Krause Lab | Crazy Mountains Basin Project

Crazy Mountains Basin Project, Montana
1982 - present

In the ten million years following the extinction of dinosaurs, during the Paleocene epoch (ca. 65-55 mya), mammals underwent a major adaptive radiation and became dominant land animals. However, despite the fact that almost one-half of the known orders of Cenozoic mammals arose in the Paleocene, less is known about composition and diversity of mammalian faunas during this time than during any of the later epochs. A large-scale turnover in mammalian faunas, among the most dramatic during the Early Cenozoic, occurred near the middle Paleocene and serves as a basis for splitting the Paleocene into early and late intervals.

The Crazy Mountains Basin (CMB) Project was initiated by Dave in 1982. The eastern CMB of south-central Montana already contained the best-known sequence of late Early-to-early Late Paleocene localities for fossil mammals in the world, thanks to the previous efforts of E. Douglass, J. W. Gidley, A. C. Silberling, G. G. Simpson and others in the early part of the 20th century. Field crews consisting largely of students from Stony Brook University and participants from EARTHWATCH/The Center for Field Research made massive collections from previously known localities (e.g., Douglass and Scarritt quarries) and discovered and developed several new ones (e.g., Bingo, Azzara, and Simpson quarries) from 1982 into the early 1990s. Some of the large collections amassed by these teams have been described and analyzed to address questions regarding phylogenetic relationships, functional morphology, faunal and climatic change, and the biogeographic origins of the modern orders of mammals. Much of these collections, however, remained to be studied at the time that Dave initiated the Mahajanga Basin Project in 1993. Therefore, the CMB Project was resurrected, reconstituted, and refocused in 2002 through the involvement of Jon Bloch and Doug Boyer. In addition to making important new collections from the eastern part of the basin, a freshwater limestone locality (the Bangtail locality) in the western part of the basin, known for its remarkable preservation of small mammal skeletons, was relocated, a second older limestone locality was discovered, and additional collections were made. These localities continue to yield new, articulated material of small mammals otherwise unavailable from the Paleocene of North America.

The massive collections from both the eastern and western parts of the CMB have been and are being utilized to (1) document the composition of mammalian faunas on either side of the Torrejonian (To) (late Early Paleocene)-Tiffanian (Ti) (early Late Paleocene) boundary; (2) evaluate phylogenetic relationships of represented mammalian taxa; (3) refine the litho-, magneto- and biostragraphy of the CMB in an effort to correlate with mammalian faunas from other parts of the Western Interior of North America; and (4) assemble paleoclimatic data (from leaf fossils and stable isotope analyses of mammalian teeth) through this section. These data form the basis for testing hypotheses concerning: (1) the magnitude of faunal turnover across the To-Ti boundary, (2) the mechanisms of faunal turnover (migration vs. pseudo-extinction), (3) the cause of faunal turnover (e.g., climatic change), and (4) the order and timing of character acquisitions in the early evolutionary history of various placental mammalian taxa.

The CMB project has been supported by the National Geographic Society (1983-1984), EARTHWATCH/The Center for Field Research (1983-1986), and the National Science Foundation (1984-1986, 1988-1991, 1992-1993, 2003-2005).

PRINCIPAL INVESTIGATORS

Jon Bloch • Ph.D., Associate Curator of Vertebrate Paleontology, Florida Museum of Natural History; Associate Professor of Geological Sciences, Anthropology, and Zoology, University of Florida. •

Jon's primary research interests lie with addressing questions surrounding the first appearance and early evolution of the modern orders of mammals. Specific research topics include: (1) the response of mammalian communities to climatic change; (2) use of phylogenetic methods to infer hypotheses of relationships; and (3) use of functional morphology to study the evolution and paleoecology of small mammals. Jon has concentrated on the interval from the terminal Cretaceous through the early Eocene, and, in addition to work in the Crazy Mountains Basin, conducts field-related research in the Paleocene and Eocene of the Clarks Fork and Bighorn basins of Wyoming and the Cerrejon and Bogota formations of northern Colombia. His research in the Crazy Mountains Basin began in 2003 and he has co-led, with Doug Boyer, four (2003-2006) expeditions to the basin.

Douglas Boyer • Ph.D., Postdoctoral Associate, Department of Ecology and Evolution, Department of Anthropology, Stony Brook University •

While still a graduate student advised by Dave in the Department of Anatomical Sciences, Doug, along with Jon Bloch (see above), re-initiated field work in the Crazy Mountains Basin. Doug is primarily interested in reconstructing the ecological and evolutionary history of early mammalian clades. An ultimate goal of his research is to amass data that can test and generate hypotheses regarding evolutionary mechanisms and environmental selection pressures that lead to mammalian faunal change through the Early Tertiary. In addition to work in the Crazy Mountains Basin, Doug has conducted field research in the Paleocene and Eocene of the Bighorn, Clark's Fork, Hanna, and Washakie basins of Wyoming. He has also participated in field work in Madagascar with Dave, and in field work in Egypt's Fayum Depression with Erik Seiffert.

Dave Krause • Ph.D., Distinguished Service Professor, Department of Anatomical Sciences, Stony Brook University •

Dave initiated the Crazy Mountains Basin Project in 1982 after conducting reconnaissance fieldwork in the basin as a Ph.D. student at the University of Michigan. The collections amassed by his field crews from 1982-1993 lead to Dave's involvement in the descriptions of entire quarry faunas (e.g., Gingerich et al., 1983; Krause and Gingerich, 1983); descriptions of individual taxa, primarily multituberculates (e.g., Krause, 1987a, b; Krause and Kielan-Jaworowska, 1993; Scott and Krause, 2006) but also others (e.g., plesiadapiforms - Silcox et al., 2001; "condylarths" - Zack et al., 2005; St. Clair et al., in press); evaluation of the utility of enamel microstructure in reconstructing multituberculate phylogeny (e.g., Carlson and Krause, 1985; Krause and Carlson, 1986, 1987); documentation of geological context (e.g., Butler et al., 1987; Hartman and Krause, 1983; Hartman et al., 1989); evaluation of hypotheses concerning ecological interactions and faunal change (e.g., Krause, 1986; Krause and Maas, 1990; Maas and Krause, 1994; Maas et al., 1988, 1995); and formulation of an hypothesis concerning the biogeographic origins of the modern orders of mammals (Krause and Maas, 1990).

OTHER CURRENT RESEARCH COLLABORATORS

Mary Silcox • Ph.D., Asssociate Professor, Department of Anthropology, University of Winnipeg, Winnipeg, Manitoba, Canada •

Mary's research focuses on the evolution of stem-primates (plesiadapiforms). Her interest and involvement in the Crazy Mountains Basin fieldwork lies in the potential for discovering new and more complete representatives of the plesiadapiform radiation that can contribute to an improved understanding of the major features of the evolutionary history of stem-primates (e.g., Silcox et al., 2001). Such information also provides a better-resolved view of euprimate origins.

Elizabeth St. Clair • Ph.D. student, Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University •

Liz's current research includes faunal descriptions of the early Tiffanian quarries in the Crazy Mountains Basin, Montana (e.g., St. Clair et al., in press), with wider interests in biogeography and faunal turnover in Paleocene and Eocene mammals. Her own dissertation research focuses on the relationship between morphological diversity and ecological variation in extant and fossil primates. Analysis of morphological diversity in the skeleton and dentition of extant platyrrhine and 'prosimian' primates provides a context in which to understand the acquisition of morphological diversity in evolving lineages of primates during the Eocene.

PUBLICATIONS - CRAZY MOUNTAINS BASIN PROJECT

(1982-present, listed alphabetically by author)

Anthony, M. R. L., and M. C. Maas. 1990. Biogeographic provinciality in North American Paleocene mammalian faunas. Journal of Vertebrate Paleontology 10:12A.

Anthony, M. R. L., M. C. Maas, and D. W. Krause. 1991. New collections of mammals from late Torrejonian localities in the eastern Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 11:14A.

Archibald, J. D., W. A. Clemens, P. D. Gingerich, D. W. Krause, E. H. Lindsay, and K. D. Rose. 1987. First North American Land Mammal Ages of the Cenozoic Era. Pages 24-76 in M. O. Woodburne (ed.), Cenozoic Mammals of North America, University of California Press, Berkeley.

Biknevicius, A. 1985. Dental function and diet in the Carpolestidae (Primates: Plesiadapiformes). Unpublished M.A. thesis, State University of New York at Stony Brook.

Biknevicius, A. 1986. Dental function and diet in the Carpolestidae (Primates: Plesiadapiformes). American Journal of Physical Anthropology 71:157-171.

Bloch, J. I., D. M. Boyer, and D. W. Krause. 2006. New mammal-bearing quarry from the earliest Tiffanian (early Late Paleocene) of the eastern Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 26:43A.

Bloch J. I., M. T. Silcox, D. M. Boyer, and E. J. Sargis. 2007. New Paleocene skeletons and the relationship of plesiadapiforms to crown-clade primates. Proceedings of the National Academy of Sciences 104: 1159-1164.

Boyer, D. M., and J. I. Bloch. 2003. Comparative anatomy of the pentacodontid Aphronorus orieli (Mammalia, Pantolesta) from the Paleocene of the western Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 23:36A.

Boyer, D. M., and J. A. Georgi. 2007. Cranial morphology of a pantolestid eutherian mammal from the Eocene Bridger Formation, Wyoming, USA: implications for relationships and habitat. Journal of Mammalian Evolution 14:239-280.

Boyer, D. M., A. Evans, J. Jernvall. Accepted pending minor revisions. Evidence of dietary differentiation among late Paleocene-early Eocene plesiadapids (Mammalia, Primates). American Journal of Physical Anthropology.

Boyer, D. M., M. Bolortsetseg, J. I. Bloch, and D. W. Krause. In prep. First skeletal remains of a neoplagiaulacid multituberculate (Mammalia: Theriiformes) from the Torrejonian-Tiffanian transition of Montana.

Boyer, D. M., J. M. Pares, J. I, Bloch, and D. W. Krause. 2004. Refining intra- and inter-basinal chronostratigraphic correlations of Paleocene mammal-bearing localities in the Crazy Mountains Basin, Montana: Initial paleomagnetic results. Geological Society of America Abstracts with Programs 36(5):363.

Buckley, G. A. 1988. A new Purgatorius-like mammal from Simpson Quarry (Puercan), Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology, Abstracts of Papers 8:10.

Buckley, G. A. 1989. A new Puercan species of Catopsalis (Taeniolabididae, Multituberculata) and the evolution of North American taeniolabidids. Journal of Vertebrate Paleontology, Abstracts of Papers 9:14-15.

Buckley, G. A. 1993. Magnetostratigraphy of the Late Cretaceous and early-middle Paleocene formations of the Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology, Abstracts of Papers 13:28.

Buckley, G. A. 1994. Paleontology, geology and chronostratigraphy of Simpson Quarry (Early Paleocene), Bear Formation, Crazy Mountains Basin, south-central Montana. Ph.D. dissertation, Department of Geological Sciences, Rutgers University, 459 pp.

Buckley, G. A. 1995. Biochronology and magnetostratigraphy of Simpson Quarry (Bear Formation, Crazy Mountains Basin, south-central Montana) and a reassessment of the Puercan NALMA. Geological Society of America, Abstracts with Programs 27(6).

Buckley, G. A. 1995. The multituberculate Catopsalis from the early Paleocene of the Crazy Mountains Basin in Montana. Acta Palaeontologica Polonica 40:389-398.

Buckley, G. A. 1997. A new species of Purgatorius (Mammalia; Primatomorpha) from the lower Paleocene Bear Formation, Crazy Mountains Basin, south-central Montana. Journal of Paleontology 71:149-155.

Buckley, G. A., and D. W. Krause. 1987. Simpson Quarry: the first fossil mammal locality in the lower Paleocene Bear Formation, Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology, Abstracts of Papers 7:12.

Butler, R. F., D. W. Krause, and P. D. Gingerich. 1987. Magnetic polarity stratigraphy and biostratigraphy of middle-late Paleocene continental deposits of south-central Montana. Journal of Geology, 95:647-657.

Carlson, S. J. and D. W. Krause. 1982. Multituberculate phylogeny: evidence from tooth enamel ultrastructure. Geological Society of America, Abstracts with Programs, 14:460.

Carlson, S. J. and D. W. Krause. 1985. Enamel ultrastructure of multituberculate mammals: an investigation of variability. University of Michigan Museum of Paleontology Contributions, 27:1-50. PDF

Dumont, E. R. 1990. Enamel microstructural evidence for the affinities of proposed Early Tertiary archontan taxa. Journal of Vertebrate Paleontology 10:21A.

Gingerich, P. D., P. Houde and D. W. Krause. 1983. A new earliest Tiffanian (late Paleocene) mammalian fauna from Bangtail Plateau, western Crazy Mountain Basin, Montana. Journal of Paleontology, 57:957-970. PDF

Hartman, J. H., and D. W. Krause. 1993. Cretaceous and Paleocene stratigraphy and paleontology of the Shawmut Anticline and the Crazy Mountains Basin, Montana: Road log and overview of recent investigations. Montana Geological Society -- South-Central Field Conference Guidebook, pp. 71-84.

Hartman, J. H., G. A. Buckley, D. W. Krause, and T. J. Kroeger. 1989. Paleontology, stratigraphy, and sedimentology of Simpson Quarry (early Paleocene), Crazy Mountains Basin, south-central Montana. Montana Geological Society, 1989 Field Conference Guidebook, Montana Centennial Edition, D. E. French and R. F. Grabb, eds., vol. II, pp. 173-185.

Hartman, J. H., D. W. Krause, G. A. Buckley, and T. J. Kroeger. 1989. Paleocene biochronology in the northern Great Plains: nonmarine Mollusca and Mammalia from the Crazy Mountains Basin. Montana Geological Society, 1989 Field Conference Guidebook, Montana Centennial Edition, D. E. French and R. F. Grabb, eds., vol. I, pp. xxii-xxiii.

Krause, D. W. 1984. Mammalian evolution in the Paleocene: Beginning of an era. In T. W. Broadhead (ed.), Mammals: Notes for a Shortcourse. University of Tennessee Department of Geological Sciences Studies in Geology, 8:87-109.

Krause, D. W. 1986. Competitive exclusion and taxonomic displacement in the fossil record: the case of rodents and multituberculates in North America. In Vertebrates, Phylogeny, and Philosophy: a Tribute to George Gaylord Simpson (K. M. Flanagan and J. A. Lillegraven, eds.), University of Wyoming Contributions to Geology, Special Paper No. 3:95-117.

Krause, D. W. 1987. Baiotomeus, a new ptilodontid multituberculate (Mammalia) from the middle Paleocene of western North America. Journal of Paleontology, 61:595-603.

Krause, D. W. 1987. Systematic revision of the genus Prochetodon (Multituberculata, Mammalia) from the late Paleocene and early Eocene of western North America. University of Michigan Museum of Paleontology Contributions, 27:221-236. PDF

Krause, D. W. 2004. Systematic revision of the genus Ptilodus (Ptilodontidae, Multituberculata) from the Paleocene of western North America. Journal of Vertebrate Paleontology 24:80A.

Krause, D. W. and S. J. Carlson. 1985. The evolution of prismatic enamel in multituberculate mammals. American Society of Mammalogists, Abstracts with Program, p. 9.

Krause, D. W. and S. J. Carlson. 1986. The enamel ultrastructure of multituberculate mammals: a review. Scanning Electron Microscopy/1986:1591-1607. Reprinted as pp. 165-180 in L. Martin, A. Boyde, F. Grine, and S. Jones (eds.), Scanning Microscopy of Vertebrate Mineralized Tissues (1988). Scanning Microscopy International, Chicago, 384 pp.

Krause, D. W. and S. J. Carlson. 1987. Prismatic enamel in multituberculate mammals: tests of homology and polarity. Journal of Mammalogy, 68:755-765.

Krause, D. W., and P. D. Gingerich. 1983. Mammalian fauna from Douglass Quarry, earliest Tiffanian (late Paleocene) of the eastern Crazy Mountain Basin, Montana. University of Michigan Museum of Paleontology Contributions, 26:157-196.

Krause, D. W., and M. C. Maas. 1987. Composition and diversity of mammalian faunas across the Torrejonian-Tiffanian boundary in western North America. For symposium volume: "Dawn of the Age of Mammals in the northern part of the Western Interior," T. M. Bown and K. D. Rose, eds. Geological Society of America (Rocky Mountain Section), Abstracts with Program, 19:287.

Krause, D. W., and M. C. Maas. 1988. The biogeographic origins of Clarkforkian and Wasatchian mammalian immigrants to the Western Interior. Journal of Vertebrate Paleontology, 8:19A.

Krause, D. W., and M. C. Maas. 1990. The biogeographic origins of late Paleocene - early Eocene mammalian immigrants to the Western Interior of North America. In "Dawn of the Age of Mammals in the northern part of the Rocky Mountain Interior, North America." T. M. Bown and K. D. Rose, eds. Geological Society of America, Special Paper 243:71-105.

Krause, D. W., and Z. Kielan-Jaworowska. 1993. The endocranial cast and encephalization quotient of Ptilodus (Multituberculata, Mammalia). Palaeovertebrata 22:99-112.

Lukowski, S. M., J. I. Bloch, and D. W. Krause. 2004. Several new species of Ectocion from the Crazy Mountains Basin of Montana and stratocladistic analysis of Paleocene Phenacodontidae. Journal of Vertebrate Paleontology 24:86A.

Maas, M. C., and D. W. Krause. 1989. Mammalian faunal turnover in North America during the Paleocene. Fifth International Theriological Congress, Abstracts (Symposium on Mammalian Evolutionary Paleoecology), Rome, vol. 2, p. 641.

Maas, M. C., and D. W. Krause. 1994. Mammalian turnover and community structure in the Paleocene of North America. Historical Biology 8:91-128.

Maas, M. C., D. W. Krause, and S. G. Strait. 1988. The decline and extinction of Plesiadapiformes (Mammalia: ?Primates) in North America: displacement or replacement? Paleobiology, 14:410-431.

Maas, M. C., S. Strait, and D. W. Krause. 1987. The decline and extinction of plesiadapiform primates. American Journal of Physical Anthropology, 72:228.

Maas, M. C., P. D. Gingerich, G. Gunnell, and D. W. Krause. 1992. Patterns of faunal turnover and diversity in the Wyoming-Montana Paleogene in relation to regional and global events. Fifth North American Paleontological Convention - Abstracts and Program (eds., S. Lidgard and P. R. Crane). The Paleontological Society, Special Publication No. 6:191.

Maas, M. C., M. R. L. Anthony, P. D. Gingerich, G. F. Gunnell, and D. W. Krause. 1995 Mammalian generic diversity and turnover in the Late Paleocene and Early Eocene of the Bighorn and Crazy Mountains Basins, Wyoming and Montana (USA). Palaeogeography, Palaeoclimatology, Palaeoecology 115:181-207.

Mawyin, C., J. Groenke, D. M. Boyer, and J. I. Bloch. 2004. Novel use for cyclododecane in acid preparation of recently recovered Paleocene limestones from the western Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 24:90A-91A.

McCullough, G. M., M. T. Silcox, J. I. Bloch, D. M. Boyer, and D. W. Krause. 2004. New palaechthonids (Mammalia, Primates) from the Paleocene of the Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 24:91A.

Scott, C. S., and D. W. Krause. 2006. Multituberculates (Mammalia, Allotheria) from the earliest Tiffanian (Late Paleocene) Douglass Quarry, eastern Crazy Mountains Basin, Montana. University of Michigan Museum of Paleontology Contributions 31(10):211-243. PDF

Silcox, M. T., D. W. Krause, M. C. Maas, and R. C. Fox. 2001. New specimens of Elphidotarsius russelli (Mammalia, ?Primates, Carpolestidae) and a revision of plesiadapoid relationships. Journal of Vertebrate Paleontology 21:132-152.

St. Clair, E., D. W. Krause, and D. B. Boyer. 2005. Pantodonts (Mammalia) from the early Tiffanian (Paleocene) of the Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 25:118A.

St. Clair, E., D. M. Boyer, J. I. Bloch, and D. W. Krause. 2008. New records of Goniacodon levisanus (Mammalia, Triisodontinae) from the late Paleocene of the Crazy Mountains Basin, Montana. Journal of Vertebrate Paleontology 28:147A.

St. Clair, E. M., D. M. Boyer, J. I. Bloch, and D. W. Krause. In press. First records of a triisodontine mammal, Goniacodon levisanus, in the late Paleocene of the northern Great Plains, North America. Journal of Vertebrate Paleontology.

Strait, S. G. 1990. Food consistency and the dental morphology of extant faunivorous mammals: implications for reconstructing diet in the fossil record. Journal of Vertebrate Paleontology 10:44A.

Strait, S. G. 1991. Molar microwear in small-bodied faunivorous mammals. Journal of Vertebrate Paleontology 11:57A.

Strait, S. G., and D. W. Krause. 1988. New Paleocene fossils from the Crazy Mountains Basin, Montana: implications for plesiadapid (Mammalia, ?Primates) systematics and biochronology. Journal of Vertebrate Paleontology 8:27A.

Thewissen, J. G. M. 1990. Evolution of Paleocene and Eocene Phenacodontidae (Mammalia, "Condylarthra"). University of Michigan Papers on Paleontology 29:1-107.

Wall, C. E. 1990. Biomechanical correlates of inferred feeding behavior in Ptilodus (Multituberculata). Journal of Vertebrate Paleontology 10:47A.

Wall, C. E., and D. W. Krause. 1992. A biomechanical analysis of the masticatory apparatus of Ptilodus (Multituberculata). Journal of Vertebrate Paleontology 12:172-187.

Watters, J. P. and D. W. Krause. 1986. Plesiadapid primates and biostratigraphy of the North American late Paleocene. American Journal of Physical Anthropology, 69:277.

Weil, A., and D. W. Krause. 2008. Chapter 2: Multituberculata. Pp. 19-38 in C. M. Janis, G. F. Gunnell, and M. D. Uhen (eds.), Evolution of Tertiary Mammals of North America. Volume 2: Small Mammals, Xenarthrans, and Marine Mammals. Cambridge University Press, Cambridge, UK.

Zack, S., T. Penkrot, D. W. Krause, and M. C. Maas. 2005. A new apheliscine "condylarth" from the Tiffanian (Late Paleocene) of Montana and Alberta, and the phylogeny of "hyopsodontids." Acta Palaeontologica Polonica 50(4):809-830.