Plants Invade the Land

Plants Invade the Land: Evolutionary and Environmental Perspectives

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  • Book Info
    Plants Invade the Land
    Book Description:

    What do we now know about the origins of plants on land, from an evolutionary and an environmental perspective? The essays in this collection present a synthesis of our present state of knowledge, integrating current information in paleobotany with physical, chemical, and geological data.

    eISBN: 978-0-231-50496-6
    Subjects: Paleontology, Environmental Science, Botany & Plant Sciences, Ecology & Evolutionary Biology

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
    (pp. ix-xii)
  4. 1 Introduction
    (pp. 1-2)
    Patricia G. Gensel

    The invasion of the land by organisms is one of the major events in the evolution of life, permanently altering the conditions on Earth and essentially resulting in the diversification of the kingdom Plantae as presently defined. As a result of recent research, remains of terrestrial plants occur as early as basal Ordovician. The record of terrestrial animals now dates from the Middle–Late Silurian, and an earlier timing is possible. It has been postulated for some time that fungi and other types of organisms also may have inhabited the land since at least 450 million years ago. That terrestrial...

  5. 2 Embryophytes on Land: The Ordovician to Lochkovian (Lower Devonian) Record
    (pp. 3-28)
    Dianne Edwards and Charles Wellman

    This chapter is primarily concerned with the documentation of the record of land plants from their earliest occurrences in the Ordovician to the end of the Lochkovian in the Lower Devonian. It covers the initial radiation of the embryophytes in the Ordovician; the emergence of tracheophytes, including the lycophytes, in the Silurian; the proliferation of axial plants with terminal sporangia around the Silurian–Devonian boundary; and, at the end of the Lochkovian, the first major radiation of the zosterophylls. The record remains a very patchy one and makes any conclusions on phylogenetic relationships, evolutionary and migration rates, and global distribution...

  6. 3 Rustling in the Undergrowth: Animals in Early Terrestrial Ecosystems
    (pp. 29-51)
    William A. Shear and Paul A. Selden

    The study of animals in early terrestrial ecosystems as represented in the fossil record, long a neglected field, has undergone a striking renaissance in the past decade and a half. Spurred on at first by the recognition of unconventional kinds of fossil remains (Shear et al. 1984), we have now seen the exploration of informative new sites ( Jeram et al. 1990; Shear et al. 1996), the development of new trace fossil evidence (e.g., Retallack and Feakes 1987; Banks and Colthart 1993; Trewin and McNamara 1995; Wright et al. 1995), attempts to integrate the animal evidence with that of plants...

  7. 4 New Data on Nothia aphylla Lyon 1964 ex El-Saadawy et Lacey 1979, a Poorly Known Plant from the Lower Devonian Rhynie Chert
    (pp. 52-82)
    Hans Kerp, Hagen Hass and Volker Mosbrugger

    The Lower Devonian chert from the Rhynie locality, Aberdeenshire, Scotland, has become famous as one of the finest sources of information on early life on land, for the flora as well as for the fauna (Trewin 1994; Cleal and Thomas 1995). Some of the plants originally described by Kidston and Lang in their classical monograph series (1917, 1920a,b, 1921a,b) are the best known and most detailed fossil land plants [e.g., Aglaophyton major (D. S. Edwards 1986; Remy and Hass 1996)]. Other taxa remain very incompletely known. These include Nothia aphylla, a taxon for which only aerial axes, sporangia, and small...

  8. 5 Morphology of Above- and Below-Ground Structures in Early Devonian (Pragian–Emsian) Plants
    (pp. 83-102)
    Patricia G. Gensel, Michele E. Kotyk and James F. Basinger

    The Pragian–Emsian of the Lower Devonian is distinguished by plants that were much larger in axial diameter and height, were more complex in branching pattern, sporangial morphology, and internal histology, and exhibited greater variation in morphology and arrangement of reproductive organs than those of earlier ages. Vascular plant diversity, as measured by number of genera, peaks in the Emsian (Knoll et al. 1984; Niklas et al. 1983, 1985). This paper documents and considers certain aspects of overall growth form, architecture, and size of shoot and root systems among Lower Devonian (Pragian–Emsian) plants. Aerial (shoot) systems are reviewed to...

  9. 6 The Posongchong Floral Assemblages of Southeastern Yunnan, China—Diversity and Disparity in Early Devonian Plant Assemblages
    (pp. 103-119)
    Hao Shou-Gang and Patricia G. Gensel

    Most knowledge about the morphology, comparative level of complexity, evolutionary trends, interrelationships, and diversity of early land plants has been derived from fossil plants of the Laurussian paleocontinents (Laurentia and Baltica—i.e., present-day central and northern Europe, Greenland, and North America) because of the long history of research in these areas (Banks 1968; Chaloner and Sheerin 1979; Edwards 1980, 1990; Gensel and Andrews 1984).

    A considerable amount of new information about the morphology and diversity of early land plants has accrued since Banks (1968, 1975c) divided the “psilophytes“ into three new subdivisions: the Rhyniophytina, the Zosterophyllophytina, and the Trimerophytina, mainly...

  10. 7 The Middle Devonian Flora Revisited
    (pp. 120-139)
    Christopher M. Berry and Muriel Fairon-Demaret

    The Middle Devonian (Eifelian, Givetian) flora usually receives little attention in syntheses of Devonian plants when compared with the recent intensity of studies in the Early and Late. In this paper, we shall try to give an overview of the floras of this age, presenting modern concepts of the plants involved and their ecological associations.

    We include in this study reports from the Eifelian up to the lowermost beds of the Frasnian (earliest Late Devonian). In North America, whence probably the most complete succession of Middle Devonian floras is presently known, many elements of the Middle Devonian flora continue into...

  11. 8 The Origin, Morphology, and Ecophysiology of Early Embryophytes: Neontological and Paleontological Perspectives
    (pp. 140-158)
    Linda E. Graham and Jane Gray

    Most chapters in this book recount paleontological or paleochemical evidence bearing on tracheophyte diversification and concomitant changes in atmospheric chemistry and climate. This chapter is focused on the evolutionary transition from aquatic algal ancestors to pretracheophyte terrestrial embryophytes, the possible morphological and physiological characteristics of earliest land-adapted embryophytes, and the environment that may have led to terrestrialization. Conclusions or hypotheses are deduced from neontological evidence (including molecular phylogenetics and physiological information), and comparison between microfossil remains linked to earliest (Ordovician) pretracheophyte land plants and the cells and tissues of extant seedless plants and algae.

    Neontological and paleontological evidence is consistent...

  12. 9 Biological Roles for Phenolic Compounds in the Evolution of Early Land Plants
    (pp. 159-172)
    Gillian A. Cooper-Driver

    Edwards and Selden (1993) recognize four phases in the early colonization of the land. First there was colonization by Precambrian microbial mats comprising prokaryotes and later photosynthesizing protists. Second, in the Ordovician, the land surface was colonized by bryophyte-like plants, as evidenced by the presence of fossil spores and cuticles. Third, there appear in the fossil record small axial vascular plants, such as the rhyniophytoids in the Silurian (Gray 1985). These then diversified into taller vascular plants, the rhyniophytes, zosterophyllophytes, lycophytes, and trimerophytes, by the Late Silurian—Early Devonian.

    The earliest fossil evidence for terrestrial arthropods and microorganisms is approximately...

  13. 10 The Effect of the Rise of Land Plants on Atmospheric CO₂ During the Paleozoic
    (pp. 173-178)
    Robert A. Berner

    On a multimillion-year time scale, the major process affecting atmospheric CO₂ is exchange between the atmosphere and carbon stored in rocks. This long-term, or geochemical, carbon cycle is distinguished from the more familiar short-term cycle that involves the transfer of carbon between the oceans, atmosphere, biosphere, and soils. In the long-term cycle, loss of CO₂ from the atmosphere is accomplished by the burial of organic matter in sediments and the conversion of atmospheric CO₂ to dissolved HCO₃ in soil and groundwater via the weathering of Ca—Mg silicate minerals. Silicate weathering is followed by the transport of Ca++, Mg++, and...

  14. 11 Early Terrestrial Plant Environments: An Example from the Emsian of Gaspé, Canada
    (pp. 179-212)
    C. L. Hotton, F. M. Hueber, D.H. Griffing and J. S. Bridge

    The origin of embryophytes in the Ordovician and their subsequent radiation in the Silurian and Devonian were profoundly important events in the history of life. Land plants ameliorated an initially hostile terrestrial environment, paving the way for colonization by other organisms. Rhizoid and root activity reduced substrate instability, promoted chemical weathering, and increased nutrient availability; the establishment of a plant canopy dampened fluctuations in humidity and temperature, greatly augmented primary productivity, and opened up niches for exploitation by other organisms (Beerbower 1985). Increased incorporation of CO₂ into organic carbon by land plants over the course of the Siluro-Devonian was apparently...

  15. 12 Effects of the Middle to Late Devonian Spread of Vascular Land Plants on Weathering Regimes, Marine Biotas, and Global Climate
    (pp. 213-236)
    Thomas J. Algeo, Stephen E. Scheckler and J. Barry Maynard

    The Middle to Late Devonian was an interval of major changes in both the terrestrial and marine biospheres. In the terrestrial realm, evolutionary innovations among early vascular land plants resulted in a far-reaching transformation of the structure and composition of terrestrial floras, heralded by the appearance of the first trees and forests and the spread of plants into harsher upland habitats. Increases in the size and geographic distribution of land plants at this time led to transient elevation of chemical and physical weathering rates, rapid increases in soil volume, and long-term changes in the hydrologic cycle, sediment fluxes, and landform...

  16. 13 Diversification of Siluro-Devonian Plant Traces in Paleosols and Influence on Estimates of Paleoatmospheric CO₂ Levels
    (pp. 237-254)
    Steven G. Driese and Claudia I. Mora

    Plant rhizome, plant root, and animal traces are abundant in paleosols (fossil soils) preserved in Paleozoic terrigenous successions within the Appalachian Basin. This “pedological signature’’ of vascular land plant evolution and diversification has been largely ignored by paleobotanists. Paleosols crop out extensively in the Appalachian region of eastern North America, from the Canadian Maritime Provinces southward to the Tennessee—Alabama border along the western side of the Appalachian Orogen (figure 13.1). The paleosols occur primarily in terrigenous clastic redbed deposits ranging in age from Late Ordovician to Early Permian (Mora and Driese 1999), which encompasses a time interval characterized by...

    (pp. 255-290)
  18. INDEX
    (pp. 291-308)