Dissertations / Theses on the topic 'Paleobotany'
To see the other types of publications on this topic, follow the link: Paleobotany.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Paleobotany.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Emerson, Lisa Francis. "The early Miocene Cape Blanco flora of coastal Oregon /." Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2009. http://hdl.handle.net/1794/10343.
Full text
2
Blinnikov, Mikhail S. "Late-Pleistocene history of the Columbia Basin grassland based on phytolith records in loess /." view abstract or download file of text, 1999. http://wwwlib.umi.com/cr/uoregon/fullcit?p9948017.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 1999.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 202-211). Also available for download from the Internet; free to University of Oregon users. Address: http://wwwlib.umi.com/cr/uoregon/fullcit?p9948017.
3
Carlson, Lisa Jo. "Describing the postglacial pattern and rate of Picea expansion in Alaska using paleoecological records /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/5452.
Full text
4
Tomescu, Alexandru Mihail Florian. "Late Ordovician - Early Silurian terrestrial biotas of Virginia, Ohio, and Pennsylvania : an investigation into the early colonization of land /." Ohio University / OhioLINK, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1108479418.
Full text
5
Hill, Robert S. "Evolution of the Australian flora in response to Cenozoic climate change /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09S.D/09s.dh6469.pdf.
Full text
6
Currano, Ellen Diane. "Variations in insect herbivory on angiosperm leaves through the late Paleocene and early Eocene in the Bighorn Basin, Wyoming, USA /." View online, 2008. http://etda.libraries.psu.edu/theses/approved/WorldWideFiles/ETD-2863/Thesis_Currano_final.pdf.
Full text
7
Blake, Bascombe Mitchel. "Carboniferous paleobotany and paleoclimatology of the central Appalachian Basin, West Virginia, U.S.A." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10655.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains xi, 240 p. : ill. (some col.), maps (some col.). Vita. Includes abstract. Includes bibliographical references.
8
Sweet, Natalie L. "Paleoecology and sedimentology of late Silurian biogenic structures in the Duoro and Devon Island Formations on western Devon and southwestern Ellesmere Islands, Arctic Canada." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10385.
Full textAbstract:
Carbonate buildups of late-Ludlow-Pridoli age occur within an extensive Silurian reef 'belt' in the Canadian Arctic Islands. Two phases of mound development were documented. The buildups include mudmounds in the uppermost Douro Formation on western Devon Island, and skeletal mounds in the Devon Island Formation on southwestern Ellesmere, North Kent, and Seal islands and Colin Archer Peninsula on Devon Island. The mudmounds average 50m in diameter and 15m in height, and are composed predominantly of sparsely fossiliferous lime mudstone containing sponge spicules and micrite fabrics of probable microbial tabulate origin. In a few small ($\sim$3m diameter x 0.5m high) mudmounds, abundant, well-preserved lithistid sponges and distinct microbial fabrics represent an intimate association of encrusting, binding, baffling and sediment-producing constructors. Coral skeletal mounds, averaging 100m in diameter and 35m in height, have stromatactoid-rich mudstone cores and grade upwards from mudstone into fasciculate coral-floatstone and crinoidal wackestone. In contrast, in a skeletal mound core on North Kent Island, a floatstone facies characterized by fasciculate rugose and tabulate corals, and large tabular stromatoporoids, is overlain by a mudstone core facies. Although the skeletal mounds have been completely altered to a fine-grained dolomite, relict fabrics are preserved and suggest a diagenetic sequence similar to that for the mudmounds. The mudmounds grew during a period of substantial platform drowning, apparently related to tectonic movement on the Boothia Uplift. Farther north, growth of the skeletal mounds began on favourable highs of the drowned carbonate ramp, and continued as basinal siliciclastic muds accumulated. The event represented by the hardground and associated physical features can be correlated with related features in buildups farther south where the Douro ramp instead evolved into a carbonate shelf, represented by the Barlow Inlet Formation. (Abstract shortened by UMI.)
9
Wymer, Dee Anne. "The paleoethnobotanical record of central Ohio - 100 B.C. to A.D. 800 : subsistence continuity amid cultural change." Connect to resource, 1987. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1219945114.
Full text
10
Hoyt, Cathryn A. "Grassland to desert : Holocene vegetation and climate change in the northern Chihuahuan Desert /." Digital version:, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992819.
Full text
11
Nelson, Nathan Alfred. "Holocene fire and climate in rangeland ecosystems of Southwestern Idaho." [Boise, Idaho] : Boise State University, 2009. http://scholarworks.boisestate.edu/td/24/.
Full text
12
Oswald, William Wyatt. "Holocene vegetational history of the central Arctic foothills, northern Alaska : pollen representation of tundra and edaphic controls on the response of tundra to climate change /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/5578.
Full text
13
Brunelle-Daines, Andrea. "Holocene changes in fire, climate and vegetation in the northern Rocky Mountains of Idaho and western Montana /." view abstract or download file of text, 2002. http://wwwlib.umi.com/cr/uoregon/fullcit?p3061935.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 2002.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 170-178). Also available for download via the World Wide Web; free to University of Oregon users.
14
Rowett, A. "The megafossil and microfossil floras of the Curlew Formation, Queensland /." Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phr8812.pdf.
Full text
15
Ingram, Steven. "Palynology of the Cape's top ten richest families and its taxonomic implications." Bachelor's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/23943.
Full textAbstract:
Principal pollen characters, of the Cape floristic Regions ten richest families, which are phylogenetically useful at higher taxonomic levels (including aperture type, exine structure, pollen-unit, polarity, symmetry, shape), and their evolutionary trends are examined. Monocotyledons differ from eu-dicotyledons (and eu-dicots from basal-dicots) in their aperture number and form, and exine structure and are discussed in relation to their pollination syndrome aswell as their evolutionary trends. We also discuss the possibilities of creating a taxonomic key at species level, if not only for use at the vegetation-type scale for paleobotanists aswell as honey farmers.
16
Baghai, Nina Lucille. "An analysis of palynomorphs from upper Cretaceous sedimentary rocks with emphasis in the Aguja Formation, Big Bend National Park, Brewster County, Texas /." Digital version, 1996. http://wwwlib.umi.com/cr/utexas/fullcit?p9719292.
Full text
17
Madigosky, Stephen R. "Palynological and paleoecological assessment of a Pennsylvanian shale overlying the Danville coal member (VII) in Sullivan County, Indiana." Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/536305.
Full textAbstract:
Shale samples from three Upper Pennsylvanian assemblages overlying the Danville (No. 7) Coal Member in Sullivan County, Indiana were compared with respect to miospore content. Eight samples from each of the Hawthorn, Dugger and Minnehaha mines were chemically macerated and analyzed for pollen/spore content. A total of 108 species assigned to 40 genera were recovered. A comparison of the palynoflora from the three assemblages reveals 17 genera and 32 species found in common. The palynoflora is dominated by the following four genera: Lycospora, Laevigatosporites. Punctatisporites and Punctatosporites. Genera of secondary importance include: Spinosporites, Crassispora, Calamospora, Latosporites, Cycloqranisporitesand Thymospora. These findings are similar to other palynofloras of comparable age from the United States and Europe.Abundance data at each site from the three localities were analyzed using cluster analysis. This was achieved employing the Baroni-Urboni-Buser correlation coefficient (complete linkage, furthest neighbor strategy). This method uses presence-absence data to indicate association between sites. Results revealed few taxonomic differences within or between mines. The uniformity in palynoflora observed between all sites is indicative of contemporaneous deposition which represents a regional flora. Percentage of miospore components assigned to previously established plant affinities were arranged by major plant groups. This allowed indirect comparison with megaflora from the same area as reported by Pheifer (1979). Results were found to be complementary and corroborative. Data from the three mines revealed an abundance of arborescent lycopods, ferns and sphenopsids with few gymnosperms. This is suggestive of current paleoenvironmental models which indicate a wet swamp regime.It is likely that the three areas in this study represent a small portion of a vast freshwater swamp located on the eastern periphery of the Illinois Coal Basin. This interpretation is substantiated by species composition, uniformity in palynoflora and absence of species associated with saline environments.Department of Biology
18
Anshari, Gusti Zakaria. "Late quaternary vegetation and environments in the Lake Sentarum Wildlife Reserve, West Kalimantan, Indonesia." Monash University, School of Geography and Environmental Science, 2000. http://arrow.monash.edu.au/hdl/1959.1/9252.
Full text
19
Woolfenden, Wallace Bird 1941. "Late Quaternary vegetation history of the southern Owens Valley region, Inyo County, California." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282184.
Full textAbstract:
This study analyzes the pollen, spores, and algae in the upper 90 m section of a mostly continuous, well dated, 323 m core (OL-92) from Owens Lake, southeastern California. The entire core has produced a paleoclimatic record for the past ∼800 ka. The 90 m interval dates from ∼9 ka to ∼151 ka beginning with the penultimate glaciation and ending during the termination of the last glaciation. The record shows high amplitude fluctuations in the abundances of pine, juniper, saltbush, sagebrush, chenopods/amaranths, and Ambrosia-type pollen. High percentages of juniper pollen with low percentages of desertscrub pollen during the intervals ∼150 ka to ∼120 ka and 73 ka to ∼20 ka alternate with low juniper pollen and relatively high percentages of desertscrub and oak pollen during the intervals ∼118 ka to ∼103 ka and ∼18 ka ∼10 ka and into the Holocene. Sagebrush pollen varies with juniper pollen but has a tendency to lead it in time. Pine and fir pollen tends to vary inversely with juniper over the long term. These trends are interpreted as vegetation change in response to glacial-interglacial cycles: During cold-wet glacial climates there was a downslope expansion of juniper woodland and sagebrush scrub, contraction of Sierra Nevada mixed conifer forest, and displacement of warm desertscrub, suggesting average temperature and precipitation departures from modern values ranging from -2°C to -6°C and from +100 mm to +350 mm. Conversely under warmer and drier interglacials warm desert shrubs expanded their range in the lowlands, juniper and sagebrush retreated upslope, and the Sierran forests expanded. Estimated average temperature and precipitation departures from modern values ranged from -0.5°C to +3.7°C and +13 to -26 mm. Comparison of the pollen spectra spanning the penultimate and ultimate glacial maxima shows the former to have been longer and more intense, in accord with the Sierra Nevada glacial record. Similarly, the higher abundances of Ambrosia pollen during the last interglaciation, compared to the Holocene, indicate warmer temperatures in the former. The presence of high oak percentages also during the last interglaciation suggest an expansion of the summer monsoon. Finally, the match of the juniper curve with the marine oxygen isotope chronostratigraphy suggests a link between vegetation change in the southern Owens Valley and global climate.
20
Shafer, David Scott. "The timing of late Quaternary monsoon precipitation maxima in the southwest United States." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184766.
Full textAbstract:
The southwest monsoon is responsible for a summer precipitation maximum for much of the southwest U.S. Biostratigraphies of pollen, plant macrofossils, and aquatic fossils in lakes from near modern monsoon boundaries in conjunction with climate modelling suggests variations in strength of the monsoon system during the late Quaternary. At Montezuma Well, Arizona, high percentages of Pinus and Juniperus pollen as well as maximum influxes of Quercus and Gramineae pollen suggest a shift from dominantly winter to summer precipitation between ca. 12,000 and 9000 yr BP. Maximum aridity occurred 7000-4000 yr BP, coincident with lowest lake levels. In the High Plateaus region of the Colorado Plateau, high Artemisia to Chenopodiaceae-Amaranthus pollen ratios suggests precipitation maxima until ca. 6000 yr BP at Fryingpan Lake and 5000 yr BP at Posy Lake. Pollen records suggest that Pinus edulis, P. ponderosa, and Quercus gambelii, were present on the western Colorado Plateau throughout the Holocene. Expansion of shadscale steppe vegetation at low elevations and upslope movement of ecotones for Pinus edulis, P. ponderosa, and Q. gambelii after ca. 6000 yr BP and low lake levels ca. 5000-3700 yr BP, suggest a period of maximum aridity from decreased summer precipitation. In the San Luis Valley, Colorado, pollen records from Head Lake on the basin floor suggest an expansion of oaks and junipers at the Pleistocene/Holocene boundary that may indicate increased summer precipitation. Lake levels of Head Lake fell sharply after ca. 9500 yr BP. Pollen records from Como Lake in the Sangre de Cristo Mountains suggest that Pinus ponderosa was established in the area by ca. 12,000 yr BP and Pinus edulis by ca. 9500 yr BP. Highland regions such as the High Plateaus (until ca. 6000-5000 yr BP) and central Colorado (until ca. 4000 yr BP) may have experienced Holocene summer precipitation maxima later into the Holocene than sites in lower elevation regions. Regional orographic uplift as a catalyst for convective summer precipitation may be responsible for the duration of summer precipitation maxima in these regions. On a longitudinal gradient, sites to the west such as in the southern Great Basin and Mohave Desert may have recorded enhanced summer precipitation earlier, reflecting different histories of the low-level jets in the southwest. The paleoecologic record generally confirm predictions of general circulation models (GCMs) that southwest monsoon circulation was enhanced from 12,000-6000 yr BP in response to peaks in annual (11,500-11,000 yr BP) and summer insolation (10,000-9000 yr BP) during the late Quaternary.
21
Milburn, Paula. "Palaeoenvironmental investigation into aspects of the vegetation history of north Fife and south Perthshire, Scotland." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/10541.
Full textAbstract:
Results from the palaeoenvironmental investigations into the Holocene vegetation history of three sites in eastern lowland Scotland are presented. Two of the sites, Cruvie and Pitbladdo, are located in north Fife; the third site, Methvern is situated in south Perthshire. Cruvie is located in a kettle-hole and provides data extending from the Late-glacial to ea. 3900 BP. Pitbladdo is a former bog and cores from this site provide data on the period from ca. 8000 to 3900 BP. Methvern is a well-maintained raised bog and provides data that spans the entire Holocene. Relative, concentration and pollen preservation data are supplemented by loss-on-ignition, pH and magnetic susceptibility analyses. Microscopic charcoal data are also recorded. Radiocarbon dates allow comparisons to be made between similar events at different sites, resulting in a detailed picture of temporal and spatial patterns of palaeoecological change within a small geographical area. Attention is focused upon the identification of human impact on the environment during the early to mid Holocene. The influences of succession and climate change in determining patterns of vegetation change are also considered. The data obtained indicate that human activity may have had a limited impact on the environment in this area during the Mesolithic, but no unequivocal evidence is recorded. Anthropogenic impacts are more clearly identified during the Neolithic period and from the late Neolithic/early Bronze Age, human activity is considerable and includes pastoral and mixed farming. The value of tephra as a dating tool in this area of eastern Scotland is considered. The absence of tephra at the three sites investigated has led to the formulation of a hypothesis linking patterns of orographic rainfall and tephra deposition within Scotland. The study highlights the difficulties of determining the causal factors of vegetation change and the limitations of palaeoecological data in the identification of anthropogenic activity during the early Holocene. The recognition of climate signals is discussed and the routine counting of microscopic charcoal at all sites is proposed. It is suggested that further research is required to clarify the boundaries of tephra deposition in Britain. Finally the diverse patterns of change recorded within the study area emphasise the need for a network of closely spaced and well dated palaeoenvironmental sites covering the regions of Scotland, leading to the recognition of local patterns of environmental change.
22
Sandau, Stephen D. "The Paleoclimate and Paleoecology of a Uintan (Late Middle Eocene) flora and fauna from the Uinta Basin, Utah /." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd719.pdf.
Full text
23
Scharf, Elizabeth Ann. "Long-term interactions of climate, vegetation, humans, and fire in eastern Washington /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/6444.
Full text
24
Scholtz, Anton. "Palynological and palaeobotanical studies in the Southern Cape." Thesis, [S.l. : s.n.], 1986. http://hdl.handle.net/10019/877.
Full text
25
Valentina, Corti. "Palynology and Paleobotany of Permo-Triassic Beacon Supergroup at Allan Hills, South Victoria Land, Antarctica: stratigraphical and paleoenvironmental change implications." Doctoral thesis, Università di Siena, 2021. http://hdl.handle.net/11365/1133988.
Full textAbstract:
Nowadays the Antarctic continent is almost entirely covered by ice (around 98% of the total land surface) and the conditions are inhospitable for vegetation, apart from very few species such as mosses and lichens.
During the geological time however, conditions were very different and the Phanerozoic fossil record documents several occurrences of vegetation remains also indicating the presence of wide high latitude forests. The life of plants in the continent was obviously strictly influenced by the evolving paleogeography and paleoenvironmental conditions and their mutual interactions during each time age of vegetation record.
The thesis project has been finalized to define, constrain and discuss with new field and laboratory data the most likely Late Permian and Triassic paleoenvironmental reconstructions for the Victoria Land region in Antarctica, on the basis of a new set of paleobotany and palynological investigations of the unique fossiliferous strata recently found in the Beacon Supergroup of Allan Hills (South Victoria Land).
The study was developed following a broad multidisciplinary and multi-analytical methodology in which paleobotany (including innovative approaches), palynology and palynostratigraphy methods and techniques play a key role in the reconstruction of the paleoenvironmental conditions and their changes through the time.
In the palynostratigraphic sequence of Allan Hills were recovered the EPE, a strata horizon with long-shaped inertinite probably referred to a paleo-fire, situated in the last level of coal of the Permian sequence; going up in the sequence the paleoflora is affected by deeply change, as an adaptation to the new environmental condition up to the PTB, were the major samples were completely inert, due to a poor presence of flora and a changing of the sedimentary condition. After the PTB the first palynomorphs recovered are associated to an intensive fungal and algae activity, and just at the end of the Early Triassic, the flora came back to be flourishing, even if with a quite completely new association of pollen and spores, where is dominant the genus of Alisporites in the whole Middle and Late Triassic. The genus of Alisporites is probably linked to the Dicroidium macroflora, playing a central role during the Triassic time, replacing the Glossopteris flora which, on the other hand, dominated the Permian landscape. The Dicroidium, together with other genera, were recovered in great abundance in the Middle Triassic deposits of the Lashly Formation in Allan Hills, particularly within a horizon containing a so-called “Allan Hills Fossil Forest”, even if the term “forest “ is not strictly pertinent, as a way the trunks were deposited and transported by a massive flow, and no more in the growth-position.
With an innovative technique was possible to reconstruct the main differences between the trunks there deposited and some other Permian fossil trunks outcropping in other areas of South Victoria Land. From this study, after a completely reconstruction of 237 years, that is the longest life-time never done for so old samples, were possible to note that the amplitude of the rings is probably linked to the amount of hours of sunlight during the years, so they are linked to the latitude to which the land was at time life-time of the trees.
The last topic analysed about the “Allan Hills fossil forest” is the peculiar kind of fossilization, with a multianalytic approach were in fact possible to reconstruct modalities of coalification/charcoalification and multi-phase fossilization.
The PAHs analysis highlights the presence of a high percentage of PAHs >4 ringed polynuclear aromatic hydrocarbons, that are typical attribute to pyrogenetic materials as fluoranthene, 9,10-dimethylanthracene and Pyrene, moreover also the δ13C measured on the growth tree rings shows a shifting of the curve in the more external rings, as an enrichment of 13C due to a partial combustion.
After a first phase where the trunks were partially burned due to paleofires, they were transported through massive water flows. Subsequently, they were buried, deformed and petrified by a massive silica gel, probably occurred mainly during the Jurassic sill intrusion. The last step of the fossilization is the precipitation of calcite in a rounded shape occurred for some samples.
Taken together the results of the study provide new important constraints and implications for reconstructing the history of sedimentary processes and coupled changing of the paleo-flora during a transition of deeply transformation of the biodiversity linked to the onset of greenhouse conditions, which occurred after the Permo-Triassic boundary, particularly during the Early Triassic.
26
Capretz, Robson Louiz [UNESP]. "Paleoecologia e tafonomia da floresta petrificada do Tocantins setentrional (Bacia do Parnaíba, Permiano)." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/103007.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:32:21Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-08-16Bitstream added on 2014-06-13T21:04:03Z : No. of bitstreams: 1
capretz_rl_dr_rcla.pdf: 3353928 bytes, checksum: 7e9219802799c05db6d9550923870f72 (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
No presente estudo é descrita uma floresta do Eopermiano do Norte do Gondwana, dominada por pteridófitas arborescentes, gimnospermas, licófitas e esfenófitas. Esta rica assembléia fossilífera localiza-se no Monumento Natural das Árvores Fossilizadas do Tocantins (MNAFTO), na Bacia do Parnaíba, Norte do Brasil. Dois aspectos se destacam: a abundância dos fitofósseis e seu excepcional nível de preservação. Os vegetais fósseis guardam semelhanças com aqueles do mesmo período em Chemnitz (Alemanha), na Província Euroamericana, e com a Flora Gondvânica, na Bacia do Paraná (Brasil), entre outros. A análise dos padrões de orientação de 178 caules, junto com observações geológicas, sugere paleocorrentes no sentido Oeste-Leste predominantemente, originadas durante tempestades de monções, com área-fonte muito distante a Oeste, talvez em um contexto de leque aluvial distal. A vegetação das margens dos principais canais fluviais e suas planícies de inundação era dominada por pteridófitas arborescentes no estrato superior da floresta (dossel), com licófitas, esfenófitas e outras pteridófitas menores ocupando o estrato inferior (sub-bosque). Gimnospermas ocupavam regiões mais distantes das margens dos canais. A comparação entre pteridófitas arborescentes permianas (do MNAFTO) com pteridófitas arborescentes atuais (em remanescentes de Floresta Ombrófila Densa Submontana) permitiu discutir nichos ecológicos ocupados por estas plantas, a estrutura da floresta em ambos os casos, e a inferência da altura verdadeira dos fitofósseis, em uma aplicação inédita de técnicas alométricas a estudos paleontológicos
This present study describes a Lower Permian forest in Northern Gondwana, composed by tree ferns, gymnosperms, lycophytes and sphenopsids. This fossil assemblage is located at Tocantins Fossil Trees Natural Monument (MNAFTO) at Parnaíba Basin, Northern Brazil. There are two remarkable aspects: the abundance of fossils and their exceptional level or preservation. The vegetation is similar to the plant fossils found at Chemnitz (Germany), to Euroamerican Flora sites, and to Gondwanian Flora at Paraná Basin (Brazil), among others. Orientation pattern analyses of 178 stems with geological observations suggest paleocurrents in West-East direction, in monsoon storms. The source area should be at West, several quilometers away, probably in a distal alluvial fan context. The forest in the margins of main fluvial channels was occupied by tree ferns at canopy, and lycophytes, sphenopsids and other small ferns at understory. Gymnosperms probably lived in more distant areas from the fluvial channels. The comparison between fossil tree ferns (from MNAFTO) and modern tree ferns (in Submontane Tropical Rain Forest remnants at the present) allowed discussions about ecological niche, forest structure and estimations of real height of fossil tree ferns, in a new way to apply allometric techniques to paleontological studies
27
Stranks, Lena. "Physiognomic and taphonomic studies in New Zealand and Australia : implications for the use of palaeobotany as a tool for palaeoclimate estimation." Thesis, University of Oxford, 1996. http://ora.ox.ac.uk/objects/uuid:478a83e2-5954-4c4f-b1ce-a8f7b6933011.
Full textAbstract:
Measurements of surface uplift rate potentially hold the key to understanding the tectonics of mountain belts and areas of uplift. Wolfe (1993) compiled a multicharacter data set (CLAMP) of the physiognomy of woody dicotyledon leaves with a view to using it to extract climatic information from fossil floras. The limited extent of this data set, along with the anomalous behaviour of some outliers cause me to question the global relationship between physiognomy and climate which has been implicitly assumed in all analyses of the data conducted to date. Additional data collected from native vegetation in New Zealand and Australia are compared to the CLAMP data set. These data include samples along altitudinal transects and from different forest types growing in the same climatic regime. In addition taphonomic samples were collected from lake bottom sediments and their physiognomic signals compared to those of the adjacent living vegetation. The possibility that the relationship between climate and physiognomy is sufficiently non-linear that only local relationships should be sought is investigated. To estimate the climate at a certain flora, resemblance functions are used to select physiognomically similar sites. Estimations of climate are formed using only these sites. The power of this approach to estimate mean annual temperature, mean annual precipitation, mean growing season precipitation, and moist enthalpy is investigated using the modern sites, and varying the number of nearest neighbours and dimensions used as well as the type of ordination. The collection of altitudinal transects has allowed the study of physiognomic change with altitude. Because these transects were collected over a very restricted area it was possible to observe this change without the superimposed effects of changing continentality and variation in latitude. In addition studies made of adjacent floras in similar climatic regimes and taphonomic studies of leaves in lacustrine sediments has allowed the beginning of a realistic assessment of possible errors in climate estimation for fossil sites. Fossil sites examined using CLAMP and related methods are re-examined using the nearest neighbour approach.
28
Huerta, Mariana Angelica. "Postglacial vegetation, fire, and climate history of Blacktail Pond, Northern Yellowstone National Park, WY." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/huerta/HuertaM0508.pdf.
Full textAbstract:
Previous studies in Yellowstone National Park (YNP) suggest intensification of the summer-dry and summer-wet patterns in Yellowstone during the early Holocene when increased summer insolation caused atmospheric circulation patterns to strengthen. To examine this hypothesis further, pollen and high-resolution charcoal records were analyzed from Blacktail Pond to reconstruct fire and vegetation histories near the present transition between summer-wet and summer-dry conditions. The site currently lies in Pseudotsuga parkland with Artemisia steppe at lower elevations around the pond. The site supported sparse tundra prior to 12,000 cal yr B.P. and fires were uncommon. Between 12,000 and 11,000 cal yr B.P, fire activity increased and Picea-Pinus parkland was established. These changes are consistent with increasing temperature and moisture. Between 11,000 and 7600 cal yr B.P., pollen evidence of a Pinus-Picea-Abies forest is consistent with increased winter moisture, while high fire activity at this time indicates that summers had lower effective moisture than at present. Between 7600 and 4000 cal yr B.P., vegetation around the site shifted to parkland dominated by Pinus, Picea, Pseudotsuga, and Artemisia indicating that effective winter moisture decreased. Fire activity continued to be high during this time suggesting summers maintained low effective moisture. The development of Artemisia steppe around the site over the last 4000 years indicates that effective winter moisture decreased, while decreased fire activity indicates that effective summer moisture increased during this time. Winter conditions during the early Holocene that resemble a summer-wet site along with summer conditions at the same time resembling a summer-dry site could be a result of the geographical setting of Blacktail Pond near the boundary between these two precipitation regimes. Poaceae/Artemisia pollen ratios were used to infer wet/dry climate oscillations during the late Holocene. The fluctuations correspond well with other paleoclimate data from northern Yellowstone National Park (Gennett and Baker, 1986; Hadly, 1996; Meyer et al., 1995), and suggest that conditions were drier from 3775-3125, 2475-2225, 1700- 675, and 425-75 cal yr B.P.
29
Morgans, Helen Sarah. "Early to middle Jurassic stratigraphic development, vegetation and climate change in north-western Europe." Thesis, University of Oxford, 1997. http://ora.ox.ac.uk/objects/uuid:4b5cae3c-7562-45b9-b2a2-543b2649b24f.
Full textAbstract:
The aim of work presented in this thesis was to explore the inter-relationships of cyclic sedimentation, relative sea-level change, and palaeoclimate as inferred from plant megafossils. To this end, the investigation focused on the classic plant-bearing Middle Jurassic succession of Yorkshire. The Middle Jurassic (Aalenian-Bathonian) Ravenscar Group of the Cleveland Basin (Yorkshire) comprises a predominantly fluvio-deltaic succession intercalated between thinner, laterally persistent marine units. There is a pronounced lateral facies change across the basin, from mainly alluvial sediments in the north to more marine deposits in the south. Although variable in character, the facies composing the sequence are described by four principal environments of deposition: alluvial, estuarine, lagoonal and marine. In an attempt to achieve a more accurate stratigraphic control on the succession, sequence-stratigraphic concepts are applied to outcrop exposures and subsurface cores. The identification of 'key surfaces' in the sequence resolves a series of lithological cycles which reflect relative sea-level fluctuations. Using this approach the Aalenian-Bathonian sequence can be subdivided into two large-scale (second-order) transgressive-regressive cycles onto which six medium-scale (thirdorder) cycles of transgression and regression are superimposed. The potential for correlating these lithological cycles regionally has been assessed by comparing coeval sections from southern Scandinavia. Plant-bearing fluvio-deltaic sequences from Bornholm and Scania were chosen as a means for appraising the lateral continuity of the cycles, and assessing what factors might have controlled their development. Study of floral remains from the Ravenscar Group within the context of this stratigraphic framework yields valuable palaeoclimatic information. Growth-ring analysis of fossil wood of Late Pliensbachian to Late Bathonian age indicates a distinctly seasonal climate with low to moderate interseasonal variation in tree growth. Significant intraseasonal influences on wood production are implicit in the abundance of false rings. Consideration of these results within a stratigraphic context suggests that conditions during the Bathonian were comparatively hostile: a finding which is interpreted to be due to more frequent and extended water shortages associated with a drier climate. These palaeoclimatic inferences are substantiated by evidence obtained from the examination of the flora using Correspondence Analysis (CA). This approach verifies the presence of a temporal fluctuation in the flora found by previous investigations and, furthermore, highlights physiognomic trends in the flora with time. The results from CA also indicate adverse growing conditions during the Bathonian, emphasized by the prevalence of xeromorphic taxa.
30
Davies, Katherine Siân. "Early Palaeocene vegetation and climate of North America." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:4e48bfd5-f749-4d84-a132-c45fd8429fdc.
Full textAbstract:
Early Palaeocene floras from twenty seven sites within the Raton, southern Powder River and south-western Williston Basins of the western interior of North America were collected, and their leaf physiognomy, ecological character and depositional setting compared. Such a spread of samples enabled the study of spatial and temporal vegetational and climatic variations in the region, following the Cretaceous-Tertiary boundary event. Climatic changes are observed across the Cretaceous-Tertiary boundary. Precipitation increased dramatically, and remained relatively high throughout the earliest Palaeocene. Temperatures were somewhat lower, compared to those of the Late Cretaceous, and seasonality in climate increased. Climatic and vegetation zones shifted southwards as latitudinal climatic equability decreased. Palaeotemperature and palaeoprecipitation were determined using CLAMP and leaf margin analysis. Experiments carried out to assess the robustness of CLAMP to loss of foliar physiognomic data revealed that this data loss did not drastically effect palaeoclimatic determinations but that information about leaf size and margin type had the most effect on results. Vegetation was of low diversity directly after the boundary event, but recovered to stable, but still relatively low levels, within a short time. Changes in diversity are difficult to interpret due to masking by taphonomic biases, which are important within the depositional environments analysed in this study. Climatic deterioration and the prevalence of disturbed environments ultimately facilitated expansion of the angiosperms, although their aspect was changed with a general increase in deciduous forms, in relation to increased seasonality and decreased equability. These trends cannot be related merely to the impact of a bolide at the Cretaceous-Tertiary boundary, but reflect the more global and wide-ranging changes of the period, which were punctuated by this brief, deleterious event. Previous work has tended to concentrate on the North American continent but a more global perspective reveals that the Cretaceous-Tertiary boundary event was not a world-wide catastrophe within terrestrial environments.
31
Biedenbender, Sharon Helen 1950. "Landscape-scale vegetation change indicated by carbon isotopes in soil organic matter for a semidesert grassland in southeastern Arizona." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/284017.
Full textAbstract:
Vegetation change, particularly from the grass to shrub lifeform, is a critical issue on the world's rangelands. The plant community present on a site is the primary determinant of the land's value for watershed protection, wildlife habitat, livestock production, and recreation. Studying past vegetation composition can help separate natural from anthropogenic sources of change and guide natural resource conservation and management decisions. Stable carbon isotope (δ¹³C) values and associated radiocarbon ages from soil organic matter (SOM) were used to evaluate vegetation change across five landscape positions at a small enclosed basin in southeastern Arizona. The utility of the carbon isotope method was verified for this site based on the clear and wide separation in δ¹³C values between grasses having the C₄ photosynthetic pathway and shrubs having the C₃ pathway. The direction and timing of vegetation dynamics differed with landscape position along a gentle elevation gradient from the basin outlet to a nearby volcanic ridge top. Warm-season C₄ perennial grasses have dominated the basin outlet, center, and toe slope landscape positions since at least 5000-6000 yr BP, except for a dramatic increase in C₃ plants at the bottom of the outlet excavation around 5000 yr BP. This isotopic change is associated with rounded cobbles that may have been a stream channel, suggesting the presence of C₃ herbaceous or woody riparian vegetation. On mid-slope and ridge top landscape positions, where semidesert shrubs now dominate, warm-season perennial grass, composition decreased from approximately 60% as recently as 400 yr BP to only 1.5% now. SOM density separates were also analyzed. The youngest SOM is represented by the <2 g/cm³ density fraction that turns over in a few years to several decades and has a post-bomb radiocarbon age. For the ridge top landscape position, this fraction yielded 39% C₄ vegetation, suggesting that the conversion from grass to shrub vegetation occurred recently.
32
Calentine, Leighann. "The Spoon Toe Site (11MG179) Middle Woodland gardening in the lower Illinois River Valley /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4256.
Full textAbstract:
Thesis (M.A.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (November 27, 2006) Vita. Includes bibliographical references.
33
Scrivan, Leonie Jane. "Diversity of the mid-Eocene Maslin Bay flora, South Australia /." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phs434.pdf.
Full text
34
Kauffmann, Marjorie 1982. "Mapeamento geológico e levantamento paleontológico do Monumento Natural das Árvores Fossilizadas, Bacia do Parnaíba, Estado do Tocantins." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287749.
Full textAbstract:
Orientadores: Frésia Soledad Ricardi Torres Branco, André JasperTese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências
Made available in DSpace on 2018-08-27T04:59:02Z (GMT). No. of bitstreams: 1 Kauffmann_Marjorie_D.pdf: 10896204 bytes, checksum: e87c18b3f56ed15a1ab698a2c00261cf (MD5) Previous issue date: 2014
Resumo: O presente trabalho foi desenvolvido no Monumento Natural das Árvores Fossilizadas do Tocantins (MNAF), um rico sítio paleobotânico depositado na Bacia Sedimentar do Parnaíba onde os fósseis afloram nas Formações Pedra de Fogo e Motuca. Pela importância científica e patrimonial deste local o estudo foi norteado objetivando aprofundar os conhecimentos, geológicos e paleobotânicos, além de promover medidas conservacionistas para área, tendo como foco o geoturismo. Os componentes foram abordados de forma integrada e complementar, viabilizando a construção de conhecimento acadêmico com possível reflexo no manejo do patrimônio fitofossilífero da área. Para a realização do mapeamento geológico atualizado foram levantados perfis colunares em 17 pontos distribuídos na área do MNAF e seu entorno, os quais foram compilados em 11 seções geológicas elaboradas a partir da correlação entre os dados de campo e a bibliografia existente para região. A avaliação da paleoflora local se deu com coleta de dados de carácter quali-quantitativo em 12 parcelas de área fixa de 25 m², executadas em sítios paleontológicos conhecidos na área do MNAF e seu entorno, distribuídas nos quadrantes NO, NE, SE e SO (totalizaram três parcelas por quadrante). Os resultados do levantamento paleobotânico foram tratados estatisticamente com o programa SPSS Statistics, o teste escolhido foi ANOVA, o objetivo principal foi averiguar as características da distribuição dos fitofósseis por ordem botânica (Equisetales, Marattiales e Coniferales) na área proposta. Para a avaliação da efetiva proteção do patrimônio a pesquisa se desenvolveu com a revisão de arquivos documentais envolvidos direta e indiretamente com a unidade de conservação, buscando avaliar a existência e eficiência das ações de conservação e desenvolvimento sustentável do local. Ainda, foram sugeridos e descritos três locais potenciais para instalação de Geosítios, propícios para uso turístico pela beleza cênica e/ou conteúdo presente. O mapa geológico atualizado para área do MNAF e seu entorno apresenta uma distribuição das formações aflorantes atualmente no MNAF com detalhes das colunas estratigráficas de cada ponto amostrado. Os afloramentos fitofossíliferos estudados foram classificados como pertencentes á Formação Motuca, que foi também a formação dominante na área do parque. Os dados paleobotânicos não demonstraram diferenças estatísticas significativas na distribuição das ordens Equisetales, Marattiales e Coniferales dentro da área do MNAF e seu entrono, sendo assim se pode concluir que a preservação é importante em todo este perímetro. Quanto à relevância patrimonial revelou que, ainda que o MNAF possua um plano de manejo aprovado e bem elaborado, este é minimamente implementado. Os programas específicos de educação ambiental e desenvolvimento de estratégicas de turismo sustentável demandam ênfase e efetivação, o que certamente serão de grande valia, principalmente para a população que reside no entorno ou dentro da área do parque. Foram indicadas como áreas potenciais ao geoturismo três geosítios, Fazenda Andradina, Fazenda Buritirana e Fazenda Torre da Lua, os dois primeiros pela importância paleobotânica e o último pela beleza cênica estampada na geologia local
Abstract: This work was developed in the Monumento Natural das Árvores Fossilizadas (MNAF), a rich palaeobotanical site deposited in the Parnaíba Sedimentary Basin where fossils outcrop in the formations "Pedra de Fogo" and "Motuca". Because of the scientific and patrimonial importance of this site, the study was guided aiming to deepen geological and paleobotanical knowledge as well as promoting conservation measures for the area, focusing on geotourism. The components were addressed in an integrated and complementary way, enabling the construction of academic knowledge with possible effect in the handling of the fossil plant area. For the realization of the updated geologic mapping columnar profiles were surveyed in 17 points distributed in the MNAF area and its surroundings, which were compiled into 11 geological sections drawn from the correlation between the field data and the existing literature about the region. The evaluation of the local paleoflora was made through collection of qualitative and quantitative data in 12 plots of equal area of 25 m², executed in paleontological sites known in MNAF¿s area and surroundings distributed in quadrants NW, NE, SE and SW (totaled three installments per quadrant). The results of palaeobotanical survey were statistically analyzed with the SPSS Statistics program, the chosen test was ANOVA, the main objective was to investigate the characteristics of the distribution of plant fossils by botanical order (Equisetales, Marattiales and Coniferales) in the proposed area. For the evaluation of the effective protection of heritage, the research has been developed with the review of documentary files directly and indirectly involved with the conservation unit, aimed at assessing the existence and effectiveness of conservation and sustainable development actions of the site. Also three potential locations for installation of geological sites have been suggested and described, which are propitious to the tourist use either for its scenic beauty and / or the present content. The updated geological map for the MNAF¿s area and surroundings, presents a distribution of the outcropping formations currently on MNAF with details of stratigraphic columns from each sampled. The plant fossil outcrops studied were classified as belonging to the Motuca formation, which was also the dominant formation in the park area. Paleobotanists data showed no statistically significant differences in the distribution of orders Equisetales, Marattiales and Coniferales inside the area of MNAF and its surroundings, thus it is possible to conclude that preservation is important in this whole perimeter. As for the patrimonial relevance, it was revealed that, although the MNAF contains a well-developed and approved handling plan, it is minimally implemented. The specific environmental education programs as well as the development of strategic sustainable tourism, demand emphasis and effectiveness, which will certainly be of great value, especially for the population residing in the vicinity or within the park area. Three geological sites were indicated as potential areas to geotourism, "Fazenda Andradina", "Fazenda Buritirana" and "Fazenda Torre da Lua", the first two by their paleobotany importance and the last by the scenic beauty stamped in the local geology
Doutorado
Geologia e Recursos Naturais
Doutora em Ciências
35
Crawford, Laura J. Dr. "The Role of Selectivity on Alaskan Fuel Management Strategies." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1600964489257755.
Full text
36
Greenwood, David Robert. "The foliar physiognomic analysis and taphonomy of leaf beds derived from modern Australia rainforest." Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phg8165.pdf.
Full text
37
Duncan, Faith Louise, and Faith Louise Duncan. "Botanical reflections of the encuentro and the Contact Period in southern Marin County, California." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185977.
Full textAbstract:
Plant indicator species and longitudinal paleobotanical data were used as independent measures to document the human ecological record of the contact period in southern Marin County, California. These data suggest that archaeological and documentary records are insufficient for examining changes in land management and use during the contact period. Prior to A.D. 1579, Western Miwok peoples had not encountered Europeans face to face. This early phase of the contact period is marked the possible introduction of New World species through passive cultural vectors. Two brief encounters occurred between the Miwok and Europeans between A.D. 1579 and 1775. Introduced and weedy plant species from fossil samples appear to confirm these encuentros and confirm the archeological evidence for intermittent contact during the second phase of the contact period. Modern and fossil pollen samples suggest that the intensity of human disturbance is geographically stratified and related to exploration, procurement, and management of specific resources. Coastal prairie, the redwood forest, and Bay salt marshes were the most affected by the second phase of the contact period. Shifts in vegetation diversity and increases in the numbers of introduced and weedy species were compared between ruderal and undisturbed contexts. These data were used as analogs to monitor the final phase of contact between A.D. 1775 to 1817. Hypotheses derived from ethnohistoric and ethnographic sources that suggest rapid shifts in land management practices and changes in plant representation were corroborated by some pollen data. Specifically, the ecological responses to the suppression of anthropogenic burning, changes in land tenure and parcelization, and the initiation of grazing and logging practices were examined. The cumulative impacts of introduced plants, shifts in land management from Miwok to Euroamerican-dominated resource procurement and subsistence practices, and ecological responses of plant species suggests that the contact period might better be defined on ecological terms rather than by purely material cultural or ethnographic definitions. In southern Marin, paleobotanical data provide a measurable indication of the ecological character of the pre-contact landscape and the cultural processes that effectively altered its character during the contact period.
38
Capretz, Robson Louiz. "Paleoecologia e tafonomia da floresta petrificada do Tocantins setentrional (Bacia do Parnaíba, Permiano) /." Rio Claro : [s.n.], 2010. http://hdl.handle.net/11449/103007.
Full textAbstract:
Orientador: Rosemarie Rohn DaviesBanca: Fresia Soledad Ricardi Torres Branco
Banca: Roberto Ianuzzi
Banca: Joel Carneiro de Castro
Banca: Luis Gustavo Ferreira de Oliveira
Resumo: No presente estudo é descrita uma floresta do Eopermiano do Norte do Gondwana, dominada por pteridófitas arborescentes, gimnospermas, licófitas e esfenófitas. Esta rica assembléia fossilífera localiza-se no Monumento Natural das Árvores Fossilizadas do Tocantins (MNAFTO), na Bacia do Parnaíba, Norte do Brasil. Dois aspectos se destacam: a abundância dos fitofósseis e seu excepcional nível de preservação. Os vegetais fósseis guardam semelhanças com aqueles do mesmo período em Chemnitz (Alemanha), na Província Euroamericana, e com a Flora Gondvânica, na Bacia do Paraná (Brasil), entre outros. A análise dos padrões de orientação de 178 caules, junto com observações geológicas, sugere paleocorrentes no sentido Oeste-Leste predominantemente, originadas durante tempestades de monções, com área-fonte muito distante a Oeste, talvez em um contexto de leque aluvial distal. A vegetação das margens dos principais canais fluviais e suas planícies de inundação era dominada por pteridófitas arborescentes no estrato superior da floresta (dossel), com licófitas, esfenófitas e outras pteridófitas menores ocupando o estrato inferior (sub-bosque). Gimnospermas ocupavam regiões mais distantes das margens dos canais. A comparação entre pteridófitas arborescentes permianas (do MNAFTO) com pteridófitas arborescentes atuais (em remanescentes de Floresta Ombrófila Densa Submontana) permitiu discutir nichos ecológicos ocupados por estas plantas, a estrutura da floresta em ambos os casos, e a inferência da altura verdadeira dos fitofósseis, em uma aplicação inédita de técnicas alométricas a estudos paleontológicos
Abstract: This present study describes a Lower Permian forest in Northern Gondwana, composed by tree ferns, gymnosperms, lycophytes and sphenopsids. This fossil assemblage is located at Tocantins Fossil Trees Natural Monument (MNAFTO) at Parnaíba Basin, Northern Brazil. There are two remarkable aspects: the abundance of fossils and their exceptional level or preservation. The vegetation is similar to the plant fossils found at Chemnitz (Germany), to Euroamerican Flora sites, and to Gondwanian Flora at Paraná Basin (Brazil), among others. Orientation pattern analyses of 178 stems with geological observations suggest paleocurrents in West-East direction, in monsoon storms. The source area should be at West, several quilometers away, probably in a distal alluvial fan context. The forest in the margins of main fluvial channels was occupied by tree ferns at canopy, and lycophytes, sphenopsids and other small ferns at understory. Gymnosperms probably lived in more distant areas from the fluvial channels. The comparison between fossil tree ferns (from MNAFTO) and modern tree ferns (in Submontane Tropical Rain Forest remnants at the present) allowed discussions about ecological niche, forest structure and estimations of real height of fossil tree ferns, in a new way to apply allometric techniques to paleontological studies
Doutor
39
Moraweck, Karolin. "Potential and significance of leaf trait changes of long lived species during the Paleogene." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-227800.
Full textAbstract:
Fossil plants are regard to be excellent proxies to trace paleoclimatic and paleoatmospheric changes. The vegetational response to changing paleoclimate and paleoatmospheric conditions has already been known for a long time and is well documented for the Paleogene of central Europe. Methods such as the Coexistence Approach (CA) and the Climate Leaf Analyses Multivariate Program (CLAMP) analyze the composition of fossil plant assemblages. Changes in paleoclimate and CO2 through time can be tracked also via changes in morphometric parameters such as leaf area, leaf size and leaf shape or epidermal (cuticular) parameters as for instance stomata density (SD), stomata index (SI) and stomata size. The multivariate gas exchange model combines morphometric and cuticular parameters, together with assumed paleoclimate conditions and physiological data of nearest living equivalents to determine paleo-CO2. Plants show differences in morphological, morphometric and cuticular parameters, not only in response to overall changes in CO2 and climate, but also due to their immobility and dependency on light intensity, water availability and soil conditions at the respective site. In this study leaf traits of both Rhodomyrtophyllum reticulosum and Platanus neptuni from 23 sites in Germany, Austria and the Czech Republic covering a time span from the late early Eocene to the early Miocene of central Europe are investigated. Alongside the stratigraphic range of the data set, which allows for tracing long-term variations in the respective parameters, sites of different depositional facies types (maar deposits, marine deposits and fluvial-lacustrine deposits) were included. It has been proven that the investigation of single species and their correspondence to global and regional paleoclimatic and paleoatmospheric shifts has to be done considering differences in the respective depositional setting and thus habitat. Regional effects influence the peculiarity of leaf traits greatly which implies that regional and site related patterns partly overweigh global correspondences. The weak correlation of leaf trait changes to global changes in paleoclimate and CO2 implies that the long-lived species Rhodomyrtophyllum reticulosum and Platanus neptuni are not suitable to track these changes due their high plasticity and adaptability. The long stratigraphic range of the investigated species therefore point out the high adaption potential which by implication leads to a lower correspondence to global paleoclimatic changes. The determination of crucial leaf traits and their response to overall changes in paleoclimate and CO2 hampers the fact that the fossil record bears mainly elements present in azonal vegetation which is caused by predominantly burial of fossils in aquatic bodies. Hence, long-lived species could have been survived these remarkable changes in climate from the end of the Early Eocene Climatic Optimum to the Oligocene icehouse world due to their occurrence in azonal assemblages, buffering global effects in climate variability to a certain degree. The investigation of long-lived fossil species therefore has to be done by coincident consideration of the composition of the whole plant assemblage, which reflects both azonal and partly zonal vegetation of the respective time interval.
40
Watanasak, Manas. "Mid-tertiary palynology of onshore and offshore Thailand /." Title page, contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phm267.pdf.
Full text
41
Grigg, Laurie Davis. "Millennial-scale vegetation and climate variations in the Pacific Northwest during the last glacial period (60,000-16,000 cal yr B.P.) /." view abstract or download file of text, 2000. http://wwwlib.umi.com/cr/uoregon/fullcit?p9998032.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 2000.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 237-250). Also available for download via the World Wide Web; free to University of Oregon users.
42
Sandau, Stephen Dee. "A Uintan (Late Middle Eocene) Flora and Fauna from the Uinta Basin, Utah." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/247.
Full textAbstract:
Late Middle Eocene time marks one of the most dynamic periods of the Paleogene in the western interior of North America. Analysis of an extensive, new collection of plant, invertebrate, and vertebrae fossils from the Uinta Formation in the Uinta Basin, south of Myton, Utah, USA, provides evidence of environmental change. Paleobotanical specimens are preserved in late stage Uinta Lake sediments and coarse-grained fluvial sediments which are stratigraphically 650 to 660 m above the Green River Formation. Deposition rates estimates of 18 to 55 cm/kyr, for Uinta Lake sediments in the Uinta Basin suggest a period of 1.18 Ma to 3.69 Ma to deposit the thick section of lacustrine and fluvial sediments that separates the well-documented Green River Flora from this new fossil leaf assemblage, the Wells Draw flora. Prolific invertebrate trace fossils and invertebrates have a preference for areas with high to fluctuating water tables and soil moistures. The trace fossils are similar to traces of extant invertebrates found in temperate to tropical climates. A variety of reptiles, namely eight species of turtles/tortoise, one lizard (first report of Saniwa from the Uinta Formation), and at least two crocodilian species, are indicative of warm-temperate to subtropical climatic zones.
Flow direction data derived from sedimentary structures in sandstone channel-fills confirms previous studies which indicate the major sediment source area was to the east with a prevailing westward to northwestward flow direction. The presence of higher elevation plant material within the flora, however, implies possible hydraulic transport from the nearby Uinta Mountain highlands, located north of the basin.
The first report of Palmoxylon from the Uinta Formation, included in this report, corroborates the faunal indicators of a tropical climate. Physiognomical analysis of the flora yields a mean annual temperature (MAT) of 16.1◦C and a mean annual precipitation (MAP) of 56 cm. Compared with older Green River flora, these new data suggest a slight drying and cooling trend toward the end of the Eocene. Leaf types also indicate possible seasonality with seasonally dry periods and an overall warm-temperate environment with extreme minima temperatures not much below freezing.
43
Meyer, Laura (Laura B. ). "High precision U/Pb geochronology on the Cenomanian Dakota Formation, Utah : implications for paleobotany and the transgression of the Western Interior Seaway preceding Oceanic Anoxic Event 2." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/114377.
Full textAbstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 31-35).
The Dakota Formation was deposited during the Cenomanian, a time when the Western Interior Seaway spanned much of North America. The Dakota Formation contains a rich record of plant and animal fossils. Key to understanding their importance, it is imperative to precisely place the Dakota Formation within the geological time scale. Volcanic ash samples interlayed with fossil bearing sandstones of the Dakota were collected from two localities in Westwater, and Henrieville, Utah. Samples were dated using isotope dilution thermal ionization mass spectrometry (ID-TIMS). The samples collected from the Westwater, Utah localities have a weighted mean 206Pb/238U date of 97.656±0.082 Ma, while the samples taken from Henrieville, Utah have weighted mean 206Pb/238U dates of 95.170 0.056 Ma and 94.941±0.032 Ma. Based on an analysis of stratigraphic, paleontological, and geochronological data, the Dakota Formation was then correlated across much of the Western Interior. These dates provide a base of the initiation of the transgression across Utah, and set a context for the CT boundary and OAE2 that follow.
by Laura Meyer.
S.B.
44
Souza, Isabel Cortez Christiano de 1983. "Nova abordagem para os estudos paleobotânicos neopaleozóicos da borda leste na porção brasileira da bacia do Paraná utilizando sistemas de informação geográfica." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287395.
Full textAbstract:
Orientador: Frésia Soledad Ricardi Torres BrancoAcompanha 1 mapa acondicionado em bolso no [anexo IV]
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
Made available in DSpace on 2018-08-19T16:09:15Z (GMT). No. of bitstreams: 1 Souza_IsabelCortezChristianode_M.pdf: 9651668 bytes, checksum: 4da84ef5f4b99b65a558d352d48494b0 (MD5) Previous issue date: 2011
Resumo: A presente dissertação buscou revisar as publicações acerca dos fitofósseis da Bacia do Paraná, permitindo visualizar a distribuição espacial das ocorrências fossilíferas. Para tanto foram selecionadas as Paleofloras Pré-Glossopteris e Glossopteris, presentes nos períodos Neocarbonífero e Permiano da borda leste da porção brasileira da Bacia do Paraná. Tal escolha se deu devido a grande quantidade de publicações sobre o tema (mais de 158), o que permite o estudo da distribuição florística mais completo. Primeiramente se construiu um banco de metadados, onde critérios de interesse para cada dado foram adicionados, incluindo sua localização geográfica, sistemática, geologia e referências. Posteriormente os dados georreferenciados foram transferidos para mapas de distribuição fossilífera, o que permitiu diferentes abordagens sobre o mesmo banco de dados. Desta maneira, foram computadas 1208 ocorrências em 281 afloramentos. Os gêneros que tiveram maior número de ocorrências foram Glossópteris (201 ocorrências), seguido de Paracalamites (143 ocorrências) e Pecópteris (107 ocorrências). A distribuição espacial dos afloramentos cadastrados demonstra que estes se encontram dispersos ao longo da área de deposição estudada. Apesar de se constatar o registro de alguns gêneros que persistem ao longo do tempo, verifica-se a existência de outros que perduram durante curtos intervalos de tempo, havendo assim, da Base (Grupo Itararé) até seu topo (Formação Rio do Rasto) uma substituição, além de uma diminuição significativa no número de gêneros (de 45 no Grupo Itararé para 11 na Formação Rio do Rasto)
Abstract: This study describes the formulation of a metadata base of the neopaleozoic phytofossiliferous occurrences of the paleoflorístic province of late Paleozoic Gondwana, on the eastern edge of the Paraná Basin, related to the southwestern corner of the Gondwana, with an analysis through the Geographic Information System (GIS). This mapping allows a spatial study of most species mentioned in the literature, in addition to the intersection of the specific information of each occurrence. This affords an integrated analysis of geological, stratigraphic, biostratigraphic, climatic, and botanic data for the period ? a task never before accomplished for that basin. Thus, a number of maps were generated on the distribution of fossiliferous occurrences ? of all outcrops included in the metadata base, of the distribution of cases according to Floras and Phyitozones proposed in the literature, of the genres regarded as most important, of transport, and of humid environments ? which are regarded as most conducive to fossilization. The possibilities of cross-referencing are endless. Here we show the basic alternatives that the use of this tool allows
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
45
Neregato, Rodrigo [UNESP]. "Esfenóitas do monumento natural das árvores fossilizadas do Tocantins, Bacia do Parnaíba (Permiano, Brasil)." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/102860.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:32:17Z (GMT). No. of bitstreams: 0
Previous issue date: 2012-10-08Bitstream added on 2014-06-13T21:03:55Z : No. of bitstreams: 1
neregato_r_dr_rcla.pdf: 6620889 bytes, checksum: 7be6212f3d43bf983cee3190210e2efb (MD5)Pela primeira vez são descritos, em detalhe, caules de esfenófitas permianos da Bacia do Parnaíba, atribuídos ao gênero Arthropitys, anteriormente conhecidos nas Províncias Florísticas Euramericana e Cataísica. Apresentam-se permineralizados por sílica, com preservação celular, em depósitos fluviais que provavelmente foram controlados por estações secas e úmidas bem definidas. Diversos exemplares possuem ramos conectados ou tocos de ramos. Com base em suas características anatômicas e morfológicas, estão sendo propostas cinco novas espécies: Arthropitys isoramis e Arthropitys tabebuiensis apresentam cavidades medulares grandes, enquanto Arthropitys buritiranensis possui cavidade de dimensões médias; estas espécies possivelmente habitaram as margens dos rios; Arthropitys tocantinensis e Arthropitys barthelli apresentam cavidades das medulas muito pequenas com corpo secundário bastante maciço, interpretando-se que tenham ocupado áreas mais afastadas das drenagens, com substratos mais firmes. Um exemplar de Arthropitys isoramis, com 2.35 m de comprimento e 12 cm de diâmetro máximo, é o primeiro, em âmbito mundial, a preservar a raiz. Ao contrário das reconstruções clássicas do gênero, nas quais a raiz seria similar ao da esfenófita moderna Equisetum, o sistema radicular está disposto verticalmente e de modo contínuo em relação ao caule, formado por três eixos verticais e outros mais oblíquos. Arthropitys tabebuiensis assemelha-se significativamente a Arthropitys bistriata do Asseliano-Sakmariano de Chemnitz, Alemanha, o que corrobora outras evidências paleobotânicas desta idade para a Formação Motuca e sugere algum intercâmbio florístico entre a região da Bacia do Parnaíba e a Província Euramericana
Permian sphenophyte stems from the Parnaíba Basin are described in detail for the first time and classified into Arthopitys genera, previously known in the Euramerican and Cathaysian Floristic Province. They are silica-permineralized with cell preservation and were found in fluvial deposits, which originated under probable marked dry and wet seasons. Several specimens have connected branches or branch-stumps. Based on their anatomical and morphological characteristics, five new species are proposed: Arthropitys isoramis and Arthropitys tabebuiensis have large pith cavities whereas Arthropitys buritiranaensis show a little smaller pith; these species possibly lived at the river side sites. Arthropitys tocantinensis and Arthropitys barthelli have relatively small pith cavitys and massive secondary bodies, suggesting that they occupied distal areas, where the soil was more aggregate. One of the specimens of Arthropitys isoramis has 2.35 m long and 12 cm wide and present exceptional preservation, and is the first in global ambit to preserve an attached root. Differently from the traditional reconstructions based on the modern Equisetum, the studied specimen presents a vertical root which is continuous with respect to the stem, formed by three vertical axes and smaller more oblique axes. Arthropitys tabebuiensis is relatively similar to Arthropitys bistriata from the Asselian-Sakmarian interval in Chemnitz, Germany. This fact corroborates other paleobotanical evidence of this age to Motuca Formation suggesting that there were some floristic relationships with the Euramerican Province during the Permian
46
Tavares, Tatiane Marinho Vieira [UNESP]. "Estudo de marattiales da Floresta Petrificada do Tocantins Setentrional (Permiano, Bacia do Parnaíba)." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/102995.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:32:21Z (GMT). No. of bitstreams: 0
Previous issue date: 2011-10-11Bitstream added on 2014-06-13T19:21:54Z : No. of bitstreams: 1
tavares_tmv_dr_rcla.pdf: 22064000 bytes, checksum: c51a1bd0310cf6dd42d21d4038317172 (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
O trabalho apresenta descrições morfo-anatômicas de samambaias arborescentes permianas (Marattiales) permineralizadas por sílica da Formação Motuca, Bacia do Parnaíba, no Monumento Natural das Árvores Fossilizadas do Tocantins, Norte do Brasil. Os fósseis compreendem caules, folhas férteis, estéreis e raques. Os caules classificam-se em Tietea ou Psaronius. Os primeiros são muito abundantes e, mesmo sem ápice preservado, podem chegar a 12 m de comprimento. É apresentada emenda à diagnose específica de Tietea singularis Solms-Laubach, 1913 no que se refere ao desenvolvimento dos meristelos e à modificação gradual do estelo no sentido proximaldistal, de cilíndrico para quadrangular, analisando-se inúmeras seções transversais polidas em longas extensões de caules. Novos exemplares de Psaronius arrojadoi Pelourde, 1914 permitiram aprimorar os conhecimentos sobre a sua ontogenia e também substanciam uma emenda à diagnose específica. Na área de estudo, Psaronius sinuosus Herbst, 1999 está mal representada, porém continua válida. A priori, não foram encontrados novos exemplares de Psaronius brasiliensis Brongniart, 1872, que é a primeira espécie fóssil formalmente descrita no Brasil. Levantou-se a possibilidade de que esta espécie seja equivalente a porções mais basais dos caules de Tietea singularis, porém exemplares mais completos precisam ser encontrados. É introduzido o táxon Fernia costata gen. et sp. nov. para pinas e pínulas férteis preservadas tridimensionalmente que possuem duas fileiras de sinângios sésseis (cada um com três ou quatro esporângios) totalmente recobertos por longos e grossos lobos laterais do limbo foliar. Tais características distinguem Fernia das folhas férteis da Flora Euramericana designadas...
This work presents morpho-anatomical descriptions of Permian silica-permineralized tree-ferns (Marattiales) from the Motuca Formation, Parnaíba Basin, in the Tocantins Fossil Trees Natural Monument, in North Brazil. The fossils are stems, fertile and sterile leaves and fern rachises. The stems belong to Tietea or Psaronius. The first ones are very abundant and, even without preserved apex, may reach 12 m in length. An emendation to the diagnosis of Tietea singularis Solms-Laubach, 1913 is presented in relation to the meristele development and proximal-distal stele modification from cylindrical to quadrangular form, according to several polished sections of long stem intervals. New specimens of Psaronius arrojadoi Pelourde, 1914 improved ontogenetic knowledge and also substantiated an emended diagnosis. In the study area, Psaronius sinuosus Herbst, 1999 is not well represented, but remains a valid species. Psaronius brasiliensis Brongniart, 1872 corresponds to the first formally described fossil species from Brazil, but no additional equivalent stems were found. Possibly this species represents more basal parts of the Tietea singularis stems, but additional complete samples have to be collected. Fernia costata n. gen. et sp. is introduced for fertile pinnules and pinnae that have two rows of sessile synangia (each one with three or four sporangia) completely protected by curled thick linear long lobes of the leaf laminae. These characteristics distinguish Fernia from fertile leaves of the Euramerican Flora, namenly Scolecopteris or Acitheca. The sterile pinnules and pinnae were identified only at the genus level as Pecopteris sp.I and Pecopteris sp.II. Finally Tocantinorachis buritiranaensis n. gen. et sp. is proposed to designate fragmented rachises with morphological and anatomical similarity to Tietea singularis... (Complete abstract click electronic access below)
47
Faria, Rafael Souza de 1985. "Licofitas Guadalupianas da Bacia do Parana : Novos dados morfo-anatomicos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287313.
Full textAbstract:
Orientador: Fresia Soledad Ricardi-BrancoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias
Made available in DSpace on 2018-08-12T21:47:49Z (GMT). No. of bitstreams: 1 Faria_RafaelSouzade_M.pdf: 4846121 bytes, checksum: 06fbb408dd12015c7f8b819ab250dae9 (MD5) Previous issue date: 2009
Resumo: Lycopodiopsis derbyi é a espécie à qual mais comumente se relacionam os fragmentos caulinares licofíticos encontrados em estratos guadalupianos da Bacia do Paraná. Tipicamente caracteriza-se por um cilindro vascular sifonostélico com o anel descontínuo cortado por raios medulares e pela presença de almofadas foliares rômbicas com vesícula infrafoliar e cicatrizes foliares sem sinais de páricnos. Microfilos fragmentados geralmente ocorrem associados aos caules. Aqui foram tomadas três localidades no estado de São Paulo (de afloramentos da Formação Corumbataí), uma no estado do Paraná e uma em Santa Catarina (ambas de afloramentos da Formação Teresina) para as quais se estudaram os caules e microfilos de licófitas encontrados. Os caules foram diagnosticados como L. derbyi. Análises morfológicas levaram a sugestão de um possível modelo ontogenético relacionando as almofadas foliares e o diâmetro dos ramos. Nas análises anatômicas interpretou-se o córtex de maneira diferente a de autores anteriores. Com base nos dados adquiridos propõe-se uma emenda à diagnose da espécie e ainda sugere-se uma modificação da chave de identificação de Thomas e Meyen (1984) para as Lepidodendrales do Paleozóico superior. Para os microfilos definiu-se uma nova organo-espécie com base em amostras de Piracicaba (SP), Lepidophylloides corumbataensis. Tal organo-espécie é a primeira do gênero formalmente descrita para o Brasil e possivelmente para o Gondwana. Representa ainda o primeiro registro de tecido paliçádico numa espécie de Lepidphylloides. A organização dos fexies de xilema em forma de crescente sugere uma proximidade às espécies da Catásia. A íntima associação com Lycopodiopsis derbyi indica que provavelmente representem as folhas dos mesmos. Compararndo as ocorrências de microfilos estudadas nas formações Teresina e Corumbataí, concluiu-se que na primeira aqueles ocorrem r em menores concentrações e sem anatomia preservada, indicando maior transporte.
Abstract: Master degree dissertation Rafael Souza de Faria Lycopodiopsis derbyi is the most common species to which the lycopod stem fragments found in the Guadalupian strata from the Paraná Basin are assigned. A vascular cylinder represented by a siphonostele with a discontinuous ring crossed by medular rays and the presence of rhombic leaf cushions with infrafoliar bladders and leaf scars without any sign of pharichnos typically characterize the species. Fragmented microphylls occur in general associated with the stems. Here three localities in the state of São Paulo (from outcrops of Corumbataí Formation), one in Paraná state and one in Santa Catarina state (from outcrops of Teresina Formation) where lycopods stems and microphylls are found have been studied. The stems were diagnosed as L. derbyi. Morphological analyses suggest a possible ontogenetic model relating the leaf cushions to the branch diameter. In the anatomical analyses the cortex was interpreted differently from previous authors. Based on the data acquired an emended diagnoses is proposed for the species together with a modification of the Thomas and Meyen's (1984) identification key for the Upper Paleozoic Lepidodendrales. With regard to the microphylls, a new organo-species based on samples from Piracicaba (São Paulo state) was defined, Lepidophylloides corumbatensis. This organo-species is the first of the genus formally described for Brazil and probably for Gondwanaland. It also represents the first register of palisade tissue in a Lepidophylloides species. The xylem bundle organization in crescent shape suggests a close relation with the catasian species The association with Lycopodiopsis derbyi indicates that they represent the leaves of the such stems. Comparing the mycrophylls studied from the Teresina and Corumbataí formations, the ones occuring in the first are commonly in lower concentrations and with no preserved anatomy, indicating more transport.
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
48
Tavares, Tatiane Marinho Vieira. "Estudo de marattiales da "Floresta Petrificada do Tocantins Setentrional" (Permiano, Bacia do Parnaíba) /." Rio Claro : [s.n.], 2011. http://hdl.handle.net/11449/102995.
Full textAbstract:
Orientador: Rosemarie Rohn DaviesBanca: Jefferson Prado
Banca: Fresia Soledad Ricardi Torres Branco
Banca: Roberto Iannuzzi
Banca: Joel Carneiro de Castro
Resumo: O trabalho apresenta descrições morfo-anatômicas de samambaias arborescentes permianas (Marattiales) permineralizadas por sílica da Formação Motuca, Bacia do Parnaíba, no Monumento Natural das Árvores Fossilizadas do Tocantins, Norte do Brasil. Os fósseis compreendem caules, folhas férteis, estéreis e raques. Os caules classificam-se em Tietea ou Psaronius. Os primeiros são muito abundantes e, mesmo sem ápice preservado, podem chegar a 12 m de comprimento. É apresentada emenda à diagnose específica de Tietea singularis Solms-Laubach, 1913 no que se refere ao desenvolvimento dos meristelos e à modificação gradual do estelo no sentido proximaldistal, de cilíndrico para quadrangular, analisando-se inúmeras seções transversais polidas em longas extensões de caules. Novos exemplares de Psaronius arrojadoi Pelourde, 1914 permitiram aprimorar os conhecimentos sobre a sua ontogenia e também substanciam uma emenda à diagnose específica. Na área de estudo, Psaronius sinuosus Herbst, 1999 está mal representada, porém continua válida. A priori, não foram encontrados novos exemplares de Psaronius brasiliensis Brongniart, 1872, que é a primeira espécie fóssil formalmente descrita no Brasil. Levantou-se a possibilidade de que esta espécie seja equivalente a porções mais basais dos caules de Tietea singularis, porém exemplares mais completos precisam ser encontrados. É introduzido o táxon Fernia costata gen. et sp. nov. para pinas e pínulas férteis preservadas tridimensionalmente que possuem duas fileiras de sinângios sésseis (cada um com três ou quatro esporângios) totalmente recobertos por longos e grossos lobos laterais do limbo foliar. Tais características distinguem Fernia das folhas férteis da Flora Euramericana designadas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This work presents morpho-anatomical descriptions of Permian silica-permineralized tree-ferns (Marattiales) from the Motuca Formation, Parnaíba Basin, in the Tocantins Fossil Trees Natural Monument, in North Brazil. The fossils are stems, fertile and sterile leaves and fern rachises. The stems belong to Tietea or Psaronius. The first ones are very abundant and, even without preserved apex, may reach 12 m in length. An emendation to the diagnosis of Tietea singularis Solms-Laubach, 1913 is presented in relation to the meristele development and proximal-distal stele modification from cylindrical to quadrangular form, according to several polished sections of long stem intervals. New specimens of Psaronius arrojadoi Pelourde, 1914 improved ontogenetic knowledge and also substantiated an emended diagnosis. In the study area, Psaronius sinuosus Herbst, 1999 is not well represented, but remains a valid species. Psaronius brasiliensis Brongniart, 1872 corresponds to the first formally described fossil species from Brazil, but no additional equivalent stems were found. Possibly this species represents more basal parts of the Tietea singularis stems, but additional complete samples have to be collected. Fernia costata n. gen. et sp. is introduced for fertile pinnules and pinnae that have two rows of sessile synangia (each one with three or four sporangia) completely protected by curled thick linear long lobes of the leaf laminae. These characteristics distinguish Fernia from fertile leaves of the Euramerican Flora, namenly Scolecopteris or Acitheca. The sterile pinnules and pinnae were identified only at the genus level as Pecopteris sp.I and Pecopteris sp.II. Finally Tocantinorachis buritiranaensis n. gen. et sp. is proposed to designate fragmented rachises with morphological and anatomical similarity to Tietea singularis... (Complete abstract click electronic access below)
Doutor
49
Neregato, Rodrigo. "Esfenóitas do monumento natural das árvores fossilizadas do Tocantins, Bacia do Parnaíba (Permiano, Brasil) /." Rio Claro, 2012. http://hdl.handle.net/11449/102860.
Full textAbstract:
Orientador: Rosemaire Rohn DaviesBanca: Joel Carneiro de Castro
Banca: Roberto Iannuzzi
Banca: Fresia Soledad Ricardi-Branco
Banca: Jefferson Prado
Resumo: Pela primeira vez são descritos, em detalhe, caules de esfenófitas permianos da Bacia do Parnaíba, atribuídos ao gênero Arthropitys, anteriormente conhecidos nas Províncias Florísticas Euramericana e Cataísica. Apresentam-se permineralizados por sílica, com preservação celular, em depósitos fluviais que provavelmente foram controlados por estações secas e úmidas bem definidas. Diversos exemplares possuem ramos conectados ou tocos de ramos. Com base em suas características anatômicas e morfológicas, estão sendo propostas cinco novas espécies: Arthropitys isoramis e Arthropitys tabebuiensis apresentam cavidades medulares grandes, enquanto Arthropitys buritiranensis possui cavidade de dimensões médias; estas espécies possivelmente habitaram as margens dos rios; Arthropitys tocantinensis e Arthropitys barthelli apresentam cavidades das medulas muito pequenas com corpo secundário bastante maciço, interpretando-se que tenham ocupado áreas mais afastadas das drenagens, com substratos mais firmes. Um exemplar de Arthropitys isoramis, com 2.35 m de comprimento e 12 cm de diâmetro máximo, é o primeiro, em âmbito mundial, a preservar a raiz. Ao contrário das reconstruções clássicas do gênero, nas quais a raiz seria similar ao da esfenófita moderna Equisetum, o sistema radicular está disposto verticalmente e de modo contínuo em relação ao caule, formado por três eixos verticais e outros mais oblíquos. Arthropitys tabebuiensis assemelha-se significativamente a Arthropitys bistriata do Asseliano-Sakmariano de Chemnitz, Alemanha, o que corrobora outras evidências paleobotânicas desta idade para a Formação Motuca e sugere algum intercâmbio florístico entre a região da Bacia do Parnaíba e a Província Euramericana
Abstract: Permian sphenophyte stems from the Parnaíba Basin are described in detail for the first time and classified into Arthopitys genera, previously known in the Euramerican and Cathaysian Floristic Province. They are silica-permineralized with cell preservation and were found in fluvial deposits, which originated under probable marked dry and wet seasons. Several specimens have connected branches or branch-stumps. Based on their anatomical and morphological characteristics, five new species are proposed: Arthropitys isoramis and Arthropitys tabebuiensis have large pith cavities whereas Arthropitys buritiranaensis show a little smaller pith; these species possibly lived at the river side sites. Arthropitys tocantinensis and Arthropitys barthelli have relatively small pith cavitys and massive secondary bodies, suggesting that they occupied distal areas, where the soil was more aggregate. One of the specimens of Arthropitys isoramis has 2.35 m long and 12 cm wide and present exceptional preservation, and is the first in global ambit to preserve an attached root. Differently from the traditional reconstructions based on the modern Equisetum, the studied specimen presents a vertical root which is continuous with respect to the stem, formed by three vertical axes and smaller more oblique axes. Arthropitys tabebuiensis is relatively similar to Arthropitys bistriata from the Asselian-Sakmarian interval in Chemnitz, Germany. This fact corroborates other paleobotanical evidence of this age to Motuca Formation suggesting that there were some floristic relationships with the Euramerican Province during the Permian
Doutor
50
Crifo, Camilla. "VARIATIONS IN ANGIOSPERM LEAF VEIN DENSITY HAVE IMPLICATIONS FOR INTERPRETING LIFE FORM IN THE FOSSIL RECORD." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1375987428.
Full text