A
groups B . From DiMichele and Phillips, 1994. groups B . From DiMichele and Phillips, 1994. PALEOECOLOGY PLANTS IN THEIR ENVIRONMENT Paleoecology, the study of past environments, is a rapidly changing field that involves the integration and synthesis of both botanical and geological information. In recent years there has been a concerted effort by many paleobotanists to understand the paleoenvironment of fossil land plants more completely. For example, Bateman and Scott 1990 examined the famous...
Molds And Casts
In addition to two-dimensional plant parts, such as leaves, three-dimensional structures, such as stems, seeds, or fruits, can also be carried into sites where sediment is accumulating and buried. During flood events, massive trunks and tree branches can be moved some distance before they are eventually deposited. If these plant parts became crushed over time, they would be preserved as compression or impression fossils. If, however, the sediment surrounding the three-dimensional plant parts...
Determining Paleoclimate From Fossil Plants
Understanding climates of the past has become more and more crucial to appreciating the changes occurring on our warming planet today, and paleobotany is very important in providing baseline data to reconstruct past climates and in calibrating paleoclimate models based on physical parameters Steppuhn et al., 2007 . This area is rapidly expanding, so we will only cover a few of the many ways in which plant fossils can be used to reconstruct paleoclimate Data from fossil tree rings...
Nomenclature Of Fossil Plants
Historically, paleobotanists have utilized a somewhat artificial classification system, since in almost all instances and discussed with other paleobotanists. The other reason is that some identical plant parts may be attached to different plants, for example the Carboniferous lycopsid rooting organ Stigmaria, a morphogenus, has been found attached to different genera of stems. In a case like this, the name of the part is maintained, even though the entire plant has subsequently been...
Classification Of Organisms
Each author has his or her own ideas concerning the way organisms should be organized, or in the case of plants, whether they represent a single kingdom or multiple kingdoms. With this in mind, the classification scheme in Appendix 1 is presented merely as a guide to the groups of algae, fungi, bryophytes, and vascular plants that are discussed in this book. In the case of some groups, such as the hyperdiverse flowering plants, there are so many families with a meager fossil record, or no...
Introduction to Paleobotany
The Objectives of Paleobotany 2 Form and Function in Fossil Plants 4 Biostratigraphy and Correlation 4 Paleoecology Plants in Their Environment 5 Determining Paleoclimate from Fossil Plants 6 Summary 7 Preservation How Plant Fossils are Formed and Depositional Environments of Fossil Plants 8 Biofilms and Plant Fossil Preservation 16 Geochronology and Biostratigraphy 36 Systematics and Classification 40 Nomenclature of Fossil Plants 41
4
Figure 1.65 Winged angiosperm seeds preserved in amber Miocene . Bar 1 cm. Courtesy G. O. Poinar. Figure 1.65 Winged angiosperm seeds preserved in amber Miocene . Bar 1 cm. Courtesy G. O. Poinar. large number of plants phytochemistry, infrared spectrophotometry, and X-ray diffraction have proved to be important analytical tools in determining the botanical origins of fossil resins Langenheim, 2003 . Because of its sticky consistency when it was produced by the plant, amber has also served as...
Form And Function In Fossil Plants
From many plant fossils, it is possible to understand the relationship between form and function in ancient plants, that is, what advantages or limitations are imposed on the growth and development of a plant based on certain biomechanical properties For example, are all arborescent treelike plants constructed of cells and tissue systems of the same type If not, in what other ways can plants grow to tower over their neighbors Studies of this type examine the anatomical and morphological...
Evolution Of Plant Groups
Paleobotanists are also interested in the origin and subsequent evolution of major groups of plants and their interrelationships. When did plants first inhabit the Earth and what did they look like When did the first representatives of different groups of plants first arise Other researchers want Figure 1.4 Permineralized wood extending from paleostream channel in the Triassic of Antarctica. Figure 1.4 Permineralized wood extending from paleostream channel in the Triassic of Antarctica. FiguRE...
Paleoecology
Palynology has also been extensively used as a method of characterizing past depositional systems paleoenvironments Farley and Traverse, 1990 . Here palynomorphs play an important role in defining, for example, the extent of a marine or terrestrial environment. In other instances, certain types of palynomorphs may provide valuable information about water depth, temperature, salinity, and nutrient levels where the organisms once lived. In a few cases where vertebrates and invertebrates are found...
Unaltered Plant Material
Some plant parts are found as fossils in an unaltered form, either as body fossils or as chemical fossils. Pollen grains and spores FIG. 1.58 I , diatom frustules, cuticle envelopes, various types of resins, such as amber FIG. 1.59 and calcium carbonate remains of certain types of algae are all examples of unaltered plant fossils. In some instances even the soft parts are sufficiently preserved so that comparisons can be made at the cytoplasmic and ultrastructural level Wolfe et al., 2006 ....
Coal And Charcoal
Technically, coal FIG. 1.30 comes under the definition of a compression fossil, since it represents a complex, heterogeneous mixture of macromolecular organic compounds derived from plant material that has been compressed over time Scott, 1987 . In general, the lower the rank of the coal the degree of coalification , the more details of plant structure one can observe. The higher the rank, the more the coal has been metamorphosed and the higher the carbon content. Ranks from lowest to highest...
B
FIGURE 1.42 Diagrammatic representations of the steps involved in the preparation of the coal ball peel technique. A. Section of coal ball slab calcium carbonate matrix containing plant material crosshatched B. coal ball slab after acid etching to partially expose plant material C. etched coal ball slab surface with cellulose acetate sheet in place D. cellulose acetate sheet peel being pulled from the surface with adhering plant material and E. coal ball peel containing embedded plant material....
Chapter 6
Parka 188 Isolated Fragments Clues to the Transition to Land 189 Cuticle and Cuticle-Like Material 189 Structural Support and Water Transport 195 Protection Against Desiccation and Radiation 195
Chapter 7
Introduction to Vascular Plant Morphology and Anatomy 201 Plant Tissues and Primary Growth 207 Arrangement of Primary Tissues 210 Primary Xylem Maturation Patterns 212 Stele Types 216 Primitive Vascular Plants Vascular Cryptogams 216 Leaf Morphology and Anatomy 221
Compressions
As sediments accumulate, such as in an oxbow lake, water is squeezed out, so the sediments become much more compact, and plant fragments contained within them become flattened Rex and Chaloner, 1983 Chaloner, 1999a . Internal structure is usually obliterated as the cells become flattened, and frequently all that is left is a delicate carbonaceous film that conforms to the original outline of the plant part. This type of fossil is called a compression FIG. 1.13 , and it is one of the most common...
Late Paleozoic and Mesozoic Foliage 651
Late Paleozoic Foliage Adiantites Alethopteris Aneimites Aphlebia Alloiopteris Botrychiopsis Callipteridium Cardiopteridium Cardiopteris Fryopsis Charliea Cyclopteris Dicksoniites Discopteris Eremopteris Ginkgophytopsis Kankakeea Karinopteris, Mariopteris, and Pseudomariopteris Lesleya Linopteris, Reticulopteris, and Barthelopteris Lobatopteris Lonchopteridium and Lonchopteris Megalopteris Neuropteris sensu lato Laveinopteris Macroneuropteris Margaritopteris Neuralethopteris Neurocallipteris...
The Objectives Of Paleobotany
One of the aspects of paleobotany, which makes it unusual and interesting, is that it is inherently interdisciplinary and can be approached from either a biological or a more geological perspective or both together. Each perspective presents a variety of questions that are unique to that discipline. Today more than ever before, the questions being asked by paleo-botanists necessitate that both the botanical and geological perspectives be fully understood. To a large degree, the research...
Impressions
When a paleobotanist splits a rock that contains fossil plant fragments along a bedding plane, it is sometimes possible to see the carbonaceous film of a compression along one face, and a negative imprint of the plant part, with little or no carbon adhering, on the other face FIG. 1.32 these two faces are called part and counterpart in paleobotany. The fossil with little or no carbonaceous material is called an impression FIGURE 1.34 Impression of Sigillaria leaf bases showing parichnos scars...
acknowledgments
We are truly indebted to a large number of individuals and institutions who eagerly assisted us in the preparation of this book. This includes all of our colleagues both past and present, who readily contributed illustrations as well as the various professional journals, book publishers, and professional organizations that granted permission to use copyrighted material. We are also indebted to numerous colleagues who took the time to read chapters and sections of the book, and freely discussed...
Preservation How Plant Fossils Are Formed And Preserved
A relatively small fraction of the plants and other organisms that live on the Earth at any particular time will ever become fossils. Most dead plant material is decayed by aerobic oxygen-loving fungi and bacteria. So, the first requirement for fossilization is that dead plants must be deposited in an environment where air is excluded, that is an anaerobic environment. This usually involves deposition in a body of water discussed below , but not always. Once deposited, the plants must be buried...