creek ( Montana), 57 Viret, J., 94 Simpson, G. G., 12, 34, 38, 47, 77, thompsoni, Domnina, 47, 48, 49 Virgin Valley ( Nevada ), 34 79, 80, 102, 109 Thomson, A., 8 Vista fauna, 7, 26, 27, 31 sinapius, Amphicyon, 34, 35, 110 thomsoni, Eutypomys, 66 Vista member, 7, 10, 13, 15, 16-18, Sinclair, W. J., 81, 82 Thorpe, M. R., 18, 26, 75, 87, 88, 21, 23, 24, 25, 27, 71 Sioux County, Nebraska, 59, 71 100, 102 Vista Triangulation Station, 13, 18, 24 Skull Spring ( Oregon ), 34, 96 thorpei, Proheteromys, 66 volcanic ash, 16, 20, 22 Snake Creek ( Nebraska ), 32, 34 Ticholeptus, 104 vu/pinus, Nothocyon, 91, 100 Snake Creek beds ( Nebraska ), 102, Ticholeptus-Merychip pus zone, 104 vu/pinus coloradoensis, Nothocyon, 107 Titanothere zone, 28 100 Snake Creek fauna, lower ( Nebraska ), Titanotheriomys, 7, 28, 29, 51, 58 Walker Museum, University of 32, 33, 98, 101, 107 Titanotherium beds, 8, 28 Chicago, 77 socialis, Perchoerus, 86 Tomarctus, 32, 34, 35, 100 Wallace, R. E., 94 Solenodontidae, 7, 42 Tonapah fauna ( Nevada ), 107 Wallace County, Kansas, 26 Soricid, 32, 92 Tordoff, H. B., 40 Ward, C., 8 Soricidae, 7, 46, 92 Tri gonias, 28, 82, 83 wardi, Cedromus, 29, 54, 59, 62, 63 South Dakota, 7, 8, 10, 12, 28, 44, 48, Trigonias Quarry ( Denver Museum of warreni, Germs, 110 71, 72, 82, 83, 85, 87, 104 Natural History), 14, 28, 40 warreni, Meryceros, 34, 35, 110 South Platte River, 9, 10, 14 trilophus, Gymnoptychus, 58 Weld County, Colorado, 7, 8, 9, 10, spectabilis, Leptochoerus, 29, 31, 83, trilophus, Paradjidaumo, 28, 29, 58 11, 12, 14, 18, 19, 20, 22, 24, 27, 84 Troxell, E. L., 57, 58, 85, 97 32, 36, 38, 40, 46, 47, 83, 81, 82, sphenodus, Hippotherium, 105 troxelli, Ischyromys, 28, 58 83, 85, 99, 100, 102, 103, 107, 108, sphenodus, Merychippus, 34, 35, 105, turgidus, Megala gus, 29, 51 109 106 turgidus, Palaeola gus, 51 Welles, S. P., 38 squalidens, Daptophilus, 80 Two Mile Creek, 103 West Plains, Colorado, 8 squalidens, Dinictis, 80 typus, Ischyromys, 29, 57, 58 westoni, Merychip pus, 106 Sterling, Colorado, 9, 106 uni pedalis, Cremastosaurus, 39 Wetmore, A., 38 Stibarus, 28, 29, 83-84 unipedalis, Diacium, 39 "white marker," 15, 16, 17, 24, 25 Stirton, R. A., 34, 36, 98, 105, 106, University of California, 10 White River beds, upper, 28 107 University of California Museum of White River formation, 7, 10, 11, 12- Stock, C., 90 Paleontology, 40 18, 22, 23, 24, 25, 26, 27, 28 Stone Ranch, 76, 83 University of Chicago, 77 Whitney member ( Nebraska), 14, 30 Stout, T. M., 14, 30, 57, 63, 96 University of Colorado Museum, 41, Williams, E. E., 38 Stylemys, 38 51, 52, 55, 56, 57, 58, 59, 60, 62, Willow Spring, 106 Subhyracodon, 29, 31, 83 68, 67, 69, 70, 72, 74, 75, 82, 83, Wilson, R. W., 8, 10, 12, 18, 36, 57, Sucker Creek fauna ( Oregon ), 34 84, 85, 86, 88, 89, 98, 103, 110 59, 62, 65, 67, 68, 69, 73, 94, 103, Swineford, A., 22 University of Kansas, 8, 22 108, 110 Talpid, 32, 93 University of Kansas Museum of Nat- wilsoni, Rhineura, 39 Talpidae, 49, 50, 93 ural History, 10, 31, 36, 38, 50, wilsoni, Pabrotherium, 29, 88, 89 talpivorus, Calamagras, 39 51, 74, 77, 83, 87, 104, 106, 109, Wood, A. E., 51, 52, 57, 58, 62, 83, talpivorus, Aphelophis, 39 110 65, 69, 70, 82, 97 Tapiravus, 34, 107 University of Michigan Museum of Wood, H. E., 8, 28, 82, 83, 107 Tapir Hill, 101 Paleontology, 39 Wood, H. E., et al., 12, 14, 19, 32, Tapiridae, 107 University of Nebraska State Museum, 34, 36, 37 Tapirus, 107 30, 63, 96 woodi, Heliscomys, 65 Tayassuid, 33, 108 University of Wyoming, 32 Wortman, J. L., 101 Tayassuidae, 85, 108 Ursavus, 34, 101 wortmani, Leptarctus, 102 Taylor, E. H., 8, 39, 40 Ursidae, 101 Wray, Colorado, 103 taylori, Trigonias, 82 Ustatochoerus, 34, 35, 92, 108 Wyoming, 8, 9, 10, 18, 35, 49, 58, 95, Teleoceras, 34, 35, 103, 107, 108 va fer, Canis, 100 100 Teleocerine sp., 108 va fer Leptocyon, 34, 35, 100, 101 Xestops, 39 Teleostean, 91 veredus, Bathornis, 40 Yale University Peabody Museum of temerarius, Canis, 100 vetustus, Prosciurus, 52, 53, 62 Natural History, 40, 58, 85, 86, 91, temerarius, Tomarctus, 100 veterior, Titanotheriomys, 28, 58 97, 100, 102 temnodon, Cynodictis, 76 vetus, Daphoenus, 29, 76 youngi, Peratherium, 41 temnodon, Pseudocynodictis, 31, 76 vetus, Heliscomys, 29, 63-65, 66 Yuma County, Colorado, 103 tenuiceps, Heliscomys, 29, 65 vetus, Leidymys, 72, 74 Zapodidae, 7, 99 terrenus, Arctoryctes, 49 vetus, Mesogaulus, 96 Testudines, 38, 91 Vim Postoffice, Colorado, 32 UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

ISSUED SERIAL PUBLICATIONS NUMBER JEFFoRDs, R. M., Pennsylvanian lophophyllidid corals: Coelenterata, Article 1, pp. 1-84, pls. 1-28, figs. 1-9. ( Issued January 20, 1947.) 1 MILLER, A. K. and YOUNGQUIST, WALTER, Lower Permian cephalopods from the Texas Colorado River Valley: Mollusca, Article 1, pp. 1-15, pls. 1-3, figs. 1-4. ( Issued August 29, 1947.) 2 Penn- MILLER, A. K. LANE, J. H., JR., and UNKLEssAy, A. G., A nautiloid cephalopod fauna from the sylvanian ,Winterset limestone of Jackson County, Missouri: Mollusca, Article 2, pp. 1-11, pls. 1-5, figs. 1-2. ( Issued August 29, 1947.) 3 TuomrsoN, M. L., Studies of American fusulinids• Protozoa, Article 1, pp. 1-184, pls. 1-38, figs. 1-8. ( Issued October 15, 1948.) 4 LALICKER, C. G., Foraminifera of the Ellis group, Jurassic, at the type locality: Protozoa, Article 2, pp. 3-20, pls. 1-4, figs. 1-5. ( Issued February 24, 1950.) 5 LOEBLICH, A. R., JR., and TAPPAN, HELEN, Foraminifera of the type ICiowa shale, Lower Cretaceous, of Kansas: Protozoa, Article 3, pp. 1-15, pls. 1-2. ( Issued February 24, 1950.) 6 ZELLER, E. J. Stratigraphic significance of Mississippian endothyroid Foraminifera: Protozoa, Article 4, pp. 1-2,3, pls. 1-6. ( Issued February 24, 1950.) 7 LEONARD, A. B., A Yarmouthian molluscan fauna in the midcontinent region of the United States: Mollusca, Article 3, pp. 1-48, pls. 1-6, figs. 1-4. (Issued March 24, 1950.) 8 LEONARD, A. B., Illinoian and Wisconsinan molluscan faunas in Kansas: Mollusca, Article 4, pp. 1 - 38, pls. 1-5, figs. 1-15. ( Issued February 15, 1952.) 9 PEABODY, F. E., Petrolacosaurus kansensis LANE, a Pennsylvanian reptile from Kansas: Vertebrata, Article 1, pp. 1-41, pls. 1-3, figs. 1-11. ( Issued March 20, 1952.) 10 HIBBARD, C. W., Vertebrate fossils from late Cenozoic deposits of central Kansas: Vertebrata, Article 2, pp. 1-14, figs. 1-14. ( Issued March 20, 1952.) 11 FAY, R. O., Catalogue of conodonts: Vertebrata, Article 3, pp. 1-206, figs. 1-109. ( Issued Decem- ber 1, 1952.) 12 GALBREATH, E. C., A contribution to the Tertiary geology and paleontology of northeastern Colorado: Vertebrata, Article 4, pp. 1-120, pls. 1-2, figs. 1-26. ( Issued March 15, 1953.) 13

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