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Volume 27.1
January–April 2024
Full table of contents
ISSN: 1094-8074, web version;
1935-3952, print version
Recent Research Articles
See all articles in 27.1 January-April 2024
See all articles in 26.3 September-December 2023
See all articles in 26.2 May-August 2023
See all articles in 26.1 January-April 2023
TABLE 1. Measurements (in mm) of Primates from TBM (b = broken dimension, p. = partial).
Taxon/Specimen Number | Position | ap | tr | tra | trp |
Uintasorex parvulus | |||||
SDSNH 110359 | p. M2 | 1.18b | 1.41b | - | - |
SDSNH 110358 | dp4 | 1.08 | - | 0.52 | 0.64 |
DMNH 75287 | m2 | 1.14 | - | 0.83 | 0.88 |
Microsyops annectans | |||||
UCM 67984 | m1 | 4.59 | - | 3.50 | 3.67 |
UCM 70315 | m2 | 5.05 | - | 3.53 | 3.91 |
Omomys carteri | |||||
SDSNH 110357 | M3 | 2.35 | 3.55 | - | - |
UCM 68564 | p4 | 2.58 | 1.78 | - | - |
SDSNH 110355 | m2 | 2.31b | - | 1.60b | 1.80b |
DMNH 75326 | m3 | 2.69 | - | 1.62 | 1.54 |
UCM 95772 | m3 | 2.90 | - | 1.80 | 1.75 |
Washakius insignis | |||||
UCM 68541 | M1 or 2 | 2.60 | 3.41 | - | - |
Trogolemur myodes | |||||
UCM 78097 | m2 | 1.67 | - | 1.44 | 1.49 |
UCM 67883 | m3 | 2.13 | - | 1.30 | 1.26 |
Notharctus robustior | |||||
DMNH 75300 | M1 | 7.06 | 8.57 | - | - |
UCM 78457 | p. M1 or 2 | - | 8.10b | - | - |
UCM 69054 | M3 | 5.00 | 6.50b | ||
UCM 72600 | p3 | 4.17 | 3.14 | - | - |
UCM 72600 | p. p4 | 5.15b | 4.36 | - | - |
TABLE 2. Measurements (in mm) of Ischyromyidae and Rodentia, family undetermined from TBM (* = probably associated teeth).
Taxon/Specimen Number | Position | ap | tr | tra | trp |
Microparamys minutus | |||||
UCM 66310 | dP4 | 1.15 | 1.26 | - | - |
UCM 95696 | P4 | 1.16 | 1.28 | - | - |
SDSNH 110373 | dp4 | 1.23 | - | 0.75 | 0.90 |
SDSNH 110374 | p4 | 1.18 | - | 0.82 | 1.06 |
SDSNH 110375 | m1 or 2 | 1.31 | - | 1.16 | 1.17 |
DMNH 74140 | m1 or 2 | 1.35 | - | 1.18 | 1.36 |
Microparamys sp. | |||||
SDSNH 110395 | dP4 | 1.26 | 1.40 | - | - |
SDSNH 110360 | p4* | 1.36 | - | 0.93 | 1.16 |
SDSNH 110361 | m1* | 1.41 | - | 1.23 | 1.41 |
SDSNH 110362 | m2* | 1.49 | - | 1.44 | 1.50 |
Thisbemys corrugatus | |||||
UCM 70671 | m1 | 4.04 | - | 3.76 | 3.90 |
Rodentia, family undet. | |||||
UCM 95700 | m1 or 2 | 1.54 | - | 1.18 | 1.20 |
TABLE 3. Comparison of P4/p4 ap reduction in size (in percent) relative to M1/m1-2 aps in sciuravids and 'Microparamys' scopaiodon (* = percentages for means of isolated teeth that can only be identified as M1 or 2 and m1 or 2, ** = percentage based on alveolar ap of p4 or m1). References: 1 Bown (1982); 2 Burke (1937); 3 Dawson (1962); 4 Dawson (1966); 5 Dawson (1968); 6 Emry and Korth (1989); 7 Flanagan (1986); 8 Gazin (1952); 9 Gazin (1961); 10 Guthrie (1971); 11 Ivy (1990); 12 Korth (1984); 13 Korth (1994); 14 Loomis (1907); 15 Marsh (1871); 16 Marsh (1872); 17 Nelson (1974); 18 Peterson (1919); 19 Rasmussen et al. (1999); 20 Troxell (1923a); 21 Walsh (1997); 22 Walton (1993); 23 Walton and Porter (2008); 24 West (1973); 25 Wilson (1938a); 26 Wilson (1938b); 27 Wilson (1938c); 28 Wilson (1940); 29 Wood (1959b); 30 Wood (1962); 31 Wood (1965).
Taxon | P4 ap/M1 ap | p4 ap/m1 ap | p4 ap/m2 ap | References |
Knightomys huerfanensis | 95%* | 80% | 81% | 12, 30 |
Knightomys minor | 83% | 90%* | 85%* | 11, 31 |
Knightomys senior | - | 93% | 90% | 8, 9, 11 |
Knightomys reginensis | 85% | - | - | 7, 12 |
Knightomys cuspidatus | 77% | 74% | 72% | 1, 12 |
Knightomys depressus | 93% | 87% | 82% | 8, 11, 14, 30, 31 |
Knightomys cremneus | - | 79% | 79-85% | 11, 23 |
Sciuravus wilsoni | - | 95% | 90% | 9, 30 |
Sciuravus nitidus | 85% | 84-93% | 74-87% | 15, 24 |
'Sciuravus' bridgeri | - | 93% | 88% | 26 |
Sciuravus eucristadens | 79% | 87.50% | 79% | 2, 5 |
Sciuravus powayensis | 70% | 82% | 78-82% | 21, 28 |
Sciuravus altidens | 87% | - | - | 18 |
Sciuravid sp. Powder Wash | 91%* | 88%* | - | 5 |
Sciuravid sp. Br3 | 79% | - | - | 3 |
Sciuravus popi | 79% | - | - | 5, 19 |
'Sciuravus' rarus | - | 59% | - | 25 |
'Microparamys' scopaidon | - | ~65%** | 3% | 12, 13, 22 |
'Pauromys' schaubi | - | ~75% | ~80%** | 21, 29 |
Pauromys perditus | - | 56% | 56% | 5, 20 |
Pauromys lillegraveni | 57% | 50% | 56% | 22 |
Pauromys exallos | - | 101% | 92% | 6, 21 |
Pauromys sp. Powder Wash | - | 59% | - | 4, 22 |
Pauromys sp. Lost Cabin | - | 85% | 76% | 12 |
Taxymys lucaris | 84% | - | - | 16, 27 |
Tillomys senex | - | ~75%** | - | 16, 27 |
Tillomys? sp. Fowkes | 74% | 97% | - | 17 |
TABLE 4. Measurements (in mm) of specimens of Sciuravus, Taxymys , Tillomys, Pauromys sp., cf. P. perditus, sciuravid sp. B, sciuravid sp. C and Sciuravidae, genus and species undetermined from TBM (a = approximate; p. = partial).
Taxon/Specimen Number | Position | ap | tra | trp |
Sciuravus nitidus | ||||
UCM 68430 | p. P4 | 1.97 | 2.42 | 2.28a |
Taxymys lucaris | ||||
UCM 68307 | M1 or 2 | 1.97 | 1.97 | 2.13 |
UCM 95759 | M1 or 2 | 1.87 | 1.87 | 1.70 |
UCM 95762 | M1 or 2 | 1.90 | 2.05 | 1.87 |
UCM 68924 | M1 or 2 | 1.82 | 1.82 | 1.92 |
UCM 68921 | p. M3 | 1.72 | 1.77 | - |
DMNH 75336 | M3 | 1.77 | 1.80 | 1.41 |
Tillomys senex | ||||
SDSNH 110363 | m1 or 2 | 1.96 | 1.82 | 1.92 |
DMNH 75279 | m1 or 2 | 1.96 | 1.67 | 1.88 |
DMNH 75328 | m1 or 2 | 2.05 | 1.80 | 1.97 |
UCM 78451 | m1 or 2 | 1.92 | 1.57 | 1.72 |
UCM 95753 | m1 or 2 | 1.95 | 1.54 | 1.69 |
Tillomys? parvidens | ||||
SDSNH 110379 | m1 or 2 | 1.87 | 1.50 | 1.64 |
DMNH 75329 | m1 or 2 | 1.82 | 1.30 | 1.51 |
UCM 68533 | p. m1 or 2 | 1.74 | - | - |
DMNH 75288 | m3 | 1.81 | 1.51 | 1.46 |
Pauromys sp., cf. P. perditus | ||||
SDSNH 110414 | m1 | 1.00 | 0.72 | 0.82 |
Sciuravid sp. B | ||||
SDSNH 110412 | M1 or 2 | 1.06 | 1.05 | 1.08 |
Sciuravid sp. C | ||||
UCM 68672 | M1 or 2 | 1.13 | 1.23 | 1.18 |
SDSNH 110447 | M1 or 2 | 1.12 | 1.23 | 1.13 |
SDSNH 110443 | M1 or 2 | 1.13 | 1.26 | 1.10 |
SDSNH 110439 | m3 | 1.16 | 0.95 | 0.87 |
SDSNH 110441 | m3 | 1.16 | 1.02 | 0.93 |
Sciuravidae, gen. and sp. undet. | ||||
SDSNH 110462 | P4 | 0.77 | 1.00 | 0.95 |
SDSNH 140176 | p. p4 | 0.67 | - | 0.55 |
SDSNH 110454 | p. p4 | - | - | 0.80 |
TABLE 5. Measurements (in mm) of Sciuravid sp. A from TBM (p. = partial).
Specimen Number | Position | ap | tra | trp |
UCM 68425 | M1 or 2 | 1.25 | - | 1.13 |
UCM 70910 | M1 or 2 | 1.28 | 1.35 | 1.23 |
UCM 71413 | M1 or 2 | 1.33 | 1.26 | 1.13 |
UCM 95763 | M1 or 2 | 1.29 | 1.23 | 1.10 |
UCM 95692 | M1 or 2 | 1.28 | 1.33 | 1.25 |
UCM 95696 | M1 or 2 | 1.28 | 1.34 | 1.28 |
UCM 95694 | m1 | 1.23 | 0.90 | 1.00 |
UCM 95812 | p. m1 | 1.21 | - | 1.00 |
SDSNH 110398 | p. m1 | 1.18 | - | - |
UCM 71414 | m1 | 1.26 | 1.00 | 1.05 |
UCM 68969 | m2 | 1.36 | 1.06 | 1.13 |
UCM 71415 | m2 | 1.28 | 1.03 | 1.10 |
UCM 77428 | m2 | 1.28 | 1.03 | 1.21 |
UCM 95754 | m2 | 1.34 | 1.05 | 1.19 |
UCM 95755 | m2 | 1.36 | 1.18 | 1.26 |
UCM 95757 | m2 | 1.30 | 1.10 | 1.13 |
UCM 95698 | m2 | 1.31 | 1.18 | 1.26 |
UCM 95699 | m2 | 1.26 | 1.08 | 1.17 |
SDSNH 110458 | m2 | 1.22 | 1.08 | 1.08 |
SDSNH 110459 | m2 | 1.21 | 1.07 | 1.10 |
SDSNH 110460 | m2 | 1.23 | 1.04 | 1.10 |
UCM 71516 | m3 | 1.39 | 1.08 | 1.06 |
UCM 95752 | m3 | 1.43 | 1.01 | 1.04 |
UCM 95756 | m3 | 1.46 | 1.14 | 1.11 |
SDSNH 110440 | m3 | 1.28 | 1.00 | 0.95 |
TABLE 6. Dental measurements (in mm) and dental ratios of unworn to early wear teeth of cf. Pareumys sp. from the TBM (a = approximate, pch = protocone or protoconid height of unworn teeth1 or teeth in early wear stage2; p. = partial).
Specimen Number | Position | ap | tra | trp | pch | pch/ap | pch/tra |
UCM 95760 | P4 | 1.48 | 1.69 | 1.64 | 1.142 | 0.86 | 0.85 |
DMNH 75335 | P4 | 1.36 | 1.76 | 1.72 | - | - | - |
DMNH 75337 | P4 | 1.35 | 1.77 | 1.69 | - | - | - |
SDSNH 110435 | p. P4 | 1.49 | - | - | - | - | - |
UCM 68942 | M1 or 2 | 1.67 | 1.82 | 1.74 | 1.511 | 0.90 | 0.83 |
UCM 95758 | M1 or 2 | 1.51 | 1.79 | 1.67 | - | - | - |
DMNH 75334 | M1 or 2 | 1.51 | 1.53 | 1.43 | 1.301 | 0.86 | 0.85 |
SDSNH 110396 | M1 or 2 | 1.69 | 1.86 | 1.79 | 1.641 | 0.97 | 0.88 |
SDSNH 110397 | M1 or 2 | 1.71 | 1.85a | 1.67 | - | - | |
UCM 67987 | M3 | 1.51 | 1.67 | 1.31 | - | - | - |
UCM 70905 | M3 | 1.57 | 1.56 | 1.46 | 1.261 | 0.80 | 0.81 |
UCM 69974 | m1 | 1.56 | 1.39 | 1.36 | - | - | - |
UCM 67885 | m2 | 1.61 | 1.39 | 1.44 | - | - | - |
SDSNH 110366 | m2 | 1.64 | 1.54 | 1.58 | - | - | - |
SDSNH 110365 | m2 | 1.57a | - | 1.49 | - | - | - |
SDSNH 110367 | m3 | 1.97 | 1.46 | 1.51 | - | - | - |
SDSNH 110368 | p. m3 | 1.77a | - | - | - | - | - |
SDSNH 110434 | m3 | 1.77 | 1.54 | 1.57 | 1.472 | 0.83 | 0.96 |
TABLE 7. Dental measurements (in mm) and statistics for Metanoiamys sp. from TBM.
Position | N | Mean | Observed range | SD | CV | |
dP4 | ap | 3 | 0.97 | 0.93-1.00 | 0.04 | - |
tra | 3 | 0.81 | 0.79-0.82 | 0.02 | - | |
trp | 3 | 0.81 | 0.77-0.85 | 0.04 | - | |
P4 | ap | 3 | 0.83 | 0.77-0.89 | 0.06 | - |
tra | 3 | 0.88 | 0.80-1.00 | 0.09 | - | |
trp | 3 | 0.84 | 0.77-0.93 | 0.07 | - | |
M1 or 2 | ap | 14 | 1.02 | 0.90-1.09 | 0.05 | 4.9 |
tra | 13 | 1.03 | 0.95-1.10 | 0.05 | 4.8 | |
trp | 13 | 1.01 | 0.89-1.09 | 0.06 | 5.9 | |
M3 | ap | 6 | 0.89 | 0.83-0.93 | 0.05 | 5.6 |
tra | 6 | 0.94 | 0.83-1.00 | 0.06 | 6.3 | |
trp | 6 | 0.79 | 0.77-0.82 | 0.03 | 3.7 | |
dp4 | ap | 1 | 0.80 | - | - | - |
tra | 1 | 0.49 | - | - | - | |
trp | 1 | 0.70 | - | - | - | |
p4 | ap | 6 | 0.86 | 0.79-0.93 | 0.06 | 6.5 |
tra | 6 | 0.67 | 0.58-0.70 | 0.03 | 4.6 | |
trp | 6 | 0.79 | 0.70-0.84 | 0.04 | 5.1 | |
m1 or 2 | ap | 10 | 1.00 | 0.89-1.07 | 0.06 | 6.0 |
tra | 10 | 0.88 | 0.80-1.00 | 0.07 | 7.9 | |
trp | 10 | 0.94 | 0.82-1.04 | 0.08 | 8.5 | |
m3 | ap | 4 | 1.05 | 1.00-1.08 | 0.04 | - |
tra | 4 | 0.92 | 0.85-0.98 | 0.06 | - | |
trp | 4 | 0.85 | 0.79-0.93 | 0.06 | - |
TABLE 8. Measurements (in mm) of SDSNH specimens of Elymys ? emryi new species from TBM (a = approximate, enamel abraded; p. = partial).
Specimen Number | Position | ap | tra | trp |
110466 (holotype) | M1 | 1.17 | 0.95 | 0.95 |
110465 | M1 | 1.18 | 0.96 | 0.96 |
110463 | M1 | 1.20 | 1.07 | 1.15 |
110464 | p. M1 | 1.18 | - | 1.13 |
110444 | M2 | 1.21 | 1.10 | 1.10 |
110448 | M3 | 0.98 | 1.00 | 0.82 |
110455 | m1 | 1.23 | 0.54 | 0.89 |
110456 | m1 | 1.16 | 0.52 | 0.81 |
110405 | m2 | 1.18a | 0.92a | 0.90a |
110457 | m2 | 1.28 | 0.98 | 1.05 |
110461 | m3 | 1.21 | 1.00 | 0.82 |
TABLE 9. Comparison of lower molar characters of UCM 95700, Ailuravus michauxi, Eohaplomys, Haplomys and Spurimus scotti (presumed shared characters in bold; character states after Rensberger [1975] and Korth [1988]).
Character | UCM 95700 | Ailuravus | Eohaplomys | Haplomys | Spurimus |
1. angle between labial and posterior margins | nearly square - 790-850 | more acute - 600 -730 on m1-2, nearly square on m3 | nearly square - 790-850 | more acute - 600-730 | more acute - 600-730 |
2. trigonids proportions | Relatively wide trigonid basin with longer metalophulids I and II | Relatively wide trigonid basin with longer metalophulids I and II | Relatively wide trigonid basin with longer metalophulids I and II, especially in m3 | trigonid basins narrower with shorter metalophulid I and II, especially m3 | trigonid basins narrower with shorter metalophulid I and II, especially m3 |
3. metastylid crest | Strongly developed | Strongly developed | Strongly developed | More weakly developed | More weakly developed |
4. metastylid | Absent | Absent | Absent or sometimes incipient on posterior edge of metastylid crest | Present - well developed | Absent |
5. entoconid | Bulbous | Bulbous | Bulbous | Not bulbous, more anteroposteriorly compressed | Not bulbous, more anteroposteriorly compressed |
6. hypolophid and hypolophid connection | Incomplete, extending into central basin with no connection | Usually incomplete, extending into central basin, especially m3, or sometimes connecting to posterior cingulid | Commonly complete, but low labially, connects to mesoconid | Complete, tall and usually connects to posterior corner of ectolophid | Complete, tall and usually connects to posterior corner of ectolophid |
7. mesoconid | small - oval shaped | Commonly present - usually oval shaped | Present - oval shaped | More triangularly shaped with labial crest | Absent |
8. ectolophid | straight | Relatively straight | Relatively straight | Inflected | Inflected |
9. space (or valley) between entoconid, hypolophid and posterior cingulid | Wide | Wide | Wide | Narrow | Narrow |
10. crenulated enamel | Yes | Yes | Yes | No | No |
Thomas S. Kelly. Research Associate, Vertebrate Paleontology Department, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, California 90007, USA, tom@tskelly.gardnerville.nv.us
Thomas Kelly received his B.A. and M.S. degrees in Biology from the California State University at Northridge (1968 and 1969) and a doctorate in Veterinary Medicine (DVM) from the University of California at Davis (1973). He did postgraduate research concentrating on the phylogenetic systematics of heteromyid rodents with Dr. Robert L. Rudd of the Department of Zoology, University of California, Davis in 1973-74. Since 1988, Dr. Kelly been a Research Associate in the Vertebrate Paleontology Department at the Natural History Museum of Los Angeles County and has been working as a consultant for paleontological resource impact mitigation projects in California for the last 25 years. He has published 46 paleontological articles, 35 of which were in peer-reviewed scientific journals. He has been the author or co-author of a number of new taxa in the paleontological literature, including nine mammal genera, 29 mammal species and one fish species. His interests are primarily in mammalian systematics and biostratigraphy.
Paul C. Murphey. Research Associate, Department of Paleontology, San Diego Museum of Natural History, 1788 El Prado, San Diego, California 92101, USA, pmurphey@sdnhm.org
Paul Murphey received a doctorate in geological sciences with an emphasis in vertebrate paleontology from the University of Colorado at Boulder in 2001. His professional experience includes appointments as the Collections Manager of Paleontology, Geology and Osteology in the Geology Section of the University of Colorado Museum; instructor in the Museum and Field Studies Program at the University of Colorado Museum; and graduate faculty member in the Department of Geological Sciences at the University of Colorado. He was an Associate Curator in the Department of Paleontology and the Associate Director of the Department of PaleoServices at the San Diego Natural History Museum. Dr. Murphey has been working as a consultant and Principal Investigator for paleontological resource impact mitigation projects throughout the United States for approximately 20 years. He was the Principal Paleontologist of the Paleontological Resources Program at SWCA Environmental Consultants for 11 years. In 2014, he joined Los Angeles–based Paleo Solutions as a partner and Vice President, forming Denver-based Rocky Mountain Paleo Solutions. Dr. Murphey is currently a research associate in the Department of Earth Sciences at the Denver Museum of Nature and Science and the Department of Paleontology at the San Diego Natural History Museum. His research is focused on the evolutionary history, stratigraphy, biochronology, and depositional environments of Paleogene fossil mammals and associated rock units in the Rocky Mountain region and southern California.
FIGURE 1. Map of study area showing modern and historical geographic terminology along with geographic position of type section of Turtle Bluff Member, Bridger Formation (modified after Murphey [2001]). The light purple shading represents areas on the lower slopes of the principal mountain landforms and the green shading represents areas above the base of the uppermost slopes for each landform (approximate elevations in feet are shown). Insert map shows location of study area in state of Wyoming.
FIGURE 2. Schematic stratigraphic column of type section of Turtle Bluff Member on southwest flank of Cedar Mountain, Bridger Formation, showing relative stratigraphic positions of SDSNH, DMNH and UCM localities (along with the locality names in parentheses) that yielded the fossils described in this paper (modified and corrected after Gunnell et al., [2009]). Locality MPM 2970 occurs on southwest flank of Sage Creek Mountain and its approximate relative stratigraphic position is projected onto type section. Abbreviations are: Lithostr., lithostratigraphic; NALMA, North American Land Mammal age.
FIGURE 3. Microsyopidae from TBM. 1-4, Uintasorex parvulus: 1, RM1 or 2, SDSNH 110359; 2-3, Rdp4, SDSNH 110358; 4, Lm2, DMNH 75287. 5-7, Microsyops annectans: 5, Rm1, UCM 68541; 6-7, partial dentary with Rm2, UCM 70315. 1-2, 4-6, occlusal views. 3 and 7, labial views. Scale bars equal 1 mm for 1-6 and scale bar for 7 equals 5 mm.
FIGURE 4. Primates from TBM. 1-3, Notharctus robustior: 1, RM1, DMNH 75300; partial RM1 or 2, UCM 78457; 3, partial RM3, UCM 69054. 4-5, Trogolemur myodes: 4, Rm2, UCM 78097; 5, Rm3, UCM 67883. 6, Washakius insignis, LM1 or 2, UCM 68541. 7-9, Omomys carteri: 7, LM3, 110357; 8, Lm1, SDSNH 110355; 9, Rm3, DMNH 75326. All occlusal views. Scale bar equals 1 mm.
FIGURE 5. Microparamys from TBM. 1-5, Microparamys minutus : 1, LdP4, UCM 66310; 2, LP4, UCM 95695; 3, LM1 or 2, UCM 95697; 4, Rp4, SDSNH 110374; 5, Lm1 or 2, DMNH 74140. 6-9, Microparamys sp.: 6, LdP4, SDSNH 110395; 7, Lp4, SDSNH 110360; 8, Lm1, SDSNH 110361; 9, Lm2, SDSNH 110362. All occlusal views. Scale bar equals 1 mm.
FIGURE 6. Thisbemys and Rodentia, family undetermined from TBM. 1, Thisbemys corrugatus, Rm1, UCM 70671. 2-3, Rodentia, family undetermined, Rm1 or 2, UCM 95700. 1-2, occlusal views. 3, oblique labial view. Scale bar equals 1 mm.
FIGURE 7. Larger Sciuravidae from TBM. 1, Sciuravus nitidus, RP4, UCM 68430. 2-4, Taxymys lucaris: 2, RM1 or 2, UCM 68307; 3, LM1 or 2, UCM 95762; 4, LM3, DMNH 75336. 5-7, Tillomys senex: 5, Lm1 or 2, DMNH 75328; 6, Rm1 or 2, DMNH 75279; 7, Rm1 or 2, SDSNH 110363. 8-9, Tillomys ? parvidens: 8, Rm1 or 2, SDSNH 110379; 9, Lm3, DMNH 75288. All occlusal views. Scale bar equals 1 mm.
FIGURE 8. Smaller Sciuravidae from TBM. 1, Pauromys sp., cf. P. perditus , Lm1, SDSNH 110414. 2, sciuravid sp. B, RM1 or 2, SDSNH 110412. 3-4, sciuravid sp. C: 3, RM1 or 2, SDSNH 110443; 4, Lm3, SDSNH 110441. 5-7, sciuravid premolars: 5, LP4, SDSNH 110462; 6, partial Rp4, SDSNH 110454; 7, partial Rp4, SDSNH 140176. All occlusal views. Scale bar equals 1 mm.
FIGURE 9. Sciuravid sp. A from TBM: 1, RM1 or 2, UCM 709102; 2, RM1 or 2, UCM 68903; 3, LM1 or 2, UCM 71413; 4, LM1 or 2, UCM 95763; 5, Rm1, UCM 95694; 6, Lm1 or 2, UCM 95757; 7, Rm1 or 2, SDSNH 110459; 8, Rm1 or 2, UCM 95699; 9, Lm3, UCM 95756. All occlusal views. Scale bar equals 1 mm.
FIGURE 10. cf. Pareumys sp. from TBM: 1, RP4, UCM 95760; 2-3, RM1 or 2, SDSNH 110396; 4, RM1 or 2, SDSNH 110397; 5, RM1 or 2, DMNH 75334; 6, LM1 or 2, UCM 95758; 7, LM3, UCM 67987; 8, Rm1, UCM 69974; 9, Lm2, SDSNH 110366; 10, Rm3, SDSNH 110367; 11-12, Rm3, SDSNH 110434. 1-2, 4-11 occlusal views. 3, anterior view. 12, labial view. Scale bar equals 1 mm.
FIGURE 11. Metanoiamys sp. from TBM: 1, LdP4, DMNH 74135; 2, LP4, DMNH 75331; 3, LM1 or 2, DMNH 74136; 4, LM1 or 2, DMNH 75251; 5, RM1 or 2, SDSNH 110442; 6, LM3, UCM 98813; 7, Rdp4, SDSNH 110369; 8, Lp4, DMNH 74143; 9, Lm1 or 2, DMNH 75252; 10, Lm1 or 2, DMNH 75250; 11, Lm1 or 2, DMNH 75254; 12, Lm3, DMNH 74144. All occlusal views. Scale bar equals 1 mm.
FIGURE 12. Elymys ? emryi new species from TBM, macrophotographs with corresponding line drawings of specimens: 1 and 9, LM1, SDSNH 110463; 2 and 10, RM1, SDSNH 110465; 3 and 11, RM1 (holotype), SDSNH 110466; 4 and 12, RM2, SDSNH 110444; 5 and 13, LM3, SDSNH 110448; 6 and 14, Rm1, SDSNH 110456; 7 and 15, Lm2, SDSNH 110457; 8 and 16, Lm3, SDSNH 110461. All occlusal views. Scale bar equals 1 mm.
Mammals from the earliest Uintan (middle Eocene) Turtle Bluff Member, Bridger Formation, southwestern Wyoming, Part 1: Primates and Rodentia
Plain Language Abstract
In the type area of the Bridger Basin, the middle Eocene Bridger Formation is divided into three members; the Blacks Fork Member (lower Bridger), the Twin Buttes Member (upper Bridger), and Turtle Bluff Member (uppermost Bridger). For over a 100 years, the Turtle Bluff Member (TBM) had yielded only a few fragmentary specimens. As the result of many years of field work, numerous mammal fossils have now been recovered from the TBM, including marsupials, 'insectivores,' primates, rodents, artiodactyls, perissodactyls (a large rhino-like brontothere, a small rhinocerotoid, and a primitive horse), and an uintathere (primitive large ungulate). Many of these specimens have been included in published faunal lists, but, except for a new species of Tarsier-like primate (Hemiacodon engardae), they have never been formally described or illustrated. In this paper, we provide detailed systematic accounts of the primates and rodents from the TBM. A complete understanding of the faunal composition from the Turtle Bluff Member is important because it has been designated as the stratotype section for the earliest Uintan (biochron Ui1a) North American Land Mammal age. Except for H. engardae, all the primates from the TBM are holdover taxa from the earlier Bridgerian Land Mammal age, whereas the rodents exhibit a modest diversification during the earliest Uintan. The rodents Elymys? emryi new species and four informal species (Microparamys sp., sciuravid sp. A, cf. Pareumys sp., and Metanoiamys sp.) make their appearances in the TBM and, as such, can be added to the list of index species characterizing biochron Ui1a.
Resumen en Español
Mamíferos del Uintano temprano (Eoceno medio) del Miembro Turtle Bluff, Formación Bridger, sudoeste de Wyoming, Parte 1: Primates y Rodentia
El Miembro Turtle Bluff (MTB) es la sección estratotipo del biocrón más temprano del Uintano, Ui1a, de la Edad Mamífero norteamericana Uintano del Eoceno medio. Por más de un siglo, se han extraído del MTB únicamente unos pocos especímenes fragmentarios. Como resultado de muchos años de trabajo de campo, recientemente se han hallado numerosos fósiles de mamíferos que proveen una oportunidad sin precedentes de definir mejor este intervalo pobremente conocido. Esta es la primera de una serie de publicaciones que proveen descripciones detalladas y revisiones taxonómicas de la fauna del MTB. Aquí documentamos la ocurrencia de los siguientes taxones en el MTB: Uintasorex parvulus; Microsyops annectans; Notharctus robustior; Omomys carteri; Trogolemur myodes; Washakius insignis; Thisbemys corrugatus, Microparamys minutus; Microparamys sp.; Sciuravus nitidus; Tillomys senex; Tillomys? parvidens; Taxymys lucaris; Pauromys sp., cf. P. perditus; tres especies informales de sciurávidos (sp. A, B y C); cf. Pareumys sp.; Metanoiamys sp.; y Elymys? emryi especie nueva. Excepto por el previamente descripto Hemiacodon engardae, todos los primates del MTB son taxones remanentes de la Edad Mamífero Bridgeriano mientras que los roedores exhiben una modesta diversificación durante el Uintano más temprano. Elymys? emryi y cuatro especies informales de roedores adicionales (Microparamys sp., sciurávido sp. A, cf. Pareumys sp., y Metanoiamys sp.) aparecen en el MTB y, por ende, pueden ser agregadas a la lista de especies guía que caracterizan al biocrón Ui1a.
Palabras clave: bioestratigrafía; Eoceno; mamíferos; especie nueva; Uintano
Traducción: Diana Elizabeth Fernández
Résumé en Français
Mammifères de l'Uintien basal (Éocène moyen) du membre Turtle Bluff, formation de Bridger, sud-ouest du Wyoming, 1ère partie : Primates et Rodentia
Le membre Turtle Bluff (TBM) est la section stratotype du plus ancien biochrone de l'Uintien basal, Ui1a, dans l'Éocène moyen de l'âge uintien de l'échelle chronostratigraphique des mammifères terrestres d'Amérique du Nord (NALMA). Pendant plus d'un siècle, le TBM n'a livré que quelques spécimens fragmentaires. De nombreuses années de terrain ont abouti à la découverte de nombreux fossiles de mammifères et fournissent la possibilité inédite de mieux définir cet intervalle de temps mal connu. Ce papier est le premier d'une série de papiers qui fournit des descriptions détaillées et des révisions taxinomiques de la faune du TBM. Nous documentons ici l'occurrence des taxons suivants dans le TBM : Uintasorex parvulus ; Microsyops annectans ; Notharctus robustior ; Omomys carteri ; Trogolemur myodes ; Washakius insignis ; Thisbemys corrugatus ; Microparamys minutus ; Microparamys sp. ; Sciuravus nitidus ; Tillomys senex ; Tillomys? parvidens ; Taxymys lucaris ; Pauromys sp. ; cf. P. perditus ; trois espèces non nommées de sciuravidés (sp. A, B et C) ; cf. Pareumys sp. ; Metanoiamys sp. ; et Elymys? emryi sp. nov. À l'exception de l'espèce Hemiacodon engardae, précédemment décrite, tous les primates du TBM sont des taxons vestiges des dépôts plus anciens de l'âge Bridgérien de l'échelle chronostratigraphique des mammifères terrestres d'Amérique du Nord, alors que les rongeurs montrent une diversification modérée pendant l'Uintien basal. Elymys? emryi sp. nov. et quatre espèces supplémentaires non nommées de rongeurs (Microparamys sp., sciuravidé sp. A, cf. Pareumys sp., et Metanoiamys sp.) font leur apparition dans le TBM, et peuvent donc être ajoutées à la liste des espèces marqueurs caractérisant le biochrone Ui1a.
Mots-clés : biostratigraphie ; Éocène ; mammifères ; nouvelle espèce ; Uintien
Translator: Antoine Souron
Deutsche Zusammenfassung
Säugetiere aus dem Turtle Bluff Member (frühestes Uintium, mittleres Eozän), Bridger Formation, südwestliches Wyoming, Teil 1: Primaten und Rodentia
Das Turtle Bluff Member (TBM) ist die Stratotyp-Sektion für das früheste Uintium Biochron, Uila, der mitteleozänen Uintium Nordamerikanischen Landsäugetier Stufe. Die TBM hat für mehr als ein Jahrhundert nur fragmentarische Stücke hervorgebracht. In mehreren Jahren Feldarbeit wurden nun viele Fossilien entdeckt, die eine beispiellose Möglichkeit zu einer besseren Definition dieser wenig bekannten Zeitspanne bieten. Dies ist die erste Veröffentlichung einer Serie, die detaillierte Beschreibungen und taxonomische Revisionen der TBM-Fauna liefert. Hier dokumentieren wir das Vorkommen folgender Taxa in der TBM: Uintasorex parvulus; Microsyops annectans; Notharctus robustior; Omomys carteri; Trogolemur myodes; Washakius insignis; Thisbemys corrugatus, Microparamys minutus; Microparamys sp.; Sciuravus nitidus; Tillomys senex; Tillomys? parvidens; Taxymys lucaris; Pauromys sp., cf. P. perditus; drei informelle Sciuraviden-Arten (sp. A, B und C); cf. Pareumys sp.; Metanoiamys sp.; und Elymys? emryi neue Art. Außer des vorher beschriebenen Hemiacodon engardae, sind alle Primaten aus der TBM Überbleibsel aus der frühen Bridgerium-Landsäugetier-Stufe, wohingegen die Nagetiere eine geringe Diversifikation während des frühesten Uintium zeigen. Elymys? emryi und vier zusätzliche informelle Nagetierarten (Microparamys sp., sciuravid sp. A, cf. Pareumys sp., und Metanoiamys sp.) tauchen in der TBM auf und können als solche zur Liste der Indexarten, die die Biochrone Uila charakterisieren hinzugefügt werden.
Schlüsselwörter: Biostratigraphie; Eozän; Säugetiere; neue Arten; Uintium
Translator: Eva Gebauer
Arabic
Translator: Ashraf M.T. Elewa
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Review: The Princeton Field Guide to Mesozoic Sea Reptiles
The Princeton Field Guide to Mesozoic Sea Reptiles
Article number: 26.1.1R
April 2023