Bothrops bilineatus é uma das seis espécies presentes no grupo taeniatus, é reconhecida atualmente por duas sub-espécies: B. b. smaragdinus que se distribui pelo oeste Amazônico e B. b. bilineatus com distribuição disjunta pela Amazônia e Mata Atlântica. Este trabalho tem como objetivo testar a validade das duas sub-espécies com base em ferramentas moleculares, morfométricas, merísticas, hemipenianas e osteológicas, reconhecendo e delimitando as linhagens encontradas. Pretende-se ainda investigar as relações filogeográficas entre as populações ao longo da sua distribuição, analisando o tempo de divergência e os possíveis eventos associados a sua diversificação. Além disso, pretende-se comparar a variação molecular e hemipeniana de B. bilineatus com B. taeniatus (espécie filogeneticamente próxima) e as existentes nos outros grupos de espécies do gênero. Os resultados mostram que a variação genética e hemipeniana encontram se em diferentes níveis ao longo dos grupos de espécies em Bothrops, fornecendo informação relevante a nível intra e inter-específico. Foram recuperados seis clados estruturados para Bothrops bilineatus, representando quatro linhagens independentes e diagnosticáveis com base conjunta nos caracteres morfológicos, hemipenianos, osteológicos e moleculares: linhagem 1 - Amazônia central, basal as outras, linhagem 2 - Mata Atlântica+Escudo das Guianas externa às linhagens 3 e 4 Amazônia oeste parte sul e norte, respectivamente. Já para B. taeniatus quatro clados representando três linhagens foram recuperadas com bases nos caracteres moleculares e hemipenianos, porém se faz necessário buscar por mais caracteres morfológicos e osteológicos para melhor delimitar e diagnosticar as linhagens. As mudanças paleoclimáticas e geomorfológicas ocorridas na transição Terciário/Quaternário parecem ser os principais eventos a influenciar na diversificação das linhagens encontradas em Bothrops bilineatus e B. taeniatus / Bothrops bilineatus is one of six species in the taeniatus group, is now recognized by two subspecies: B. b. smaragdinus that distributes through western Amazon and B. b. bilineatus with disjunct distribution through Amazon and Atlantic Forest. This work aims to test the validity of these two sub-species, based on molecular, morphometric tools, meristic, osteological and hemipenial data, recognizing and delimiting lineages found. We also intend to investigate the phylogeographic relationships among populations throughout its distribution, analyzing the divergence time and possible events associated with it diversification. In addition, we intend to compare the molecular and hemipenial variation presented in B. bilineatus with B. taeniatus (phylogenetically close species) and those in the other groups of the genus. The genetic and hemipenial results show different levels of variation along the groups of Bothrops species, providing significant intra-and inter-specific information. Six clades structured to Bothrops bilineatus were recovered, representing four independent lineages diagnosable with joint based on morphology, hemipenial, osteological and molecular characters: lineage 1 - central Amazon, basal the others, lineage 2 - Atlantic Forest + Guayana Shield region recovered outside the sisters lineages 3 and 4 - western Amazon, southern part and western Amazon, northern part, respectively. As for B. taeniatus four clades representing three lineages were recovered with bases in molecular and hemipenial characters, however it is necessary to search for more morphological and osteological characters to better delimit and diagnose the lineages. Paleoclimatic and geomorphic changes in the transition Tertiary/Quaternary, probably are the major events influencing the diversification of lineages found in Bothrops bilineatus and B. taeniatus

Bothrops bilineatus é uma das seis espécies presentes no grupo taeniatus, é reconhecida atualmente por duas sub-espécies: B. b. smaragdinus que se distribui pelo oeste Amazônico e B. b. bilineatus com distribuição disjunta pela Amazônia e Mata Atlântica. Este trabalho tem como objetivo testar a validade das duas sub-espécies com base em ferramentas moleculares, morfométricas, merísticas, hemipenianas e osteológicas, reconhecendo e delimitando as linhagens encontradas. Pretende-se ainda investigar as relações filogeográficas entre as populações ao longo da sua distribuição, analisando o tempo de divergência e os possíveis eventos associados a sua diversificação. Além disso, pretende-se comparar a variação molecular e hemipeniana de B. bilineatus com B. taeniatus (espécie filogeneticamente próxima) e as existentes nos outros grupos de espécies do gênero. Os resultados mostram que a variação genética e hemipeniana encontram se em diferentes níveis ao longo dos grupos de espécies em Bothrops, fornecendo informação relevante a nível intra e inter-específico. Foram recuperados seis clados estruturados para Bothrops bilineatus, representando quatro linhagens independentes e diagnosticáveis com base conjunta nos caracteres morfológicos, hemipenianos, osteológicos e moleculares: linhagem 1 - Amazônia central, basal as outras, linhagem 2 - Mata Atlântica+Escudo das Guianas externa às linhagens 3 e 4 Amazônia oeste parte sul e norte, respectivamente. Já para B. taeniatus quatro clados representando três linhagens foram recuperadas com bases nos caracteres moleculares e hemipenianos, porém se faz necessário buscar por mais caracteres morfológicos e osteológicos para melhor delimitar e diagnosticar as linhagens. As mudanças paleoclimáticas e geomorfológicas ocorridas na transição Terciário/Quaternário parecem ser os principais eventos a influenciar na diversificação das linhagens encontradas em Bothrops bilineatus e B. taeniatus / Bothrops bilineatus is one of six species in the taeniatus group, is now recognized by two subspecies: B. b. smaragdinus that distributes through western Amazon and B. b. bilineatus with disjunct distribution through Amazon and Atlantic Forest. This work aims to test the validity of these two sub-species, based on molecular, morphometric tools, meristic, osteological and hemipenial data, recognizing and delimiting lineages found. We also intend to investigate the phylogeographic relationships among populations throughout its distribution, analyzing the divergence time and possible events associated with it diversification. In addition, we intend to compare the molecular and hemipenial variation presented in B. bilineatus with B. taeniatus (phylogenetically close species) and those in the other groups of the genus. The genetic and hemipenial results show different levels of variation along the groups of Bothrops species, providing significant intra-and inter-specific information. Six clades structured to Bothrops bilineatus were recovered, representing four independent lineages diagnosable with joint based on morphology, hemipenial, osteological and molecular characters: lineage 1 - central Amazon, basal the others, lineage 2 - Atlantic Forest + Guayana Shield region recovered outside the sisters lineages 3 and 4 - western Amazon, southern part and western Amazon, northern part, respectively. As for B. taeniatus four clades representing three lineages were recovered with bases in molecular and hemipenial characters, however it is necessary to search for more morphological and osteological characters to better delimit and diagnose the lineages. Paleoclimatic and geomorphic changes in the transition Tertiary/Quaternary, probably are the major events influencing the diversification of lineages found in Bothrops bilineatus and B. taeniatus

Tropidolaemus wagleri is a species of Asian pitviper with a geographic range including Thailand, Vietnam, Malaysia, Singapore, Bruniei, parts of Indonesia, and the hilippines. Tropidolaemus is a member of the Crotalinae subfamily, within Viperidae. The genus Tropidolaemus includes five species, and was once included within the genus Trimeresurus. While some osteologic characteristics have been noted a comprehensive description of cranial elements has not been produced for T. wagleri. An in-depth description of the cranial skeleton of Tropidolaemus wagleri lays the foundation for future projects to compare and contrast other taxa within Crotalinae and Viperidae. The chosen reference specimen was compared to the presumed younger specimens to note any variation in ontogeny. The study here provides a comprehensive description of isolated cranial elements as well as a description of ontogenetic change within the specimens observed. This study contributes to the knowledge of osteological characters in T. wagleri and provides a foundation for a long term project to identify isolated elements in the fossil record.

As generic and higher-scale evolutionary relationships are increasingly well understood, systematists move research in two directions: 1) understanding specieslevel relationships with dense taxon sampling, and 2) evaluating evolutionary patterns using phylogeny. In this study I address both foci of systematic research using pitvipers, subfamily Crotalinae. For direction one, I evaluate the relationships of 96% of pitvipers by combining independent sets of molecular and phenotypic data. I find the inclusion of species with low numbers of informative characters (i.e. less than 100) negatively impacts resolution of the phylogeny, and the addition of independent datasets has no effect on or a small benefit to confidence in estimated evolutionary relationships. Combined evidence is extremely useful in evaluating taxonomy; I use it with South American bothropoid pitvipers. Previous work found the genus Bothrops paraphyletic, but no study had included enough species to propose a taxonomic resolution. I resolve the relationships of 90% of bothropoid pitvipers, and support the paraphyly of Bothrops as previously defined, but find it consists of three well-supported clades distinguished by distinct habitats and geographic ranges. I propose the division of Bothrops sensu lato into three genera. To address research direction two, I investigate the change in reproductive mode from egg-laying (oviparity) to livebearing (viviparity) in vipers, as well as the expansion of pitvipers through South America. I resolve the phylogeny and the divergence times for subgroups of interest then use model comparison and ancestral character state or iv geographic range estimation to trace the evolution of reproductive mode or geographic range across evolutionary history. For vertebrates, the predominant explanation for the evolution of reproductive mode is Dollo’s Law of unidirectional evolution. This law has been challenged for a number of characters in different systems, but the phylogenetic methods that found those violations were criticized. I find support for unidirectional evolution in two analyses and rejection of it in others, and therefore do not reject Dollo’s Law for the evolution of reproductive mode in vipers. In the case of geographic range, dozens of hypotheses have been proposed to explain the great biodiversity in South America, but tests of these hypotheses are lacking. I define specific time- and space-based predictions for seven hypotheses based on geological and climatic events – uplift of the Andes Mountains, saltwater inundation of inland areas, change in river flow, and Pleistocene climate changes. I find some support for half of the hypotheses, including one allopatric, one parapatric, and one based on climate change. I conclude that the evolution of South American pitvipers is extremely complex. Through fulfillment of both systematic research directions, I generated new knowledge about pitvipers and evolutionary processes. My methods of evaluating evolutionary patterns provide frameworks for different research questions in these areas, and I suggest that other researchers apply similar techniques to evaluate other portions of the Tree of Life