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Geologia e paleontologia de dep?sitos fossil?feros pleistoc?nicos do Rio Grande do NorteSantos, Maria de F?tima Cavalcante Ferreira dos 19 May 2006 (has links)
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Previous issue date: 2006-05-19 / This study deals with origin, sedimentary filling and fossil content of three tanks situated at Ant?nio Martins, Barcelona, Rui Barbosa, and Apodi counties, Rio Grande do Norte State. In addition, fossil materials from the C?mara Cascudo Museum - UFRN - Funda??o Amigos do Lajedo Soledade - FALS, and from private ownership were investigated. The following families were identified: Megatberiidae, Gomphotheriidae, Mylodontidae, Equidae, Felidae, Canidae, Hydrochoeridae, Camelidae, Cervidae, Dasypodidae, Glyptodontidae, Macraucheniidae, Toxodontidae, and an undetermined Edentata Pilosa. The megafauna analysis indicated that herbivorc families occur mainly in tanks, whereas carnivore families occur in a vast proportion in an investigated ravine. Taphonomie analyses were limited to physical features because the vast majority of fossils were previously colleted without appropriate care for this kind of study. The main fossization processes were identified during diagenetie investigation. Permineralization is the most important process and replacement is the secondary one during fossilization. The study concluded that paleoenvironmental conditions during the late Pleistocene were more humid than the current one. Tropical savana, characterized by fields and cerrados , was the dominant vegetation / Neste trabalho s?o abordados alguns aspectos sobre os processos de forma??o, o preenchimento sedimentar e sobre o conte?do fossil?fero de tr?s "tanques" localizados nos munic?pios de Ant?nio Marfins, Barcelona, Rui Barbosa, e de uma ravina localizada em Apodi, todos no Estado do Rio Grande do Norte. Al?m do material fossil?fero coletado durante as etapas de campo foram tamb?m estudadas algumas pe?as pertencentes ao Museu c?mara Cascudo/UFRN, a FALS (Funda??o Amigos do Lajedo de Soledade) e tamb?m sob guarda pm1icular. Foram identificadas as fam?lias Megatheriidae, Gomphotheriidae, Mylodontidae, Equidae, Felidae, Canidae, Hydrochoeridae, Camelidae, Cervidae, Dasypodidae, Glyptodontidae, Macraucheniidae, Toxodontidae e de um Edentata Pilosa lndetetminado. A an?lise de megafauna presente nos diferentes dep?sitos mostrou que nos tanques predominam as formas herb?voras, enquanto que a representa??o coletada na ravina ? mais diversificada, incluindo tipos diferentes de carn?voros. Observa??es tafon?micas foram limitadas aos aspectos f?sicos observ?veis em laborat?rio, pois a grande maioria dos f?sseis j? havia sido coletada, sem que fossem observados os cuidados m?nimos indispens?veis a esse tipo de estudo. Os estudos diagen?ticos permitiram a identifica??o dos principais processos de fossillza??o: sendo a permineraliza??o o processo de preserva??o predominante, ocorrendo subordinadamente substitui??o. A interpreta??o das condi??es paleoambientais necess?rias para dar suporte as fam?lias identificadas, conduziu a infer?ncia de condi??es clim?ticas, durante o Pleistoceno superior, diferentes das atuais, mais ?mido com vegeta??o semelhante a de uma savana tropical, onde estariam presentes campos e cerrados
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Hist?ria evolutiva dos lagartos an?es (Lygodactylus, Gekkonidae) no continente Sul AmericanoLanna, Fl?via M?l 21 February 2017 (has links)
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Previous issue date: 2017-02-21 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Quais os processos e mecanismos respons?veis pela diversifica??o das esp?cies? Essa ? uma
quest?o antiga que tem sido revolucionada com o avan?o tecnol?gico, computacional e
metodol?gico, e tem sido agora compreendida de uma forma que antes n?o era poss?vel. A
filogeografia ? uma multidisciplina que utiliza ferramentas derivadas da biogeografia, filogenia
molecular e gen?tica de popula??es para entender o contexto da distribui??o dos genes no tempo
e espa?o. O presente estudo utiliza an?lises filogen?ticas e filogeogr?ficas para inferir os
processos determinantes na diversifica??o de lagartos do g?nero Lygodactylus nas Florestas
Tropicais Sazonalmente Secas (FTSS) da Am?rica do Sul. No primeiro cap?tulo n?s
investigamos as rela??es entre os Lygodactylus Sul Americanos, buscando entender a influ?ncia
do Arco Pleistoc?nico em sua diversifica??o e se essas esp?cies representam um grupo
monofil?tico. Atrav?s de an?lises filogen?ticas e de delimita??o de esp?cie, n?s recuperamos o
monofiletismo do grupo quando comparado com as esp?cies Africanas e reconhecemos L. klugei
como um complexo de esp?cies cr?pticas. N?s sugerimos o aumento de duas para cinco esp?cies
de Lygodactylus na Am?rica do Sul. O tempo de diverg?ncia entre L. klugei e as esp?cies
candidatas end?micas das FTSSs n?o foi congruente com a hip?tese do Arco Pleistoc?nico.
Por?m, a fragmenta??o das FTSS pode ter influenciado na diverg?ncia de L. wetzeli e uma
esp?cie candidata end?mica de um enclave de FTSS no Cerrado (S?o Domingos, regi?o do Vale
do Paran?). No segundo cap?tulo investigamos a diversifica??o dentro da Caatinga, testando o
papel do rio S?o Francisco (RSF) como barreira geogr?fica nesse bioma. Utilizamos um lagarto
end?mico dessa regi?o (L. klugei) como modelo de estudo. N?s delimitamos as poss?veis
linhagens, investigamos as rela??es filogen?ticas entre elas, a hist?ria de difus?o espa?otemporal
e, para testar a hip?tese do rio (barreira para fluxo g?nico), n?s utilizamos uma an?lise de migra??o. N?s recuperamos duas linhagens estruturadas de acordo com o RSF: uma ao norte e outra ao sul do rio. A diverg?ncia dessas linhagens ocorreu ? 295 mil anos atr?s, congruente com a mudan?a do curso do RSF para seu atual curso. N?o encontramos influ?ncia do paleocurso do RSF na estrutura??o de L. klugei. / Which processes and mechanisms are responsible for species diversification? This old question
has been revolutionized with technological, computational and methodological advancements,
and is now being understood in a way that was previously not possible. Phylogeography is a
multidiscipline that uses tools derived from biogeography, molecular phylogeny, and population
genetics to understand the context of gene distribution in time and space. The present study uses
phylogenetic and phylogeographic analyses to infer determinant processes in the diversification
of the lizard genus Lygodactylus in Seasonally Dry Tropical Forests (SDTF) in South America.
In the first chapter we investigate the relationships among South American Lygodactylus species,
seeking to understand the influence of the Pleistocenic Arc on its diversification and whether
these species represent a monophyletic group. Through phylogenetics and species delimitation
analyses we recovered the monophyly of the group in relation to African species and recognized
L. klugei as a cryptic species complex. We suggest that Lygodactylus in South America actually
comprises five species instead of two. The divergence time among L. klugei and candidate
species endemic to SDTFs was not congruent with the Pleistocenic Arc Hypothesis. However,
we suggest that the fragmentation of SDTFs likely influenced the divergence of L. wetzeli, and of
a candidate species endemic to a SDTF enclave within the Cerrado biome (S?o Domingos, Vale
do Paran? region). In the second chapter we investigate the diversification within the Caatinga,
testing the role of the S?o Francisco River (SFR) as a prominent geographic barrier. We used a
lizard endemic to this region (L. klugei) as study model. We delimited the existent lineages,
investigated the genetic relationships between them, the spatio-temporal diffusion history, and
used a migration analysis to test the riverine hypothesis (barrier to gene flow). We recovered two
lineages structured in respect to the SFR: a northern and a southern one. Lineage divergence occurred 295 kya, congruent with the course change of the SFR to its current position. We found
no influence of the paleo-SFR on L. klugei structure.
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