Evolution in the Genus Rhinella: A Total Evidence Phylogenetic Analysis of Neotropical True Toads (Anura: Bufonidae)

True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridiza-tion and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R . horribilis (“ghost introgression”) and of R . dorbignyi into R . bernardoi; therefore, the mitochondrial and nuclear data-sets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmono-phyletic due to the position of R . ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R . ceratophrys is excluded, the genus Rhinellais monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R . spinulosa Group (including R . gallardoi); the mono-phyletic R . granulosa, R . crucifer, and R . marina Groups; and a clade composed of the mitochondrial sequences of R . horribilis. The other major clade is strongly supported and composed of all the spe-cies from the non-monophyletic R . veraguensis and R . margaritifera Groups, the former R . acrolophaGroup, and R . sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morpho-logical character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and “ghost introgression”; the incomplete phenotypic evidence (including putative character systems that could be used for future phy-logenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses.Peer reviewe

Análise filogenética das rãs de desenvolvimento direto (Anura, Terrarana, Craugastoridae)

A major recent trend in systematics is the re-integration of morphological data into total evidence analysis. To date, few studies have explored the effects of incorporating morphological and molecular data into total evidence analyses; however, those that have done so have found that even a comparatively small phenomic dataset can have disproportionately large impacts on results. Given the demonstrated importance of morphological characters in testing the phylogenetic relationships, herein I provide a case in point for the exploration of the effects of incorporating morphological evidence as an independent source of phylogenetic evidence, and an important framework to test hypotheses supported by molecular evidence, in the superfamily Brachycephaloidea. In this study, 338 amphibian species are included, of which 318 species correspond to the superfamily Brachycephaloidea. All known genera within the superfamily were sampled. The complete dataset included 13,686 molecular characters (mitochondrial and nuclear markers) and 185 morphological characters, which were analyzed together. In addition, I performed additional analyses modifying the complete datasets to evaluate the effects of character and taxon sampling. As results, I found that the superfamily Brachycephaloidea does not represent a monophyletic as previously thought. Likewise, the phylogeny resulting from this analysis showed several taxa to be nonmonophyletic: Brachycephalidae and Craugastoridae as well as genera Craugastor, Psychrophynella, and Pristimantis. From the detailed examination of the impact of both character and taxon sampling on the phylogenetic relationships of the superfamily Brachycephaloidea, I found that the inclusion of a comparatively small phenomic dataset (185 character) as well as the inclusion of two key taxa (Atopophrynus syntomopus and Dischidodactylus duidensis) had disproportionately large impacts on the tree topology. Finally, I provide a new taxonomy for this group. In this, I recognize five families, of which three are morphologically diagnosable (Eleutherodactylidae, Hypodactylidae, and Strabomantidae) whereas the other two are diagnosable solely with molecular evidence (Ceuthomantidae and Craugastoridae). Likewise, 12 out of 26 genera included are morphologically diagnosable.Uma grande tendência em estudos de sistemática filogenética é a reintegração de dados morfológicos em análises de evidência total. Até o momento, poucos estudos exploraram os efeitos da incorporação de dados morfológicos conjuntamente com dados moleculares em análises de evidência total. No entanto, aqueles que o fizeram concluíram que mesmo uma pequena base de dados fenômicos pode ter grandes e desproporcionais impactos nos resultados. Dada a demonstrada importância de caracteres morfológicos em testes de relacionamentos filogenéticos, aqui apresento um caso de exploração dos efeitos da incorporação de evidência morfológica como uma fonte independente de evidência filogenética e como importante \"framework\" para testar hipóteses suportadas por evidência molecular na superfamília Brachycephaloidea. Nesse estudo, 338 espécies de anfíbios foram incluídas, das quais 318 correspondem a espécies da superfamília Brachycephaloidea. Todos os gêneros conhecidos da superfamília foram amostrados. A base de dados completa inclui 13.686 caracteres moleculares (marcadores mitocondriais e nucleares) e 185 caracteres morfológicos, que foram analisados conjuntamente. Ademais, realizei análises adicionais modificando as bases de dados para avaliar os efeitos de amostragem de caracteres e táxons. Como resultado, encontrei que a superfamília Brachycephaloidea não é monofilética, como anteriormente considerada. Da mesma forma, a filogenia resultante da análise de evidência total mostrou que vários outros táxons também não são monofiléticos: as famílias Brachycephalidae e Craugastoridae, assim como os gêneros Craugastor, Psychrophrynella e Pristimantis. Através do exame detalhado do impacto de diferentes amostragens de caracteres e táxons sobre as relações filogenética na superfamília Brachycephaloidea, encontrei que a inclusão de dois táxons chaves (Atopophrynus syntomopus e Dischidodactylus duidensis) tiveram grandes e desproporcionais impactos na topologia das árvores. Finalmente, eu apresento uma nova taxonomia para as rãs de desenvolvimento direto, reconhecendo cinco famílias, das quais três são morfologicamente diagnosticáveis (Eleutherodactylidae, Hypodactylidae e Strabomantidae), enquanto as outras duas são diagnosticáveis apenas com evidência molecular (Ceuthomantidae e Craugastoridae). Da mesma forma, 12 dos 26 gêneros inclusos são morfologicamente diagnosticáveis

Revisión morfológica de las ranas del género Strabomantis (Anura: Brachycephalidae Sensu frost et al. 2006)

Las Ranas de desarrollo directo o carentes de etapas larvales en su desarrollo (Eleutherodactylus sensu lato) han presentado significantes cambios en su clasificación, inicialmente basada en morfología y más recientemente en herramientas moleculares. En este contexto el siguiente trabajo empleó caracteres osteológicos y miológicos en los grupos de especies que conforman el género Strabomantis, con el objetivo de buscar homologías que puedan apoyar la monofilia de estos grupos, así como también la del género. Se encontró evidencia en donde se demuesta que los grupos de especies deben ser reorganizados, en cuanto al género Strabomantis se encontró que es parafilético con respecto al género Hypodactylus. Se hace necesario la reevaluación detallada del estatus genérico de Strabomantis zygodactylus, pues esta especie según la evidencia mostrada, está más relacionada con las especies del género Craugastor y Oreobates.Abstract. The Direct-developing frogs or frogs without larval stage development (Eleutherodactylus sensu lato) have undergone significant changes in their systematics, initially based on morphology and more recently on molecular data. In this context, this work used osteological and miological characters in the species groups that comprise the Strabomantis genus, aiming to search for homologies that could support the monophyly of these groups, as well as that of the genus. The evidence supports the reorganization of groups and demonstrates Strabomantis genus is paraphyletic with respect to the Hypodactylus genus. It is necessary a detailed evaluation of generic status of Strabomantis zygodactylus because this species, according to the evidence shown, is more closely related to the species of Craugastor and Oreobates genus.Maestrí

The Complex Evolutionary History of the Tympanic Middle Ear in Frogs and Toads (Anura)

Most anurans possess a tympanic middle ear (TME) that transmits sound waves to the inner ear; however, numerous species lack some or all TME components. To understand the evolution of these structures, we undertook a comprehensive assessment of their occurrence across anurans and performed ancestral character state reconstructions. Our analysis indicates that the TME was completely lost at least 38 independent times in Anura. The inferred evolutionary history of the TME is exceptionally complex in true toads (Bufonidae), where it was lost in the most recent common ancestor, preceding a radiation of \u3e150 earless species. Following that initial loss, independent regains of some or all TME structures were inferred within two minor clades and in a radiation of \u3e400 species. The reappearance of the TME in the latter clade was followed by at least 10 losses of the entire TME. The many losses and gains of the TME in anurans is unparalleled among tetrapods. Our results show that anurans and especially bufonid toads, are an excellent model to study the behavioural correlates of earlessness, extratympanic sound pathways and the genetic and developmental mechanisms that underlie the morphogenesis of TME structures

Evolution in Rhinella (Anura: Bufonidae)

155 pages : illustrations (some color) ; 26 cm.True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridization and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R. horribilis ("ghost introgression") and of R. dorbignyi into R. bernardoi; therefore, the mitochondrial and nuclear datasets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmonophyletic due to the position of R. ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R. ceratophrys is excluded, the genus Rhinella is monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R. spinulosa Group (including R. gallardoi); the monophyletic R. granulosa, R. crucifer, and R. marina Groups; and a clade composed of the mitochondrial sequences of R. horribilis. The other major clade is strongly supported and composed of all the species from the non-monophyletic R. veraguensis and R. margaritifera Groups, the former R. acrolopha Group, and R. sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morphological character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and "ghost introgression"; the incomplete phenotypic evidence (including putative character systems that could be used for future phylogenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses

Evolution in the genus Rhinella: A total evidence analysis of Neotropical true toads (Anura: Bufonidae)

True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridization and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R. horribilis ("ghost introgression") and of R. dorbignyi into R. bernardoi; therefore, the mitochondrial and nuclear datasets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmonophyletic due to the position of R. ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R. ceratophrys is excluded, the genus Rhinella is monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R. spinulosa Group (including R. gallardoi); the monophyletic R. granulosa, R. crucifer, and R. marina Groups; and a clade composed of the mitochondrial sequences of R. horribilis. The other major clade is strongly supported and composed of all the species from the non-monophyletic R. veraguensis and R. margaritifera Groups, the former R. acrolopha Group, and R. sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morphological character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and "ghost introgression"; the incomplete phenotypic evidence (including putative character systems that could be used for future phylogenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses.Fil: Pereyra, Martín Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Blotto Acuña, Boris Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Baldo, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Chaparro, Juan C.. Museo de Biodiversidad del Perú; PerúFil: Ron, Santiago R.. Pontificia Universidad Católica del Ecuador; EcuadorFil: Elías Costa, Agustín Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Iglesias, Patricia Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Venegas, Pablo J.. Centro de Ornitología y Biodiversidad, Lima; PerúFil: Thomé, Maria Tereza C.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Ospina Sarria, Jhon Jairo. Universidade de Sao Paulo; BrasilFil: Maciel, Natan M.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rada, Marco. Universidade de Sao Paulo; BrasilFil: Kolenc, Francisco. Museo Nacional de Historia Natural; UruguayFil: Borteiro, Claudio. Museo Nacional de Historia Natural; UruguayFil: Rivera Correa, Mauricio. Universidad de Antioquia; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Rojas Runjaic, Fernando J. M.. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Moravec, Jirí. National Museum; República ChecaFil: de la Riva, Ignacio María. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales; EspañaFil: Wheeler, Ward C.. American Museum of Natural History; Estados UnidosFil: Castroviejo Fisher, Santiago. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Grant, Taran. Universidade de Sao Paulo; BrasilFil: Baptista Haddad, Célio Fernando. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Faivovich, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin