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  • 1.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology.
    Zetter, Reinhard (Contributor)
    Pollen and spores of the uppermost Eocene Florissant Formation, Colorado: A combined light and scanning electron microscopy study2016In: Grana, Vol. 55, no 3, p. 179-245Article in journal (Refereed)
    Abstract [en]

    The uppermost Eocene Florissant Formation, Rocky Mountains, Colorado, has yielded numerous insect, vertebrate, and plant fossils. Three previous comprehensive palynological studies investigated sections of lacustrine deposits of the Florissant Formation and documented the response of plant communities to volcanic eruptive phases but overall found little change in plant composition throughout the investigated sections. These studies reported up to 150 pollen and spore phenotypes. In the present paper we used a taxonomic approach to the investigation of dispersed pollen and spores of the Florissant Formation. Sediment samples from the shale units containing macrofossils were investigated using light microscopy (LM) and scanning electron microscopy (SEM). The general picture of the palynoflora is in agreement with previous studies. However, the combined LM and SEM investigation provides important complementary information to previous LM studies. While a fairly large amount of previous pollen determinations could be confirmed, the purported taxonomic affinities of several pollen phenotypes need to be revised. For example, pollen referred to as Podocarpus or Podocarpidites sp. belongs to the Pinaceae Cathaya, Malus/Pyrus actually belongs to Dryadoideae, pollen of the form genus Boehlensipollis referred to as Proteaceae/Sapindaceae/Elaeagnaceae or Cardiospermum belongs to Sapindaceae but not to Cardiospermum, and pollen of Persicarioipollis sp. B with previously assumed affinities to Polygonaceae actually belongs to Thymelaeaceae. Pandaniidites and one type of Malvacipollis cannot be linked with Pandanaceae and Malvaceae. A few taxa are new records for Florissant (Ebenaceae: Diospyros; Mernispermaceae; Trochodendraceae: Tetracentron). In general, SEM investigations complement the LM palynological studies and improve the identification of dispersed pollen and spores and enable integration of data from dispersed fossil pollen into a wide range of comparative morphological, taxonomic, evolutionary, biogeographic, and phylogenetic studies.

  • 2.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    An overview of the palynoflora of the Miocene Yatağan basin, Turkey2014Conference paper (Other academic)
    Abstract [en]

    The palynoflora of the lignite strip mines of the Yatağan basin, located in the Muğla province of western Turkey, is the focus of this study. Samples were taken from the Eskihisar, Salihpasalar and Tinaz mines. In the Yatağan basin two Miocene formations, formed from river and lake deposits, Eskihisar Formation (middle Miocene) and Yatağan Formation (late Miocene) have been designated. Both show a general lithology consisting of conglomerate, sandstone, claystone, limestone and tuffite, the mined/excavated lignite bearing strata are restricted to the Eskihisar Formation.

    Until now, pollen from the Yatağan basin has mostly been described according to conventional morphological nomenclature, using light microscopy (LM) only. In this study, the same individual pollen grains are investigated by using both, LM and scanning electron microscopy (SEM). The  high resolution pictographs allow a higher taxonomic resolution.

    The rich palynoflora (Table 1) is comprised of diverse spores (at least nine morphotypes), gymnosperm pollen from Cupressaceae, Gnetales, Pinaceae, and angiosperm pollen from Poaceae, Typhaceae, Altingiaceae,  Amaranthaceae (Chenopodieae), Anacardiaceae, Apiaceae, Betulaceae, Buxaceae, Caprifoliaceae (Dipsacoideae, Lonicera) Caryophyllaceae, Compositae (Asteroideae, Cichoriodeae), Cornaceae, Eucommiaceae, Fabaceae, Fagaceae (Fagus, Quercus, Trigonobalanopsis) Geraniaceae, Juglandaceae, Malvaceae, Myricaceae, Nymphaeaceae, Oleaceae, Palmae, Plumbaginaceae (Armeria, Plumbago), Polygonaceae (Rumex), Salicaceae, Sapindaceae (Acer), Smilacaceae, and Ulmaceae (Cedrelospermum, Ulmus, Zelkova).

  • 3.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    Palynostratigraphical correlation of the excavated Miocene lignite seams of the Yatağan basin (Muğla Province, south-western Turkey)2016Conference paper (Other academic)
    Abstract [en]

    The excavated main lignite seams and overlying lacustrine sediments of the opencast mines Eskihisar, Salihpaşalar, and Tınaz, Muğla Province, south-western Turkey were investigated using a high taxonomic resolution palynological approach.

    The Eskihisar section comprises 47m and 56 samples of which 30 were usable for palynological analysis. The Tınaz section comprises 75 m and 29 samples of which 15 were usable for palynological analysis. Finally, the Salihpaşalar section comprises 25 m and 26 samples of which 16 were usable for palynological analysis. The age of the palynological sections is middle to late Miocene based on radiometric dating and vertebrate fossils.

     

    In order to investigate dispersed pollen and spores and their botanical affinities a combined light microscopy and scanning electron microscopy approach was used. The rich palynoflora comprises seven types of algal cysts (Botryococcus, Zygnemataceae), seventeen spore types (Lycopsida, Marsileaceae, Osmundaceae, Pteridaceae, Polypodiaceae), 14 types of gymnosperm pollen (Ephedraceae, Cupressaceae, Pinaceae), five types of monocotyledone pollen (Poaceae, Typhaceae) and ca 90 dicotyledone pollen types (Altingiaceae, Amaranthaceae, Anacardiaceae, Apiaceae, Aquifoliaceae, Asteraceae, Betulaceae, Campanulaceae, Cannabaceae, Caprifoliaceae, Caryophyllaceae, Ericaceae, Eucommiaceae, Euphorbiaceae, Fabaceae, Fagaceae, Geraniaceae, Juglandaceae, Lamiaceae, Linaceae, Lythraceae, Malvaceae, Myricaceae, Oleaceae, Onagraceae, Plumbaginaceae, Polygonaceae, Ranunculaceae, Rosaceae, Salicaceae, Sapindaceae, Sapotaceae, Ulmaceae).

     

    The objectives of this investigation were (1) to evaluate whether the three palynological sections were deposited at the same time, and (2) to show regional vegetation differences within a single sedimentary basin.

     

    We found three general pollen zones corresponding to different sedimentary settings and palaeoenvironments. The first pollen zone was linked to lignite formation (swamp forest, fern spores, Alnus, Decodon). The second pollen zone reflects lacustrine conditions (Typhaceae) and surrounding hinterland vegetation dominated by Fagaceae. The third pollen zone is dominated by herbaceous taxa, whereas woody taxa are less diverse and less abundant.

     

    In general, the three palynological sections are congruent in reflecting distinct pollen zones. However main vegetation types may be represented by different dominating taxa (e. g. Alnus dominace in Eskihisar and Tınaz localities while absent in Salihpaşalar) and rare taxa may differ between localities.

     

    Our results demonstrate that in order to achieve a comprehensive understanding of environmental and vegetation conditions in a sedimentary basin, a single palynological section (locality) may not capture the entirety of environmental conditions and changes.

  • 4.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    Zetter, Reinhard
    The middle Miocene palynoflora and palaeoenvironments of Eskihisar (Yatağan Basin, southwestern Anatolia):: a combined LM and SEM investigation2016In: Botanical journal of the Linnean Society, ISSN 0024-4074, E-ISSN 1095-8339, Vol. 182, no 1, p. 14-79Article in journal (Refereed)
    Abstract [en]

    Anatolia was a crossroads for mammal migration during the Miocene due to intermittent land connections between Africa and Anatolia and persisting warm conditions. Here, we investigated a palynological section from middle Miocene sediments of Eskihisar (southwestern Anatolia) in order to establish biogeographic links of the palynoflora and to infer the palaeoenvironment. Four algal palynomorphs, nine spore taxa, eight gymnosperms, three monocots, and 67 dicot pollen types were encountered and investigated using the “single grain method” that combines light microscopy and scanning electron microscopy. Two pollen zones reflect different phases of basin development. Zonal vegetation remained fairly stable across the section and reflects heterogeneous environments including broad-leaved deciduous forest, subtropical forest, and sclerophyllous and semi-evergreen oak forest. Conifers were accessory elements in the broad-leaved deciduous forest communities and replaced these at higher elevations. Some herbaceous taxa (Plumbaginaceae) indicate scattered occurrences of sandy and/or rocky soils. Biogeographic affinities are general Northern Hemispheric, North American, and East Asian as also suggested by the macro fossil record. Only two taxa provide potential biogeographic links with the African flora. This suggests that biome shifts of plant taxa between African subtropical /tropical biomes and Anatolian (western Eurasian) temperate forests and shrublands may have been rare in the middle Miocene.

  • 5. Bouchal, Johannes M.
    et al.
    Dojen, C.
    Denk, Thomas
    Die Neubearbeitung der fossilen Flora von Leše/Liescha am Landesmuseum für Kärnten: vorläufige Mitteilung2017In: Carinthia II, Vol. 207, no 127, p. 395-400Article in journal (Refereed)
  • 6.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    Zetter, Reinhard
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Some new pollen taxa from the middle Miocene of south western Anatolia2016Conference paper (Other academic)
    Abstract [en]

    In an ongoing study, focussing on the plant fossils and palynofloras of the lignite strip mines of the Yatağan basin(Muğla province), a number of pollen taxa, previously not reported from middle Miocene terrestrial sediments of Anatolia were encountered.

  • 7.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Güner, Tuncay H.
    Swedish Museum of Natural History, Department of Paleobiology. Faculty of Forestry, Department of Forest Botany, Istanbul University Cerrahpa¸sa, 34473 Bahçeköy, Istanbul, Turkey.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Middle Miocene climate of southwestern Anatolia from multiple botanical proxies2018In: Climate of the Past Discussions, ISSN 1814-9340, E-ISSN 1814-9359, Vol. 14, p. 1427-1440Article in journal (Other academic)
    Abstract [en]

    The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO2. The MMCT coincided with the European  Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia  and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed  open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we  infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8–13.2 Ma) of an intramontane basin in southwestern Anatolia using three2palaeobotanical proxies: (i) Köppen signatures based on the nearest-living-relative principle. (ii) Leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP). (iii) Genus-level biogeographic affinities of fossil floras with modern regions. The three proxies reject tropical climates for the MMCT of southwestern Anatolia and instead infer warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record does resolve transitions from the warm Miocene Climatic Optimum (MCO, 16.8–14.7 Ma) into the MMCT (14.7–13.9 Ma), and a more pronounced cooling at 13.9–13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO floras (MN5), whereas in MMCT floras (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7+8 dominated by herbaceous taxa. The boundary MN6 and MN7+8, roughly corresponding to a first abrupt cooling at 13.9–13.8 Ma, possibly might be associated with this herb-rich pollen zone.

  • 8.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Güner, Tuncay H.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Palynological and palaeobotanical investigations in the Miocene Yatağan basin, Turkey: High-resoluton taxonomy and biostratigraphy2015Conference paper (Other academic)
    Abstract [en]

    The subject of this study is the palynology (biostratigraphic and taxonomic) and the plant remains of the lignite strip mines of Eskihisar, Salihpasalar, and Tinaz (Muğla province, western Turkey). In the Yatağan basin two Miocene to Pliocene formations are present, the Eskihisar Formation (early to middle Miocene) and the Yatağan Formation (late Miocene to early Pliocene). Both formations represent river and lake deposits consisting mainly of conglomerate, sandstone, claystone, limestone, tuffite, and intercalated lignite; the thickest, actively mined lignite seams occur in the Sekköy member of the Eskihisar Formation.

    Previous palynological studies of the palynoflora of the Yatağan basin mainly focussed on its biostratigraphic and palaeoclimatic significance, using conventional morphological nomenclature and light microscopy (LM).

    In this study the „single grain method“ is applied. Using this method, the same individual pollen grains are investigated by using both LM and scanning electron microscopy (SEM). The resulting high-resolution pictographs enable a much higher taxonomic resolution.

     

    The studied palynoflora is very rich and taxonomically diverse. Cryptogams are represented by more than ten spore morphotypes of at least three families (Osmundaceae, Pteridaceae, Polypodiaceae). Gymnosperm pollen is dominated by Cupressaceae, Gnetales (Ephedra), and Pinaceae (Cathaya, Keteleeria, Pinus). Angiosperm pollen can be assigned to 57 different genera belonging to Poaceae, Typhaceae, Altingiaceae, Amaranthaceae (Chenopodieae), Anacardiaceae, Apiaceae (three types), Asteraceae (Asteroideae, Cichoriodeae), Betulaceae (Alnus, Betula, Carpinus, Ostrya) Buxaceae, Campanulaceae, Caprifoliaceae (Lonicera), Caryophyllaceae, Dipsacaceae, Eucommiaceae, Euphorbiaceae, Fabaceae, Fagaceae (Fagus, Quercus, Trigonobalanopsis) Geraniaceae, Juglandaceae, Linnaceae (Linnum), Malvaceae, Myricaceae, Nymphaeaceae, Oleaceae (four different types), Plumbaginaceae (Armeria,), Polygonaceae (Rumex), Rosaceae, Sapindaceae (Acer), Ulmaceae (Cedrelospermum, Ulmus, Zelkova), and Zingiberales (Spirematospermum).

     

    In addition, more than two thousand plant macrofossils were collected in the course of repeated field trips, including remains of Pinaceae, Berberidiaceae (Mahonia), Betulaceae (Alnus, Carpinus), Buxaceae (Buxus), Fagaceae (Fagus, Quercus), Lauraceae, Malvaceae (Tilia), Myricaceae (Myrica), Rosaceae, Salicaceae (Populus, Salix), Sapindaceae (Acer), Smilacaceae (Smilax), Typhaceae (Typha), Ulmaceae (Zelkova).

     

    A combined analysis integrating these rich and diverse plant macro- and microfossil records will lead to a better understanding and refined reconstruction of the vegetation in the Yatağan basin during the middle to late Miocene.

  • 9. Bouchal, Johannes, M.
    et al.
    Mayda, S.
    Akgün, F.
    Grímsson, F.
    Zetter, R.
    Denk, Thomas
    Miocene palynofloras of the Tınaz lignite mine, Muğla, southwest Anatolia: taxonomy, palaeoecology and local vegetation change2017In: Review of Palaeobotany and Palynology, ISSN 0034-6667, E-ISSN 1879-0615, Vol. 243, p. 1-36Article in journal (Refereed)
  • 10.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mayda, Serdar
    Natural History Museum, Ege University, 35100 Izmir, Turkey.
    Zetter, Reinhard
    University of Vienna, Department of Palaeontology, Vienna, Austria.
    Grímsson, Fridgeir
    University of Vienna, Department of Palaeontology, Vienna, Austria.
    Akgün, Funda
    Dokuz Eylül University, Department of General Geology, 35210 Izmir, Turkey.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Miocene palynofloras of the Tınaz lignite mine, Muğla, southwest Anatolia: taxonomy, palaeoecology and local vegetation change2017In: Review of Palaeobotany and Palynology, ISSN 0034-6667, E-ISSN 1879-0615, Vol. 243, p. 1-36Article in journal (Refereed)
    Abstract [en]

    Middle Miocene deposits exposed at the Tınaz lignite mine, Yatağan Basin, Muğla, southwestern Turkey, were palynologically investigated. The Tınaz lignite mine section belongs to the Eskihisar Formation. The lignite seam at the base of the section represents the uppermost part of the Turgut Member. Above, c. 65 m of clayey siltstone, limestone, and marls represent the Sekköy Member. Nine spores, zygospores and cysts of fungi and algae, seven moss and fern spores, 12 gymnosperm pollen types, and more than 80 angiosperm pollen taxa were recovered from the Tınaz lignite mine section. Three pollen zones were recognized, of which pollen zone 1 corresponds to the formation of the main lignite seam and reflects the change from a fluviatile to a lacustrine depositional setting. Pollen zones 2 and 3 and a transitional zone 2-3 reflect different stages of lake development and a shift in local vegetation from forested (pollen zones 1 and 2) to more open (transitional zone 2-3, zone 3). Interpreting changes in regional vegetation from pollen zones 1 to 3 is not straightforward as changes in the pollen spectra may be affected by changing contributions of airborne and water transported pollen and spores to the observed palynoassemblages. Age inference for the Tınaz lignite mine section has been complicated by the absence of datable ash layers, associated mammal faunas, or marine sediments. However, pollen zone 3 shares key features with the pollen spectrum recovered from the nearby mammal site Yenieskihisar (upper part of Sekköy Member) for which an age of 12.5-11.2 Ma has been suggested, and to the youngest pollen zone recovered from the mammal locality Çatakbağyaka, 10 km south of Tınaz, that probably represents mammal zone MN7/8 instead of MN5 or MN6 as previously suggested. In contrast, pollen zones 1 and 2 are fairly similar to the basal parts of the Çatakbağyaka pollen flora (uppermost parts of Turgut Member, basalmost parts of Sekköy Member). Furthermore, new mammal data from the Yatağan basin suggest that the layers below pollen zone 1 are MN4/5, and that carnivores cooccuring with pollen zone 1 in the main lignite seam of Eskihisar probably belong to MN6. Hence, a Langhian to Serravallian age can be inferred for pollen zones 1 and 2 of the Tınaz lignite mine section, and a late Serravallian age for pollen zone 3. Palaeobiogeographic relationships of the palynofloras are generally northern hemispheric, with many north temperate tree taxa showing modern disjunctions East Asia- NorthAmerica (Tsuga, Carya), East Asia- western Eurasia (Zelkova), East Asia- North America- western Eurasia (Liquidambar), or restricted to East Asia (Cathaya, Eucommia) or North America (Decodon). A few taxa belong to extinct lineages that have complex biogeographic patterns (Engelhardioideae, Cedrelospermum). The presence of Picrasma (Simaroubaceae) in the lower lignite layers of pollen zone 1 is remarkable, as the botanical affinities with the enigmatic flower Chaneya present in early to middle Miocene deposits of Turkey and Central Europe have recently been shown to be with Picrasma

  • 11. Denk, Thomas
    Palaeoecological interpretation of the late Miocene landscapes and vegetation of northern Greece: a comment to Merceron et al., 2016 (Geobios, doi:10.1016/j.geobios.2016.01.004).2016In: Geobios, ISSN 0016-6995, E-ISSN 1777-5728, Vol. 49, p. 135-146Article in journal (Refereed)
  • 12. Denk, Thomas
    Zohner, Constantin M. (Contributor)
    Renner, Susanne S.
    Plant fossils reveal major biomes occupied by the late Miocene Old-World Pikermian fauna2018In: Nature Ecology & Evolution, E-ISSN 2397-334X, Vol. 2, p. 1864-1870Article in journal (Refereed)
  • 13. Denk, Thomas
    et al.
    Grimm, Guido W.
    Manos, Paul S.
    Deng, Min
    Hipp, Andrew S.
    An updated infrageneric classification of the oaks: review of previous taxonomic schemes and synthesis of evolutionary patterns2017In: Oaks Physiological Ecology. Exploring the Functional Diversity of Genus Quercus / [ed] Gil-Peregrin, E., Peguero-Pina, J.J., Sancho-Knapik, D., Cham, Switzerland: Springer, 2017, 1, p. 13-38Chapter in book (Refereed)
    Abstract [en]

    In this chapter, we review major classification schemes proposed for oaksby John Claudius Loudon, Anders Sandøe Ørsted, William Trelease, Otto Karl AntonSchwarz, Aimée Antoinette Camus, Yuri Leonárdovich Menitsky, and Kevin C.Nixon. Classifications of oaks (Fig. 2.1) have thus far been based entirely on morphologicalcharacters. They differed profoundly from each other because each taxonomistgave a different weight to distinguishing characters; often characters that arehomoplastic in oaks. With the advent of molecular phylogenetics our view hasconsiderably changed. One of the most profound changes has been the realisation thatthe traditional split between the East Asian subtropical to tropical subgenusCyclobalanopsis and the subgenus Quercus that includes all other oaks is artificial.The traditional concept has been replaced by that of two major clades, each comprisingthree infrageneric groups: a Palearctic-Indomalayan clade including GroupIlex (Ilex oaks), Group Cerris (Cerris oaks) and Group Cyclobalanopsis (cycle-cupoaks), and a predominantly Nearctic clade including Group Protobalanus (intermediateor golden cup oaks), Group Lobatae (red oaks) and Group Quercus (white oaks, with most species in America and some 30 species in Eurasia). In addition, recentphylogenetic studies identified two distinct clades within a wider group of white oaks: the Virentes oaks of North America and a clade with two disjunct endemic species inwestern Eurasia and western North America, Quercus pontica and Q. sadleriana. Themain morphological feature characterising these phylogenetic lineages is pollenmorphology, a character overlooked in traditional classifications. This realisation,along with the now available (molecular-)phylogenetic framework, opens new avenuesfor biogeographic, ecological and evolutionary studies and a re-appraisal of thefossil record. We provide an overview about recent advances in these fields andoutline how the results of these studies contribute to the establishment of a unifyingsystematic scheme of oaks. Ultimately, we propose an updated classification ofQuercus recognising two subgenera with eight sections. This classification considersmorphological traits, molecular-phylogenetic relationships, and the evolutionaryhistory of one of the most important temperate woody plant genera.

  • 14. Denk, Thomas
    et al.
    Güner, H. T.
    Grimm, G. W.
    From mesic to arid: Leaf epidermal features suggest preadaptation in Miocene dragon trees (Dracaena)2014In: Review of Palaeobotany and Palynology, Vol. 200, p. 211-228Article in journal (Refereed)
  • 15.
    Denk, Thomas
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Güner, Tuncay H.
    , Istanbul University, Istanbul, Turkey.
    Kvaček, Zlatko
    Charles University, Prague, Czech Republic.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology. johannes.bouchal@nrm.se.
    The early Miocene flora of Güvem (Central Anatolia, Turkey): a window into early Neogene vegetation and environments in the Eastern Mediterranean2017In: Acta Palaeobotanica, ISSN 0001-6594, E-ISSN 1427-6402, Vol. 57, no 2, p. 237-338Article in journal (Refereed)
    Abstract [en]

    The early Burdigalian (MN3) plant assemblage of the Güvem area (northwestern Central Anatolia) is preserved in lacustrine sediments of the Dereköy pyroclastics. Its age is well constrained by radiometric dates of basaltic rocks bracketing the pyroclastics, making the Güvem flora one of the extremely few precisely dated early Miocene floras in the Mediterranean region. The rich assemblage of impression fossils comprises ferns and fern allies (2 species), gymnosperms (12 spp.) and angiosperms (129 spp.). Ilex miodipyrena sp. nov. is described as a new fossil-species. The most diverse families in the assemblage are the Fagaceae with 12 taxa and the Fabaceae with 12 leaf morphotypes and one fruit taxon. Aquatic plants are represented by seven taxa, riparian (including palms) and swamp forest elements by >35 taxa, and lianas by three taxa (Smilax spp., Chaneya). The relatively large number of aquatic and riparian/swamp elements is congruent with the rich fish, amphibian and reptile record of the Güvem area. Another characteristic feature of the plant assemblage is the presence of various lobed leaves which show similarities with modern species of different families (e.g. Alangium, various Malvales). Trees and shrubs growing on well-drained soils and forming closed-canopy and open-canopy forests are the most diversified group (>70 taxa). In terms of number of specimens in the collection and based on field observations, by far the most abundant leaf fossils belong to evergreen oaks of Quercus drymeja and Q. mediterranea and to various types of foliage that cannot be assigned to a particular extant or extinct genus of Fagaceae. These sclerophyllous trees must have covered vast areas surrounding the wetlands that developed during the early Miocene in the Güvem Basin. Based on a recent reassessment of the ecology and taxonomic affinity of these trees, they are considered to reflect humid temperate climatic conditions but with a brief drier season during the winter months. These forests are more similar to the laurel forests of the southeastern United States and those stretching in a narrow belt south of the Himalayas to eastern central China. The large number of Fabaceae may indicate the presence of warm subtropical environments but this is difficult to assess, as they are known for having wide ecological ranges today and in the past. All in all, a larger part of the plant taxa point to forested vegetation. This is in agreement with previous palynological studies which detected only small amounts of herbaceous and grass pollen. Open patches of vegetation may have been restricted to river banks and to rocky areas in a volcanic landscape. The biogeographic patterns detected for the early Miocene of the Güvem assemblage are manifold; most taxa are widespread Northern Hemispheric elements. A substantial part of the species migrated from Asia into Europe during the (late) Paleogene and reached Anatolia during the early Miocene (Fagus, Paliurus, Chaneya, Ailanthus, Quercus kubinyii, Davallia haidingeri, Acer angustilobum, A. palaeosaccharinum). Fewer taxa may have been in Anatolia before they migrated to Europe (e.g. Nerium, Smilax miohavanensis, Quercus sosnowskyi). Finally, very few taxa are Anatolian endemics (e.g. Ilex miodipyrena).

  • 16. Denk, Thomas
    et al.
    Tekleva, Maria V.
    Pollen morphology and ultrastructure of Quercus with focus on Group Ilex (=Quercus Subgenus Heterobalanus (Oerst.) Menitsky): implications for oak systematics and evolution2014In: Grana, ISSN 0017-3134, E-ISSN 1651-2049, Vol. 53, p. 255-282Article in journal (Refereed)
  • 17.
    Denk, Thomas
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Velitzelos, Dimitrios
    National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Department of Historical Geology and Paleontology, Panepistimiopolis, Athens 15784, Greece.
    Güner, Tuncay H.
    Istanbul University, Faculty of Forestry, Department of Forest Botany, 34473 Bahceköy, Istanbul, Turkey.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    University of Vienna, Department of Palaeontology, 1090 Vienna, Austria.
    Grimm, Guido
    Department für Paläontologie, Universität Wien, Wien, Austria.
    Taxonomy and palaeoecology of two widespread western Eurasian Neogene sclerophyllous oak species: Quercus drymeja Unger and Q. mediterranea Unger2017In: Review of Palaeobotany and Palynology, ISSN 0034-6667, E-ISSN 1879-0615, ISSN 0034-6667, Vol. 241, p. 98-128Article in journal (Refereed)
    Abstract [en]

    Sclerophyllous oaks (genus Quercus) play important roles in Neogene ecosystems of south-western Eurasia. Modern analogues (‘nearest living relatives’) for these oaks have been sought among five of six infrageneric lineages of Quercus, distributed across the entire Northern Hemisphere. A revision of leaf fossils from lower Miocene to Pliocene deposits suggests that morphotypes of the Quercus drymeja complex are very similar to a number of extant Himalayan, East Asian, and Southeast Asian species of Quercus Group Ilex and may indicate subtropical, relatively humid conditions. Quercus mediterranea comprises leaf morphotypes that are encountered in modern Mediterranean species of Quercus Group Ilex, but also in Himalayan and East Asian members of this group indicating fully humid or summer-wet conditions. The fossil taxa Quercus drymeja and Q. mediterranea should be treated as morphotype complexes, which possibly comprised different biological species at different times. Quercus mediterranea, although readily recognizable as a distinct morphotype in early to late Miocene plant assemblages, may in fact represent small leaves of the same plants that constitute the Quercus drymeja complex. Based on the available evidence, the taxa [GG1] forming the Q. drymeja complex and Q. mediterranea thrived in fully humid or summer-wet climates. The onset of the modern vegetational context of Mediterranean sclerophyllous oaks is difficult to trace, but may have been during the latest Pliocene/early Pleistocene.

  • 18.
    Denk, Thomas
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Zohner, Constantin M.
    Institute of Integrative Biology, ETH Zurich (Swiss Federal Institute of Technology), Zurich, Switzerland..
    Grimm, Guido W.
    unaffiliated.
    Renner, Susanne S.
    Plant fossils reveal major biomes occupied by the late Miocene Old-World Pikermian fauna2018In: Nature Ecology & Evolution, E-ISSN 2397-334X, Vol. 2, p. 1864-1870Article in journal (Refereed)
    Abstract [en]

    Reconstruction of palaeobiomes, ancient communities that exhibit a physiognomic and functional structure controlled by their environment, depends on proxies from different disciplines. Based on terrestrial mammal fossils, the late Miocene vegetation from China to the eastern Mediterranean and East Africa has been reconstructed as a single cohesive biome with increasingly arid conditions, with modern African savannahs the surviving remnant. Here, we test this reconstruction using plant fossils spanning 14–4 million years ago from sites in Greece, Bulgaria, Turkey, the Tian Shan Mountains and Baode County in China, and East Africa. The western Eurasian sites had a continuous forest cover of deciduous or evergreen angiosperms and gymnosperms, with 15% of 1,602 fossil occurrences representing conifers, which were present at all but one of the sites. Raup–Crick analyses reveal high floristic similarity between coeval eastern Mediterranean and Chinese sites, and low similarity between Eurasian and African sites. The disagreement between plant-based reconstructions, which imply that late Miocene western Eurasia was covered by evergreen needleleaf forests and mixed forests, and mammal-based reconstructions, which imply a savannah biome, throws into doubt the approach of inferring Miocene precipitation and open savannah habitats solely from mammalian dental traits. Organismal communities are constantly changing in their species composition, and neither animal nor plant traits by themselves are sufficient to infer entire ancient biomes. The plant fossil record, however, unambiguously rejects the existence of a cohesive savannah biome from eastern Asia to northeast Africa.

  • 19. Grimm, G. W.
    et al.
    Denk, Thomas
    The Colchic region as refuge for relict tree lineages: cryptic speciation in field maples2014In: Turkish Journal of Botany, ISSN 1300-008X, E-ISSN 1303-6106, Vol. 38, p. 1050-1066Article in journal (Refereed)
  • 20. Grimm, Guido
    et al.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Potts, Alastair
    Fables and foibles: A critical analysis of the Palaeoflora database and the Coexistence Approach for palaeoclimate reconstruction2016In: Review of Palaeobotany and Palynology, ISSN 0034-6667, E-ISSN 1879-0615, Vol. 233, p. 216-235Article in journal (Refereed)
    Abstract [en]

    The ‘Coexistence Approach’ is amutual climate range (MCR) technique combinedwith the nearest-living relative (NLR) concept. It has been widely used for palaeoclimate reconstructions based on Eurasian plant fossil assemblages; most of them palynofloras (studied using light microscopy). The results have been surprisingly uniform, typically converging to subtropical, per-humid or monsoonal conditions. Studies based on the Coexistence Approach have had a marked impact in literature, generating over 10,000 citations thus far. However, recent studies have pointed out inherent theoretical and practical problems entangled in the application of this widely used method. But so far little is known how results generated by the Coexistence Approach are affected by subjective errors, data errors, and violations of the basic assumptions. The majority of Coexistence Approach studies make use of the Palaeoflora database (the combination of which will be abbreviated to CA + PF). Testing results produced by CA + PF studies has been hindered by the general unavailability of the contents in the underlying Palaeoflora database; two exceptions are the mean-annual temperature tolerances and lists of assigned associations between fossils and nearest-living relatives. Using a recently published study on the Eocene of China,which provides the first and only insight into the data structure of the Palaeoflora database,we compare the theory and practice of Coexistence Approach using the Palaeoflora database (CA+PF).We show that CA+PF is riddled by association and climate data error.We reveal flaws in the application of the Coexistence Approach,which is often in stark contrast to the theory of the method. We show that CA + PF is highly vulnerable against numerous sources of errors, mainly because it lacks safeguards that could identify unreliable data. We demonstrate that the CA+PF produces coherent, pseudo-precise results even for artificially generated, randomplant assemblages. AlternativeMCR-NLR methods can surpass the most imminent deficits of the Coexistence Approach, and may be used as a stop-gap until more accurate bioclimatic and distribution data on potential Eurasian NLRs, and theoretically and statistically robust methods will become available. Finally, general guidelines are provided for the future application of methods using the mutual climatic range with nearest living relatives approach when reconstructing climate from plant fossil assemblages.

  • 21. Grímsson, F
    et al.
    Zetter, R.
    Grimm, G. W.
    Pedersen, G. K.
    Pedersen, A. K.
    Denk, Thomas
    Fagaceae pollen from the early Cenozoic of West Greenland: revisiting Engler’s and Chaney’s Arcto-Tertiary hypotheses2014In: Plant Systematics and Evolution, ISSN 0378-2697, E-ISSN 1615-6110, Vol. 301, p. 809-832Article in journal (Refereed)
  • 22. Grímsson, Fridgeir
    et al.
    Grimm, Guido W.
    Zetter, Reinhard
    Denk, Thomas
    Cretaceous and Paleogene Fagaceae from North America and Greenland: evidence for a Late Cretaceous split between Fagus and the remaining Fagaceae.2016In: Acta Palaeobotanica, ISSN 0001-6594, E-ISSN 1427-6402, Vol. 56, p. 247-305, article id DOI: 10.1515/acpa-2016-0016.Article in journal (Refereed)
  • 23. Güner, H. Tuncay
    et al.
    Bouchal, Johannes M.
    Köse, N.
    Denk, Thomas
    Wetter and cooler: pronounced temperate climate conditions in western Anatolia during the Middle Miocene Climatic Optimum2017Conference paper (Other academic)
  • 24.
    Güner, Tuncay H.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology. Faculty of Forestry, Department of Forest Botany, Istanbul University Cerrahpa¸sa, 34473 Bahçeköy, Istanbul, Turkey.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology.
    Köse, Nesibe
    University of Istanbul, Faculty of Forestry, Department of Forest Botany, Istanbul, Turkey.
    Göktaş, Fikret
    Mayda, Serdar
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Landscape heterogeneity in the Yatağan Basin (southwestern Turkey) during the middle Miocene inferred from plant macro fossils2017In: Palaeontographica. Abteilung B, Palaophytologie, ISSN 0375-0299, Vol. 296, p. 113-171Article in journal (Refereed)
    Abstract [en]

    Plant macro fossils from the lignite mines of Eskihisar, Tınaz, and Salihpaşalar (Yatağan Basin, southwestern Anatolia) were investigated. The fossils were collected from marls overlying the exploited lignite seams and represent three subbasins within the main Yatağan Basin. The age of the Eskihisar lignite seam is well constrained by vertebrate fossils (MN 6, middle Miocene). Further, lithological and palynological correlation suggests that the lignite seams and overlying marls in the three lignite mines were formed at the same time. Three distinct zonal vegetation types are reflected in the local plant assemblages: (i) In Eskihisar, Fagus and evergreen Quercus mediterranea-Q. sosnowskyi communities formed important parts of the zonal vegetation along with the deciduous Quercus kubinyii; (ii) in Tınaz, Quercus sosnowskyi-Q. mediterranea-Q. drymeja communities occurred, while Fagus is rarely encountered in the macrofossil record. (iii) In Salihpaşalar, Quercus mediterranea and Q. drymeja are the most abundant elements, while Fagus and Q. sosnowskyi are absent or nearly so. This demonstrates that local environmental conditions within a geographically restricted region varied and probably were controlled by slope aspects, edaphic conditions, and river drainage. Overall, the zonal vegetation is characterized by a high diversity of evergreen and deciduous oaks belonging to Quercus subgen. Cerris sect. Ilex and sect, Cerris and the local dominance of Fagus. The riparian vegetation was dominated by Populus, Salix and Acer, whereas Alnus and taxodiaceous Cupressaceae and ferns were very rare or absent. The mass occurrence of Quercus sosnowskyi in the Yatağan Basin floras is biogeographically interesting, as this distinct sclerophyllous oak has previously been known to occur only in late Miocene sediments of northern Greece and Abkhasia (Georgia). 

  • 25. Renner, Susanne S.
    et al.
    Grimm, Guido W.
    Kapli, Pashalia
    Denk, Thomas
    Species relationships and divergence times of beeches (Fagus): New insights from the inclusion of numerous fossil beech species in a birth-death clock approach.2016In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, article id DOI: 10.1098/rstb.2015.0135Article in journal (Refereed)
  • 26. Sadowski, Eva-Maria
    Denk, Thomas (Contributor)
    Synchrotron X- ray imaging of a dichasium cupule of Castanopsis from Eocene Baltic amber2018In: American Journal of Botany, ISSN 0002-9122, E-ISSN 1537-2197, Vol. 105, no 12, p. 1-12Article in journal (Refereed)
  • 27.
    Sadowski, Eva-Maria
    et al.
    Department of Geobiology, University of Göttingen Goldschmidtstraße 3, 37077 Göttingen, Germany.
    Hammel, Jörg U.
    Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Synchrotron X-rayimaging of a dichasium cupule of Castanopsis from Eocene Baltic amber2018In: American Journal of Botany, ISSN 0002-9122, E-ISSN 1537-2197, Vol. 105, p. 2015-2036Article in journal (Refereed)
    Abstract [en]

    The partial female inflorescence reported here provides an important addition to acorns of Castanopsis described from middle Eocene strata of Europe. Furthermore, the intercontinental distribution of Castanopsis in the Eocene is confirmed. The amber fossil also broadens the picture of the Baltic amber source area, indicating oligotrophic, sandy, bog-like habitats. Finally, this study underscores the great benefit of SRμCT as a powerful tool to investigate plant inclusions from amber in a nondestructive way.

  • 28. Simeone, Marco C.
    Piredda, Roberta (Contributor)
    Imperatori, F. (Contributor)
    Avishai, Michael (Contributor)
    Grimm, Guido W. (Contributor)
    Denk, Thomas
    Comparative systematics and phylogeography of Quercus Section Cerris in western Eurasia: inferences from plastid and nuclear DNA variation2018In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 6, no e5793Article in journal (Refereed)
  • 29. Simeone, Marco Cosimo
    et al.
    Grimm, Guido W.
    Papini, A.
    Vessella, F.
    Cardoni, S
    Tordoni, E.
    Piredda, R.
    Franc, A.
    Denk, Thomas
    Plastome data reveal multiple geographic origins of Quercus Group Ilex.2016In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 4:e, no 1897, article id DOI 10.7717/peerj.1897Article in journal (Refereed)
  • 30.
    Velitzelos, Demitrios
    et al.
    Athens University.
    Bouchal, Johannes Martin
    Swedish Museum of Natural History, Department of Paleobiology. University of Vienna.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Review of the Cenozoic floras and vegetation of Greece2014In: Review of Palaeobotany and Palynology, ISSN 0034-6667, Vol. 204, p. 56-117Article in journal (Refereed)
    Abstract [en]

    Oligocene to Pleistocene floras of Greece are reviewed based on published and unpublishedmaterial. Oldest plant-bearing sediments of Rupelian–Chattian age are exposed in eastern Thrace (Evros) and were deposited after the closure of the Turgai Seaway. They contain a blend of (i) taxa that migrated to western Eurasia from the East (Alnus, Fagus), (ii) characteristic Oligocene taxa (Nyssa altenburgensis, Ampelopsis hibschii), and (iii) extinct (Eotrigonobalanus, Quasisequoia) and modern genera (Calocedrus, Quercus Group Lobatae) from older epochs. Coastal palmswamps and laurel forests of the hinterland indicate a subtropical, fully humid to winter-dry climate (Cfa, Cwa according to Köppen). The Aquitanian–Burdigalian plant assemblage of Lesbos is intermediary between Evros and the Burdigalian floras of Euboea sharing taxa with Evros (palms), and with Euboea and early Miocene floras of Anatolia (Güvem, Tilia). In the early Miocene (Burdigalian) floras of Euboea, species of Quercus Group Ilex (Quercus drymeja, Quercus mediterranea) characteristic of fully humid or winter-dry (monsoon) climates (Cf, Cw) became dominant elements in well-drained forests. Floristic links are with late Oligocene to middle Miocene floras of Central Asia (Tilia), AsiaMinor (cycads, Quercus Group Ilex, Tilia), and South and Central Europe (cycads, Quercus Group Ilex, palms). Middle Miocene floras are restricted to the Aegean Islands (Chios). Biogeographic links arewith early to lateMiocene floras of Central Europe (Parrotia, Podocarpium) andwithmiddle Miocene floras of Anatolia (Parrotia). UpperMiocene plant-bearing sedimentary formations aremost abundant in Greece and exposed on the Ionian Islands, Greece mainland to East Macedonia, Peloponnese, Aegean Islands, and Crete. Overall, the fossil plant assemblages from Greece mainland are indicative of fully humid conditions during this time (Cfa), with Fagus and oaks of Quercus Group Ilex being dominant elements. Seasonality may have been more pronounced on the Peloponnese and the Aegaean Islands and Crete, expressed by the rare occurrence of Fagus in the fossil records of these areas. The palaeobotanical records from Samos unambiguously point to the presence of forest vegetation during early Tortonian to Messinian (Cwa) when the famous vertebrate faunas of Samos were deposited. The Pliocene is characterized by the regional occurrence of modern types of deciduous oaks mainly of Quercus Group Cerris and Quercus subsect. Galliferae. East Asian links persist in Fagus, Quercus, and Cupressaceae,North American ones in Sabal; several othermesophytic taxa fromprevious periods are recorded as well. The modern sclerophyllous Mediterranean vegetation, thriving in a warm summer dry climate (Csa), cannot be traced prior to the Pleistocene based on the palaeobotanical record.

  • 31. Vitelli, M.
    et al.
    Vesella, F.
    Cardoni, S.
    Pollegioni, P.
    Denk, Thomas
    Grimm, Guido, W.
    Simeone, Marco Cosimo
    Phylogeographic structuring of plastome diversity in Mediterranean oaks (Quercus Group Ilex, Fagaceae)2017In: Tree Genetics & Genomes, ISSN 1614-2942, E-ISSN 1614-2950, Vol. 13, no 3, article id 10.1007/s11295-016-1086-8Article in journal (Refereed)
1 - 31 of 31
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