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The Triassic record in the SE Iberian Ranges starts with two tecto-sedimentary units of continental origin in Buntsandstein facies: and Cañizar and Eslida Formations. The Eslida Formation always lies conformably on top of the Cañizar Formation and it grades upwards into overlying coastal mud flats, traditionally assigned to the Röt facies. In the past, accurate dating of the Eslida Formation was problematic because of its continental character, absence of datable fossil remains, and lithological similarities with Middle—Upper Permian rocks. Macroflora and fossilised vertebrate footprints in the Eslida Formation indicate an Anisian age (Middle Triassic). In this work, we date the Eslida Formation on the basis of a palynological assemblage. The precise dating of the Eslida Formation is essential in order to establish stratigraphical correlations with other units in the Iberian Ranges and to obtain palaeogeographical considerations on the rapid subsidence represented by the sedimentary record of this unit in the new NNE—SSE Middle Triassic rift developed in eastern Iberia.
The Khorat Plateau, at the centre of mainland Southeast Asia, is considered a bridge connecting the biotas of Indochina and Kalimantan. The vegetation change in this area is an indicator of regional environmental change, but the history is unclear. In this study, a sand pit along an ancient fluvial terrace on this plateau was investigated palynologically. An assemblage of Abies, Pinus, Chenopodiaceae and grass suggest a temperate forest and subtropical savannah 172,739 ± 22,400 and 88,661 ± 10,600 a BP, indicating a cold and dry environment. Deciduous and mixed forests indicate a warm period from 52,296 ± 6800 to 28,150 ± 7860 a BP, accompanied by aquatic components. An increase in mangrove abundance coincided with a rise in sea level. The period 27,332 ± 3000 a BP experienced a dry, cold environment. Conclusively, pollen records from the river terrace suggest tremendous vegetation change in the history of the Khorat Plateau.
Pollen analysis from Paisley Cave 2 (35LK3400), in Oregon has produced a record of climate change affecting the Summer Lake Sub-basin during a 7000-year period beginning at roughly 14,500 cal. yr. These sediments provide an opportunity to examine questions concerning human—environmental interaction at the end of the Pleistocene Epoch, during the Younger Dryas climatic event. The sediment deposits show a relatively unchanging early Holocene environment of predominantly xeric conditions with subalpine and marsh communities nearby. Additionally, there is little evidence of culturally significant use of any specific plant species. The data shows that the overall climatic conditions in the region were slightly cooler and perhaps wetter, just prior to the end of the Late Glacial, than today. These results provide important perspective on early settlement patterns and human ecology in the far western region of North America.
A high-resolution palynological study of a recently acquired core from the southern part of the Ormen Lange field (Norway) over the Danian-aged reservoir interval revealed rich, diverse and well-preserved palynomorph assemblages. Review of these assemblages has allowed the opportunity to formally describe some dinoflagellate cysts previously left in open nomenclature and others recognised for the first time in this well. We propose in this paper the formal description of 10 new species: Achomosphaera eggadania sp. nov., Achomosphaera progranulata sp. nov., Areoligera constricta sp. nov., Areoligera pauciornata sp. nov., Deflandrea variabilis sp. nov., Eurydinium ovatum sp. nov., Glaphyrocysta pseudoreticulata sp. nov., Hystrichosphaeridium pachydermum sp. nov., Operculodinium runtata sp. nov. and Phthanoperidinium ormenlangei sp. nov. All the key diagnostic and morphological features of each species are discussed and compared with those of other forms outside and within the same genera. The new species presented all range throughout the Danian (Early Paleocene) and can be used in conjunction with other previously published markers to support and enhance the stratigraphic breakdown and subdivision of the reservoir interval across the Ormen Lange field, and potentially other areas in the North Sea basin.
Monthly corbicular samples derived from weekly collections of Melipona (Melikerria) interrupta (Apidae: Meliponini) were analyzed alongside a single honey sample between January to December 2012. The botanical families Arecaceae, Melastomataceae and Solanaceae were the most representative in the corbicular load samples, with five temporary specialization events (>90%) being detected for representatives of Melastomataceae and Solanaceae. Furthermore, Melastomataceae also exhibited a greater contribution of pollen types in the honey samples, particularly because of the occurrence of Miconia type (87.17%), followed by Solanaceae, represented by types Solanum stramonifolium (5.00%) and Solanum aculeatissimum (2.50%). The low richness of pollen types in the corbicular pollen samples (n = 16) in this study suggests that M. interrupta may act as a specialist due to the low availability of apiculture resources in terra-firme environments, where intraspecific competition might affect not only the maintenance of these colonies in this environment but also their honey production.
Renewed study of an Australian Mississippian-age palynoflora — the Grandispora maculosa zonal assemblage from the Mount Johnstone/Italia Road Formation (Hunter Valley, New South Wales) — reveals significant morphological variation in some of its key miospore components — in particular Reticulatisporites magnidictyus, the subject of the present account. Detailed microscopy of numerous topotypic specimens of this species, originally described in 1968, results in its formal emendation; this takes particular account of the hitherto unrecognised presence of a proximo-apical prominence about the confluence of the laesurae. The G. maculosa palynoflora, with its constituent R. magnidictyus, has been reported from within a ca. 30–45°S palaeolatitudinal belt, at numerous Western, Eastern, and Northern Gondwanan locations in strata of middle Visean—early Serpukhovian age, but with a possible extension into the Early Pennsylvanian (Bashkirian). Consequently, R. magnidictyus is one of a very limited group of distinctive miospore species that facilitate long-distance chronostratigraphic correlation within the supercontinent.
The diversification of protists and multicellular microorganisms is recorded in numerous worldwide Tonian age successions, including the Visingsö Group in Sweden. The Visingsö Group contains a taxonomically rich assemblage of cyanobacteria, stromatolites, algal phytoplankton and vase-shaped microfossils. A new record of organic-walled microfossils from the Visingsö 1 drillcore reveals the high taxonomic diversity. Several species are reported for the first time from the Visingsö Group, and one new species Leiosphaeridia gorda n. sp. is described. They are in gross phycoma-like cysts of the prasinophycean algae Pterospermopsimorpha, Pterospermella, Simia, Macroptycha and Dictyotidium. Morphologically similar to zygotic cysts of chlorophycean algae are Leiosphaeridia gorda n. sp., Cerebrosphaera, Culcitulisphaera and Lanulatisphaera. Schizofusa may represent the earliest yellow-green algae of the Eustigmatiphyte among Stramenopiles. The recorded biodiversity documents the global trend in the evolution of eukaryotic protists during the Tonian Period and the increased radiation of numerous, presumably photoautotrophic biotas, representing various algal lineages.
The pollen morphology of 54 species and one variety of seven genera in Polygonatae including Clintonia, Disporopsis, Disporum, Maianthemum, Polygonatum, Smilacina and Streptopus was observed and studied in detail; of these, nine species were reported for the first time. Our results showed that the surface ornamentation of pollen grains of the studied materials could be divided into seven types, namely gemmate, granulate-foveolate, perforate, reticulate, rugulate, rugulate-perforate and verrucate. In line with previous studies, we believe that (i) Smilacina ginfushanicum should be classified into the genus Heteropolygonatum rather than the genus Smilacina; (ii) Polygonatum should be divided into section Polygonatum and section Verticillata; (iii) Smilacina and Maianthemum should be combined as one genus, i.e. Maianthemum sensu lato; and (iv) Clintonia, Disporum and Streptopus should be separated from the tribe Polygonatae.
The object of this study was to morphologically characterise the pollen grains from species endemic to the Azores, Portugal, in order to devise a pollen key to identify this plant group. The pollen grains from each studied species were subjected to standard acetolysis, and were mounted on at least three permanent slides for each species, in order to observe and measure the pollen grains. Pollen surface details were described from images obtained through a scanning electron microscope. A total of 43 endemic species, distributed in 22 families and 37 genera, were analysed. It was observed that most of the studied families showed specific traits of polarity, sexine ornamentation, absence or presence of aperture and shape, and can be considered eurypalynous. Families Apiaceae, Ericaceae and Poaceae showed stenopalynous traits among species. The results obtained in this work made it possible to devise a pollen key to identify of the studied species.
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