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Faunal and Environmental Change in the Late Miocene Siwaliks of Northern Pakistan

Published online by Cambridge University Press:  14 July 2015

John C. Barry ,
Michèle E. Morgan ,
Lawrence J. Flynn ,
David Pilbeam ,
Anna K. Behrensmeyer ,
S. Mahmood Raza ,
Imran A. Khan ,
Catherine Badgley ,
Jason Hicks  and
Jay Kelley
John C. Barry
Affiliation:
Department of Anthropology and Peabody Museum, Harvard University, Cambridge, Massachusetts 02138
Michèle E. Morgan
Affiliation:
Department of Anthropology and Peabody Museum, Harvard University, Cambridge, Massachusetts 02138
Lawrence J. Flynn
Affiliation:
Department of Anthropology and Peabody Museum, Harvard University, Cambridge, Massachusetts 02138
David Pilbeam
Affiliation:
Department of Anthropology and Peabody Museum, Harvard University, Cambridge, Massachusetts 02138
Anna K. Behrensmeyer
Affiliation:
Department of Paleobiology, MRC NHB 121, Smithsonian Institution, Washington, D.C. 20560
S. Mahmood Raza
Affiliation:
Geological Survey of Pakistan, Sariab Road, Quetta, Pakistan Catherine Badgley. Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109
Imran A. Khan
Affiliation:
Geological Survey of Pakistan, Sariab Road, Quetta, Pakistan Catherine Badgley. Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109
Catherine Badgley
Affiliation:
Denver Museum of Natural History, 2001 Colorado Boulevard, Denver, Colorado 80205
Jason Hicks
Affiliation:
Department of Oral Biology, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois 60612
Jay Kelley
Affiliation:
Department of Oral Biology, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois 60612
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Abstract

The Siwalik formations of northern Pakistan consist of deposits of ancient rivers that existed throughout the early Miocene through the late Pliocene. The formations are highly fossiliferous with a diverse array of terrestrial and freshwater vertebrates, which in combination with exceptional lateral exposure and good chronostratigraphic control allows a more detailed and temporally resolved study of the sediments and faunas than is typical in terrestrial deposits. Consequently the Siwaliks provide an opportunity to document temporal differences in species richness, turnover, and ecological structure in a terrestrial setting, and to investigate how such differences are related to changes in the fluvial system, vegetation, and climate. Here we focus on the interval between 10.7 and 5.7 Ma, a time of significant local tectonic and global climatic change. It is also the interval with the best temporal calibration of Siwalik faunas and most comprehensive data on species occurrences. A methodological focus of this paper is on controlling sampling biases that confound biological and ecological signals. Such biases include uneven sampling through time, differential preservation of larger animals and more durable skeletal elements, errors in age-dating imposed by uncertainties in correlation and paleomagnetic timescale calibrations, and uneven taxonomic treatment across groups. We attempt to control for them primarily by using a relative-abundance model to estimate limits for the first and last appearances from the occurrence data. This model also incorporates uncertainties in age estimates. Because of sampling limitations inherent in the terrestrial fossil record, our 100-Kyr temporal resolution may approach the finest possible level of resolution for studies of vertebrate faunal changes over periods of millions of years.

Approximately 40,000 specimens from surface and screenwash collections made at 555 localities form the basis of our study. Sixty percent of the localities have maximum and minimum age estimates differing by 100 Kyr or less, 82% by 200 Kyr or less. The fossils represent 115 mammalian species or lineages of ten orders: Insectivora, Scandentia, Primates, Tubulidentata, Proboscidea, Pholidota, Lagomorpha, Perissodactyla, Artiodactyla, and Rodentia. Important taxa omitted from this study include Carnivora, Elephantoidea, and Rhinocerotidae. Because different collecting methods were used for large and small species, they are treated separately in analyses. Small species include insectivores, tree shrews, rodents, lagomorphs, and small primates. They generally weigh less than 5 kg.

The sediments of the study interval were deposited by coexisting fluvial systems, with the larger emergent Nagri system being displaced between 10.1 and 9.0 Ma by an interfan Dhok Pathan system. In comparison to Nagri floodplains, Dhok Pathan floodplains were less well drained, with smaller rivers having more seasonally variable flow and more frequent avulsions. Paleosol sequences indicate reorganization of topography and drainage accompanying a transition to a more seasonal climate. A few paleosols may have formed under waterlogged, grassy woodlands, but most formed under drier conditions and more closed vegetation.

The oxygen isotopic record also indicates significant change in the patterns of precipitation beginning at 9.2 Ma, in what may have been a shift to a drier and more seasonal climate. The carbon isotope record demonstrates that after 8.1 Ma significant amounts of C4 grasses began to appear and that by 6.8 Ma floodplain habitats included extensive C4 grasslands. Plant communities with predominantly C3 plants were greatly diminished after 7.0 Ma, and those with predominantly C4 plants, which would have been open woodlands or grassy woodlands, appeared as early as 7.4 Ma.

Inferred first and last appearances show a constant, low level of faunal turnover throughout the interval 10.7–5.7-Ma, with three short periods of elevated turnover at 10.3, 7.8, and 7.3–7.0 Ma. The three pulses account for nearly 44% of all turnover. Throughout the late Miocene, species richness declined steadily, and diversity and richness indices together with data on body size imply that community ecological structure changed abruptly just after 10 Ma, and then again at 7.8 Ma. Between 10 and 7.8 Ma the large-mammal assemblages were strongly dominated by equids, with more balanced faunas before and after. The pattern of appearance and disappearance is selective with respect to inferred habits of the animals. Species appearing after 9.0 Ma are grazers or typical of more open habitats, whereas many species that disappear can be linked to more closed vegetation. We presume exceptions to this pattern were animals of the mixed C3/C4 communities or the wetter parts of the floodplain that did not persist into the latest Miocene. The pace of extinction accelerates once there is C4 vegetation on the floodplain.

The 10.3 Ma event primarily comprises disappearance of taxa that were both common and of long duration. The event does not correlate to any obvious local environmental or climatic event, and the pattern of species disappearance and appearance suggests that biotic interactions may have been more important than environmental change.

The 7.8 Ma event is characterized solely by appearances, and that at 7.3 Ma by a combination of appearances and disappearances. These two latest Miocene events include more taxa that were shorter ranging and less common, a difference of mode that developed between approximately 9.0 and 8.5 Ma when many short-ranging and rare species began to make appearances. Both events also show a close temporal correlation to changes in floodplain deposition and vegetation. The 7.8 Ma event follows the widespread appearance of C4 vegetation and is coincident with the shift from equid-dominated to more evenly balanced large-mammal assemblages. The 7.3 to 7.0 Ma event starts with the first occurrence of C4-dominated floras and ends with the last occurrence of C3-dominated vegetation. Absence of a consistent relationship between depositional facies and the composition of faunal assemblages leads us to reject fluvial system dynamics as a major cause of faunal change. The close correlation of latest Miocene species turnover and ecological change to expansion of C4 plants on the floodplain, in association with oxygen isotopic and sedimentological evidence for increasingly drier and more seasonal climates, causes us to favor explanations based on climatic change for both latest Miocene pulses.

The Siwalik record supports neither “coordinated stasis” nor “turnover pulse” evolutionary models. The brief, irregularly spaced pulses of high turnover are characteristic of both the stasis and pulse models, but the high level of background turnover that eliminates 65–70% of the initial species shows there is no stasis in the Siwalik record. In addition, the steadily declining species richness and abrupt, uncoordinated changes in diversity do not fit either model.

Type
Research Article
Information
Paleobiology , Volume 28 , Issue S2 , Spring 2002 , pp. 1 - 71
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Alroy, J. 1996. Constant extinction, constrained diversification, and uncoordinated stasis in North American mammals. Pp. 285–311in Ivany, and Schopf, 1996.Google Scholar
Amano, K., and Taira, A. 1992. Two-phase uplift of Higher Himalayas since 17 Ma. Geology 20: 391–394.2.3.CO;2>CrossRefGoogle Scholar
Anonymous. 1985. Atlas of Pakistan. Survey of Pakistan, Rawalpindi.Google Scholar
Badgley, C. 1986a. Counting individuals in mammalian fossil assemblages from fluvial environments. Palaios 1: 328–338.CrossRefGoogle Scholar
Badgley, C. 1986b. Taphonomy of mammalian fossil remains from Siwalik rocks of Pakistan. Paleobiology 12: 119–142.CrossRefGoogle Scholar
Badgley, C. 1990. A statistical assessment of last appearances in the Eocene record of mammals. In Bown, T. M. and Rose, K. D., eds. Dawn of the age of mammals in the northern part of the Rocky Mountain interior, North America. Geological Society of America Special Paper 243: 153–167.CrossRefGoogle Scholar
Badgley, C. E., and Behrensmeyer, A. K. 1980. Paleoecology of Middle Siwalik sediments and faunas, northern Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology 30: 133–155.CrossRefGoogle Scholar
Badgley, C. E., and Behrensmeyer, A. K. 1995a. Long records of continental ecosystems. Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 115.CrossRefGoogle Scholar
Badgley, C. E., and Behrensmeyer, A. K. 1995b. Preservational, paleoecological and evolutionary patterns in the Paleogene of Wyoming-Montana and the Neogene of Pakistan. Pp. 319–340in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Badgley, C. E., and Gingerich, P. D. 1988. Sampling and faunal turnover in Early Eocene mammals. Palaeogeography, Palaeoclimatology, Palaeoecology 63: 141–157.CrossRefGoogle Scholar
Badgley, C. E., and Tauxe, L. 1990. Paleomagnetic stratigraphy and time in sediments: studies in alluvial Siwalik rocks of Pakistan. Journal of Geology 98: 457–477.CrossRefGoogle Scholar
Badgley, C., Tauxe, L., and Bookstein, F. L. 1986. Estimating the error of age interpolation in sedimentary rocks. Nature 319: 139–141.CrossRefGoogle Scholar
Badgley, C., Bartels, W. S., Morgan, M. E., Behrensmeyer, A. K., and Raza, S. M. 1995. Taphonomy of vertebrate assemblages from the Paleogene of northwestern Wyoming and the Neogene of northern Pakistan. Pp. 157–180in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Barndt, J. 1977. The magnetic polarity stratigraphy of the type locality of the Dhok Pathan Faunal Stage, Potwar Plateau, Pakistan. . Dartmouth College, Hanover, N.H.Google Scholar
Barndt, J., Johnson, N. M., Johnson, G. D., Opdyke, N. D., Lindsay, E. H., Pilbeam, D., and Tahirkheli, R. A. H. 1978. The magnetic polarity stratigraphy and age of the Siwalik Group near Dhok Pathan Village, Potwar Plateau, Pakistan. Earth and Planetary Science Letters 41: 355–364.CrossRefGoogle Scholar
Barry, J. C. 1984. A summary of data file structure and data standards for the Yale-Geological Survey of Pakistan Project-Siwalik fossil collections. Pp. 71–74in Shah, and Pilbeam, 1984.Google Scholar
Barry, J. C. 1995. Faunal turnover and diversity in the terrestrial Neogene of Pakistan. Pp. 115–134in Vrba, E. S., Denton, G. H., Partridge, T. C., and Burckle, L. H., eds. Paleoclimate and evolution, with emphasis on human origins. Yale University Press, New Haven, Conn.Google Scholar
Barry, J. C., Behrensmeyer, A. K., and Monaghan, M. 1980. A geologic and biostratigraphic framework for Miocene sediments near Khaur Village, northern Pakistan. Postilla 183: 1–19.Google Scholar
Barry, J. C., Johnson, N. M., Raza, S. M., and Jacobs, L. L. 1985. Neogene mammalian faunal change in southern Asia: correlations with climatic, tectonic and eustatic events. Geology 13: 637–640.2.0.CO;2>CrossRefGoogle Scholar
Barry, J. C., Flynn, L. J., and Pilbeam, D. R. 1990. Faunal diversity and turnover in a Miocene terrestrial sequence. Pp. 381–421in Ross, R. M. and Allmon, W. D., eds. Causes of evolution: a paleontological perspective. University of Chicago Press, Chicago.Google Scholar
Barry, J. C., Morgan, M. E., Winkler, A. J., Flynn, L. J., Lindsay, E. H., Jacobs, L. L., and Pilbeam, D. 1991. Faunal interchange and Miocene terrestrial vertebrates of southern Asia. Paleobiology 17: 231–245.CrossRefGoogle Scholar
Barry, J. C., Morgan, M. E., Flynn, L. J., Pilbeam, D., Jacobs, L. L., Lindsay, E. H., Raza, S. M., and Solounias, N. 1995. Patterns of faunal turnover and diversity in the Neogene Siwaliks of northern Pakistan. Pp. 209–226in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Beck, R. A., and Burbank, D. W. 1990. Continental-scale diversion of rivers: a control of alluvial stratigraphy. Geological Society of America Abstracts with Programs 22: 238.Google Scholar
Behrensmeyer, A. K. 1982. Time resolution in fluvial vertebrate assemblages. Paleobiology 8: 211–227.CrossRefGoogle Scholar
Behrensmeyer, A. K. 1987. Miocene fluvial facies and vertebrate taphonomy in northern Pakistan. In Ethridge, F. G., Flores, R. M., and Harvey, M. D., eds. Recent developments in fluvial sedimentology. Society for Economic Paleontology and Mineralogy Special Publication 39: 169–176.Google Scholar
Behrensmeyer, A. K., and Raza, M. 1984. A procedure for documenting fossil localities in Siwalik deposits of northern Pakistan. Pp. 65–69in Shah, and Pilbeam, 1984.Google Scholar
Behrensmeyer, A. K., and Tauxe, L. 1982. Isochronous fluvial systems in Miocene deposits of northern Pakistan. Sedimentology 29: 331–352.CrossRefGoogle Scholar
Behrensmeyer, A. K., Willis, B. J., and Quade, J. 1995. Flood-plains and paleosols of Pakistan Neogene and Wyoming Paleogene deposits: implications for the taphonomy and paleoecology of faunas. Pp. 37–60in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Behrensmeyer, A. K., Todd, N. E., Potts, R., and McBrinn, G. E. 1997. Late Pliocene faunal turnover in the Turkana Basin, Kenya and Ethiopia. Science 278: 1589–1594.CrossRefGoogle ScholarPubMed
Berggren, W. A., Kent, D. V., Flynn, J. J., and Van Couvering, J. A. 1985. Cenozoic geochronology. Geological Society of America Bulletin 96: 1407–1418.2.0.CO;2>CrossRefGoogle Scholar
Brett, C. E., Ivany, L. C., and Schopf, K. M. 1996. Coordinated stasis: an overview. Pp. 1–20in Ivany, and Schopf, 1996.Google Scholar
Burbank, D. W., and Beck, R. A. 1991. Models of aggradation versus progradation in the Himalayan foreland. Geologische Rundschau 80: 623–638.CrossRefGoogle Scholar
Burbank, D. W., Derry, L. A., and France-Lanord, C. 1993. Reduced Himalayan sediment production 8 Myr ago despite an intensified monsoon. Nature 364: 48–50.CrossRefGoogle Scholar
Cande, S. C., and Kent, D. V. 1992. A new geomagnetic polarity timescale for the Late Cretaceous and Cenozoic. Journal of Geophysical Research 97B: 13917–13951.CrossRefGoogle Scholar
Cande, S. C., and Kent, D. V. 1995. Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic. Journal of Geophysical Research 100B: 6093–6095.CrossRefGoogle Scholar
Cerling, T. E., Quade, J., Wang, Y., and Bowman, J. R. 1989. Carbon isotopes in soils and palaeosols as ecology and palaeoecology indicators. Nature 341: 138–139.CrossRefGoogle Scholar
Cerling, T. E., Wang, Y., and Quade, J. 1993. Expansion of C4 ecosystems as an indicator of global ecological change in the late Miocene. Nature 361: 344–345.CrossRefGoogle Scholar
Cerling, T. E., Harris, J. M., MacFadden, B. J., Leakey, M. G., Quade, J., Eisenmann, V., and Ehleringer, J. R. 1997. Global vegetation change through the Miocene/Pliocene boundary. Nature 389: 153–158.CrossRefGoogle Scholar
Cerling, T. E., Harris, J. M., MacFadden, B. J., Leakey, M. G., Quade, J., Eisenmann, V., and Ehleringer, J. R. 1998. Reply to: Miocene/Pliocene shift: one step or several? Nature 393: 127.CrossRefGoogle Scholar
Cheema, M. R., Raza, S. M., and Ahmed, H. 1977. Cainozoic. In Shah, S. M. I., ed. Stratigraphy of Pakistan. Memoirs of the Geological Survey of Pakistan 12: 56–98.Google Scholar
Coleman, M., and Hodges, K. 1995. Evidence for Tibetan Plateau uplift before 14 Myr ago from a new minimum age for east-west extension. Nature 374: 49–52.CrossRefGoogle Scholar
Copeland, P. 1992. Two-phase uplift of Higher Himalayas since 17 Ma: Comment. Geology 21: 188–189.2.3.CO;2>CrossRefGoogle Scholar
Ehrenfeld, S., and Littauer, S. B. 1964. Introduction to statistical method. McGraw-Hill, New York.Google Scholar
Filippelli, G. M. 1997. Intensification of the Asian monsoon and a chemical weathering event in the late Miocene–early Pliocene: implications for late Neogene climate change. Geology 25: 27–30.2.3.CO;2>CrossRefGoogle Scholar
Flynn, L. J. 1982. Systematic revision of Siwalik Rhizomyidae (Rodentia). Geobios 15: 327–389.CrossRefGoogle Scholar
Flynn, L. J., Pilbeam, D., Jacobs, L. L., Barry, J. C., Behrensmeyer, A. K., and Kappelman, J. W. 1990. The Siwaliks of Pakistan: time and faunas in a Miocene terrestrial setting. Journal of Geology 98: 589–604.CrossRefGoogle Scholar
Flynn, L. J., Barry, J. C., Morgan, M. E., Pilbeam, D., Jacobs, L. L., and Lindsay, E. H. 1995. Neogene Siwalik mammalian lineages: species longevities, rates of change, and modes of speciation. Pp. 249–264in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Flynn, L. J., Downs, W., Morgan, M. E., Barry, J. C., and Pilbeam, D. 1998. High Miocene species richness in the Siwaliks of Pakistan. In Tomida, Y., Flynn, L. J., and Jacobs, L. L., eds. Advances in vertebrate paleontology and geochronology. National Science Museum Monographs 14: 167–180. National Science Museum, Tokyo.Google Scholar
France-Lanord, C., and Derry, L. A. 1994. δ13C of organic carbon in the Bengal Fan: source evolution and transport of C3 and C4 plant carbon to marine sediments. Geochimica et Cosmochimica Acta 58: 4809–4814.CrossRefGoogle Scholar
Gunnell, G. F., Morgan, M. E., Maas, M. C., and Gingerich, P. D. 1995. Comparative paleoecology of Paleogene and Neogene mammalian faunas: trophic structure and composition. Pp. 265–286in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Harrison, T. M., Copeland, P., Hall, S. A., Quade, J., Burner, S., Ojha, T. P., and Kidd, W. S. F. 1993. Isotopic preservation of Himalayan/Tibetan uplift, denudation, and climatic histories of two molasse deposits. Journal of Geology 101: 157–175.CrossRefGoogle Scholar
Ivany, L. C., and Schopf, K. M., eds. 1996. New perspectives on faunal stability in the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 127.Google Scholar
Johnson, N. M., and McGee, V. E. 1983. Magnetic polarity stratigraphy: stochastic properties of data, sampling problems, and the evaluation of interpretations. Journal of Geophysical Research 88B: 1213–1221.CrossRefGoogle Scholar
Johnson, N. M., Opdyke, N. D., Johnson, G. D., Lindsay, E. H., and Tahirkheli, R. A. K. 1982. Magnetic polarity stratigraphy and ages of Siwalik group rocks of the Potwar Plateau, Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology 37: 17–42.CrossRefGoogle Scholar
Johnson, N. M., Stix, J., Tauxe, L., Cerveny, P. F., and Tahirkheli, R. A. K. 1985. Paleomagnetic chronology, fluvial processes and tectonic implications of the Siwalik deposits near Chinji Village, Pakistan. Journal of Geology 93: 27–40.CrossRefGoogle Scholar
Johnson, N. M., Sheikh, K. A., Dawson-Saunders, E., and McRae, L. E. 1988. The use of magnetic-reversal time lines in stratigraphic analysis: a case study in measuring variability in sedimentation rates. Pp. 189–200in Kleinspehn, K. L. and Paola, C., eds. New perspectives in basin analysis. Springer, New York.CrossRefGoogle Scholar
Kappelman, J., Kelley, J., Pilbeam, D., Sheikh, K. A., Ward, S., Anwar, M., Barry, J. C., Brown, B., Hake, P., Johnson, N. M., Raza, S. M., and Shah, S. M. I. 1991. The earliest occurrence of Sivapithecus from the Middle Miocene Chinji Formation of Pakistan. Journal of Human Evolution 21: 61–73.CrossRefGoogle Scholar
Koch, C. F. 1987. Prediction of sample size effects on the measured temporal and geographic distribution patterns of species. Paleobiology 13: 100–107.CrossRefGoogle Scholar
Köhler, M., Moyà-Solà, S., and Agustí, J. 1998. Miocene/Pliocene shift: one step or several? Nature 393: 126.CrossRefGoogle Scholar
Kroon, D., Steens, T., and Troelstra, S. R. 1991. Onset of monsoonal related upwelling in the western Arabian Sea as revealed by planktonic foraminifers. Proceedings of the Ocean Drilling Program, Scientific Results 117: 257–263.Google Scholar
Krynine, P. D. 1937. Petrography and genesis of the Siwalik Series. American Journal of Science 34: 422–446.CrossRefGoogle Scholar
Maas, M. C., Anthony, M. R. L., Gingerich, P. D., Gunnell, G. F., and Krause, D. W. 1995. Mammalian generic diversity and turnover in the Late Paleocene and Early Eocene of the Bighorn and Crazy Mountains Basins, Wyoming and Montana (USA). Pp. 181–207in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Magurran, A. E. 1988. Ecological diversity and its measurement. Princeton University Press, Princeton, N.J.CrossRefGoogle Scholar
Mankinen, E. A., and Dalrymple, G. B. 1979. Revised geomagnetic polarity time scale for the interval 0–5 m.y. B.P. Journal of Geophysical Research 84B: 615–626.CrossRefGoogle Scholar
Marshall, C. R. 1994. Confidence intervals on stratigraphic ranges: partial relaxation of the assumption of randomly distributed fossil horizons. Paleobiology 20: 459–469.CrossRefGoogle Scholar
Marshall, C. R. 1997. Confidence intervals on stratigraphic ranges with nonrandom distributions of fossil horizons. Paleobiology 23: 165–173.CrossRefGoogle Scholar
McKinney, M. L., Lockwood, J. L., and Frederick, D. R. 1996. Rare species and scale-dependence in ecosystem studies. Pp. 191–207in Ivany, and Schopf, 1996.Google Scholar
McMurtry, M. G. 1980. Facies changes and time relationships along a sandstone stratum, Middle Siwalik Group, Potwar Plateau, Pakistan. . Dartmouth College, Hanover, N.H.Google Scholar
McRae, L. E. 1990. Paleomagnetic isochrons, unsteadiness, and non-uniformity of sedimentation in Miocene fluvial strata of the Siwalik Group, northern Pakistan. Journal of Geology 98: 433–456.CrossRefGoogle Scholar
Meigs, J. J., Burbank, D. W., and Beck, R. A. 1995. Middle-Late Miocene (>10 Ma) formation of the Main Boundary thrust in the western Himalayan. Geology 23: 423–426.2.3.CO;2>CrossRefGoogle Scholar
Molnar, P., England, P., and Martinod, J. 1993. Mantle dynamics, uplift of the Tibetan Plateau, and the Indian monsoon. Reviews of Geophysics 31: 357–396.CrossRefGoogle Scholar
Morgan, M. E., Kingston, J. D., and Marino, B. D. 1994. Carbon isotopic evidence for the emergence of C4 plants in the Neogene from Pakistan and Kenya. Nature 367: 162–165.CrossRefGoogle Scholar
Morgan, M. E., Badgley, C., Gunnell, G. F., Gingerich, P. D., Kappelman, J. W., and Maas, M. C. 1995. Comparative paleoecology of Paleogene and Neogene mammalian faunas: body-size structure. Pp. 265–286in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Olson, E. C. 1980. Taphonomy: its history and role in community evolution. Pp. 5–19in Behrensmeyer, A. K. and Hill, A. P., eds. Fossils in the making: vertebrate taphonomy and paleoecology. University of Chicago Press, Chicago.Google Scholar
Opdyke, N. D., Lindsay, E. H., Johnson, G. D., Johnson, N. M., Tahirkheli, R. A. K., and Mirza, M. A. 1979. Magnetic polarity stratigraphy and vertebrate paleontology of the Upper Siwalik Subgroup of northern Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology 27: 1–34.CrossRefGoogle Scholar
Pagani, M., Freeman, K. H., and Arthur, M. A. 1999. Late Miocene atmospheric CO2 concentrations and the expansion of C4 grasses. Science 285: 876–879.CrossRefGoogle Scholar
Pilbeam, D., Morgan, M., Barry, J. C., and Flynn, L. 1996. European MN units and the Siwalik faunal sequence of Pakistan. Pp. 96–105in Bernor, R. L., Fahlbusch, V., and Mittmann, H.-W., eds. The evolution of western Eurasian Neogene mammal faunas. Columbia University Press, New York.Google Scholar
Prell, W. L., and Kutzbach, J. E. 1992. Sensitivity of the Indian monsoon to forcing parameters and implications for its evolution. Nature 360: 647–652.CrossRefGoogle Scholar
Prothero, D. R. 1998. Does climate control mammalian evolution? A test of the turnover pulse hypothesis. Journal of Vertebrate Paleontology 18: 70A–71A.Google Scholar
Prothero, D. R. 1999. Does climate change drive mammalian evolution? GSA Today 9(9): 1–7.Google Scholar
Quade, J., and Cerling, T. E. 1995. Expansion of C4 grasses in the Late Miocene of northern Pakistan: evidence from stable isotopes in paleosols. Pp. 91–116in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Quade, J., Cerling, T. E., and Bowman, J. R. 1989. Development of Asian monsoon revealed by marked ecological shift during the latest Miocene in northern Pakistan. Nature 342: 163–166.CrossRefGoogle Scholar
Quade, J., Cerling, T. E., Barry, J., Morgan, M. E., Pilbeam, D. R., Chivas, A. R., Lee-Thorp, J. A., and Van der Merwe, N. J. 1992. A 16-Ma record of paleodiet using carbon and oxygen isotopes in fossil teeth from Pakistan. Chemical Geology (Isotope Geoscience Section) 94: 182–192.CrossRefGoogle Scholar
Quade, J., Cater, J. M. L., Ojha, T. P., Adam, J., and Harrison, T. M. 1995. Late Miocene environmental change in Nepal and the northern Indian subcontinent: stable isotopic evidence from paleosols. Geological Society of America Bulletin 107: 1381–1397.2.3.CO;2>CrossRefGoogle Scholar
Ramstein, G., Fluteau, F., Besse, J., and Joussaume, S. 1997. Effect of orogeny, plate motion and land-sea distribution on Eurasian climate change over the past 30 million years. Nature 386: 788–795.CrossRefGoogle Scholar
Raymo, M. E., and Ruddiman, W. F. 1992. Tectonic forcing of late Cenozoic climate. Nature 359: 117–122.CrossRefGoogle Scholar
Rea, D. K. 1992. Delivery of Himalayan sediment to the northern Indian Ocean and its relation to global climate, sea level, uplift, and seawater strontium. American Geophysical Union Geophysical Monograph 70: 387–402.Google Scholar
Retallack, G. J. 1991. Miocene paleosols and ape habitats of Pakistan and Kenya. Oxford University Press, Oxford.Google Scholar
Sadler, P. M. 1981. Sediment accumulation rates and the completeness of stratigraphic sections. Journal of Geology 89: 569–584.CrossRefGoogle Scholar
Shah, S. M. I., and Pilbeam, D., eds. 1984. Contribution to the Geology of Siwaliks of Pakistan. Memoirs of the Geological Survey of Pakistan No. XI. Geological Survey of Pakistan, Quetta.Google Scholar
Shaw, A. B. 1964. Time in stratigraphy. McGraw-Hill, New York.Google Scholar
Shukla, J. 1987. Interannual variability of monsoons. Pp. 399–463in Fein, J. S. and Stephens, P. L., eds. Monsoons. Wiley, New York.Google Scholar
Stern, L. A., Johnson, G. D., and Chamberlain, C. P. 1994. Carbon isotope signature of environmental change found in fossil ratite eggshells from a South Asian Neogene sequence. Geology 22: 419–422.2.3.CO;2>CrossRefGoogle Scholar
Stix, J. 1982. Stratigraphy of the Kamlial Formation near Chinji Village, northern Pakistan. . Dartmouth College, Hanover, N.H.Google Scholar
Strauss, D., and Sadler, P. M. 1989. Classical confidence intervals and Bayesian probability estimates for ends of local taxon ranges. Mathematical Geology 21: 411–427.CrossRefGoogle Scholar
Tauxe, L., and Badgley, C. 1988. Stratigraphy and remanence acquisition of a paleomagnetic reversal in alluvial Siwalik rocks of Pakistan. Sedimentology 35: 697–715.CrossRefGoogle Scholar
Tauxe, L., and Opdyke, N. D. 1982. A time framework based on magnetostratigraphy for the Siwalik sediments of the Khaur area, northern Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology 37: 43–61.CrossRefGoogle Scholar
Turner, S., Hawkesworth, C., Liu, J., Rogers, N., Kelley, S., and van Calsteren, P. 1993. Timing of Tibetan uplift constrained by analysis of volcanic rocks. Nature 364: 50–54.CrossRefGoogle Scholar
Van Valen, L. 1973. A new evolutionary law. Evolutionary Theory 1: 1–30.Google Scholar
Vrba, E. S. 1980. Evolution, species, and fossils: how does life evolve? South African Journal of Science 76: 61–84.Google Scholar
Vrba, E. S. 1985. Environment and evolution: alternative causes of the temporal distribution of evolutionary events. South African Journal of Science 81: 229–236.Google Scholar
Vrba, E. S. 1995. On the connections between paleoclimate and evolution. Pp. 24–45in Vrba, E. S., Denton, G. H., Partridge, T. C., and Burckle, L. H., eds. Paleoclimate and evolution, with emphasis on human origins. Yale University Press, New Haven, Conn.Google Scholar
Webb, S. D. 1984. On two kinds of rapid faunal turnover. Pp. 417–436in Berggren, W. A. and van Couvering, J. A., eds. Catastrophes and earth history: the new uniformitarianism. Princeton University Press, Princeton, N.J.CrossRefGoogle Scholar
Willis, B. J. 1993a. Ancient river systems in the Himalayan foredeep, Chinji Village area, northern Pakistan. Sedimentary Geology 88: 1–76.CrossRefGoogle Scholar
Willis, B. J. 1993b. Evolution of Miocene fluvial systems in the Himalayan foredeep through a two-kilometer-thick succession in northern Pakistan. Sedimentary Geology 88: 77–121.CrossRefGoogle Scholar
Willis, B. J., and Behrensmeyer, A. K. 1994. Architecture of Miocene overbank deposits in northern Pakistan. Journal of Sedimentary Research B 64: 60–67.Google Scholar
Willis, B. J., and Behrensmeyer, A. K. 1995. Fluvial systems in the Siwalik Miocene and Wyoming Paleogene. Pp. 13–35in Badgley, and Behrensmeyer, 1995a.CrossRefGoogle Scholar
Zaleha, M. J. 1997a. Fluvial and lacustrine palaeoenvironments of the Miocene Siwalik Group, Khaur area, northern Pakistan. Sedimentology 44: 349–368.CrossRefGoogle Scholar
Zaleha, M. J. 1997b. Intra- and extrabasinal controls on fluvial deposition in the Miocene Indo-Gangetic foreland basin, northern Pakistan. Sedimentology 44: 369–390.CrossRefGoogle Scholar