Terrestrial plants and marine algae from the Late Jurassic lithographic limestone of the Causse Méjean (Lozère, southern France)

2016 ◽  
Vol 187 (2) ◽  
pp. 121-127
Author(s):  
Jean-David Moreau ◽  
Louis Baret ◽  
Gérard Lafaurie ◽  
Carmela Chateau-Smith
Keyword(s):  
Late Jurassic ◽  
Marine Algae ◽  
Coastal Areas ◽  
Land Plants ◽  
Fossil Plants ◽  
Terrestrial Plants ◽  
Southern France ◽  
Lithographic Limestone ◽  
Dry Conditions ◽  
Marine Lagoon

Abstract A new Late Jurassic flora was discovered in the fossiliferous lithographic limestone of the Causse Méjean, Lozère (southern France). It consists of the first Kimmeridgian/Tithonian plants from this area. Fossil plants are represented by megaremains preserved as impressions. This flora shows a co-occurrence of terrestrial plants and marine algae. The land plants include vegetative remains ascribed to bennettitaleans (Zamites Brongniart, 1828), conifers (Brachyphyllum Brongniart, 1828), and pteridosperms (Cycadopteris Zigno, 1853). Marine algae were ascribed to dasyclads (Goniolina D’Orbigny, 1850). Lithological and palaeontological features suggest preservation in a flat, homogeneous, protected environment, perhaps a brackish or marine lagoon, influenced by both continental and marine inputs. This discovery complements the few existing reports of European Late Jurassic floras, and indicates that coastal habitats were dominated by sub-arborescent vegetation, consisting of bennettitaleans and pteridosperms, and arborescent plants, such as conifers. Both the palaeoenvironmental context and certain xerophytic features suggest that these terrestrial plants from the Causse Méjean were well adapted to the hot, dry conditions of coastal areas.

XVII.—Studies in the Ectocarpaceæ. I. The Life-History and Cytology of Pylaiella litoralis, Kjellm

1924 ◽  
Vol 53 (2) ◽  
pp. 343-360 ◽  
Author(s):  
Margery Knight
Keyword(s):  
Life History ◽  
Characteristic Feature ◽  
Life Histories ◽  
Marine Algae ◽  
Land Plants ◽  
Terrestrial Plants ◽  
Recent Suggestion ◽  
Alternation Of Generations

During the last few years attention has been focussed somewhat sharply upon the Marine Algæ, partly on account of the recently investigated life-histories of some of the larger Phæophyceæ, and partly because of a recent suggestion that the Marine Algæ may represent the stock from which all higher land-plants have originated. Interest has naturally centred on the problem of the origin of an alternation of generations among the seaweeds, comparable to that which has become a characteristic feature in the life-histories of higher terrestrial plants.

Lowermost Jurassic dinosaur ecosystem from the Bleymard Strait (southern France): sedimentology, mineralogy, palaeobotany and palaeoichnology of the Dolomitic Formation

2021 ◽  
pp. 1-17
Author(s):  
Jean-David Moreau ◽  
Vincent Trincal ◽  
Jean-François Deconinck ◽  
Marc Philippe ◽  
Benjamin Bourel
Keyword(s):  
Clay Mineral ◽  
Sea Spray ◽  
Subtropical Climate ◽  
Coastal Environments ◽  
Southern France ◽  
Plant Remains ◽  
Dry Conditions ◽  
Male Cones ◽  
Main Component ◽  
Mineral Analyses

Abstract We report the first Hettangian theropod tracksite (~200 Ma) yielding a rich accumulation of plant remains from the Bleymard Strait (southern France). It constitutes an excellent opportunity to reconstruct lowermost Jurassic ecosystems hosting dinosaurs and which are still poorly documented in this area. Two morphotypes of tridactyl tracks are distinguished. They share similarities with Grallator and Kayentapus. Plant-bearing beds yield abundant leafy axes (Pagiophyllum peregrinum), male cones (Classostrobus sp.), wood (Brachyoxylon sp.) and pollen of conifers (Classopollis classoides). Sedimentological, petrological and mineralogical analyses demonstrated that, in the Dolomitic Formation from Bleymard, the palaeoenvironment progressively evolved from (1) a shoreface to a foreshore domain; to (2) a shallow environment that is restricted or occasionally open to the sea; then to (3) an intertidal to supratidal zone. The Hettangian theropod ecosystem of the Bleymard Strait was composed of tidal flats that were periodically emerged and bordered paralic environments inhabited by a littoral conifer-dominated forest in which Cheirolepidiaceae were the main component. The paucity of the palaeobotanical assemblage, as well as the xerophytic characteristics of Pagiophyllum, show that flora from Bleymard was adapted to withstand intense sunlight and coastal environments exposed to desiccant conditions coupled with salty sea spray, and dry conditions. These features are those of a conifer-dominated flora under a tropical to subtropical climate. The flora as well as the clay mineral analyses suggest contrasting seasons (cyclically dry then humid). This study supports that theropods were abundant and particularly adapted to this type of littoral environment bordering Cheirolepidiaceae-dominated forests.

Introduction

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.

scholarly journals Use of an in vitro model of hepatic steatosis for studying the anti-oxidant and antisteatotic effects of fucoidan polysaccharides

2020 ◽  
Author(s):  
Zeinab El Rashed ◽  
Hala Khalife ◽  
Adriana Voci ◽  
Elena Grasselli ◽  
Laura Canesi ◽  
...  
Keyword(s):  
Marine Algae ◽  
In Vitro Model ◽  
Biological Effects ◽  
Biologically Active ◽  
Terrestrial Plants ◽  
Alcoholic Fatty Liver ◽  
Anti Oxidant ◽  
Vitro Model ◽  
Alcoholic Fatty Liver Disease

Non Alcoholic Fatty Liver Disease (NAFLD) is characterised by fat accumulation in hepatocytes in the form of triacyglycerols (TAGs) within cytosolic lipid droplets. Fucoidans (FUs) are biologically active polysaccharides usually isolated from brown marine algae, but recently identified also in terrestrial plants. In this study, we aimed to investigate the anti-oxidant and anti-steatotic effects of FUs purified from C. compressa, F. hermonis, and E. globulus. To this aim, we used a validated NAFLD in vitro model consisting of rat hepatoma FaO cells exposed to an oleate/palmitate mixture. Such a model is suitable for rapid investigation of direct effects of natural and artificial compounds, together with satisfying the strategy of 3Rs for laboratory use of animals. Our results indicated that all FUs display anti-oxidant and anti-steatotic activities. Steatotic FaO cells may be employed to further study the biological effects of FUs.

scholarly journals Global Jurassic floras and climate

1992 ◽  
Vol 6 ◽  
pp. 320-320
Author(s):  
Jiping Yao
Keyword(s):  
Correspondence Analysis ◽  
Late Jurassic ◽  
Regression Line ◽  
Detrended Correspondence Analysis ◽  
Climatic Changes ◽  
Temperate Climate ◽  
Fossil Plants ◽  
Generic Level ◽  
Strong Basis ◽  
The Earth

The present day vegetation types on the earth are to a large extent controlled by climatic conditions that are mainly reflected in variations in moisture availability and temperature through the annual cycle. Therefore, fossil plants can be used as a tool to elucidate both spatial and temporal climatic changes. The global climates of the Jurassic can be interpreted with fossil floras because many parts of world have yielded abundant floral localities. Those records not only provide a strong basis for the qualitative depiction of vegetation patterns, but also provide quantitative data for the reconstruction of paleophytogeographic provinces and climatic changes. The computer program known as “Detrended Correspondence Analysis” written by Hill (1979) was used in this study. The floral data for this quantitative approach was assembled at the generic level mainly from the published literature. By definition, it is a method based on ordination scores, that is, the species ordination scores are averages of the sample ordination scores, and vice versa.The scatter diagrams of the first two axes of genera and sample sites derived by detrended correspondence analysis were obtained for the intervals of Early, Middle, and Late Jurassic. The gradient variations of both genera and sample sites are reflected by the scores along axis 1 and 2 because axis 1 and axis 2 maximize the correlation of species and sample sites according to this technique. In the ordination score diagrams, the genera in similar climatic environments and the sample sites in similar paleogeographic regions are relatively close to each other along axis1 and axis2.One of characteristics of the Jurassic vegetation is the taxonomic stability through the period compared with other periods of time. Therefore, the generic scores of axis1 for the Early and Middle, Middle and Late, and Early and Late Jurassic can be plotted against each other. The regression line can be used to assign the scores to the ordered genera. This is the technique used to complement the ordered genera from the gradient score diagrams and to eliminate the effect of some local genera. The genera adjacent to the regression line can be reliably used to reflect climatic gradients. The gradient changes were used to define biomes and to determine phytogeographic patterns on a global scale.The quantitative analysis clearly shows that the use of floral data can achieve fast and satisfactory results in paleoclimatic studies of the Jurassic. For example, the cool-wet temperate climate is reflected by a ginkgophyte dominated deciduous flora, such as Ginkgo, Czekanowskia, Phoenicopsis, and Baiera, whereas the subtropical warm and drier climate is represented by cycad dominated floras, such as Anomozamites, Nilssonia, Pterophylum, Ptilophyllwn, Ctenis, and Otozamites. The general conclusion of earlier workers that Jurassic floras were especially uniform through the earth is true in the relative sense only, and the ordination study allows for the subdivision of the rather shallow gradients that do exist.

Naturally occurring and synthetic polyyne glycosides

2009 ◽  
Vol 87 (11) ◽  
pp. 1565-1582 ◽  
Author(s):  
Yanqing Pan ◽  
Todd L. Lowary ◽  
Rik R. Tykwinski
Keyword(s):  
Natural Products ◽  
Marine Algae ◽  
Biological Activities ◽  
Terrestrial Plants ◽  
Natural Sources ◽  
Naturally Occurring

Polyyne glycosides are a class of natural products that have been found in terrestrial plants, fungi, and marine algae. Many display interesting and potentially useful biological activities, which in some cases has initiated synthetic efforts toward their formation. This review provides a comprehensive report of polyyne glycosides isolated from natural sources, as well as the synthesis of these molecules and their analogues.

scholarly journals Characterization of Lectin from Colpomenia Sinuosa and Effect of Physico Chemical Parameters on Haemagglutination Activity

2019 ◽  
Vol 8 (3S2) ◽  
pp. 844-848
Keyword(s):  
Marine Algae ◽  
Land Plants ◽  
Plant Tissues ◽  
Biological Applications ◽  
Carbohydrate Specificity ◽  
Chemical Parameters ◽  
Lectin Activity ◽  
Physico Chemical ◽  
Haemagglutination Activity

Lectin is a protein which has the ability to bind carbohydrates and named as haemagglutinin. Lectins with specific carbohydrate specificity have been purified from various plant tissues and other organisms and exploited extensively in many aspects of biochemistry and biomedicine. Similar to land plants, lectins from marine algae appear to be useful in some biological applications. Although several studies on lectins from marine algae have been reported till date, few lectins from algae have been characterized in detail. The present study was focused on the lectin isolated from C.sinuosa. The algal lectin has high sugar specificity with N-acetylglucosamine and higher enzyme activity with trypsin. This lectin was identified as CaCl2 dependent – ‘C’ type lectin and was sensitive to EDTA. Higher H.A titre value was observed with CaCl2 and the lower with MnCl2 and ZnCl2 . Significant lectin activity was observed between pH 7 to 8 and temperature between 20 to 40 O C

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