Major Patterns in Botanical Diversity

The Paleontological Society Special Publications ◽

10.1017/s2475262200014076 ◽

1999 ◽

Vol 9 ◽

pp. 171-186

Author(s):

Peter R. Crane

Keyword(s):

Fossil Record ◽

Pollen Grains ◽

Terrestrial Ecosystems ◽

Plant Evolution ◽

Cambrian Explosion ◽

Fossil Plants ◽

Plant Parts ◽

Plant Fossil ◽

Public Consciousness ◽

The Rich

At a time when the popular perception of paleontology is dominated by images of dinosaurs and other spectacular vertebrates, or the mysteries surrounding the Cambrian “explosion” of animal life, it is perhaps not surprising that the rich and informative fossil record of plants has scarcely made an impact on the public consciousness. In reality, as one would expect from those organisms that comprise the bulk of the biological material in terrestrial ecosystems, the fossil record of plants is extensive (Stewart and Rothwell, 1993). Leaves, wood fragments, pollen grains, spores, fruits, seeds and other plant parts are the most common fossils in rocks deposited in ancient flood plains, lakes and many other environments - and they are often exquisitely preserved. This excellent fossil record provides important information about the ecology of ancient terrestrial ecosystems. The quality of the plant fossil record also makes paleobotanical data highly informative about the historical pattern of plant evolution. It is this pattern, and its congruence with patterns in the characters of living and fossil plants — as summarized in a classification — that is the focus of this chapter.

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Major Patterns in Botanical Diversity

The Paleontological Society Special Publications ◽

10.1017/s2475262200009874 ◽

2002 ◽

Vol 11 ◽

pp. 139-150

Author(s):

Peter R. Crane

Keyword(s):

Fossil Record ◽

Pollen Grains ◽

Terrestrial Ecosystems ◽

Plant Evolution ◽

Cambrian Explosion ◽

Fossil Plants ◽

Plant Parts ◽

Plant Fossil ◽

Public Consciousness ◽

The Rich

At a time when the popular perception of paleontology is dominated by images of dinosaurs and other spectacular vertebrates, or the mysteries surrounding the Cambrian “explosion” of animal life, it is perhaps not surprising that the rich and informative fossil record of plants has scarcely made an impact on the public consciousness. In reality, as one would expect from those organisms that comprise the bulk of the biological material in terrestrial ecosystems, the fossil record of plants is extensive (Stewart and Rothwell, 1993). Leaves, wood fragments, pollen grains, spores, fruits, seeds, and other plant parts are the most common fossils in rocks deposited in ancient flood plains, lakes, and many other environments—and they are often exquisitely preserved. This excellent fossil record provides important information about the ecology of ancient terrestrial ecosystems. The quality of the plant fossil record also makes paleobotanical data highly informative about the historical pattern of plant evolution. It is this pattern, and its congruence with patterns in the characters of living and fossil plants—as summarized in a classification—that is the focus of this chapter.

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Did Ground Cover Change Over Geologic Time?

The Paleontological Society Papers ◽

10.1017/s1089332600000759 ◽

2000 ◽

Vol 6 ◽

pp. 171-182 ◽

Cited By ~ 4

Author(s):

Ben A. LePage ◽

Hermann W. Pfefferkorn

Keyword(s):

Fossil Record ◽

Ground Cover ◽

The Other ◽

Detailed Account ◽

Geologic Time ◽

The Past ◽

Other Hand ◽

Plant Fossil

When one hears the term “ground cover,” one immediately thinks of “grasses.” This perception is so deep-seated that paleobotanists even have been overheard to proclaim that “there was no ground cover before grasses.” Today grasses are so predominant in many environments that this perception is perpetuated easily. On the other hand, it is difficult to imagine the absence or lack of ground cover prior to the mid-Tertiary. We tested the hypothesis that different forms of ground cover existed in the past against examples from the Recent and the fossil record (Table 1). The Recent data were obtained from a large number of sources including those in the ecological, horticultural, and microbiological literature. Other data were derived from our knowledge of Precambrian life, sedimentology and paleosols, and the plant fossil record, especially in situ floras and fossil “monocultures.” Some of the data are original observations, but many others are from the literature. A detailed account of these results will be presented elsewhere (Pfefferkorn and LePage, in preparation).

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A fossil record of land plant origins from charophyte algae

Science ◽

10.1126/science.abj2927 ◽

2021 ◽

Vol 373 (6556) ◽

pp. 792-796 ◽

Cited By ~ 1

Author(s):

Paul K. Strother ◽

Clinton Foster

Keyword(s):

Fossil Record ◽

Evolutionary History ◽

Phylogenetic Signal ◽

Land Plant ◽

Fossil Plants ◽

Fossil Plant ◽

Molecular Phylogenetic ◽

History Of ◽

Time Gap ◽

Evolutionary Continuity

Molecular time trees indicating that embryophytes originated around 500 million years ago (Ma) during the Cambrian are at odds with the record of fossil plants, which first appear in the mid-Silurian almost 80 million years later. This time gap has been attributed to a missing fossil plant record, but that attribution belies the case for fossil spores. Here, we describe a Tremadocian (Early Ordovician, about 480 Ma) assemblage with elements of both Cambrian and younger embryophyte spores that provides a new level of evolutionary continuity between embryophytes and their algal ancestors. This finding suggests that the molecular phylogenetic signal retains a latent evolutionary history of the acquisition of the embryophytic developmental genome, a history that perhaps began during Ediacaran-Cambrian time but was not completed until the mid-Silurian (about 430 Ma).

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A Conspectus of Phytotaphonomy

The Paleontological Society Special Publications ◽

10.1017/s247526220000486x ◽

1988 ◽

Vol 3 ◽

pp. 14-28 ◽

Cited By ~ 7

Author(s):

Robert A. Gastaldo

Keyword(s):

Fossil Record ◽

Traumatic Loss ◽

Plant Parts

The fossil record of plants principally results from individuals, variously sampled from one or more communities, that generally are associated with a depositional site. The processes responsible for the transfer of plant parts from the biosphere to the lithosphere may be biotic (e.g. physiological, animal herbivory, etc.) or abiotic (e.g. traumatic loss by wind and/or water; Krassilov, 1975) in nature. The factors ultimately responsible for the preservation of these plant parts are sedimentological and geochemical. The goals of the subdiscipline of Taphonomy, the study of processes of preservation and how they affect information in the fossil record (Behrensmeyer and Kidwell, 1985), are to understand fossilization through necrology, biostratinomy, and diagenesis (Figure 1). The purpose of this chapter is to provide an overview of taphonomic factors responsible for the generation and preservation of plant macrodetritus. It is not meant to be an exhaustive dissertation or definitive discussion on phytotaphonomy.

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Conductance in the wood of selected Carboniferous plants

Paleobiology ◽

10.1017/s0094837300013804 ◽

1986 ◽

Vol 12 (3) ◽

pp. 302-310 ◽

Cited By ~ 33

Author(s):

Michael A. Cichan

Keyword(s):

Wood Anatomy ◽

Growth Habit ◽

Secondary Xylem ◽

Middle Part ◽

Specific Conductance ◽

Plant Evolution ◽

Seed Plant ◽

Fossil Plants ◽

Tracheary Elements ◽

Conducting Tissue

Specific conductance was calculated for secondary xylem in seven Carboniferous stem taxa utilizing an equation derived from the Hagen-Poiseuille relation. Arborescent and lianoid representatives of major pteridophytic (Calamitaceae, Lepidodenraceae, Sphenophyllaceae) and gymnospermous (Cordaitaceae, Medullosaceae) groups were examined. In the calamite Arthropitys communis and the seed plant Cordaites (Cordaixylon sp. and Mesoxylon sp.), conductance corresponded approximately to the low end of the range for both extant conifers and angiosperms. A substantially higher conductance was determined for the wood of Arthropitys deltoides, conforming to the high end of the range for conifers and the low-middle part of the range for angiosperms. The highest conductance values were found in Sphenophyllum plurifoliatum, Medullosa noei, and Paralycopodites brevifolius and corresponded to the middle-high portion of the range for vessel-containing angiosperms. This outcome is particularly significant in light of the fact that tracheary elements in the fossils are imperforate. The results indicate that conductance in secondary xylem of some of the most ancient, woody groups was comparable to that in extant plants and that highly effective conducting tissue developed relatively early in plant evolution. Moreover, it is suggested that the general relationship between wood anatomy, growth habit, and ecology demonstrated for living plants can also be extended back in time to include fossil plants.

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ELECTRON MICROSCOPIC STUDIES OF SOME ANTICANCER PLANTS POLLEN GRAINS

International Journal of Advanced Research ◽

10.21474/ijar01/13695 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1386-1393

Author(s):

Jayshree Sandesh Thaware ◽

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Pollen Morphology ◽

Pollen Grains ◽

Morphological Characters ◽

Electron Microscopic ◽

Plant Parts ◽

Morphological Studies ◽

Datura Metel ◽

Scanning Electron

Pollen is appropriately referred by some as Golden dust extremely valuable on account of their tremendous applications in science, industries and public health. No other plant part even though extremely tiny in size is packed with so much information and power. Similar to other plant parts, pollen characters are so varied that the classification system of plants can be built up entirely on the basis of pollen morphology.Palynology is the distinct branch of biology that deals with the dispersed microscopic tiny living and fossil entities including pollen grains, spores, algal and fungal fragments and others. An important aspect of Palynology is the Pollen morphology. The importance of Palynology in taxonomic and phylogenetic consideration of plants is well known. The changes occurring through hybridization and years of cultivation are reflected in pollen morphology. The scope and interest in the study of pollen morphology have widened with the advent of Scanning Electron Microscopy (SEM) and with regards to unipalynous taxa particularly the understanding of finer morphology is of fundamental importance. SEM gives a correct understanding of exine surface as the electron photographs of the surface replica of the exine provides the exact picture of the ornamentation pattern. The variation in the pollen morphological characters helps in the classification of plant taxa and their assessment of their phylogenetic relationship. In the present investigation, the pollen morphological studies were carried out of some ethnomedicinal plants like Catharanthus roseus, Allamanda cathartica, Datura metel, Brassica juncea, Raphanus sativus and Cleome viscosa pollen grains by Scanning electron microscopy. All that they possess anticancer characteristics in common.

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Early fossil record of Euarthropoda and the Cambrian Explosion

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1719962115 ◽

2018 ◽

Vol 115 (21) ◽

pp. 5323-5331 ◽

Cited By ~ 34

Author(s):

Allison C. Daley ◽

Jonathan B. Antcliffe ◽

Harriet B. Drage ◽

Stephen Pates

Keyword(s):

Fossil Record ◽

Trace Fossils ◽

Cambrian Explosion ◽

Burgess Shale ◽

Crown Group ◽

Total Group ◽

Stem Lineage ◽

Coherent Picture ◽

Insight Into ◽

Phosphate Deposits

Euarthropoda is one of the best-preserved fossil animal groups and has been the most diverse animal phylum for over 500 million years. Fossil Konservat-Lagerstätten, such as Burgess Shale-type deposits (BSTs), show the evolution of the euarthropod stem lineage during the Cambrian from 518 million years ago (Ma). The stem lineage includes nonbiomineralized groups, such as Radiodonta (e.g., Anomalocaris) that provide insight into the step-by-step construction of euarthropod morphology, including the exoskeleton, biramous limbs, segmentation, and cephalic structures. Trilobites are crown group euarthropods that appear in the fossil record at 521 Ma, before the stem lineage fossils, implying a ghost lineage that needs to be constrained. These constraints come from the trace fossil record, which show the first evidence for total group Euarthropoda (e.g., Cruziana, Rusophycus) at around 537 Ma. A deep Precambrian root to the euarthropod evolutionary lineage is disproven by a comparison of Ediacaran and Cambrian lagerstätten. BSTs from the latest Ediacaran Period (e.g., Miaohe biota, 550 Ma) are abundantly fossiliferous with algae but completely lack animals, which are also missing from other Ediacaran windows, such as phosphate deposits (e.g., Doushantuo, 560 Ma). This constrains the appearance of the euarthropod stem lineage to no older than 550 Ma. While each of the major types of fossil evidence (BSTs, trace fossils, and biomineralized preservation) have their limitations and are incomplete in different ways, when taken together they allow a coherent picture to emerge of the origin and subsequent radiation of total group Euarthropoda during the Cambrian.

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Introduction

The Emerald Planet ◽

10.1093/oso/9780192806024.003.0008 ◽

2007 ◽

Author(s):

David Beerling

Keyword(s):

Environmental History ◽

Charles Darwin ◽

Earth Science ◽

Popular Science ◽

Plant Evolution ◽

Scientific Investigation ◽

Fossil Plants ◽

Terrestrial Plants ◽

Conventional View ◽

Plant Life

Charles Darwin (1809–82), the greatest naturalist of all, was fascinated by them, Richard Dawkins all but ignored them. The world, it seems, is divided about the charms of the plant kingdom. The opening quotation of this chapter is from the American popular science author Tom Weller’s witty and provocative 1985 book Science made stupid, and sums up the malaise afflicting those on one side of the great divide. To these folk, plants have an unexceptional evolutionary trajectory leading up to the emergence of our modern floras and play no appreciable role in unravelling Earth’s history. Too often, this view is reiterated, reinforced, in Earth science textbooks, where it is palmed off on the unwary reader as received wisdom. Many such scholarly tomes devote a few pages to Earth’s first green spring, that decisive moment of our past when terrestrial plants turned the continents green. A few graciously give more space—an entire chapter, perhaps—to the progression of plants up the evolutionary ladder from their earliest beginnings through to the appearance of the first forests, the emergence of seed plants, and the blooming of the Earth with the rise of flowering plants. Fewer still recognize plants as important players in the game of life. In this book I argue that Weller’s viewpoint, and the conventional view of textbooks, is now outdated, redundant even, and misguided. The scientific investigation of fossil plants is on the threshold of an exciting new era, a grand synthesis illuminating new chapters in the inseparable stories of plant evolution and Earth’s environmental history. This book is about that new science. It is an endeavour that has emerged unnoticed in the last two decades but which is proving a powerful tool for clearing a path through the dense, sterile thicket of entrenched orthodoxy. It advocates fossils not as the disarticulated remains of ancient plant life gathering dust deep within the basements of museums, but as exciting, dynamic entities brought to life in new ways by the scientific investigation of their living counterparts. The Emerald planet is not a textbook, nor an attempt at describing, blow-by-blow, the detailed evolutionary history of plant life over the ages in a manner accessible to the general reader.

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Plant Taphonomy in Fluvial and Lacustrine Systems

Notes for a Short Course: Studies in Geology ◽

10.1017/s0271164800001305 ◽

1986 ◽

Vol 15 ◽

pp. 10-26 ◽

Cited By ~ 3

Author(s):

Robert A. Spicer ◽

Anthony G. Greer

Keyword(s):

Pollen Grains ◽

Plant Organs ◽

Plant Fossil ◽

Depositional System ◽

Organ Type ◽

Fossil Assemblages ◽

Biased Samples

Plant fossil assemblages are biased samples of the capacity of the once living source vegetation to produce litter (leaves, flowers, pollen, spores, fruits, seeds, twigs, branches, trunks, roots etc.). The “image” that the depositional system “sees” of the vegetation is in terms of isolated plant organs (or parts of organs) that are produced in greater or lesser quantities depending on the organ type. For instance throughout the life of a tree hundreds of thousands of leaves, many millions of pollen grains but only one trunk are produced. Only very rarely do plant fossil assemblages consist of entire or nearly entire plants. Instead assemblages consist of a mixture of organs in various states of completeness derived from a number of different taxa (each of which produces different organs in different relative amounts) growing at various distances from the depositional site.

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