Osteology and chondrocranial morphology of Gastrophryne carolinensis (Anura: Microhylidae), with ... more Osteology and chondrocranial morphology of Gastrophryne carolinensis (Anura: Microhylidae), with a review of the osteological diversity of New World microhylids. Microhylidae is a large, cosmopolitan anuran family. Recent molecular analyses have demonstrated the monophyly of the family-a conclusion that is supported by the larval morphology, coupled with the unique mode of tongue protrusion in adults, and a suite of osteological and myological characters seemingly associated with this innovation in feeding. Despite this functional constraint, osteological diversity probably exceeds that of any other anuran family, and this diversity is especially evident in the New World microhylids that comprise two clades, Gastrophryninae and Otophryninae. To facilitate comparisons among these clades, we describe the larval chondrocranium, skeletal development, and adult osteology of Gastrophryne carolinensis. We provide a phylogenetic context for these comparisons through a novel phylogenetic analysis of 45 microhylid genera based on data for one mitochondrial and three nuclear loci from previously published studies. Nearly all relationships within the monophyletic Gastrophryninae are resolved with robust support. Based on these results, we found that the larval chondrocrania of gastrophrynines share morphological features that distinguish them from Otophryne and other anurans. Among the adults, all gastrophrynines show evidence of an anterior shift of the jaws that is correlated with specializations in the otic region, and with the alignment of the planum antorbitale, the cartilage wall separating the nasal capsule from the orbits. The
The Community Page is a forum for organizations and societies to highlight their efforts to enhan... more The Community Page is a forum for organizations and societies to highlight their efforts to enhance the dissemination and value of scientific knowledge.
The higher-level relationships of anurans have been explored by numerous studies, producing a var... more The higher-level relationships of anurans have been explored by numerous studies, producing a variety of hypotheses. The relationships of the basal anurans ('archaeobatrachians') are, however, poorly known. In part, this may be because the adult morphology of basal anurans is derived and therefore may not provide suitable phylogenetic signal. Recently, several authors have shown the phylogenetic utility of information derived from anuran larvae. In this paper we conduct separate and combined analyses of anuran relationships based on adult and larval morphology. Our combined results suggest that anurans form two major cladesthe pipoids and all other frogs. Evidence also suggests that, taken together, Neobatrachia and Pelobatoidea form a monophyletic group. We discuss support for various groupings as shown by the different data sets. We also comment on the consequences of our phylogenetic hypothesis for the interpretation of reduction of vertebral elements and evolution of Orton's tadpole types in anurans.
SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of ev... more SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of evolution within groups of organisms. But rarely has a comparative, historical approach been employed to study developmental change, particularly among anurans. A recent resurgence of interest in collecting basic ontogenetic information provides us with the opportunity to compare ontogenetic trajectories in a phylogenetic framework. Larval skeletons and osteological development were examined for 22 taxa and compared to two hypotheses of relationships-that of Cannatella, and one proposed herein based on 41 morphological characters from larvae and 62 from adults. Larval characters were mapped on the alternate cladograms using the ACCTRAN optimization criterion. Several larval features are highly conserved among some anurans, suggesting that there is some level of canalization of morphology early in ontogeny. In contrast, a number of morphologies vary among groups, supporting the fact that there have been major evolutionary modifications to anuran larval morphologies early in ontogeny and in the early evolutionary history of anurans.
... DESCRIPTION OF A NEW SPECIES OF PIPA (ANURA: PIPIDAE) FROM PANAMA LINDA TRUEB ABSTRACT: Juven... more ... DESCRIPTION OF A NEW SPECIES OF PIPA (ANURA: PIPIDAE) FROM PANAMA LINDA TRUEB ABSTRACT: Juvenile pipids from the lowlands of eastern Panama were assigned to Pipa parva by Heatwole (1963). ... Am. Mus. Novitates 1348:1-13. GOSNER, KL 1960. ...
The adult osteology of the direct-developing pipid frog, Pipa pipa, is described based on cleared... more The adult osteology of the direct-developing pipid frog, Pipa pipa, is described based on cleared-and-stained and dry skeletal specimens. Observations on skeletal development are based on cleared-and-stained embryos and young removed from the backs of preserved females. Osteologically, P.pipa is distinguished from its congeners and other pipid anurans by its large size and peculiar skull, which is extremely depressed and hyperossified. Skulls of the smallest individuals are not significantly different from those of other basal anurans at a similar stage of development; comparisons are made with Bombina orientalis, Discoglossus sardus, Spea bombifrons, Rhinophrynus dorsalis, and Xenopus laevis. The general sequence of chondrification and ossification resembles that of X.laevis; however, there is evidence that the mandible forms earlier in Pipa than in Xenopus. The major allometric transformations that result in the morphologically bizarre skull of adult P.pipa commence after the embryo has resorbed its tail, an event interpreted as marking the end of metamorphic climax in this taxon. In addition, ontogenetic comparisons reveal that the sacrum forms differently in Discoglossus sardus,Silurana tropicalis, and P.pipa. The development of the sphenethmoid region of the skull is the same in P.pipa and X.laevis, and distinctly different from the development of this region of the skull in other non-pipid basal anurans and neobatrachians for which ontogenetic descriptions exist.
Glassfrogs (family Centrolenidae) represent an exceptionally diverse group among Neotropical anur... more Glassfrogs (family Centrolenidae) represent an exceptionally diverse group among Neotropical anurans, but their evolutionary relationships never have been assessed from a molecular perspective. Mitochondrial and nuclear markers were used to develop a novel hypothesis of centrolenid phylogeny. Ingroup sampling included 100 terminals, with 78 (53%) of the named species in the family, representing most of the phenotypic diversity described for the group. Thirty-five species representing taxa traditionally associated with glassfrogs were used as outgroups. Gene sampling consisted of complete or partial sequences of three mitochondrial (12S, 16S, ND1) and three nuclear markers (c-myc exon 2, RAG1, POMC) for a total of $4362 bp. Phylogenies were estimated using maximum parsimony, maximum likelihood, and Bayesian analyses for individual genes and combined datasets. The separate analysis of mitochondrial and nuclear datasets allowed us to clarify the relationships within glassfrogs; also, we corroborate the sister-group relationship between Allophryne ruthveni and glassfrogs. The new phylogeny differs significantly from all previous morphology-based hypotheses of relationships, and shows that hypotheses based on few traits are likely to misrepresent evolutionary history. Traits previously hypothesized as unambiguous synapomorphies are shown to be homoplastic, and all genera in the current taxonomy (Centrolene, Cochranella, Hyalinobatrachium, Nymphargus) are found to be poly-or paraphyletic. The new topology implies a South American origin of glassfrogs and reveals allopatric speciation as the most important speciation mechanism. The phylogeny profoundly affects the traditional interpretations of glassfrog taxonomy, character evolution, and biogeography-topics that now require more extensive evaluation in future studies.
SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of ev... more SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of evolution within groups of organisms. But rarely has a comparative, historical approach been employed to study developmental change, particularly among anurans. A recent resurgence of interest in collecting basic ontogenetic information provides us with the opportunity to compare ontogenetic trajectories in a phylogenetic framework. Larval skeletons and osteological development were examined for 22 taxa and compared to two hypotheses of relationships-that of Cannatella, and one proposed herein based on 41 morphological characters from larvae and 62 from adults. Larval characters were mapped on the alternate cladograms using the ACCTRAN optimization criterion. Several larval features are highly conserved among some anurans, suggesting that there is some level of canalization of morphology early in ontogeny. In contrast, a number of morphologies vary among groups, supporting the fact that there have been major evolutionary modifications to anuran larval morphologies early in ontogeny and in the early evolutionary history of anurans.
The higher-level relationships of anurans have been explored by numerous studies, producing a var... more The higher-level relationships of anurans have been explored by numerous studies, producing a variety of hypotheses. The relationships of the basal anurans ('archaeobatrachians') are, however, poorly known. In part, this may be because the adult morphology of basal anurans is derived and therefore may not provide suitable phylogenetic signal. Recently, several authors have shown the phylogenetic utility of information derived from anuran larvae. In this paper we conduct separate and combined analyses of anuran relationships based on adult and larval morphology. Our combined results suggest that anurans form two major cladesthe pipoids and all other frogs. Evidence also suggests that, taken together, Neobatrachia and Pelobatoidea form a monophyletic group. We discuss support for various groupings as shown by the different data sets. We also comment on the consequences of our phylogenetic hypothesis for the interpretation of reduction of vertebral elements and evolution of Orton's tadpole types in anurans.
Osteology and chondrocranial morphology of Gastrophryne carolinensis (Anura: Microhylidae), with ... more Osteology and chondrocranial morphology of Gastrophryne carolinensis (Anura: Microhylidae), with a review of the osteological diversity of New World microhylids. Microhylidae is a large, cosmopolitan anuran family. Recent molecular analyses have demonstrated the monophyly of the family-a conclusion that is supported by the larval morphology, coupled with the unique mode of tongue protrusion in adults, and a suite of osteological and myological characters seemingly associated with this innovation in feeding. Despite this functional constraint, osteological diversity probably exceeds that of any other anuran family, and this diversity is especially evident in the New World microhylids that comprise two clades, Gastrophryninae and Otophryninae. To facilitate comparisons among these clades, we describe the larval chondrocranium, skeletal development, and adult osteology of Gastrophryne carolinensis. We provide a phylogenetic context for these comparisons through a novel phylogenetic analysis of 45 microhylid genera based on data for one mitochondrial and three nuclear loci from previously published studies. Nearly all relationships within the monophyletic Gastrophryninae are resolved with robust support. Based on these results, we found that the larval chondrocrania of gastrophrynines share morphological features that distinguish them from Otophryne and other anurans. Among the adults, all gastrophrynines show evidence of an anterior shift of the jaws that is correlated with specializations in the otic region, and with the alignment of the planum antorbitale, the cartilage wall separating the nasal capsule from the orbits. The
The Community Page is a forum for organizations and societies to highlight their efforts to enhan... more The Community Page is a forum for organizations and societies to highlight their efforts to enhance the dissemination and value of scientific knowledge.
The higher-level relationships of anurans have been explored by numerous studies, producing a var... more The higher-level relationships of anurans have been explored by numerous studies, producing a variety of hypotheses. The relationships of the basal anurans ('archaeobatrachians') are, however, poorly known. In part, this may be because the adult morphology of basal anurans is derived and therefore may not provide suitable phylogenetic signal. Recently, several authors have shown the phylogenetic utility of information derived from anuran larvae. In this paper we conduct separate and combined analyses of anuran relationships based on adult and larval morphology. Our combined results suggest that anurans form two major cladesthe pipoids and all other frogs. Evidence also suggests that, taken together, Neobatrachia and Pelobatoidea form a monophyletic group. We discuss support for various groupings as shown by the different data sets. We also comment on the consequences of our phylogenetic hypothesis for the interpretation of reduction of vertebral elements and evolution of Orton's tadpole types in anurans.
SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of ev... more SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of evolution within groups of organisms. But rarely has a comparative, historical approach been employed to study developmental change, particularly among anurans. A recent resurgence of interest in collecting basic ontogenetic information provides us with the opportunity to compare ontogenetic trajectories in a phylogenetic framework. Larval skeletons and osteological development were examined for 22 taxa and compared to two hypotheses of relationships-that of Cannatella, and one proposed herein based on 41 morphological characters from larvae and 62 from adults. Larval characters were mapped on the alternate cladograms using the ACCTRAN optimization criterion. Several larval features are highly conserved among some anurans, suggesting that there is some level of canalization of morphology early in ontogeny. In contrast, a number of morphologies vary among groups, supporting the fact that there have been major evolutionary modifications to anuran larval morphologies early in ontogeny and in the early evolutionary history of anurans.
... DESCRIPTION OF A NEW SPECIES OF PIPA (ANURA: PIPIDAE) FROM PANAMA LINDA TRUEB ABSTRACT: Juven... more ... DESCRIPTION OF A NEW SPECIES OF PIPA (ANURA: PIPIDAE) FROM PANAMA LINDA TRUEB ABSTRACT: Juvenile pipids from the lowlands of eastern Panama were assigned to Pipa parva by Heatwole (1963). ... Am. Mus. Novitates 1348:1-13. GOSNER, KL 1960. ...
The adult osteology of the direct-developing pipid frog, Pipa pipa, is described based on cleared... more The adult osteology of the direct-developing pipid frog, Pipa pipa, is described based on cleared-and-stained and dry skeletal specimens. Observations on skeletal development are based on cleared-and-stained embryos and young removed from the backs of preserved females. Osteologically, P.pipa is distinguished from its congeners and other pipid anurans by its large size and peculiar skull, which is extremely depressed and hyperossified. Skulls of the smallest individuals are not significantly different from those of other basal anurans at a similar stage of development; comparisons are made with Bombina orientalis, Discoglossus sardus, Spea bombifrons, Rhinophrynus dorsalis, and Xenopus laevis. The general sequence of chondrification and ossification resembles that of X.laevis; however, there is evidence that the mandible forms earlier in Pipa than in Xenopus. The major allometric transformations that result in the morphologically bizarre skull of adult P.pipa commence after the embryo has resorbed its tail, an event interpreted as marking the end of metamorphic climax in this taxon. In addition, ontogenetic comparisons reveal that the sacrum forms differently in Discoglossus sardus,Silurana tropicalis, and P.pipa. The development of the sphenethmoid region of the skull is the same in P.pipa and X.laevis, and distinctly different from the development of this region of the skull in other non-pipid basal anurans and neobatrachians for which ontogenetic descriptions exist.
Glassfrogs (family Centrolenidae) represent an exceptionally diverse group among Neotropical anur... more Glassfrogs (family Centrolenidae) represent an exceptionally diverse group among Neotropical anurans, but their evolutionary relationships never have been assessed from a molecular perspective. Mitochondrial and nuclear markers were used to develop a novel hypothesis of centrolenid phylogeny. Ingroup sampling included 100 terminals, with 78 (53%) of the named species in the family, representing most of the phenotypic diversity described for the group. Thirty-five species representing taxa traditionally associated with glassfrogs were used as outgroups. Gene sampling consisted of complete or partial sequences of three mitochondrial (12S, 16S, ND1) and three nuclear markers (c-myc exon 2, RAG1, POMC) for a total of $4362 bp. Phylogenies were estimated using maximum parsimony, maximum likelihood, and Bayesian analyses for individual genes and combined datasets. The separate analysis of mitochondrial and nuclear datasets allowed us to clarify the relationships within glassfrogs; also, we corroborate the sister-group relationship between Allophryne ruthveni and glassfrogs. The new phylogeny differs significantly from all previous morphology-based hypotheses of relationships, and shows that hypotheses based on few traits are likely to misrepresent evolutionary history. Traits previously hypothesized as unambiguous synapomorphies are shown to be homoplastic, and all genera in the current taxonomy (Centrolene, Cochranella, Hyalinobatrachium, Nymphargus) are found to be poly-or paraphyletic. The new topology implies a South American origin of glassfrogs and reveals allopatric speciation as the most important speciation mechanism. The phylogeny profoundly affects the traditional interpretations of glassfrog taxonomy, character evolution, and biogeography-topics that now require more extensive evaluation in future studies.
SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of ev... more SYNOPSIS. Hypotheses of relationships are critical to describing and understanding patterns of evolution within groups of organisms. But rarely has a comparative, historical approach been employed to study developmental change, particularly among anurans. A recent resurgence of interest in collecting basic ontogenetic information provides us with the opportunity to compare ontogenetic trajectories in a phylogenetic framework. Larval skeletons and osteological development were examined for 22 taxa and compared to two hypotheses of relationships-that of Cannatella, and one proposed herein based on 41 morphological characters from larvae and 62 from adults. Larval characters were mapped on the alternate cladograms using the ACCTRAN optimization criterion. Several larval features are highly conserved among some anurans, suggesting that there is some level of canalization of morphology early in ontogeny. In contrast, a number of morphologies vary among groups, supporting the fact that there have been major evolutionary modifications to anuran larval morphologies early in ontogeny and in the early evolutionary history of anurans.
The higher-level relationships of anurans have been explored by numerous studies, producing a var... more The higher-level relationships of anurans have been explored by numerous studies, producing a variety of hypotheses. The relationships of the basal anurans ('archaeobatrachians') are, however, poorly known. In part, this may be because the adult morphology of basal anurans is derived and therefore may not provide suitable phylogenetic signal. Recently, several authors have shown the phylogenetic utility of information derived from anuran larvae. In this paper we conduct separate and combined analyses of anuran relationships based on adult and larval morphology. Our combined results suggest that anurans form two major cladesthe pipoids and all other frogs. Evidence also suggests that, taken together, Neobatrachia and Pelobatoidea form a monophyletic group. We discuss support for various groupings as shown by the different data sets. We also comment on the consequences of our phylogenetic hypothesis for the interpretation of reduction of vertebral elements and evolution of Orton's tadpole types in anurans.
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Papers by L. Trueb