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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

The biology and taxonomy of Mesozoic stromatoporoids

Wood, R. A. January 1986 (has links)
The presence of spicule pseudomorphs and an aquiferous filtration system in Mesozoic stromatoporoids confirms poriferan affinity for this previously problematic group. The form, and postulated original siliceous nature of most of the spicules, indicates that the possessors of these were calcified demosponges; others with originally calcareous spicules were calcareans. Different spicule types and arrangements indicate that the possession of a calcareous skeleton is a convergent feature. Previous defining characteristics are found to be invalid and Mesozoic stromatoporoids are redefined as calcified sponges, so that the term 'stromatoporoid' now only refers to a grade of organisation of the calcareous skeleton and not a taxonomic grouping. 'Chaetetids', 'sphinctozoans' and 'sclerosponges' are also polyphyletic groupings, representing grades, where some members of which are calcified demosponges. These groupings should no longer be considered in isolation, as this has previously obscured their true nature. The original mineralogy of late Mesozoic stromatoporoids was probably low-Mg. calcite. Spicule and calcareous skeleton diagenetic lineages are given to enable workers to determine original microstructures. Analogies with Recent calcified demosponges, suggests that the fossil stromatoporoid demosponges produced a primary framework of siliceous spicules bound together with an organic matrix, which probably provided the nucleation sites for subsequent precipitation of the calcareous skeleton. A new taxonomic scheme is presented based on spicule type, arrangement and relationship of this framework to the microstructure of the calcareous skeleton. On the basis of spicule criteria, calcareous microstructure alone is found to be convergent and can no longer be used as a high-level taxonomic feature. Spiculate species are therefore redescribed and placed within the Recent poriferan classification framework. Synonyms are documented and intra-specific variation discussed. The present cnidarian-based nomenclature is replaced by one modified from Recent poriferan terminology. The possession of a calcareous skeleton is probably a relict feature of a previously widespread calcified sponge fauna. It appears that the calcareous skeleton was acquired independently in a number of lineages in the early Palaeozoic, and has subsequently been lost in many.
72

Fylogenetická a taxonomická charakterizace nových haloarcheí blízkých rodu natronomonas. / Phylogenetic and taxonomic characterization of new haloarchaea related to natronomonas.

Šantorová, Anna January 2018 (has links)
Candidate: Anna Šantorová Title of diploma thesis: Phylogenetic and taxonomic characterization of new haloarchaea related to Natronomonas. Charles University, Faculty of Pharmacy Department of Biological and Medicinal Sciences University of Sevilla, Faculty of Pharmacy Department of Microbiology and Parasitology Study program: Pharmacy This work continues with the characterization of new Archaea related to the genus Natronomonas isolated from hypersaline waters of solar salterns located near the city of Huelva in the southwest of Spain. These microorganisms need a high concentration of salts in the environment for their survival and growth. Ana Durán-Viseras started with their characterization and I was participating on the continuation of the project during my stay in Sevilla. To complete the phylogenetic studies, we amplified the rpoB' gene of the potentially new species of Archaea as a part of MLSA and we created a phylogenetic tree. Based on these results we came to the conclusion that they represent new genus, which was later confirmed by the analysis of polar lipids profile by the HPTLC method. We have determined the guanine and cytosine content, which is part of the taxonomic characterization of new prokaryotic species. We have started the phenotypic characterization.
73

A study in the experimental taxonomy of some British Sphagna (section Cuspidata), with observations of their ecology

Agnew, Shirley January 1958 (has links)
No description available.
74

Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura : Hylidae)

Estrada, Francisco Adolfo Brusquetti [UNESP] 02 September 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-09-02Bitstream added on 2014-06-13T20:00:11Z : No. of bitstreams: 1 estrada_fab_me_rcla.pdf: 2848739 bytes, checksum: 7762a98a6409bfe1118c630b45226509 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Scinax fuscomarginatus, S. parkeri, S. trilineatus e a recentemente descrita S. lutzorum são espécies muito similares morfologicamente que ocorrem em formações abertas da America do Sul ao leste dos Andes. Scinax parkeri e S. trilineatus tiveram sua validade taxonômica questionada enquanto S. fuscomarginatus é considerada por vários autores como um complexo de espécies. Levando em conta a similaridade morfológica e a incerteza taxonômica, nesse trabalho revisamos a taxonomia de Scinax fuscomarginatus, S. trilineatus, S. parkeri e S. lutzorum usando dados de morfologia externa, cantos de anúncio e sequências moleculares. Os principais objetivos foram investigar a existência de outras espécies sob o nome S. fuscomarginatus e avaliar o status taxonômico de S. parkeri, S. trilineatus, S. lutzorum e Hyla madeirae (único sinônimo de S. fuscomarginatus). Nas análises filogenéticas com dados moleculares encontramos uma profunda e rica estrutura genética tanto intra quanto inter-especifica. As amostras incluídas formaram um grupo monofilético bem suportado que está estruturado em vários clados e subclados. Hyla madeirae e a população da Serra do Cachimbo correspondem a subclados distintos enquanto as espécies atualmente válidas (S. fuscomarginatus, S. parkeri, S. trilineatus e S. lutzorum) se agrupam em um único clado. Este clado apresenta subestrutura marcada, mas a concordância entre subclados e as espécies reconhecidas é limitada. A alta variação intraespecífica e intrapopulacional encontrada nos caracteres morfológicos usados para a diagnose original das espécies não permitiu a diferenciação entre S. parkeri, S. trilineatus, S. lutzorum e S. fuscomarginatus. Entretanto, alguns caracteres permitem a distinção de Hyla madeirae e dos espécimens da Serra do Cachimbo / Scinax fuscomarginatus, S. parkeri, S. trilineatus and the recently described S. lutzorum are morphologically very similar species that occur in open formations of South America east of the Andes. Scinax parkeri and S. trilineatus had its taxonomic validity questioned, and S. fuscomarginatus is considered by many authors as a species complex. Given the morphological similarity and taxonomic uncertainty, we review the taxonomy of Scinax fuscomarginatus, S. parkeri, S. trilineatus, and S. lutzorum using data from external morphology, advertisement calls and molecular sequences. The main goals were to investigate the existence of other species under the name S. fuscomarginatus and assess the taxonomic status of S. parkeri, S. trilineatus, S. lutzorum and Hyla madeirae (the only synonym within S. fuscomarginatus). In the phylogenetic analysis obtained with the molecular data we found rich and deep genetic structure both within and between species. The samples included formed a well supported monophyletic group that is divided into several clades and subclades. The specimens of Hyla madeirae and those from Serra do Cachimbo corresponded to distinct subclades while the currently valid species (S. fuscomarginatus, S. parkeri, S. and S. trilineatus lutzorum) were grouped into a single clade. This clade showed marked substructure, but the concordance of the recognized species to subclades were limited. The high intrapopulation and intraspecific variation found in morphological characters used for the original diagnoses did not allow us to differ among S. parkeri, S. trilineatus, S. lutzorum and S. fuscomarginatus. However, some characters support the distinction of Hyla madeirae and specimens from Serra do Cachimbo. Similarly, none of valid species were distinguishable in morphometric analysis while Hyla madeirae and the specimens from Serra do Cachimbo showed a trend in having wider heads
75

The Silurian Ostracoda of the Oslo region, Norway

Pollicott, Paul D. January 1987 (has links)
A study of the ostracode fauna from the Silurian of Norway has been undertaken. All of the taxa recoverd and described are from the Llandovery and Wenlock Series; one species from the topmost part of the Ordovician of the Oslo region is also figured. Research has concentrated particularly upon the Palaeocopa Henningsmoen, 1954, but also includes the Leperditicopida Scott, 1961. The 'non-palaeocopes', because of particular problems related to preservation and taxonomy, are not treated as extensively. Primary revision has been made wherever possible. Such work has been augmented by studies of extensive new collections made from throughout the Oslo region, particularly from the Ringerike, Oslo-Asker and Holmestrand districts. This study has concentrated firstly on the taxonomy of the fauna. There are chapters on the Leperditicopa, Palaeocopa and 'non-palaeocopes'. Other chapters deal with the palaeoecology, biostratigraphy and correlation and affinities of the fauna. A full faunal and associated locality list, together with information on regional stratigraphy, is also presented. The fauna is 26 genera (2 new), 43 named species (14 new) and 15 other forms are described under open nomenclature. The Silurian ostracode fauna of Norway is mostly endemic (at specific level) but does have affinities with Gotland, Siberia and Britain. Ostracode potential for correlation between various districts of the Oslo region is best realised in the Steinsfjorden Formation. Standard micropalaeontological techniques have been used throughout, with most material being prepared by 'Vibrotool', and photographed on the Scanning Electron Microscope.
76

Cladistic analysis of Macrobunidae Petrunkevitch, 1928 new rank and revision of Macrobuninae (Araneae). / Análise cladística de Macrobunidae Petrunkevitch 1928 stat. nov. e revisão de Macrobuninae (Araneae)

Lina Maria Almeida-Silva 26 August 2013 (has links)
Macrobuninae Petrunkevitch is revised and submitted to a cladistic analysis. Macrobuninae, once considered the biggest Amaurobiidae Thorell subfamily is now proved to be not even closely related to Amaurobiinae, the \"true amaurobiids\". Our matrix, composed by 82 terminal taxa and 107 characters, includes representatives of all Macrobuninae genera and new taxa we believed to be part of Macrobuninae. As out-groups, we included representatives of the families Agelenidae Koch, Amaurobiidae, Amphinectidae Forster & Wilton, Chummidae Jocqué, Desidae Pocock, Dictynidae O. P.-Cambridge, Phyxelididae Lehtinen, Stiphidiidae Dalmas, Tengellidae Dahl, Titanoecidae Lehtinen, Zorocratidae Dahl and Zoropsidae Bertkau, which were suggested as related to Macrobuninae by previous studies. Our main results confirm Macrobuninae as not forming a monophyletic group with Amaurobiidae and shows the need to erect Macrobunidae Petrunkevitch, 1928 new rank to include Macrobuninae and relatives. Three other subfamilies are proposed here: Retirinae subfam. nov., Pakehinae subfam. nov., and Zanomyinae Ubick, 2005 new rank. Chummidae, currently composed by one genus and two species, is considered a junior-synonym with Macrobunidae. Amaurobiidae appears as sister group of the \"Oval Calamistrum Clade\" and the \"Fused Paracribellar clade\". The subfamily Macrobuninae is revised at the generic-level and redelimited to include a total of 26 genera. Of those, thirteen are newly described: Siyabonga gen. nov., Peckmaria gen. nov., Ijoubetumsam gen. nov., Imbumbulu gen. nov., Ibhulashi gen. nov., Umunwe gen. nov., Pigozzoi gen. nov., Samadhia gen. nov., Naynay gen. nov., Segoko gen. nov., Deusemais gen. nov., Madiba gen. nov. and Ushaka gen nov.. The remaining known genera are redescribed including their type-species, except the ones with recent, up to date descriptions. Seventeen new species are described: Emmenomma joshuabelli sp. nov., Macrobunus alejandrosanzi, sp. nov., Macrobunus eniomattosi sp. nov., Yupanquia lenktaitisi sp. nov., Ijoubetumsam frizzellae sp. nov., Deusemais viximaria sp. nov., Naynay meikleae sp. nov., Pigozzoi pifozonho sp. nov., Samadhia kellyfujiharae sp. nov., Siyabonga kakhulu sp. nov., Imbumbulu westhuizenis sp. nov., Madiba haddadi sp. nov., Ushaka umsila sp. nov., Ushaka philai sp. nov., Ibhulashi lakeside sp. nov., Umunwe ndabae sp. nov. and Segoko chueneorum sp. nov. Eight genera removed from Macrobuninae are assigned to other subfamilies and/or families. All taxonomic changes are justified by the phylogenetic analysis. For the first time the male specimens of Hicanodon Tullgren, Yupanquia Lehtinen and Chresiona Simon are described; Anisacate fuegianum bransfield Usher is raised to the species level, A. bransfield Usher new rank; Emmenomma beauchenicum Usher is considered junior synonym of E. oculatum Simon; Emmenomma oculatum obscurum Simon is removed from the synonym with E. oculatum and raised to the species level, Emmenomma obscurum Simon new rank. The type specimens of Macrobunus backhauseni (Simon) are considered non co-specifics and a new species Macrobunus alejandrosanzi sp. nov. is described based on the female. The true female of M. backhauseni is described for the first time. Other taxonomic changes include: removal of Notolathys Mello-Leitão from synonymy with Auximella Strand and placement as a junior synonym of Retiro Mello-Leitão; to consider Urepus Roth a junior synonym of Auximella; and Tymbira Mello-Leitão a junior synonym of Metaltella Mello-Leitão / Macrobuninae é alvo de uma revisão e análise cladística. Esta subfamília, que já foi considerada a maior de Amaurobiidae, mostra-se pouco relacionada aos Amaurobiinae ou \"amaurobiideos verdadeiros\". A matriz deste estudo, composta por 82 taxa terminais e 107 caracteres inclui representantes de todos os gêneros de Macrobuninae e novos taxa desta subfamília. Como grupo-externo, foram utilizados representantes de: Agelenidae Koch, Amaurobiidae, Amphinectidae Forster & Wilton, Chummidae Jocqué, Desidae Pocock, Dictynidae O. P.-Cambridge, Phyxelididae Lehtinen, Stiphidiidae Dalmas, Tengellidae Dahl, Titanoecidae Lehtinen, Zorocratidae Dahl e Zoropsidae Bertkau, uma vez que estas famílias foram relacionadas a Macrobuninae em outros estudos. Os resultados principais confirmam que Macrobuninae não está intimamente relacionada a Amaurobiidae e confirma a necessidade de elevar Macrobuninae à categoria de família, Macrobunidae Petrunckevitch, 1928 status nov. a fim de incluir os Macrobuninae e generos relacionados. Três subfamílias aqui descritas: Retirinae subfam. nov., Pakehinae subfam. nov., and Zanomyinae Ubick, 2005 status nov.. Chummidae Jocqué, atualmente composta por um gênero e duas espécies, passa a ser considerada sinônimo-junior de Macrobunidae. Amaurobiidae aparece como grupo-irmão dos clados \"paracribellares fundidas\" e calamistro oval. A subfamília Macrobuninae é revisada em nível genérico e redelimitada a fim de incluir um total de 26 gêneros. Destes, treze gêneros novos são descritos: Siyabonga gen . nov., Peckmaria gen. nov., Ijoubetumsam gen. nov., Imbumbulu gen. nov., Ibhulashi gen. nov., Umunwe gen. nov., Pigozzoi gen. nov., Samadhia gen. nov., Naynay gen. nov., Segoko gen. nov., Deusemais gen. nov., Madiba gen. nov. and Ushaka gen nov.. Dos treze gêneros conhecidos, apenas os que possuem descriçoões recentes e atualizadas não tiveram suas espécies-tipo redescritas. Dezessete espécies novas são descritas: Emmenomma joshuabelli sp. nov., Macrobunus alejandrosanzi, sp. nov., Macrobunus eniomattosi sp. nov., Yupanquia lenktaitisi sp. nov., Ijoubetumsam frizzellae sp. nov., Deusemais viximaria sp. nov., Naynay meikleae sp. nov., Pigozzoi pifozonho sp. nov., Samadhia kellyfujiharae sp. nov., Siyabonga kakhulu sp. nov., Imbumbulu westhuizenis sp. nov., Madiba haddadi sp. nov., Ushaka umsila sp. nov., Ushaka philai sp. nov., Ibhulashi lakeside sp. nov., Umunwe ndabae sp. nov. e Segoko chueneorum sp. nov.. Oito gêneros são removidos de Macrobuninae e transferidos para outras subfamílias e/ou famílias. As mudanças taxonômicas apresentadas são corroboradas pela análise cladística. São apresentadas as primeiras descrições de machos de espécies de Hicanodon Tullgren, Yupanquia Lehtinen e Chresiona Simon. Anisacate fuegianum bransfield Usher é elevada a categoria de espécie, A. bransfield Usher stat. nov.. Emmenomma beauchenicum Usher é considerada sinônimo junior de E. oculatum. Emmenomma oculatum obscurum Simon é removida da sinonímia e elevada a categoria de espécie, Emmenomma obscurum Simon stat. nov.. Os espécimes-tipo de M. backhauseni são aqui considerados duas espécies diferentes e com base na fêmea uma espécie nova M. alejandrosanzi sp. nov. é descrita. A verdadeira fêmea de M. backhauseni (Simon) é descrita pela primeira vez. Outras mudanças taxonômicas proveniente do estudo dos espécimes-tipo incluem remover Notolathys Mello-Leitão da sinonímia com Auximella Strand e transferir Notolathys para sinônimo-junior de Retiro Mello-Leitão; sinonimizar Urepus Roth e Auximella; considerar Tymbira Mello-Leitão sinônimo-junior de Metaltella Mello-Leitão
77

A Taxonomic Study of the Family Bacteroidaceae

Funderburk, Noel Roger 08 1900 (has links)
This study was performed to clarify the taxonomy of the bacteria in the family Bacteroidaceae.
78

A revision of some Silesian goniatites using cluster analysis

Swan, Andrew Robert Henry January 1984 (has links)
This thesis is primarily concerned with the application of numerical methods of taxonomic analysis to some Silesian goniatite assemblages. The taxa investigated here have been regarded in the past as belonging to the families Homoceratidae, Reticuloceratidae and Gastrioceratidae, plus the genus Homoceratoides. These are studied throughout their range, which is from the base of the Chokierian stage, Namurian, to the base of Westphalian C. British faunas are concentrated upon, but it is also of interest to investigate relationships with overseas faunas. The history of research into Silesian goniatites is discussed, and a brief account is given of the geological background to the subject, from which the precise difficulties and points of interest become apparent. The various taxonomic techniques which have been and are used in palaeontology are critically examined, and it is concluded that orthodox methodologies are inadequate for the present task. The statistical technique of cluster analysiS is, however, found to be suitable, and a new system of taxonomic analysis of goniatites is developed, based on phenetics. Methods of arriving at objective morphospecific divisions, higher taxonomic divisions, specimen determinations and phylogenies are devised and described. These techniques are then applied to data collected from the various goniatite faunas, and a complete and new systematic scheme is derived. British morphospecies are redescribed and all relevant genera have required redefinition. A new genus is described (Otleyoceras), and new species are described of Homoceras, Vallites, Homoceratoides, Otleyoceras, Bilinguites, Cancelloceras, Agastrioceras and Gastrioceras. The variation within faunas is described graphically and is found to have parallels with diverse other ammonoid groups. The mode of evolution is discussed, although the evidence is found to be ambiguous. and speculative phylogenies are proposed. Finally. some examples are given of how numerical analYSis can be useful in biostratigraphy.
79

Molecular taxonomic studies of selected species in the Gibberella fujikuroi complex

Steenkamp, Emma Theodora 09 June 2006 (has links)
Thesis (PhD)--University of Pretoria, 2006. / Microbiology and Plant Pathology / Unrestricted
80

Exploring evolutionary patterns and processes : a case study using the Mesozoic bivalve Buchia

Grey, Melissa 05 1900 (has links)
The fossil record is the only direct source of data for studying modes (patterns) and rates of morphological change over geologic time periods. Determining modes is critical for understanding macroevolutionary processes, but just how modes can vary within a taxon, and why, have hitherto been largely understudied. To address this, I examined patterns of morphological change in the shell of the Mesozoic marine bivalve genus Buchia over its geographic and temporal range. Buchia was chosen as a test subject because it is abundant, well-preserved across a variety of facies, and is widely distributed across the Northern Hemisphere where the likelihood of multiple lineages is low. While the focus of this thesis is on evolutionary patterns, it is also necessary to address issues of taxonomy and geographical variation, making this research applicable to a wide-variety of fields. Previous to this study there was no protocol for measuring buchiid valves, nor was the genus studied in a quantitative manner. Throughout this research I used ten morphological characters to describe shell shape and size. Multivariate methods (principle component and canonical variate analyses) were employed to discriminate between species of Buchia and examine how morphological characters change through time and space within the genus. Evolutionary patterns were delineated using two well-established programs that discriminate between multiple modes of evolution. Overall, nearly 2000 specimens from eight geographical locations around the world were studied for this thesis. I found the genus Buchia was a useful tool for evolutionary studies as it can be studied quantitatively in space and time. Specically I have found that buchiid species can be delineated using morphometrics; the genus is restricted to the Northern Hemisphere; while the environment significantly affects morphology, there is no evidence of a latitudinal gradient; diversity and disparity within Buchia are not correlated; most evolutionary modes conformed to random walks or stasis; and modes and rates vary across the geographical range of the genus. Overall, I have found that the environment plays an important role in shaping both morphology and modes. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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