Johanna Kovar-Eder

Systematic, stratigraphic, and paleoenvironmental contexts of first-appearing Hipparion in the Vienna Basin, Austria

ABSTRACT The tridactyl horse Hipparion (s.l.) has long attracted the attention of paleontologists and geologists alike for its potential use as a stratigraphic and paleoenvironmental index. A central dogma surrounding this horses record is that it first occurred abruptly and instantaneously throughout the Old World ca. 12.5 Ma, heralding a general late Miocene environmental shift from forest to savanna ecosystems. We present data on the oldest known Central European hipparions, “Hipparion” primigenium (s.s.), that bear on these issues. Our analysis of the local Vienna Basin stratigraphie sequence and Paratethys geochronology suggests that hipparions first provincial occurrence was ca. 11.0–11.5 Ma. We falsify the hypotheses of an Old World “Hipparion Datum” and the purported initial association of this horse with savanna habitats. An explicit cladistic analysis of “Hipparion” primigenium (s.s.), its North American sister taxon Cormohipparion occidentale, and several Old World primitive hipparions (“Grou...

Comparing Early to Middle Miocene floras and probable vegetation types of Oberdorf N Voitsberg (Austria), Bohemia (Czech Republic), and Wackersdorf (Germany).

The Early Miocene vegetation of western Styria, Austria, is reconstructed on the basis of detailed investigations of leaves and diaspores from the mining area Oberdorf N Voitsberg. In this paper, the flora and probable vegetation are compared with other assemblages of similar age from the Czech Republic and Germany to elucidate the diversity of wetland and mesophytic plant communities. The floristic composition and the vegetational units represented in Oberdorf are compared to the middle part of the Most Formation (M Most Fm), Cypris Shale, Mydlovary Formation (Mydlovary Fm) of Bohemia, and the Wackersdorf mining area of Bavaria. Among these sites, Oberdorf is extremely poor in hydrophytes and reed-like monocotyledons, indicating rare pond-like habitats as well as possibly more closed swamp forest conditions than, e.g. in the M Most Fm. In Oberdorf, relatively high pH-values in the lignite-forming swamps and the possible scarcity of acidic, nutrient-poor (sandy) soils have probably influenced the floristic composition of the azonal communities. The peat-forming associations in all regions share the abundance of Glyptostrobus europaeus. However, distinct differences in the accompanying elements, such as Taxodium dubium (present and abundant only in the M Most Fm) indicate even stronger floristic variability of Early(/Middle) Miocene peat-forming and riparian plant communities than previously expected. The virtual absence of Pinus, Engelhardia, Comptonia, and probably also of Quercus kubinyii/Quercus drymeja in the megafossil record of Oberdorf can possibly be explained by the edaphic conditions. The abundance of Sequoia abietina (absent in all the other compared sites), which we assign to riparian (and mesophytic) forests in Oberdorf, may have been favoured by rich alluvial soils.In the mesophytic associations, thermophilous elements of the Lauraceae, Mastixiaceae, Symplocaceae, and Rutaceae are diverse. Usually they include Trigonobalanopsis rhamnoides/Trigonobalanopsis exacantha, an evergreen Fagaceae. This assemblage type corresponds with the Younger Mastixioid Flora sensu Mai. The Younger Mastixioid Flora is best developed in Wackersdorf, less distinct in Oberdorf, and likely in the Cypris Shale and Mydlovary Fm. It is not traceable in the M Most Fm.

Floristic Changes in the Areas Surrounding the Paratethys during Neogene Time

New results are presented on the stratigraphie and palaeogeographic distribution of Platanus leucophylla, Acer quercifolium, Liquidambar europaea, Acer tricuspidatum, Ginkgo adiantoides and Cercidiphyllum crenatum. The outlined distribution patterns are based on the progressive database evaluation of the fossil Central European leaf assemblages by automatic data processing.

Der Nachweis eines fertilen Zweiges von Tetraclinis brachyodon (Brongniart) Mai et Walther aus Radoboj, Kroatien (Mittel-Miozän): The record of a fertile twig of Tetraclinis brachyodon (Brongniart) Mai et Walther from Radoboj, Croatia (Middle-Miocene)

Summary A new record of a cone-bearing twig of Tetraclinis brachyodon (B rongniart ) M ai et W alther from the Middle Miocene locality Radoboj, Croatia is presented. Taxonomical and stratigraphical implications of fossil Tetraclinis are discussed.