Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-26T01:21:57.039Z Has data issue: false hasContentIssue false
  • English
  • Français

High-elevation late Pleistocene (MIS 6–5) vertebrate faunas from the Ziegler Reservoir fossil site, Snowmass Village, Colorado

Published online by Cambridge University Press:  20 January 2017

Joseph J.W. Sertich ,
Richard K. Stucky ,
H. Gregory McDonald ,
Cody Newton ,
Daniel C. Fisher ,
Eric Scott ,
John R. Demboski ,
Carol Lucking ,
Brianna K. McHorse  and
Edward B. Davis
Joseph J.W. Sertich*
Affiliation:
Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA
Richard K. Stucky
Affiliation:
Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA
H. Gregory McDonald
Affiliation:
Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA Museum Management Program, National Park Service, 1201 Oakridge Drive, Fort Collins, CO 80525, USA
Cody Newton
Affiliation:
Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA Department of Anthropology, University of Colorado — Boulder, Hale Science 350/233 UCB, Boulder, CO 80309-0233, USA
Daniel C. Fisher
Affiliation:
Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA University of Michigan Museum of Paleontology, 1109 Geddes Avenue, Ann Arbor, MI 48109, USA
Eric Scott
Affiliation:
San Bernardino County Museum, 2024 Orange Tree Lane, Redlands, CA 92374, USA
John R. Demboski
Affiliation:
Department of Zoology, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA
Carol Lucking
Affiliation:
Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA
Brianna K. McHorse
Affiliation:
Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
Edward B. Davis
Affiliation:
Department of Geological Sciences, University of Oregon Museum of Natural and Cultural History, 1680 East 15th Avenue, Eugene, OR 97403, USA
*
⁎Corresponding author at: Department of Earth Sciences, Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO 80205, USA.E-mail address:[email protected] (J.J.W. Sertich).
Get access Rights & Permissions [Opens in a new window]

Abstract

The vertebrate record at the Ziegler Reservoir fossil site (ZRFS) near Snowmass Village, Colorado ranges from ~140 to 77 ka, spanning all of Marine Oxygen Isotope Stage (MIS) 5. The site contains at least 52 taxa of macro- and microvertebrates, including one fish, three amphibian, four reptile, ten bird, and 34 mammal taxa. The most common vertebrate is Ambystoma tigrinum (tiger salamander), which is represented by >22,000 elements representing the entire life cycle. The mastodon, Mammut americanum, is the most common mammal, and is documented by >1800 skeletal elements making the ZRFS one of the largest accumulations of proboscidean remains in North America. Faunas at the ZRFS can be divided into two groups, a lake-margin group dating to ~140–100 ka that is dominated by woodland taxa, and a lake-center group dating to ~87–77 ka characterized by taxa favoring more open conditions. The change in faunal assemblages occurred between MIS 5c and 5a (vertebrates were absent from MIS 5b deposits), which were times of significant environmental change at the ZRFS. Furthermore, the ZRFS provides a well-dated occurrence of the extinct Bison latifrons, which has implications for the timing of the Rancholabrean Mammal Age in the region.

Keywords

Ziegler Reservoir fossil siteVertebrate faunasPleistoceneSnowmass VillageRancholabrean
Type
Articles
Information
Quaternary Research , Volume 82 , Issue 3 , November 2014 , pp. 504 - 517
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agenbroad, L.D., Mead, J.I., and Nelson, L.W. Megafauna and Man: Discovery of America's Heartland. Center for the Study of the First Americans. (1990). College Station, Texas.Google Scholar
Anderson, R.S., Jiménez-Moreno, G., Ager, T., and Porinchu, D. High-elevation paleoenvironmental change during MIS 6–4 in the central Rockies of Colorado as determined from pollen analysis. Quaternary Research 82, (2014). 542–552. (in this volume) Google Scholar
Barnosky, A.D. Biodiversity Response to Climate Change in the Middle Pleistocene: The Porcupine Cave Fauna from Colorado. (2004). University of California Press, Berkeley.Google Scholar
Barnosky, A.D., and Bell, C.J. Evolution, climatic change and species boundaries: perspectives from tracing Lemmiscus curtatus populations through time and space. Proceedings: Biological Sciences 270, (2003). 2585–2590.Google Scholar
Bell, C.J., Lundelius, E.L. Jr., Barnosky, A.D., Graham, R.W., Lindsay, E.H., Ruez, D.R. Jr., Semken, H.A. Jr., Webb, S.D., and Zakrzewski, R.J. The Blancan, Irvingtonian, and Rancholabrean mammal ages. Woodburne, M.O. Late Cretaceous and Cenozoic Mammals of North America. (2004). Columbia University Press, New York. 232–314.Google Scholar
Bever, G.S. Variation in the ilium of North American Bufo (Lissamphibia; Anura) and its implications for species-level identification of fragmentary anuran fossils. Journal of Vertebrate Paleontology 25, (2005). 548–560.Google Scholar
Blaauw, M., and Christen, J.A. Flexible paleoclimate age–depth models using an autoregressive gamma process. Bayesian Analysis 6, (2011). 457–474.Google Scholar
Carrasco, M.A. Species discrimination and morphological relationships of kangaroo rats (genus Dipodomys) based on their dentition. Journal of Mammalogy 81, (2000). 107–122.Google Scholar
Cavender, T.M., and Miller, R.R. Salmo australis, a new species from southwestern Mexico. Contributions from the Museum of Paleontology 26, (1982). University of Michigan, 1–17.Google Scholar
Dalquest, W.W. Problems in the nomenclature of North American Pleistocene camelids. Annales Zoologici Fennici 28, (1992). 291–299.Google Scholar
Eisenmann, V., Alberdi, M.-T., De Giuli, C., and Staesche, U. Volume I: methodology. Woodburne, M., and Sondaar, P. Studying Fossil Horses. Collected Papers after the New York International Hipparion Conference, 1981, Brill, Leiden. (1988). (71 pp.)Google Scholar
Emslie, S.D. Late Pleistocene vertebrates from Gunnison County, Colorado. Journal of Paleontology 60, (1986). 170–176.Google Scholar
Emslie, S.D. Fossil shrews (Insectivora: Soricidae) from the late Pleistocene of Colorado. Southwestern Naturalist 47, (2002). 62–69.Google Scholar
Emslie, S.D., and Czaplewski, N.J. A new record of giant short-faced bear, Arctodus simus, from western North America with a re-evaluation of its paleobiology. Contributions in Science, Natural History Museum of Los Angeles County 371, (1985). 1–12.Google Scholar
Faunmap Working Group (Graham, R.W., Lundelius, E.L. Jr. co-directors). (1994). FAUNMAP: a database documenting late Quaternary distributions of mammal species in the United States. Illinois State Museum Scientific Papers 25, Nos. 1 and 2.Google Scholar
Fisher, J.W. Jr. Observations on the late Pleistocene bone assemblage from the Lamb Spring Site, Colorado. Stanford, D.J., and Day, J.S. Ice-age Hunters of the Rockies. (1992). Denver Museum of Natural History and University Press of Colorado, Denver.Google Scholar
Fisher, D.C., and Fox, D.L. Season of death of the Dent mammoths: distinguishing single from multiple mortality events. Brunswig, R.H., and Pitblado, B.L. From the Dent Prairie to the Peaks of the Rockies: Recent Paleoindian Research in Colorado. (2007). University of Colorado Press, Boulder. 123–153.Google Scholar
Fisher, D.C., Cherney, M.D., Newton, C., Rountrey, A.N., Calamari, T., Stucky, R., Lucking, C., and Petrie, L. Taxonomic overview and tusk growth analyses of Ziegler Reservoir proboscideans. Quaternary Research 82, (2014). 518–532. (in this volume) CrossRefGoogle Scholar
Forman, S.L., Bettis, E.A. III, Kemmis, T.J., and Miller, B.B. Chronologic evidence for multiple periods of loess deposition during the Late Pleistocene in the Missouri and Mississippi River Valley, United States: implications for the activity of the Laurentide Ice Sheet. Palaeogeography, Palaeoclimatology, Palaeoecology 93, (1992). 71–83.Google Scholar
Fox, J.W., Smith, C.B., and Lintz, D.O. Herd bunching at the Waco Mammoth Site: preliminary investigations, 1978–1987. Fox, J.W., Smith, C.B., and Wilkins, K.T. Proboscideans, and Paleoindian Interactions. (1992). Baylor University Press, Waco. 51–73.Google Scholar
Gillette, D.D., and Madsen, D.B. The Columbian mammoth, Mammuthus columbi, from the Wasatch Mountains of central Utah. Journal of Paleontology 67, (1993). 669–680.CrossRefGoogle Scholar
Graham, R.W. Variability in the size of North American Quaternary black bears (Ursus americanus) with the description of a fossil black bear from Bill Neff Cave, Virginia. Purdue, J.R., Klippel, W.E., and Styles, B.W. Beamers, bobwhites and blue points: a tribute to Paul W. Parmalee. Illinois State Museum Scientific Papers 23, (1991). Illinois State Museum, Springfield. 237–250.Google Scholar
Graham, R.W., and Kay, M. Taphonomic comparisons of cultural and noncultural faunal deposits at the Kimmswick and Barnhart sites, Jefferson County, Missouri. Laub, R.S., Miller, N.G., and Steadman, D.W. Late Pleistocene and Early Holocene paleoecology and archaeology of the Eastern Great Lakes Region. Bulletin of the Buffalo Society of Natural Sciences 33, (1988). Buffalo Museum of Science, Buffalo. 227–250.Google Scholar
Hammerson, G.A. Amphibians and Reptiles of Colorado. (1999). Colorado Division of Wildlife, Fort Collins.Google Scholar
Harris, A.H. Neotoma in the late Pleistocene of New Mexico and Chihuahua. Genoways, H.H., and Dawson, M.R. Contributions in Quaternary vertebrate paleontology: a volume in memorial to John E. Guilday. Special Publications of the Carnegie Museum of Natural History 8, (1984). Carnegie Museum of Natural History, Pittsburgh. 164–183.Google Scholar
Harris, A.H., and Mundel, P. Size reduction in bighorn sheep (Ovis canadensis) at the close of the Pleistocene. Journal of Mammalogy 55, (1974). 678–680.Google Scholar
Haynes, G. Mammoths, Mastodons and Elephants: Biology, Behavior, and the Fossil Record. (1991). Elsevier Inc., New York.Google Scholar
Helgen, K.M., Cole, F.R., Helgen, L.E., and Wilson, D.E. Generic revision in the Holarctic ground squirrel genus Spermophilus . Journal of Mammalogy 90, (2009). 270–305.Google Scholar
Hoganson, J.W., and McDonald, H.G. The first report of the occurrence of Jefferson's ground sloth (Megalonyx jeffersonii) in North Dakota and its paleobiogeographical and paleoecological significance. Journal of Mammalogy 88, (2007). 73–80.Google Scholar
Holman, J.A. Fossil Snakes of North America: Origin, Evolution, Distribution, Paleoecology. (2000). Indiana University Press, Bloomington.Google Scholar
Holman, J.A. Fossil Frogs and Toads of North America. (2003). Indiana University Press, Bloomington.Google Scholar
Holman, J.A. Fossil Salamanders of North America. (2006). Indiana University Press, Bloomington.Google Scholar
Hooper, E.T. Dental patterns in mice of the genus Peromyscus . Miscellaneous Publications Museum of Zoology 99, (1957). University of Michigan, Ann Arbor.Google Scholar
Hopkins, M.L., Bonnichsen, R., and Fortsch, D. The stratigraphic position and faunal associates of Bison (Gigantobison) latifrons in southeastern Idaho, a progress report. Tebiwa 12, (1969). 1–8.Google Scholar
Hulbert, R.C. Jr. Latest Pleistocene and Holocene leporid faunas from Texas: their composition, distribution and climatic implications. Southwestern Naturalist 29, (1984). 197–210.Google Scholar
Klingener, D. Dental evolution of Zapus . Journal of Mammalogy 44, (1963). 248–260.Google Scholar
Krutzsch, P.H. North American jumping mice (Genus Zapus). University of Kansas Publications, Museum of Natural History 7, (1954). 349–472.Google Scholar
Kurtén, B., and Anderson, E. Pleistocene Mammals of North America. (1980). Columbia University Press, New York.Google Scholar
Lariviere, S., and Walton, L.R. Lontra canadensis . Mammalian Species 587, (1998). 1–8.Google Scholar
Laub, R.S. A Hiscock Primer. Proceedings of the Rochester Academy of Science 20, (2012). 2–9.Google Scholar
Leidy, J. A memoir on the extinct sloth tribe of North America. Smithsonian Contributions to Knowledge 7, (1855). Google Scholar
Licciardi, J.M., and Pierce, K.L. Cosmogenic exposure age chronologies of Pinedale and Bull Lake glaciations in greater Yellowstone and the Teton Range, USA. Quaternary Science Reviews 27, (2008). 814–831.Google Scholar
Lucking, C., Johnson, K.R., Pigati, J.S., and Miller, I.M. Primary mapping and stratigraphic data and field methods for the Snowmastodon Project. DMNS Technical Report 2012-04. (2012). Google Scholar
Mahan, S.A., Gray, H.J., Pigati, J.S., Wilson, J., Lifton, N.A., Paces, J.B., and Blaauw, M. A geochronologic framework for the Ziegler Reservoir fossil site, Snowmass Village, Colorado. Quaternary Research 82, (2014). 490–503. (in this volume) Google Scholar
Martinson, D.G., Pisias, N.G., Hays, J.D., Imbrie, J., Moore, T.C.J., and Shackleton, N.J. Age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300,000-year chronostratigraphy. Quaternary Research 27, (1987). 1–29.Google Scholar
McDonald, H.G. Description of the Osteology of the Extinct Gravigrade Edentate Megalonyx with Observations on its Ontogeny, Phylogeny and Functional Anatomy. (Master's Thesis) (1977). Department of Zoology, University of Florida, Gainesville.Google Scholar
McDonald, J.N. North American Bison, Their Classification and Evolution. (1981). University of California Press, Berkeley.Google Scholar
McDonald, H.G. Paleoecology of extinct xenarthrans and the Great American Biotic Interchange. Bulletin of the Florida Museum of Natural History 45, (2005). 313–333.Google Scholar
McDonald, H.G., Harington, C.R., and De Iuliis, G. The ground sloth, Megalonyx, from Pleistocene deposits of the Old Crow Basin, Yukon, Canada. Arctic 53, (2000). 213–220.Google Scholar
McDonald, H.G., Holen, S.R., Carstensen, J., and Kellett, T. A new record of American Mastodon, Mammut americanum, in Colorado. Current Research in the Pleistocene 27, (2010). 179–181.Google Scholar
Mead, J.I., and Taylor, L.H. Pleistocene (Irvingtonian) Artiodactyla from Porcupine Cave. Barnosky, A.D. Biodiversity Response to Climate Change in the Middle Pleistocene. (2004). University of California Press, Berkeley. 280–292.Google Scholar
Miller, W.E. Pleistocene vertebrates of the Los Angeles Basin and vicinity (exclusive of Rancho La Brea). Los Angeles County Museum of Natural History Science Bulletin 10, (1971). 1–124.Google Scholar
Miller, W.E. Mammut americanum, Utah's first record of the American Mastodon. Journal of Paleontology 61, (1987). 168–183.Google Scholar
Miller, D.M., Miller, I.M., and Jackson, S.J. Biogeography of Pleistocene conifer species from the Ziegler Reservoir fossil site, Snowmass Village, Colorado. Quaternary Research 82, (2014). 567–574. (in this volume) Google Scholar
Miller, I.M., Pigati, J.S., Anderson, R.S., Johnson, K.R., Mahan, S.A., Ager, T.A., Baker, R.G., Blaauw, M., Bright, J., Brown, P.M., Bryant, B., Calamari, Z.T., Carrara, P.E., Cherney, M.D., Demboski, J.R., Elias, S.A., Fisher, D.C., Graham, R.W., Gray, H.J., Haskett, D.R., Honke, J.S., Jackson, S.T., Jiménez-Moreno, G., Kline, D., Leonard, E.M., Lifton, N.A., Lucking, C., McDonald, H.G., Miller, D.M., Muhs, D.R., Nash, S.E., Newton, C., Paces, J.B., Petrie, L., Plummer, M.A., Porinchu, D.F., Rountrey, A.N., Scott, E., Sertich, J.J.W., Sharpe, S.E., Skipp, G.L., Strickland, L.E., Stucky, R.K., Thompson, R.S., Wilson, J., and Research, Quaternary A high-elevation, multi-proxy biotic and environmental record of MIS 6–4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA. Quaternary Research 82, (2014). 618–634. (in this volume) Google Scholar
Muhs, D.R., Swinehart, J.B., Loope, D.B., Aleinikoff, J.N., and Beann, J. 200,000 years of climate change recorded in eolian sediments of the High Plains of eastern Colorado and western Nebraska. Lageson, D.R., Lester, A.P., and Trudgill, B.D. Colorado and adjacent areas. Geological Society of America Field Guide (1999). 71–91.Google Scholar
Nelson, R.S., Semken, H.A. Jr. Paleoecological and stratigraphic significance of the muskrat in Pleistocene deposits. Bulletin of the Geological Society of America 81, (1970). 3733–3738.Google Scholar
Neotoma Paleoecological Database, http://www.neotomadb.org (2014). Google Scholar
Pigati, J.S., Miller, I.M., Johnson, K.R., Honke, J.S., Carrara, P.E., Muhs, D.R., Skipp, G., and Bryant, B. Geologic setting and stratigraphy of the Ziegler Reservoir fossil site, Snowmass Village, Colorado. Quaternary Research 82, (2014). 477–489. (in this volume) Google Scholar
Pinsof, J.D. A cranium of Bison alaskensis (Mammalia: Artiodactylia: Bovidae) and comments on fossil Bison diversity in the American Falls area, southeastern Idaho. Journal of Vertebrate Paleontology 11, (1991). 509–514.Google Scholar
Pinsof, J.D. Current status of North American Sangamonian local faunas and vertebrate taxa. Stewart, K.M., and Seymour, K.L. Palaeoecology and Palaeoenvironments of Late Cenozoic Mammals. (1996). University of Toronto Press, Toronto. 156–190.Google Scholar
Pinsof, J.D. The American Falls local fauna: late Pleistocene (Sangamonian) vertebrates from southeastern Idaho. Akersten, W.A., McDonald, H.G., Meldrum, J., and Flint, M.T. And whereas … papers on the vertebrate paleontology of Idaho honoring John A. White. Idaho Museum of Natural History Occasional Paper 36, (1998). Idaho Museum of Natural History, Pocatello. 121–145.Google Scholar
Rogers, K.L., Larson, E.E., Smith, G., Katzman, D., Smith, G.R., Cerling, T., Wang, Y., Baker, R.G., Lohmann, K.C., Repenning, C.A., Patterson, P., and Mackie, G. Pliocene and Pleistocene geologic and climatic evolution in the San Luis Valley of south-central Colorado. Palaeogeography, Palaeoclimatology, Palaeoecology 94, (1992). 55–86.Google Scholar
Sanders, A.E. Additions to the Pleistocene mammal faunas of South Carolina, North Carolina, and Georgia. Transactions of the American Philosophical Society 92, (2002). 1–152.Google Scholar
Sanders, A.E., Weems, R.E., Albright, L.B. III Formalization of the middle Pleistocene “Ten Mile Hill Beds” in South Carolina with evidence for placement of the Irvingtonian–Rancholabrean boundary. Museum of Northern Arizona Bulletin 64, (2009). 369–375.Google Scholar
Saunders, J.J. Late Pleistocene vertebrates of the western Ozark Highland, Missouri. Reports of Investigations Illinois State Museum 33, (1977). 1–118.Google Scholar
Saunders, J.J. A model for man–mammoth relationships in late Pleistocene North America. Canadian Journal of Anthropology 1, (1980). 87–98.Google Scholar
Saunders, J.J. Fossiliferous spring sites in southwestern Missouri. Laub, R.S., Miller, N.G., and Steadman, D.W. Late Pleistocene and Early Holocene paleoecology and archaeology of the Eastern Great Lakes Region. Bulletin of the Buffalo Society of Natural Sciences 33, (1988). Buffalo Museum of Science, Buffalo. 127–149.Google Scholar
Savage, D.E. Late Cenozoic vertebrates in the San Francisco Bay region. University of California Publications, Bulletin of the Department of Geological Sciences 28, (1951). 215–314.Google Scholar
Scott, E. Pliocene and Pleistocene horses from Porcupine Cave. Barnosky, A.D. Biodiversity Response to Environmental Change in Middle Pleistocene: The Porcupine Cave Fauna from Colorado. (2004). University of California Press, Berkeley, California. 264–297.Google Scholar
Scott, E. Extinctions, scenarios, and assumptions: changes in latest Pleistocene large herbivore abundance and distribution in western North America. Quaternary International 217, (2010). 225–239.Google Scholar
Scott, E., and Cox, S.M. Late Pleistocene distribution of Bison (Mammalia; Artiodactyla) in the Mojave Desert of Southern California and Nevada. Natural History Museum of Los Angeles County Science Series 41, (2008). 359–382.Google Scholar
Scott, W.E., Pierce, K.L., Bradbury, J.P., and Forester, R.M. Revised Quaternary stratigraphy and chronology in the American Falls area, southeastern Idaho. Bonnichsen, B., and Breckenridge, R.M. Cenozoic geology of Idaho. Idaho Department of Lands, Bureau of Mines and Geology Bulletin 26, (1982). 581–595.Google Scholar
Semken, H.A. Jr., and Wallace, S.C. Key to arvicoline (“microtine” rodent) and arvicoline-like first lower molars recovered from late Wisconsinan and Holocene archaeological sites of eastern North America. Journal of Archaeological Science 29, (2002). 23–31.Google Scholar
Skinner, M.F., and Kaisen, O.C. The fossil Bison of Alaska and preliminary revision of the genus. Bulletin of the American Museum of Natural History 89, (1947). 123–256.Google Scholar
Stephens, J.J. Stratigraphy and paleontology of a late Pleistocene basin, Harper County, Oklahoma. Bulletin of the Geological Society of America 71, (1960). 1675–1702.Google Scholar
Stock, C. Cenozoic gravigrade edentates of western North America. Carnegie Institute of Washington Publication 331, (1925). Google Scholar
Strickland, L.E., Baker, R.G., Thompson, R.S., and Miller, D.M. Last interglacial plant macrofossils and climates from Ziegler Reservoir, Snowmass Village, Colorado. Quaternary Research 82, (2014). 553–566. (in this volume) Google Scholar
Stucky, R., Fisher, D., Graham, R., Holen, S., and McDonald, H.G. A new high altitude Late Pleistocene interglacial/glacial site (MIS 5?) preserving large and small vertebrate fossils from western Colorado: the Snowmastodon Site at Ziegler Reservoir, Pitkin County. Journal of Vertebrate Paleontology (2011). 201 (Online Supplement, November 2011) Google Scholar
Stucky, R., Sertich, J., Johnson, K.R., Miller, I., Fisher, D.C., Graham, R.W., McDonald, H.G., and Pigati, J.S. Ziegler Reservoir and the Snowmastodon Project: new high-elevation fossil vertebrate faunas from Snowmass Village, Colorado. Geological Society of America Abstracts with Programs 43, (2011). 265 Google Scholar
Stucky, R.K., Graham, R., Sertich, J., Demboski, J., and Nelson, C. Paleontology and paleoecology of the small vertebrates (Osteichthyes, Amphibia, Reptilia, Aves, and Mammalia including Cervidae) from Snowmass. Program and Abstracts for the First Snowmastodon Science Team Meeting. Denver, CO June 26-28, 2012. Denver Museum of Nature and Science Technical Report 2012-5. (2012). 30–32.Google Scholar
Winans, M.C. A quantitative study of North American fossil species of the genus Equus . Prothero, D.R., and Schoch, R. The Evolution of Perissodactyls. (1989). Oxford University Press, Oxford. 262–297.Google Scholar
Zakrzewski, R.J. Kangaroo rats from the Borchers local fauna, Blancan, Meade County, Kansas. Transactions of the Kansas Academy of Sciences 84, (1981). 78–88.Google Scholar