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A late Wenlock flora from Co. Tipperary, Ireland 总被引:1,自引:0,他引:1
D. EDWARDS F.L.S. J. FEEHAN D. G. SMITH 《Botanical journal of the Linnean Society. Linnean Society of London》1983,86(1-2):19-36
An assemblage of macroplants preserved as highly coalified compressions which lack anatomy is described from a Wenlock locality in County Tipperary, Ireland. Most of the fertile specimens are assigned to Cooksonia Lang. The taxonomic status of this genus is discussed. Some poorly preserved palynomorphs, including miospores, acritarchs, chitinozoans and a variety of tubes, have been isolated from associated sediments, but the age of the flora is based on graptolites. Sedimentological and palaeontological studies of the region are summarized. They provide little direct evidence for the habitats of the plants which are considered to have been terrestrial. The relevance of this flora to the current debate on the colonization of the land is evaluated and it is concluded that these plants provide the earliest record of erect fertile land plants of possible pteridophyte affinity. 相似文献
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Ludovic Stricanne Axel Munnecke Jrg Pross Thomas Servais 《Review of Palaeobotany and Palynology》2004,130(1-4):195-216
To better understand palaeoecological signatures in Palaeozoic acritarch assemblages, the distribution of palynomorphs has been quantitatively studied in eight localities from the Gorstian, lower Ludlow (Late Silurian) of Gotland, Sweden. The localities are situated along an inshore–offshore transect comprising shallow marine lagoonal environments to distal shelf facies. Process-bearing acritarchs and sphaeromorphs constitute the main components within the palynomorph assemblages. The lateral distribution of palynomorphs exhibits characteristic features at three different levels as follows. (1) With regard to the overall composition of the palynomorph assemblages, the abundance of process-bearing acritarchs increases towards the distal shelf, while the abundance of sphaeromorphs decreases. (2) At the generic level, the acritarchs Micrhystridium and Dilatisphaera are more abundant in the proximal facies, while Evittia, Percultisphaera and Oppilatala are more common in distal environments. (3) At an infrageneric level, Micrhystridium morphotypes with shorter processes are mainly present in proximal environments, while those with longer and ramified processes occur in more distal shelf environments. The palynomorph distribution along the inshore–offshore transect highlights the potential of acritarchs and prasinophytes as palaeoenvironmental indicators. 相似文献
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Over the last two decades, there has an been increasing interest in applying vibrational spectroscopy in palaeontological research. For example, this chemical analytical technique has been used to elucidate the chemical composition of a wide variety of fossils, including Archaean putative microfossils, stromatolites, chitinozoans, acritarchs, fossil algae, fossil plant cuticles, putative fossil arthropods, conodonts, scolecodonts and dinosaur bones. The insights provided by these data have been equally far ranging: to taxonomically identify a fossil, to determine biogenicity of a putative fossil, to identify preserved biologically synthesized compounds and to elucidate the preservational mechanisms of fossil material. Vibrational spectroscopy has clearly been a useful tool for investigating various palaeontological problems. However, it is also a tool that has been misapplied and misinterpreted, and thus, this review is dedicated to providing a palaeontologist who is new to vibrational spectroscopy with a basic understanding of these techniques, and the types of chemical information that can be obtained. Two example applications of these techniques are discussed in detail, one looking into fossil palynomorph taxonomy and other into the enigmatic Burgess Shale‐type preservation. 相似文献
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M.F. Quamar 《Historical Biology》2013,25(8):1070-1078
Non-pollen palynomorphs comprising algal remains, namely Botryococcus, Chara, Concentricystis, Pediastrum, Spirogyra and Zygnema as well as fungal spores such as ascospore types, Alternaria, Cookeina, Curvularia, Diplodia, Glomus, Helminthosporium, Nigrospora, Microthyriaceae and Tetraploa, well identified from the palynoslides prepared basically for the study of palaeovegetational succession and palaeoclimatic reconstructions, are discussed and illustrated from the late Quaternary sediments collected from southwestern Madhya Pradesh (India), which is regarded as one of the core monsoon zones of the Indian subcontinent. Botryococcus and zygospores of Zygnemataceae indicate warmer climate. Pediastrum–Botryococcus alternation may reflect colder–warmer climates. Botryococcus and Pediastrum may also suggest oscillations in atmospheric precipitation. They could be sensitive indicators of salinity, pH, temperature and depth changes in palaeolagoons influenced by sea-level oscillations and climate. Chara points to less oxygenated and hard water conditions. The record of fungal spores advocates the prevalence of a humid climate. 相似文献
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Sangheon Yi Songsuk YiDavid J. Batten Heysu YunSe-Jin Park 《Palaeogeography, Palaeoclimatology, Palaeoecology》2003,191(1):15-44
Palynological analyses of two wells (Haema-1 and Kachi-1) located in two sub-basins of the Northern South Yellow Sea Basin have been carried out in order to establish a palynostratigraphic breakdown of the sedimentary succession and to determine environments of deposition. Seven assemblage zones and two assemblage subzones have been erected on the basis of frequency variations in, and occurrences of, biostratigraphically significant palynomorphs as follows: Classopollis-Ephedripites Assemblage Zone (AZ): Barremian-Albian; Alisporites-Aquilapollenites-Penetetrapites AZ, which is subdivided into an Alisporites-Rugubivesiculites Assemblage Subzone: Cenomanian-Lower Maastrichtian, and an Aquilapollenites-Penetetrapites Assemblage Subzone: Upper Maastrichtian; Momipites-Coryluspollenites AZ: Paleocene; Caryapollenites-Inaperturopollenites AZ: Lower-Middle Eocene; Quercoidites-Pinuspollenites AZ: Upper Eocene; Liquidambarpollenites-Fupingopollenites-Magnastriatites AZ: Lower-Middle Miocene; Graminidites-Persicarioipollis AZ: Pliocene. The depositional environments represented by the well sections are considered to have been generally fluvio-lacustrine, and the climate to have varied between semi-arid and wet, and subtropical and warm temperate, except during the Late Eocene and Pliocene when a cool-temperate climate prevailed. Six stages in the development of the sub-basins are recognised. These are: (1) initial stage of rift or pull-apart basin-formation during the Late Jurassic?-Cretaceous; (2) subsidence from the Paleocene to Middle Eocene; (3) alternation of uplift and subsidence in the Late Eocene; (4) synrift inversion and erosion through the Oligocene; (5) uplift during the Early Miocene; and (6) widespread subsidence from the Middle Miocene onwards apart from during the Early Pliocene when the region was subjected to uplift once more. 相似文献
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Non-pollen palynomorphs from surface sediments along an altitudinal transect of the Venezuelan Andes
Palynological studies including records of non-pollen palynomorphs (NPP) are uncommon in the Neotropics, in spite of their demonstrated usefulness in other regions. Modern analog studies to improve palaeoecological interpretations of NPP are even more scarce. Here, we report the NPP assemblages recorded in modern surface samples from an altitudinal transect of the Venezuelan Andes, ranging from about 2300 and 4600 m. We compared the assemblages with the results of previous pollen analyses of the same samples. The variables considered to explain NPP patterns along the transect are altitude and the local habitat of the sampling site (“sample type”). A total of 65 NPP taxa - classified into algal and zoological remains, and fungal spores - have been found. Unidentified taxa (23) have been named with a code, depicted and described for further reference. Fungal spores are well represented along the whole transect, whereas algal and zoological remains are absent or very scarce in the lower and the uppermost ranges. The altitudinal zonation of fungal spores matches with that of pollen and the corresponding vegetation belts, suggesting a close relationship. The known environmental requirements of some of the fungi identified allowed inferences on particular ecological features, in agreement with previous palynological interpretations. Both elevation and sample type are needed to explain the observed differences in the assemblages of the three groups, the elevation being more decissive for fungal spores and the local habitat of the sampling site for algal and zoological remains. The sample type effect is minimised when the NPP studied are considered altogether, thus increasing their usefulness as palaeoecological proxies. This study reinforces the utility of modern analog surveys of NPP with palaeoecological purposes and encourages further research, particularly in poorly known areas, as for example tropical regions. 相似文献
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Beverley Adams-Groom 《Grana》2018,57(3):223-234
To provide evidence of a link between a crime scene and a suspect, pollen analysis is occasionally employed. However, experimental research linking pollen on footwear to a specific crime scene has been infrequently undertaken such that there are limited references to cite in court. In this blind study, the author had to determine, which of 12 pairs of footwear had walked on a mock scene by comparing their assemblages to those of two scene controls. An additional four control pairs of footwear that had not been worn on or near the scene were also analysed. The pollen data from the footwear was assessed and compared with the scene control samples for: number of taxa, key types, Czekanowski Coefficient and general assemblages. Results indicated that six of the pairs of footwear had walked on the scene and these were, indeed, the ones that actually had done so. The four control pairs were dissimilar in most aspects, particularly key types. This research demonstrates, with some limitations, that evidence of a match between footwear sample and location can be found, even when material from other habitats is present on an exhibit. 相似文献
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Y. Miras A. Ejarque H. Orengo S. R. Mora J. M. Palet A. Poiraud 《Plant biosystems》2013,147(4):924-939
Abstract A multi-proxy palaeoenvironmental study (pollen, non-pollen palynomorphs-NPP, macrocharcoal particles) of a small fen located in the Perafita valley (2240 m a.s.l, eastern Pyrenees, Andorra) was undertaken to trace prehistoric human activities related to woodland clearance and past land-uses at high altitudes. The results of this study constrained by 9 AMS radiocarbon measurements are combined with archaeological data and compared with similar research carried out at the same altitude in the adjacent Madriu valley (Andorra). The overall objectives of this article are, first, to formulate different chronological patterns and spatial land-use distribution at a micro-regional scale during prehistory and, second, to discuss different drivers of prehistoric occupation models in the eastern Pyrenean highlands. The palaeoecological study of the Planells de Perafita fen was performed at high temporal resolution, allowing us to focus on detailed prehistoric (mainly Mesolithic and Neolithic) and Bronze Age human activity. It demonstrates that the shaping of this cultural landscape is the result of a long-term land-use history, which began at the late Mesolithic/early Neolithic transition onwards (ca 6400–6100 cal BC). The existence of three main phases of “inter-valley” land-use variability has also been highlighted, thus testifying a complex and heterogeneous upland land-use model during the Neolithic and Bronze Age. These land-use variabilities between the two adjacent Andorran valleys provide the basis for a discussion of the way in which environmental constraints influenced prehistoric land-use spatial organisation and of how the interaction between environmental (including climatic parameters), socio-economic and cultural conditions affected the temporal and spatial dynamics of landscape shaping in the eastern Pyrenean highlands. 相似文献
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Timothy M. Mighall Scott Timpany Jeffery J. Blackford Jim B. Innes Charlotte E. O’Brien William O’Brien Stephan Harrison 《Vegetation History and Archaeobotany》2008,17(6):617-628
Despite being rich in later prehistoric and historic archaeology that includes megalithic monuments, Bronze age copper mines
and medieval castles, the Mizen Peninsula, south-west Ireland, has revealed little about its stone age past. Evidence for
a Mesolithic presence in SW Ireland is rare and, to date, all archaeological finds of this age in Co. Cork are further north
and east of the Mizen Peninsula. However a recent palaeoecological study of pollen, non-pollen palynomorph, plant macrofossil
and microscopic charcoal data from a peat bog located near Mount Gabriel has provided evidence for disturbances, characterised
by fire disturbance of woodland and exploitation of wetlands, since ca. 8400 years b.p. Two working hypotheses are considered to explain these disturbances: human activity or natural agencies. If the human activity
hypothesis is accepted, they represent the first possible evidence of a Mesolithic presence on the Mizen Peninsula. 相似文献
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