Biodiversity Response to Climate Change in the Middle Pleistocene

Biodiversity Response to Climate Change in the Middle Pleistocene: The Porcupine Cave Fauna from Colorado

Edited by ANTHONY D. BARNOSKY
Copyright Date: 2004
Edition: 1
Pages: 407
https://www.jstor.org/stable/10.1525/j.ctt1pnm37
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  • Book Info
    Biodiversity Response to Climate Change in the Middle Pleistocene
    Book Description:

    This book chronicles the discovery and analysis of animal fossils found in one of the most important paleontological sites in the world—Porcupine Cave, located at an elevation of 9,500 feet in the Colorado Rocky Mountains. With tens of thousands of identified specimens, this site has become the key source of information on the fauna of North America's higher elevations between approximately 1 million and 600,000 years ago, a period that saw the advance and retreat of glaciers numerous times. Until now, little has been understood about how this dramatic climate change affected life during the middle Pleistocene. In addition to presenting state-of-the-art data from Porcupine Cave, this study also presents groundbreaking analysis on what the data from the site show about the evolutionary and ecological adjustments that occurred in this period, shedding light on how one of the world's most pressing environmental concerns—global climate change—can influence life on earth.

    eISBN: 978-0-520-93085-8
    Subjects: Paleontology

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. PREFACE
    (pp. ix-x)
  4. ACKNOWLEDGMENTS
    (pp. xi-xii)
    A. D. Barnosky
  5. LIST OF CHAPTER APPENDIXES
    (pp. xiii-xiv)
  6. LIST OF FIGURES
    (pp. xv-xviii)
  7. LIST OF TABLES
    (pp. xix-xx)
  8. ABBREVIATIONS AND DEFINITIONS
    (pp. xxi-xxii)
  9. PART ONE The Discovery and Distribution of Fossils

    • ONE Climate Change, Biodiversity, and Ecosystem Health: The Past as a Key to the Future
      (pp. 3-5)
      ANTHONY D. BARNOSKY

      Earth’s climate is getting warmer, and it will probably continue to do so over the coming century. The emerging consensus is that human activities are stimulating an increase in global mean temperature that will amount to 1.4–5.8° C by the year 2100 (Houghton et al., 2001), with 90% probability that the change will amount to1.7–4.9° C in the absence of climate mitigation policies (Wigley and Raper, 2001). Regionally, the changes will be even greater. Average warming for the United States is predicted to be at least 3°C and possibly as much as 6°C (National Assessment Synthesis Team, 2001)....

    • TWO The Pleistocene Fossils of Porcupine Cave, Colorado: Spatial Distribution and Taphonomic Overview
      (pp. 6-26)
      ANTHONY D. BARNOSKY, CHRISTOPHER J. BELL, ROBERT G. RAYNOLDS and LOUIS H. TAYLOR

      Porcupine Cave, arguably the richest source of information in the world on Irvingtonian-age vertebrates, sits in the Colorado Rocky Mountains at 2900 m (latitude 38°43’45” N, longitude 105°51’41” W, USGS Gribbles Park 7.5’ Quad) (figures 2.1, 2.2). Situated on the southwest rim of the highest large intermountain basin in North America, known as South Park, the cave is a three-tiered chamber comprising at least 600 m of passageways (figures 2.3–2.7). South Park itself lies nearly in the center of Colorado (figure 2.1) and hosts diverse biotic communities, some of which are unique in the lower 48 United States for...

    • THREE The Modern Environment, Flora, and Vegetation of South Park, Colorado
      (pp. 27-38)
      DAVID J. COOPER

      South Park is one of the four large intermountain basins that characterize the Rocky Mountains of Colorado (figure 3.1). The basins, typically called “parks,” have relatively level to rolling floors and are surrounded by mountain ranges with peaks reaching over 4000 m elevation. The floors of all parks have arid climates with cool summers and very cold winters.

      Three characteristics of South Park distinguish it from Colorado’s three other major intermountain basins, North Park, Middle Park, and the San Luis Valley:

      1. The floor of South Park is much higher in elevation than that of any other intermountain basin in...

    • FOUR The Historical Context of Porcupine Cave: American Indians, Spaniards, Government Surveyors, Prospectors, Ranchers, Cavers, and Paleontologists in South Park, Colorado
      (pp. 39-50)
      GERALDINE J. RASMUSSEN, KIRK BRANSON and JOHN O. McKELVY

      Porcupine Cave is located at the southern end of South Park (figure 4.1), one of four spacious, high-mountain basins in Colorado. Extending approximately 80 km north to south by 56 km east to west, the floor of the South Park basin averages approximately 2700 m in elevation. The area of the floor of the basin is approximately 2300 km² ; the entire area between the surrounding mountain peaks covers over 3600 km². South Park’s northern boundary, the Park Range, runs from Kenosha Pass west to Hoosier Pass. The Mosquito Range separates the west side of the basin from the Arkansas...

    • FIVE The Geology and Speleogenesis of Porcupine Cave
      (pp. 51-56)
      ROBERT G. RAYNOLDS

      Porcupine Cave is a relatively small, dry cave with approximately 600 m of mapped passageways. The cave entrance is located within the Lower Ordovician Manitou Dolomite on the west face of a north-south-trending ridge in southern South Park, Colorado (figures 5.1, 5.2). This chapter describes our present understanding of the formation and evolution of the cave. Although well known for its Pleistocene fauna, the cave and its environs also preserve a fascinating record of the geological events that created the sepulcher containing the fossil material. The geological story of the cave is first presented from the vantage point of the...

    • SIX Magnetostratigraphic Constraints on the Age of Pleistocene Fossiliferous Strata in Porcupine Cave’s DMNH Velvet Room Excavation
      (pp. 57-63)
      S. JULIO FRIEDMANN and ROBERT G. RAYNOLDS

      Strata from the Velvet Room in Porcupine Cave contain an abundant and diverse vertebrate fossil record that suggests biostratigraphic ages ranging from as old as 2.0 Ma ago in Mark’s Sink (DMNH 1349) to as young as 600 Ka ago in the upper levels of the DMNH Velvet Room excavation (DMNH 644). Unfortunately, few external constraints on stratal age are available. This chapter attempts to improve the confidence of age assignments of the Velvet Room strata through paleomagnetic sampling and analysis.

      The aim was to assess whether polarity reversals occur within the section, and if so how they correlate to...

    • SEVEN Age and Correlation of Key Fossil Sites in Porcupine Cave
      (pp. 64-73)
      ANTHONY D. BARNOSKY and CHRISTOPHER J. BELL

      Establishing chronologic control in early and middle Pleistocene deposits is difficult, all the more so in cave deposits. In the absence of a lucky infusion of datable volcanic ash (which Porcupine Cave so far seems to lack), dating methods typically are restricted to magnetostratigraphic associations, biostratigraphic and biochronologic correlations, amino acid racemization, electron spin resonance, and uranium series dating. The latter two techniques have not been applied to samples from Porcupine Cave, although there is still opportunity for future attempts; therefore, all chronologic control comes from the former three. The chronologic information is augmented with sedimentological information that helps sort...

    • EIGHT Biology of Wood Rats as Cave Dwellers and Collectors
      (pp. 74-81)
      ROBERT B. FINLEY JR.

      Wood rats, genusNeotoma,also widely known to speleologists as packrats, are commonly found in caves within their range, but they are primarily adapted for life outside caves. They are terrestrial rodents of the family Muridae, subfamily Sigmodontinae. The center of abundance and diversity ofNeotomais in the arid southwestern United States and Mexico. Since the diet ofNeotomaconsists mainly of foliage and fruits, they must forage outside caves for food, much of which is carried inside for use or storage. The abundant fragments of plant materials, predator scats, and owl pellets dropped on the middens and rock...

    • NINE Paleopathology and Taphonomic Modification of Mammalian Bones from Porcupine Cave
      (pp. 82-92)
      C. SUZANE WARE and ELAINE ANDERSON

      The story of Porcupine Cave would be incomplete without an understanding of health, disease, trauma, and the calamities that befell the animals whose remains were fossilized, as well as the conditions that led to the accumulation of the many bones in the cave.

      Paleopathology was first defined inFunk and Wagnall’s Standard Dictionaryin 1895 and was first referred to by physician R. W. Shufeldt in 1892 (Jarcho, 1966; Ubelaker, 1982). All of the early works defined paleopathology as the study of ancient disease. Yet it was not until widespread interest in ancient Egypt took hold, and the British anatomists...

  10. PART TWO Systematic Accounts of Taxa

    • TEN A Summary of Fossilized Species in Porcupine Cave
      (pp. 95-116)
      ANTHONY D. BARNOSKY

      This chapter has been compiled from information provided by the authors of chapters in part 2.

      At least 127 species are known as fossils from the 26 localities in Porcupine Cave (2 amphibians, 4 reptiles, 48 birds, and 73 mammals). More than 20,000 specimens have been studied in detail. The fauna includes two species that are newly recognized and extinct,Brachylagus coloradoensis(Colorado pygmy cottontail) and?Cynomys andersoni(prairie dog), and two more that suggest that new species should be formally recognized when more material becomes available,Mustelasp. A (extinct marten) andMartessp. A (extinct mustelid). Twenty-eight extant...

    • ELEVEN Synopsis of the Herpetofauna from Porcupine Cave
      (pp. 117-126)
      CHRISTOPHER J. BELL, JASON J. HEAD and JIM I. MEAD

      Although the fossil herpetofauna of Porcupine Cave is depauperate relative to the avian and mammalian faunas (both taxonomically and in total numbers of specimens and number of individuals represented), even the limited record available yields important information that complements and augments the data derived from studies of the other, more extensive vertebrate groups. The combined sample of amphibians and reptiles from all localities within the cave includes only 141 specimens representing a minimum of seven taxa. The nature of the preserved material in most cases prohibits reliable identification to species or even to genus, but given the high elevation of...

    • TWELVE The Early and Middle Pleistocene Avifauna from Porcupine Cave
      (pp. 127-140)
      STEVEN D. EMSLIE

      Porcupine Cave is a multiroom limestone cave located in the southern Rocky Mountains of Park County, central Colorado, at an elevation of 2900 m. The cave was sealed for millennia until mining operations created an entrance in the late 1800s. Paleontological excavations, initiated by the Carnegie Museum of Natural History in 1986, were continued by the Denver Museum of Nature and Science. These excavations produced a rich collection of fossil vertebrates ranging in age from the early to the middle Pleistocene. Only fossils of the Carnivora and some of the rodent fauna have been reported previously (Barnosky and Rasmussen, 1988;...

    • THIRTEEN The Carnivora from Porcupine Cave
      (pp. 141-154)
      ELAINE ANDERSON

      Anderson (1996) reported 22 species and 144 specimens of carnivores from nine areas in Porcupine Cave. Since then,Ursus americanushas been added to the faunal list, 774 specimens of carnivores have been identified, and three new areas (Mark’s Sink, Will’s Hole, and Generator Dome) have been excavated. These new sites are rich in carnivores, with 376 specimens identified so far. Remains ofTaxidea taxus, Canis latrans,andSpilogale putoriusare the most numerous and account for 570 specimens. Noteworthy finds are diagnostic teeth ofMartesspecies A*, the oldest known true marten.

      Fossils were discovered in Porcupine Cave in...

    • FOURTEEN Middle Pleistocene (Irvingtonian) Ochotona (Lagomorpha: Ochotonidae) from Porcupine Cave
      (pp. 155-163)
      JIM I. MEAD, MARGARITA ERBAJEVA and SANDRA L. SWIFT

      The lagomorph family Ochotonidae, represented today by a single living genus (Ochotona[pika]), originated in the middle Oligocene of Asia. During the late Miocene and into the Pliocene, the family flourished throughout Eurasia and migrated into North America. Beginning in the late Pliocene and throughout the Pleistocene, the group has declined, survived only by the genusOchotona(Erbajeva, 1988, 1994, 1996; Erbajeva and Tyutkova, 1997).

      Today more than 23 species ofOchotonalive in Asia, and only 2 live in North America (Hoffmann, 1993). Smith et al. (1990: 14) rightly pointed out that the “Pikas are . . . a...

    • FIFTEEN Leporidae of the DMNH Velvet Room Excavations and Mark’s Sink
      (pp. 164-168)
      COLLEEN N. BAXTER

      This chapter establishes the presence of certain leporid taxa in the DMNH Velvet Room excavations and in Mark’s Sink, which here collectively are called the DMNH Velvet Room sites. As noted in chapter 2, the taphonomy of Porcupine Cave is complex. Some rooms were carnivore dens, and in others, such as the Velvet Room, wood rats (Neotomaspp.) seem to have been the principal agent for accumulation. These animals built their nests within the room, scavenging outside for bones, twigs, and other matter suitable for incorporating into their nests. Often the bones came from raptor kills and owl pellets. Over...

    • SIXTEEN Identification of Miscellaneous Mammals from the Pit Locality: Including Soricidae, Leporidae, Geomyoidea
      (pp. 169-171)
      ANTHONY D. BARNOSKY and SAMANTHA S. B. HOPKINS

      Several taxa in the Pit are represented by very few specimens or by material that is presently impossible to identify to the species level. Nevertheless, these taxa are important in characterizing the Pleistocene fauna. This chapter summarizes the criteria that were used to identify these specimens, which include soricids (shrews), leporids (rabbits and hares), and geomyoid rodents (gophers).

      IDENTIFICATION CRITERIA FOR MISCELLANEOUS SPECIES

      Class Mammalia

      Order Insectivora

      Family Soricidae

      REFERRED MATERIAL CM 65487–65489; UCMP 165581.

      DESCRIPTION AND COMMENTS Soricidae (shrews) may be possible to identify further and are under study by Russell Graham. The general morphology of the teeth...

    • SEVENTEEN Systematics and Faunal Dynamics of Fossil Squirrels from Porcupine Cave
      (pp. 172-192)
      H. THOMAS GOODWIN

      Squirrels (Rodentia, Sciuridae) are diverse taxonomically and ecologically in the extant North American fauna (Hall, 1981). On a broad scale, the roots of sciurid diversity extend deeply in time, with fossils known as far back as the early Oligocene (e.g., Sutton and Black, 1975; Emry and Thorington, 1984), but adaptive radiation leading to modern species and species groups was probably concentrated in the late Neogene. Details of this radiation remain sketchy. It is tempting to seek causation in Plio-Pleistocene environmental fluctuations associated with glacial-interglacial variation (e.g., Vrba, 1992), but testing this hypothesis is difficult. Although the latest Pleistocene record of...

    • EIGHTEEN Fossil Wood Rats of Porcupine Cave: Tectonic or Climatic Controls?
      (pp. 193-206)
      CHARLES A. REPENNING

      The evolution and paleobiogeography of wood rats (packrats), genusNeotoma,is poorly known, not because they are uncommon as fossils, but because their teeth all look alike. Living species are identified by features that are seldom preserved in fossils. Usually all that is mentioned of the teeth is the anterointernal reentrant (or “groove,” as it is most frequently called in the description of modern forms) of the M1, the alveolar length of the tooth row, and the nature of the m3. The great majority of fossil records consist only of isolated teeth, which generally have not been considered sufficient to...

    • NINETEEN Arvicoline Rodents from Porcupine Cave: Identification, Spatial Distribution, Taxonomic Assemblages, and Biochronologic Significance
      (pp. 207-263)
      CHRISTOPHER J. BELL, CHARLES A. REPENNING and ANTHONY D. BARNOSKY

      The arvicolines are a taxonomically diverse assemblage of rodents that includes the voles, lemmings, and muskrats and their extinct kin. The importance accorded by paleontologists to arvicoline rodents stems in large part from the widespread recognition of their utility as biochronologic tools. The accelerated evolutionary rates within at least some lineages of arvicolines, their impressive capacity for rapid reproduction and dispersal, and their consequent abundance in the fossil record combine to provide temporal resolution on a finer scale than is available through the biostratigraphic study of other terrestrial faunal groups. It is for this reason that, throughout the history of...

    • TWENTY Pliocene and Pleistocene Horses from Porcupine Cave
      (pp. 264-279)
      ERIC SCOTT

      Perissodactyl fossils from Porcupine Cave are relatively rare, represented by only 56 fragments of horses (Equusspp.). Given this relative paucity of material, combined with the generally nondiagnostic nature of the remains and the confused systematics of North American Pleistocene horses, the equids from Porcupine Cave cannot be conclusively identified to species. However, in some cases the size or morphology of the recovered remains permits specific or subgeneric affinities to be suggested.

      The equid fossils consist almost exclusively of isolated broken tooth portions or of distal limb elements. Most of this material was recovered from three distinct localities: the Badger...

    • TWENTY-ONE Pleistocene (Irvingtonian) Artiodactyla from Porcupine Cave
      (pp. 280-292)
      JIM I. MEAD and LOUIS H. TAYLOR

      This chapter documents the Artiodactyla recovered from various localities within Porcupine Cave. Details of the excavations, stratigraphy, and chronology are discussed in other chapters and will not be described here except when pertinent to the artiodactyls. Table 21.1 provides a summary listing of identified artiodactyls (see also chapter 10).

      All recovered artiodactyl fossils were isolated remains; articulated or semiarticulated specimens were conspicuously absent. There is definitely a selection bias by size. Most of the elements are less than 20 cm in length, and typically less than 10 cm, whether an entire bone or a fragment. Only in one instance was...

  11. PART THREE Effect of Environmental Change on the Porcupine Cave Fauna

    • TWENTY-TWO Irvingtonian Mammals from the Badger Room in Porcupine Cave: Age, Taphonomy, Climate, and Ecology
      (pp. 295-317)
      ALAN B. SHABEL, ANTHONY D. BARNOSKY, TONYA VAN LEUVAN, FAYSAL BIBI and MATTHEW H. KAPLAN

      The Porcupine Cave locality that has received the most attention in previous publications is the Pit, a stratified sequence that provides temporally successive windows into the paleoenvironmental history of South Park (Barnosky and Rasmussen, 1988; Wood and Barnosky, 1994; Barnosky et al., 1996; Bell and Barnosky, 2000). This report synthesizes and analyzes information from the Badger Room, an unstratified, bulk-sampled deposit. Similar deposits are found throughout the cave, and each one is probably unique in its depositional history and geological age.

      The Badger Room is a small chamber (2×3 m) in the Porcupine Cave system; it is located approximately 25...

    • TWENTY-THREE Faunal Dynamics of Small Mammals through the Pit Sequence
      (pp. 318-326)
      ANTHONY D. BARNOSKY

      The Pit locality, located about 35 m inside Porcupine Cave (see figure 2.3), contains a stratified, circa-2-m-thick sequence of sediment that has yielded more than 7200 identified fossils representing more than 1500 individual animals. A minimum of 1 amphibian species, 2 reptile species, 1 bird species, and 57 mammal species have been recognized (see tables 10.9, 10.10). The fossils are spread through the top 13 of the Pit’s 15 discrete stratigraphic intervals, which are numbered 1–14, with level 8 separated into 8 and 8a (figure 23.1).

      Characteristics of the sediments in the Pit have been used to divide the...

    • TWENTY-FOUR Stable Carbon and Oxygen Isotope Analysis of Marmot Cheek Teeth from the Pit Locality
      (pp. 327-331)
      ROBERT S. FERANEC

      The Pit locality within Porcupine Cave, Park County, Colorado, spans at least two glacial-interglacial cycles, the upper of which dates to somewhere between 780 and 900 Ka (Bell and Barnosky, 2000). The deposits probably correlate with parts of oxygen isotope stages 21 and 22, or, less likely, 19 and 20 (see figure 7.5). Recent work has demonstrated that carbon and oxygen isotope values found in the tooth enamel of large mammals (EquusandCuvieronius;MacFadden, 2000) and small mammals (ThomomysandGeomys;Rogers and Wang, 2002) correlate well with the marine isotope record. This chapter reports isotopic signatures of marmot...

    • TWENTY-FIVE Assessing the Effect of Middle Pleistocene Climate Change on Marmota Populations from the Pit Locality
      (pp. 332-340)
      ANTHONY D. BARNOSKY, MATTHEW H. KAPLAN and MARC A. CARRASCO

      This chapter uses fossil dental remains of marmots (genusMarmota) to examine the effects of climate changes on populations of a taxon whose modern ecology, demography, physiology, and systematics have been extensively studied (e.g., Armitage and Downhower, 1974; Svendsen, 1974; Kilgore and Armitage, 1978; Frase and Hoffmann, 1980; Schwartz and Armitage, 1980; Webb, 1981; Barash, 1989; Melcher et al., 1990; Ferron, 1996; Kwiecinski, 1998; Schwartz et al., 1998; Steppan et al., 1999; Inouye et al., 2000; Polly, 2003). The fossil sample comes from the top seven levels of the Pit sequence (UCMP V93173). Marmot specimens from level 8 were not...

    • TWENTY-SIX Effect of Climate Change on Terrestrial Vertebrate Biodiversity
      (pp. 341-346)
      ANTHONY D. BARNOSKY

      Biodiversity means different things to different people, because measures of diversity can be applied at all levels of the biological hierarchy, ranging from genes to individuals, populations, species, genera, higher taxa, trophic and size levels, landscapes, ecosystems, and globally (Norton, 1987; Erlich, 1988; Wilson, 1988; Huston, 1994; Hughes et al., 1997; Lovejoy, 1997). The Porcupine Cave data are amenable to biodiversity analyses at several of these levels: populations, species, genera, families, orders, and trophic and size structure.

      There are many reasons to expect that climate should influence biodiversity (MacDonald and Brown, 1992; Harte and Shaw, 1995; Brown et al., 1997;...

  12. LITERATURE CITED
    (pp. 347-370)
  13. LIST OF CONTRIBUTORS
    (pp. 371-372)
  14. INDEX
    (pp. 373-385)
  15. Back Matter
    (pp. 386-386)