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Fossil Leaves (fossil + leaf)
Selected AbstractsMonokotylen in der mitteleozänen Braunkohle des Geiseltales bei Merseburg (Sachsen-Anhalt) und ihre ökologische Bedeutung,FEDDES REPERTORIUM, Issue 3-4 2008Eberhard Kahlert Dipl.-Geol. Aus dem Mitteleozän des Geiseltales werden Epidermen von Dioscoreaceae, Pandanaceae, Liliaceae und zwei fossile Blätter von Alismataceae, Liliaceae und Smilacoideae beschrieben. Ökologische Hinweise auf Trockenheit durch Smilacoideae (Dry Tropic Forest) werden angezeigt. Feuchtes Klima ist nicht nachweisbar. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Epidermis of Monocotyles of Middle Eocene brown coal in the Geiseltal near Merseburg (Saxonia-Anhalt) and their ecological significance Descriptions are given of middle Eocene Epidermen of Dioscoreaceae, Pandanaceae, Liliaceae and two fossil leaves of Alismataceae, Liliaceae and Smilacoideae from Geiseltal. Smilacoideae (Dry Tropic Forest) indicate on aridity. Damp climates are not demonstrable. [source] Rhodomyrtophyllum reticulosum (Rossm.) Knobloch & Z. Kva,ek , ein bedeutendes eozänes Florenelement im Tertiär MitteleuropasFEDDES REPERTORIUM, Issue 1-2 2003U. Glinka Dipl.-Biol. Nach kritischer Überprüfung blattepidermaler und blattmorphologischer Merkmalskomplexe an Blättern und Blattresten von RhodomyrtophyllumRüffle & Jähnichen aus dem Weißelster-Becken und seiner Randgebiete in Mitteldeutschland (Raum Halle,Leipzig,Borna,Altenburg,Zeitz,Zwickau und Ostthüringen) wird nachgewiesen, dass es sich bei den Blattresten um Vertreter einer einzigen Art handelt. Die Untersuchungen stützen sich auf 465 Fossilien aus meist kohlig- oder tonig-schluffiger Facies. In einer erweiterten Diagnose wird neben Grundformen mit typischen Charakteristiken die morphologische und blattanatomische Variationsbreite angeführt, die in den natürlichen Grenzen einer Species liegt. Untersuchungen an Blättern weiterer Fundorte in Europa kommen zum gleichen Ergebnis. An Arten von 21 Gattungen rezenter Myrtaceae erfolgen detaillierte Untersuchungen der Blattmorphologie und vor allem der Epidermisstruktur, die markante Ähnlichkeiten zur fossilen Sippe zeigen, was besonders bei Arten der Gattungen SyzygiumGaertn. und Eugenia L. erkennbar ist. Rhodomyrtophyllum reticulosum (Rossm.) Knobloch & Z. Kva,ek , a significant Eocene floral element in the Tertiary of Central Europe The leaf remains of RhodomyrtophyllumRüffle & Jähnichen from the Eocene occurring in the Weißelster Basin in central Germany (area Halle,Leipzig,Borna,Altenburg,Zeitz,Zwickau and Eastern Thuringia) have been proven to belong to a single species. This has been documented by analysing gross morphology and epidermical structure of 465 fossil leaves and leaf fragments from coal sand coal-silt facies. An emended diagnosis characterises besides basic forms with typical gross morphology and leaf anatomy, also extreme specimens within the limits of natural variability of Rhodomyrtophyllumreticulosum. These results correspond with studies from other European localities. Furthermore, detailed analyses of leaf morphology and epidermal structure of 21 recent species of the Myrtaceae are given. These demonstrate analogies of the fossil taxon studied especially among representatives of SyzygiumGaertn. and Eugenia L. [source] Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core recordsJOURNAL OF QUATERNARY SCIENCE, Issue 1 2002J. C. Mcelwain Abstract A recent high-resolution record of Late-glacial CO2 change from Dome Concordia in Antarctica reveals a trend of increasing CO2 across the Younger Dryas stadial (GS-1). These results are in good agreement with previous Antarctic ice-core records. However, they contrast markedly with a proxy CO2 record based on the stomatal approach to CO2 reconstruction, which records a ca. 70 ppm mean CO2 decline at the onset of GS-1. To address these apparent discrepancies we tested the validity of the stomatal-based CO2 reconstructions from Kråkenes by obtaining further proxy CO2 records based on a similar approach using fossil leaves from two independent lakes in Atlantic Canada. Our Late-glacial CO2 reconstructions reveal an abrupt ca. 77 ppm decrease in atmospheric CO2 at the onset of the Younger Dryas stadial, which lagged climatic cooling by ca. 130 yr. Furthermore, the trends recorded in the most accurate high-resolution ice-core record of CO2, from Dome Concordia, can be reproduced from our stomatal-based CO2 records, when time-averaged by the mean age distribution of air contained within Dome Concordia ice (200 to 550 yr). If correct, our results indicate an abrupt drawdown of atmospheric CO2 within two centuries at the onset of GS-1, suggesting that some re-evaluation of the behaviour of atmospheric CO2 sinks and sources during times of rapid climatic change, such as the Late-glacial, may be required. Copyright © 2002 John Wiley & Sons, Ltd. [source] Carbon isotope composition of fossil leaves , revealing ecophysiological responses to past environmental changeNEW PHYTOLOGIST, Issue 2 2002Wolfram M. Kürschner No abstract is available for this article. [source] | ||||||||||