Copies of author's previously published articles inserted. / Bibliography: leaves 195-196. / xv, 196 leaves : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of this research is to observe the evolutionary relationships within and between frog species, as well as to discover potentially useful medicinal peptides. The two main areas of research of this thesis are the characterisation of peptides from frogs belonging to the genus Litoria and the analysis of negative ion fragmentations from large peptides. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 1997?

Orientadora: Profª Drª Vanessa Kruth Verdade / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Evolução e Diversidade, 2016. / Anfíbios vem sofrendo severos declínios populacionais em escala global desde a década de 1980. As causas mais frequentemente apontadas são alterações climáticas, poluição e doenças emergentes (sobretudo a quitridiomicose), agindo isoladamente ou em conjunto. A região de Paranapiacaba é uma das localidades brasileiras para as quais existem registros confiáveis de declínios populacionais de anfíbios. Encontra-se dentro da área de ocorrência do fungo quitrídeo, no entanto, também é uma região afetada por poluentes, e o foi muito mais intensamente na década de 80. Neste trabalho apresentamos a descrição da taxocenose de anfíbios associados a ambientes lóticos no Parque Natural Municipal Nascentes de Paranapiacaba. Nossos dados baseiam-se no estudo concomitante de adultos e girinos, coleta de dados abióticos e de aspectos clínicos que demonstram a saúde geral desses animais. Encontramos 20 espécies no local, das quais 108 indivíduos adultos e 156 larvas foram estudadas em relação aos aspectos clínicos. Afora algumas larvas com malformação nas partes bucais, o que pode indicar tanto a presença do fungo como a exposição a poluentes, não há evidências da presença de quitrídio em adultos. Nossas análises mostram interação entre espécies, meio físico e problemas de saúde, sugerindo forte correlação entre problemas hepáticos e renais e o modo de vida dos animais coletados. As lesões encontradas podem ter origem viral ou serem decorrentes do metabolismo, indicando presença de poluentes ambientais. Ainda que a associação direta entre os declínios de Paranapiacaba com poluentes não seja possível, os resultados obtidos chamam atenção para esse fator potencial e diminuem a importância do fungo quitrídio no panorama. / Amphibian has suffered severe population declines on a global scale since the 1980s. The potential factors leading to these declines are climate change, pollution and emerging diseases (especially chytridiomycosis), acting alone or sinergisticallytogether. The Paranapiacaba region is one of the Brazilian localities for which there are reliable records of amphibian population declines. It lies within the chytrid fungus occurrence range, however, is also a region intensely affected by pollutants at the 80s. We present here the description of the assemblage of amphibians associated to streams in the Parque Natural Municipal Nascentes de Paranapiacaba. We have studied adults and tadpoles, abiotic data and clinical features that demonstrate the overall health of these animals. We found 20 species counting 108 adult frogs and 156 tadpoles. Aside from the detection of some larvae with malformation in mouth parts (which can indicate both the presence of the fungus and exposure to pollutants), no adult tested positive for the chytrid fungus. Our analysis shows interaction between species, physical environment and health problems, suggesting strong correlation between liver and kidney problems and the habits (reophilic, cryptozoic or arboreal) of the frogs studied. The lesions may be viral or resulting from metabolism, suggesting cronic exposition to environmental pollutants. Although the cause-effect association between pollutants and the declines in Paranapiacaba is still premature, the results draw attention to this potential factor and decrease the importance of chytrid fungus in the local scenery.

Classified in the Lissamphibia, modern amphibians are the only non-amniote tetrapods living today. They consist of three morphologically distinct groups: the tailless frogs and toads (Anura), the limbless caecilians (Gymnophiona), and the tailed salamanders and newts (Urodela). With 205 species, the caecilians are highly specialized worm-like forms that live a fossorial lifestyle, with a relatively narrow distribution in the tropic rainforests of South America, Africa and Asia (Duellman and Trueb, 1994; Amphibiaweb, 2015). Salamanders, with 683 species, are widely distributed in the North America, Asia and Europe, with a few plethodontids extending to Central and South America (Duellman and Trueb, 1994; Amphibiaweb, 2015). Frogs are the most diverse amphibian groups, with 6644 species distributed over all continents except Antarctica (Duellman and Trueb, 1994; Amphibiaweb, 2015). Both frogs and salamanders develop a wide array of lifestyles, ranging from terrestrial, aquatic, fossorial to aboreal lifestyles (Duellman and Trueb, 1994). During ontogeny, amphibian larvae usually undergo a drastic post-embryonic shift into an adult form, a term known as metamorphosis. In salamanders, another developmental pathway – neoteny – also occurs, in which the larval morphology is retained in sexually mature adults (Duellman and Trueb, 1994; Rose, 2003). Because of the diverse lifestyles and developmental pathways, frogs and salamanders are often used as model systems in many fields of biology (e.g., evo-devo). Over a century, but especially in the past two decades, a wealth of frog and salamander fossils has been discovered from the Mesozoic and Cenozoic of East Asia (e.g., Noble, 1924; Young, 1936; Borsuk-Bialynicka, 1978; Gao, 1986; Dong and Wang, 1998; Gao and Shubin, 2001, 2003, 2012; Gao and Wang, 2001; Gao and Chen, 2004; Wang and Rose, 2005; Wang and Evans, 2006b; Zhang et al., 2009; Chen et al., 2016; this study). Some of these fossils represent the earliest members of many crown clades, including the earliest crown salamanders from the Middle Jurassic (~165 Ma, Gao and Shubin, 2003), the earliest salamandroid from the Late Jurassic, the earliest sirenid from the Late Jurassic (this study), and the earliest spadefoot toads from the late Paleocence (Chen et al., 2016). Other fossils also bear important anatomical, temporal and geographical information in understanding their evolution. Unfortunately, the importance of many of these fossils remains obscure in a phylogenetic context. For example, an early-middle Oligocene Mongolian spadefoot toad Macropelobates osborni (Noble, 1924) was discovered outside the current distribution of spadefoot toads, yet its phylogenetic position and its implication on spadefoot toad biogeography remain not well understood. A major reason for the poor understanding of these fossils can be attributed to a trend of dichotomy between morphological and molecular phylogenies on amphibians. Whereas morphologists and paleontologists sometimes use a relatively small morphological dataset to reconstruct relationships (e.g., Gao and Shubin, 2012; Henrici, 2013), large-scale phylogenies are almost always conducted with molecular data with only living taxa (e.g., Roelants and Bossuyt, 2005; Pyron and Wiens, 2011). Very few studies on amphibian phylogeny have combined morphological and molecular data together, and even fewer also combined fossils. Because of this, the positions of many important fossils remains unclear, and the evolutionary scenarios inferred from only living species can sometimes be inconsistent with fossil evidence. In this thesis, I adopt a total-evidence approach to understand the evolution of amphibians, especially frogs and salamanders. I will incorporate information from fossils, morphology and molecules together to reconstruct the relationships. Compared with studies with each individual datasets, this approach incorporates all available data in a single analysis, with a goal to reach robust and congruent results that allow further discussions on character evolution and biogeographic reconstruction. The inclusion of fossils directly into the combined analysis provides the time dimension that is independent from molecular data (Norell, 1992). The anatomical combination of fossils can represent intermediate forms that help to solve the “long branch” problems caused by highly specialized modern taxa. The morphological dataset, despite its much smaller size with molecular data, is the only link between fossils and modern taxa. The inclusion of key morphological characters in both reconstructing phylogenetic hypotheses and examining character evolution provide consistent results that allow discussion on the homology/homoplasy of a certain character without ambiguity. The molecular sequence data provides overwhelmingly large data on modern taxa for phylogenetic reconstructions compared with morphological data, which helps to reach a robust hypothesis. Although fossils contain no molecular data, the inclusion of molecular sequence data into the combined analysis does have an effect on the positions of fossil taxa. By altering the relationship “framework” of modern taxa, the character optimization of fossils and other taxa of a combined analysis also varies compared with results of morphology-only analysis, thus changing the positions of fossils. In the following five chapters, I will describe a number of fossil amphibian species, reconstruct three combined phylogenies, and use the results for discussions on character evolution and biogeography. In Chapter 1 and Chapter 2, I focus on a frog clade called spadefoot toads (Anura: Pelobatoidea). In Chapter 1, I provide descriptions on three important fossil spadefoot toads from the Cenozoic of East Asia and North America: Macropelobates osborni from the early-middle Oligocene of Mongolia, Prospea holoserisca from the latest Paleocene of Mongolia, and Scaphiopus skinneri from the middle Oligocene of the United States. In Chapter 2, I conduct a combined phylogenetic analysis of archaeobatrachian frogs, and discuss the evolution of the bony spade and the historical biogeography of spadefoot toads based on the results of the phylogeny. In Chapter 3, I describe a new fossil frog from the Early Cretaceous of Inner Mongolia, China. The unique morphology of the new fossil is distinct from previous Early Cretaceous frogs from the Jehol Biota of China. Results of the combined analysis show that the new frog represents a basal member of the Pipanura. Comparisons between the Early Cretaceous frogs from China, Spain and Brazil show a high diversity of species coupled with a high degree of endemism during the Early Cretaceous. I discuss in the phylogenetic context how early frogs gradually reach their postcranial body plan with a shortened vertebral column, loss of ribs, and specialized pelvic regions. In Chapter 4, I provide a brief review of Mesozoic fossil salamanders from northern China, and describe a new fossil from the Late Jurassic of Liaoning Province, China. I conduct a combined phylogeny of higher-level relationships of salamanders. The new fossil, despite its general-looking appearance, represents a basal member of the highly specialized eel-like neotenic family Sirenidae on the cladogram. I discuss character evolutions in the Sirenidae, and how the neotenic developmental pathway evolved in early salamanders. In Chapter 5, I conduct a combined phylogenetic analysis of the salamander suborder Cryptobranchoidea, consisting of the neotenic giant salamanders (Cryptobranchidae) and the metamorphic Asiatic salamanders (Hynobiidae). The new morphological matrix includes new characters that were previously less sampled in the hynobranchial region. The monophyly of the Hynobiidae are confirmed by the new analysis, and four unequivocal synapomorphies are found for the clade. An S-DIVA biogeographic reconstruction is conducted to disscuss the distributional patterns of the Hynobiidae.

Les herpétofaunes du Maastrichtien du Bassin de Hateg (Roumanie) et du Paléocène Moyen du Bassin de Mons (Belgique) ont été analysées dans le but d’étudier l’influence de la crise Crétacé/Paléogène sur ces faunes en Europe et de contribuer à élucider leur origine biogéographique. Pour ce faire, nous disposions de 228, 56 et 19 spécimens provenant respectivement des gisements roumains de Pui-Islaz, Totesti-baraj et Nãlat-Vad ainsi que de 1054 spécimens provenant du puits de Hainin. Les herpétofaunes du Bassin de Hateg se composent d’au moins un allocaudate albanerpetontidé du genre Albanerpeton, de deux anoures discoglossidés, de deux lacertiliens paramacellodidés ainsi que du premier vrai téiidé identifié jusqu’au niveau spécifique en Europe et d’un serpent madtsoiidé. Les herpétofaunes du Bassin de Mons nous indiquent quant à elles que les caudates sont représentés par 3 nouvelles espèces de salamandridés, les anoures par un nouveau genre de discoglossidé ainsi que par une nouvelle espèce de palaeobatrachidé. La présence des lacertiliens est attestée par 2 nouveaux genres de scincoïdes ainsi que par 6 autres scincomorphes indéterminés, par un nouveau genre d’amphisbène et peut-être également par un anguidé apode. Les serpents sont quant à eux représentés par le plus ancien boidé d’Europe ainsi que par le plus ancien scolécophidien découvert jusqu’ici. Ces données paléontologiques ainsi que les données lithologiques des deux localités analysées, indiquent que le climat était tempéré chaud et humide avec des étendues d’eaux stagnantes. Ce travail permet également de conclure que la crise Crétacé/Paléogène n’a pas influencé les faunes européennes de manière dramatique.<p>Seuls les allocaudates albanerpetontidés, les lacertiliens polyglyphanodontinés et les serpents madtsoiidés disparaissent après la crise tandis que les caudates salamandridés et batrachosauroididés, les anoures discoglossidés et palaeobatrachidés, et les lacertiliens scincoïdes et amphisbènes, ne semblent pas avoir été affectés par cette crise en Europe. Par ailleurs, les herpétofaunes du Maastrichtien européen ont subi une influence nord-américaine suite à une migration ayant eu lieu durant le Crétacé Supérieur. Une vague de migration se serait également produite au Paléocène Supérieur, entre le MP1-5 et le MP6, et une autre au début de l’Eocène correspondant à celle déjà mise en évidence pour les mammifères. Cette dernière vague serait responsable de l’arrivée de nombreuses familles modernes de lacertiliens tels les agamidae, geckonidae, varanidés, helodermatidés et lacertidés. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished