| 1. |
- Adroit, Benjamin, et al.
(författare)
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Are morphological characteristics of Parrotia (Hamamelidaceae) pollen species diagnostic?
- 2022
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Ingår i: Review of Palaeobotany and Palynology. - Amsterdam : Elsevier BV. - 0034-6667 .- 1879-0615. ; 307, s. 104776-104776
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Tidskriftsartikel (refereegranskat)abstract
- Parrotia persica is one of the most notable endemic relict tree species growing in the Hyrcanian forest at the southern Caspian Sea. The recent discovery of sibling species Parrotia subaequalis, occurring in the temperate forests of south-eastern China, offers the opportunity to compare their morphology and ecological preferences and to dig deeper into the paleophytogeographic history of the genus from a perspective. Since pollen morphology of these species would be essential to unravel the origin and evolution of these Arcto-Tertiary species, the present study aimed to investigate whether it is possible to segregate pollen from these two species. Therefore, a detailed combined light- and scanning electron microscopy-based pollen-analysis of each taxon was conducted, the pollen was described, measured, and compared using statistical approaches and principal component analyses to establish unbiased results. The correlation-based principal component analysis achieved for each species shows an overall good superposition of pollen grains measured in equatorial and polar views in the first principal plane, revealing that the P. persica pollen is morphometrically as homogeneous as that of P. subaequalis. Then, the significant difference, mainly driven by lumen density, has been highlighted between the two species. Ultimately, the cross-validation of the resulting two-species linear discriminants classifier shows that based upon this reference dataset, (sub)fossil pollen grain can now be confidently assigned to either of the two species with an 85.8% correct-assignment rate. This opens new doors in the affiliation of fossil Parrotia pollen and suggests that previous pollen records need to be revised.
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| 2. |
- Bouchal, Johannes M., 1979-, et al.
(författare)
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Miocene palynofloras of the Tınaz lignite mine, Muğla, southwest Anatolia: taxonomy, palaeoecology and local vegetation change
- 2017
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Ingår i: Review of Palaeobotany and Palynology. - Amsterdam : Elsevier. - 0034-6667 .- 1879-0615. ; 243, s. 1-36
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Bouchal, Johannes M., 1979-
(författare)
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Pollen and spores of the uppermost Eocene Florissant Formation, Colorado: A combined light and scanning electron microscopy study
- 2016
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Ingår i: Grana. - : Taylor & Francis Group. - 0017-3134 .- 1651-2049. ; 55:3, s. 179-245
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Bouchal, Johannes M., 1979-, et al.
(författare)
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Some new pollen taxa from the middle Miocene of south western Anatolia
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 5. |
- Bouchal, Johannes M., 1979-, et al.
(författare)
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The middle Miocene palynoflora and palaeoenvironments of Eskihisar (Yatağan Basin, southwestern Anatolia): : a combined LM and SEM investigation
- 2016
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Ingår i: Botanical journal of the Linnean Society. - : John Wiley & Sons. - 0024-4074 .- 1095-8339. ; 182:1, s. 14-79
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
- Geier, Christian, et al.
(författare)
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Paleovegetation and paleoclimate inferences of the early late Sarmatian palynoflora from the Gleisdorf Fm. at Gratkorn, Styria, Austria
- 2022
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Ingår i: Review of Palaeobotany and Palynology. - Amsterdam : Elsevier. - 0034-6667 .- 1879-0615. ; 307, s. 1-65
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Tidskriftsartikel (refereegranskat)abstract
- The Gleisdorf Formation (Fm.) deposits in the clay pit at Gratkorn, Styria, Austria, are dated to 12.2–12 Ma,and are of late Middle Miocene age (late Serravallian or Sarmatian). To reconstruct the paleovegetation and estimate the paleoclimate at this important vertebrate site, the palynoflora close to the boundary between the vertebrate-bearing layers of the Gratkorn Fm. and the overlying limnic clay deposits of the Gleisdorf Fm. was investigated. Using the single-grain method, 140 palynomorphs were identified. The palynoflora suggests that the paleovegetation was characterised by well-drained lowland and upland forests, riparian forest, and swamp forests. Depending on the dominating tree species, lowland and upland forests might have had closed or more open canopies. Open habitats included wet meadows and shrublands. In addition, conifers were present in theswampy lowlands and the forested uplands. The most prominent paleoclimatic signatures of the palynoflora indicate a fully humid warm temperate climate, with hot to warm summers and cool winters (Cfa-, Cfb-climate), and a seasonal climate with cool and drier winters and hot to warm and wetter summers (Cwa-, Cwb-climate). Our results align with existing studies bordering the Styrian Basin and support the presence of subtropical to warm-temperate vegetation around Gratkorn during the Sarmatian.
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| 7. |
- Grímsson, Fridgeir, et al.
(författare)
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Cenozoic vegetation and phytogeography of the sub-arctic North Atlantic
- 2021
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Ingår i: Biogeography in the Sub-Arctic: The Past and Future of the North Atlantic Biotas. - : John Wiley & Sons. - 9781118561478 ; , s. 29-49
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Bokkapitel (refereegranskat)abstract
- This chapter provides a review of Cenozoic plant assemblages from the sub-arctic North Atlantic region and their biogeographic implications. Previous work is reviewed and new data are presented that considerably change our understanding of the role of the northern North Atlantic for plant dispersal and evolution of plant lineages during the Paleogene and Neogene. Paleogene plant fossils in this region are known from West and East Greenland, the Faroe Islands and Scotland. In contrast to the widely held view that most Paleogene plant taxa of Greenland belong to extinct lineages, we provide evidence for the presence of several extant genera in these floras (e.g. Fagus, Quercus). Thus, Engler’s hypothesis about the ‘Arcto-Tertiary element’ remains a fundamental hypothesis about the origin of northern temperate tree genera. In general, a remarkable diversity of extinct and modern lineages of Fagaceae is documented for Palaeocene and Eocene floras. Neogene fossils are found in Iceland and provide records of climate evolution in the sub-arctic North Atlantic and of the duration of a functioning land bridge for plant migration between North America and Europe. Counter to the traditional view suggesting a functioning land bridge only during the Paleogene, there isnow convincing evidence that this link was available for plants until the latest Miocene. This has important implications for understanding low genetic differentiation documented in extant plant groups having a disjunct distribution in northern temperate regions of Europe, North America and East Asia. Relatively warm conditions persisted in the sub-arctic North Atlantic until the end of the Zanclean (early Pliocene) based on plant fossil evidence from Iceland. The shift to modern tundra conditions occurred during the Piacenzian (late Pliocene) and is documented in the Pliocene and Pleistocene fossil plant assemblages of Iceland.
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| 8. |
- Grímsson, F.
(författare)
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Combined LM and SEM study of the middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin, Austria: Part III. Magnoliophyta 1 – Magnoliales to Fabales
- 2015
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Ingår i: Grana. - 0017-3134 .- 1651-2049. ; 54, s. 85-128
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies on the palynoflora from the Lavanttal Basin show that it contains a richassemblage of spores and gymnosperm pollen. Present and ongoing investigations ofdispersed angiosperm pollen suggest a high diversity within this group, and due to theexcellent preservation of the material some rare pollen types are recognized. The Magnolialesto Fabales pollen record documented here contains 30 different taxa. Only a few pollen typesare assigned to Magnoliids (four taxa); these are rare in the pollen record. Similarly, theCommelinids comprise five taxa and are also rare. Most of the angiosperm pollen originatefrom Eudicots, 21 taxa. Of the angiosperm taxa documented here, Magnolia , Carex ,Ranunculaceae, Platanus , Trochodendron , Buxus , Cercidiphyllum , Daphniphyllum ,Distylium , Fortunearia , Parrotia , Parthenocissus , Vitis , Euphorbia , Salix , andPapilionoideae are recorded for the first time from the Lavanttal Basin. This also includes thefirst fossil pollen record of Trochodendron worldwide and the first reliable pollen record ofDaphniphyllum . Several of the taxa described here had a wide Northern Hemisphericdistribution from Eocene until the end of the Miocene. Also, key relatives of the fossil taxaare presently confined to humid warm-temperate environments, suggesting a very mildclimate during the middle Miocene (Sarmatian) of the Lavanttal area. Some of the taxaencountered also support previous observations that the sediments of the Lavanttal Basinaccumulated in a lowland wetland environment. This is based on pollen from aquatic taxathriving in lakes, streams and swamps, and pollen of terrestrial plant taxa occupying marginsof lakes and streams, backswamps, floodplains, river plains, and hummocks. Other angiosperm pollen clearly originate from plants thriving on drier substrates, reflecting variousvegetation units of the mixed evergreen/deciduous broad-leaved/conifer forests surroundingthe wetland basin.
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| 9. |
- Grímsson, F.
(författare)
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Combined LM and SEM study of the middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin, Austria: part IV. Magnoliophyta 2 – Fagales to Rosales
- 2016
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Ingår i: Grana. - : Informa UK Limited. - 0017-3134 .- 1651-2049.
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Tidskriftsartikel (refereegranskat)abstract
- An ongoing investigation of the middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin continues to show that it contains an extremely rich assemblage of angiosperm taxa. The Fagales to Rosales pollen record documented here contains 34 different taxa belonging to the Betulaceae (Alnus, Betula, Carpinus, Corylus, Ostrya), Fagaceae (Castanea, Fagus, Quercus Groups Cerris, Ilex, Cyclobalanopsis, Quercus/Lobatae), Juglandaceae (Engelhardioideae, Carya, Juglans, Pterocarya), Myricaceae (Morrella vel Myrica), Cannabaceae (Celtis), Elaeagnaceae (Elaeagnus), Rhamnaceae, Rosaceae (Prunus) and Ulmaceae (Cedrelospermum, Ulmus, Zelkova). Two of the pollen types represent extinct genera, Trigonobalanopsis and Cedrelospermum, and are also reported for the first time from the Lavanttal Basin along with pollen of Rhamnaceae and Prunus. The different types of Quercus pollen are now affiliated with Groups Cerris, Cyclobalanopsis, Ilex and Quercus/Lobatae based on sculpturing elements observed using scanning electron microscopy (SEM). Köppen signatures of potential modern analogues of the fossil Fagales and Rosales suggest a subtropical (Cfa, Cwa) climate at lower elevation and subsequent subtropical to temperate climate with altitudinal succession (Cfa→Cfb/Dfa→Dfb; Cwa→Cwb→Dwb) in the Lavanttal area during accumulation of the palynoflora. Most of the fossil taxa have potential modern analogues that can be grouped as nemoral and/or merido-nemoral vegetation elements, and the diversity of Fagales indicates a varying landscape with a high variety of niches.
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| 10. |
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