Taran Grant

Taran Grant
University of São Paulo | USP · Department of Zoology (IB)

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80
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Publications

Publications (80)
Article
Sequestration of chemical defenses from dietary sources is dependent on the availability of compounds in the environment and the mechanism of sequestration. Previous experiments have shown that sequestration efficiency varies among alkaloids in poison frogs, but little is known about the underlying mechanism. The aim of this study was to quantify t...
Article
We describe the hand and foot musculature of the fossorial Indian purple frog, Nasikabatrachus sahyadrensis, and compare it to other members of Sooglossoidea: the Seychellean sooglossid genera Sechellophryne and Sooglossus. Due to the key phylogenetic position of Sooglossoidea, we compare its members with the diversity of Anura and define 52 charac...
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The hands of adult males of many dendrobatid poison frogs and their relatives possess swelling formed by glandular tissue hypothesized to secrete courtship pheromones delivered to the female during cephalic amplexus. Variation in the occurrence and external morphology of the swelling of finger IV has provided important evidence for dendrobatoid sys...
Article
Several species of Cophomantini are known to have an enlarged prepollex, commonly modified as an osseous spine. We surveyed the osteology and myology of the prepollex and associated elements of 94 of the 190 species of Cophomantini, sampling all genera, except Nesorohyla. Two distinct prepollex morphologies were found: a bladeshaped and a spine-sha...
Article
en The evolutionary success of anurans can be partially explained by the occurrence of free-living larvae. Tadpoles occupy several distict habitats, including the terrestrial environment. Semiterrestriality appears to have evolved seven times in anurans, and tadpoles of distantly related lineages have converged in a set of phenotypic characters, su...
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The following list includes all recognized species of amphibians, known by vouchers or published information to occur within the political borders of Brazil (as of April 2021). Supra-generic taxonomy follows Frost (2021), as do most generic and species names. Other taxonomic decisions and species exclusions are explained below. All inclusions relat...
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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...
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We studied the larval morphology of the dendrobatid frog genus Silverstoneia and closely related species of Colostethinae. After describing external, buccopharyngeal, larval muscle, and chondrocranium morphology, we delimit 17 new larval characters, including the following 12 new unambiguously optimized synapomorphies of Silverstoneia: (a) medial e...
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Although studies of anuran hand and foot musculature began in the first half of the 19th century, all studies to date have been taxonomically or anatomically restricted in scope, and none has considered the diversity of autopodial myology in Anura as a whole. As a model for future comparisons, we thoroughly describe the hand and foot musculature of...
Article
The relationships of the hyline tribe Dendropsophini remain poorly studied, with most published analyses dealing with few of the species groups of Dendropsophus. In order to test the monophyly of Dendropsophini, its genera, and the species groups currently recognized in Dendropsophus, we performed a total evidence phylogenetic analysis. The molecul...
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Ambient mass spectrometry is useful for analyzing compounds that would be affected by other chemical procedures. Poison frogs are known to sequester alkaloids from their diet, but the sequestration pathway is unknown. Here, we describe methods for whole‐body cryosectioning of frogs and use Desorption Electrospray Ionization Mass Spectrometry Imagin...
Article
The South American and West Indian Casque-headed Treefrogs (Hylidae: Hylinae: Lophyohylini) include 85 species. These are notably diverse in morphology (e.g. disparate levels of cranial hyperossification) and life history (e.g. different reproductive modes, chemical defences), have a wide distribution, and occupy habitats from the tropical rainfore...
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The amount of short wavelength (ultraviolet (UV), violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographic...
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Tetrodotoxin (TTX), one of the most toxic substances in nature, is present in bacteria, invertebrates, fishes, and amphibians. Marine organisms seem to bioaccumulate TTX from their food or acquire it from symbiotic bacteria, but its origin in amphibians is unclear. Taricha granulosa can exhibit high TTX levels, presumably concentrated in skin poiso...
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As is typical of chemically defended animals, poison frogs present high variability in their alkaloid-based defenses. Previous studies have shown that geographically separated color morphs of Oophaga and Dendrobates species differ in both alkaloid composition and arthropod palatability. Here, we tested the generality of that finding by studying the...
Preprint
Full-text available
The amount of short wavelength (UV, violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographic distributions...
Data
Links to files containing ocular media transmittance and spectral sensitivities datasets
Article
Full-text available
Background: Lizards are excellent models to study the adaptations of the visual system to different scenarios, and surface-dwelling representatives have been relatively well studied. In contrast, very little is known about the functional anatomy of the eyes of fossorial lineages, and properties such as the light transmission by the ocular media hav...
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The transmittance properties of the cornea, lens and humours of vertebrates determine how much light across the visible spectrum reaches the retina, influencing sensitivity to visual stimuli. Amphibians are the only vertebrate class in which the light transmittance of these ocular media have not been thoroughly characterised, preventing large-scale...
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Nuptial pads are patches of thickened skin, associated with sexually dimorphic skin glands, present only in the thumbsand fingers of male anurans, and hence considered dimorphic sexual characters. Despite the morphological description for many species,the evolution and function of nuptial pads are still unclear. In this study, we describe the prese...
Article
The Neotropical hylid genus Sphaenorhynchus includes 15 species of small, greenish treefrogs widespread in the Amazon and Orinoco basins, and in the Atlantic Forest of Brazil. Although some studies have addressed the phylogenetic relationships of the genus with other hylids using a few exemplar species, its internal relationships remain poorly unde...
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Introduction: Amphibians secrete a wide diversity of chemicals from skin glands as defense against predators, parasites, and pathogens. Most defensive chemicals are produced endogenously through biosynthesis, but poison frogs sequester lipophilic alkaloids from dietary arthropods. Alkaloid composition varies greatly, even among conspecific individ...
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Bufonid poison frogs of the genus Melanophryniscus contain alkaloid-based chemical defenses that are derived from a diet of alkaloid-containing arthropods. In addition to dietary alkaloids, bufadienolide-like compounds and indolealkylamines have been identified in certain species of Melanophryniscus. Our study reports, for the first time, the co-oc...
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We describe two new species of Anomaloglossus from Roraima State, Brazil, that are likely endemic to single mountains currently isolated among lowland forest and savanna ecosystems. The first species, Anomaloglossus tepequem sp. nov. was collected in 1986 and 1992 along a single stream at >500 m elevation on a tepui-like mountain named Tepequém, bu...
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Efforts to find and gather data on natural history, including geographic records, of species considered threatened are an important tool to assess and update its conservation status. Little is known about the threatened South American red belly toad, Melanophryniscus macrogranulosus, endemic from northeastern Rio Grande do Sul, southern Brazil. The...
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A phylogeny of the species-rich clade of the Neotropical frog genus Leptodactylus sensu stricto is presented on the basis of a total evi- dence analysis of molecular (mitochondrial and nuclear markers) and non-molecular (adult and larval morphological and behavioral characters) sampled from > 80% of the 75 currently recognized species. Our results...
Article
Padial et al. (2014) applied the name Pristimantinae Ohler & Dubois, 2012 to a taxon including the genera Ceuthomantis, Dischidodactylus, Pristimantis, and Yunganastes. However, Ceuthomantidae Heinicke, Duellman, Trueb, Means, MacCulloch & Hedges, 2009, type genus Ceuthomantis Heinicke, Duellman, Trueb, Means, MacCulloch & Hedges, 2009, has priorit...
Article
The relationship between invasion success and native biodiversity is central to biological invasion research. New theoretical and analytical approaches have revealed that spatial scale, land-use factors and community assemblages are important predictors of the relationship between community diversity and invasibility and the negative effects of inv...
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We describe a new species of the Rhinella acrolopha group (previously Rhamphophryne) from mid-elevations (1800–2500 m) of the Cordillera Occidental of Colombia. It is found exclusively in cloud forest habitats and is not associated with streams or other bodies of water. The species is characterized by possessing eight presacral vertebrae, fusion of...
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The facial pits of rattlesnakes, copperheads, lanceheads, bushmasters and other American and Asian pitvipers (Crotalinae) are highly innervated and densely vascularized infrared (IR) receptor organs. For over a century, studies have focused on a small sample of model species from North America and Asia. Based on an expanded survey of Central and So...
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h D epartement Syst ematique et Evolution, Mus eum national d'Histoire naturelle, CP 51, 55 rue Buffon, 75231, Paris, France; i National Museum of Marine Biology and Aquarium, No. 2, Houwan Road, Checheng, Pingtung, 944, Taiwan; j Department of Science and Education, The Field Museum, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA; k D eparte...
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Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleuthe...
Article
The dendrobatid genus Silverstoneia is a clade of forest-dwelling frogs that share small adult size (<22 mm snout-vent length), basal webbing between toes a solid blackish brown flank divided by a conspicuous pale oblique lateral stripe from the groin to the eye, a pale ventrolateral stripe, finger I>II, male nurse frogs (known in four species), an...
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The New World direct-developing frogs (Terrarana) comprise more than 970 species distributed from the southern United States to northern Argentina. Although the composition of this clade has been remarkably stable for many decades, evidence for its monophyly is derived mostly from DNA sequences with putative phenotypic synapomorphies limited to the...
Article
The effects of invasive species on native taxa due to direct predation, food, and space competition, and disease transmission are well documented. However, the effects of acoustic invaders on animal communication have not been explored. We simulated an invasion of the acoustic niche by exposing calling native male white-banded tree frogs (Hypsiboas...
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The occurrence in Panama is documented for the South American frog genus Anomaloglossus (Dendrobatoidea: Aromobatidae). Two species are described from a low, forested uplift in east-central Panama, just northeast of Panama City. These low mountains, unnamed on maps, are designated the "Chagres Highlands" because a large part of the uplift lies in t...
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We describe a new species of bufonid from a lowland, sandy soil, restinga habitat in the state of Espírito Santo, southeastern Brazil. Based on the shared occurrence of putative mor-phological synapomorphies of Melanophryniscus and the results of a phylogenetic analysis of DNA sequences of a broad sample of bufonids, and other anurans, we assign th...
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The most common method for identifying individual amphibians is toe-clipping (TC), whereby captured individuals are marked by a unique combination of amputated phalanges that corresponds to a unique alphanumeric code. However, ethical and methodological objections to this method have been raised and there is broad interest in developing alternative...
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Invasive species are known to affect native species in a variety of ways, but the effect of acoustic invaders has not been examined previously. We simulated an invasion of the acoustic niche by exposing calling native male white-banded tree frogs (Hypsiboas albomarginatus) to recorded invasive American bullfrog (Lithobates catesbeianus) calls. In r...
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The red-belly toads (Melanophryniscus) of southern South America secrete defensive alkaloids from dermal granular glands. To date, all information on Mela-nophryniscus alkaloids has been obtained by extraction from either skins or whole organisms; however, in other amphibians, tetrodotoxins, samandarines, and bufadieno-lides have been detected in b...
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Most amphibians with biphasic life cycles have aquatic eggs and larvae and terrestrial adults that migrate between terrestrial habitats and aquatic breeding sites. Migration usually occurs at night in order to avoid desiccation and predation. However, some amphibians also migrate during the day, and it has been proposed that this may have evolved a...
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The directional orientation of pre- and post-reproductive migration was studied in the Brazilian red-bellied toad Melanophryniscus cambaraensis, a species that forms explosive-breeding aggregations at irregular intervals throughout the entire year. Migrating toads were captured by enclosing the breeding site in dual drift fences with inward- and ou...
Article
Parsimony remains one of the most widely used optimality criteria in phylogenetic systematics. There are many practical reasons for this, including parsimony's intuitive simplicity, applicability to diverse character data, computational speed, and unique statistical properties as a nonparametric method. The epistemological argument for parsimony as...
Article
The relative optimality of the best and next-best hypotheses indicates the strength of support for the optimal hypothesis and may be calculated as either the difference or ratio of their optimality scores. The Goodman-Bremer support measure (GB) calculates the support for a given clade in the most parsimonious tree as the difference between the len...
Article
In addition to hypothesis optimality, the evaluation of clade (group, edge, split, node) support is an important aspect of phylogenetic analysis. Here we clarify the logical relationship between support and optimality and formulate adequacy conditions for support measures. Support, S, and optimality, O, are both empirical knowledge claims about the...
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Wiens (2007, Q. Rev. Biol. 82, 55–56) recently published a severe critique of Frost et al.'s (2006, Bull. Am. Mus. Nat. Hist. 297, 1–370) monographic study of amphibian systematics, concluding that it is “a disaster” and recommending that readers “simply ignore this study”. Beyond the hyperbole, Wiens raised four general objections that he regarded...
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We describe a new species of Allobates from the Magdalena Valley in Colombia. The new species and its sister species, A. talamancae, are the only two species of Allobates known to occur west of the Andes. The new species differs from A. talamancae in being smaller, possessing a diffuse pale oblique lateral stripe, and exhibiting strong swelling of...
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The known diversity of dart-poison frog species has grown from 70 in the 1960s to 247 at present, with no sign that the discovery of new species will wane in the foreseeable future. Although this growth in knowledge of the diversity of this group has been accompanied by detailed investigations of many aspects of the biology of dendrobatids, their p...
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Traditional justifications of parsimony in phylogenetic inference assume a correspondence between character-state similarity and steps (character transformation events). In addition to similarity, justifying arguments appeal to conviction, descriptive efficiency, ad hoc hypotheses of homoplasy and frequentist probability. Each of these rationales f...
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The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living...
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The purpose of this application, under Article 81 of the Code, is to conserve the subsequent spelling of the specific name Hyloxalus panamensis as a justified emendation of Hyloxalus panamansis Dunn, 1933 (currently Colostethus panamansis) for a Central American dendrobatid frog species which is the subject of important behavioural, environmental a...
Article
We examine recently proposed justifications of sensitivity analysis sensuWheeler (1995), here referred to as weighted-classes sensitivity analysis (WCSA). We refute Giribet's (2003a) claim that WCSA is the strictest possible test for a given phylogenetic hypothesis. Giribet's (2003a) classification of data exploration methods as evaluating “nodal s...
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For the past several decades, it has been thought that Colostethus inguinalis (Cope, 1868) (type species of Prostherapis Cope, 1868) is distributed in the Chocoregion of western Co- lombia and throughout much of Panama. This study shows that C. inguinalis is a Colombian endemic known only from the lowlands of the Chocoand Magdalena Valley—an unusua...
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An ideographic concept of character is indispensable to phylogenetic inference. Hennig proposed that characters be conceptualized as ''transformation series'', a proposal that is firmly grounded in evolutionary theory and consistent with the method of inferring transformation events as evidence of phylogenetic propinquity. Nevertheless, that concep...
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The methods of data exploration have become the centerpiece of phylogenetic inference, but without the scientific importance of those methods having been identified. We examine in some detail the procedures and justifications of WheelerÕs sensitivity analysis and relative rate comparison (saturation analysis). In addition, we review methods designe...
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In 1992 parties to the Convention on Biological Diversity (CBD) agreed to develop and implement policies to regulate and facilitate access to genetic resources (AGR). We examine regulations and agreements in Brazil, Colombia, and the Philippines in detail and discuss how these countries are implementing the AGR mandate. In particular, we evaluate p...
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The rising preeminence of Phylogenetic Systematics runs the risk of being self defeating, for it is becoming more and more common for practitioners of other approaches to pay lip-service to phylo-genetic principles. . . This tendency seems to be most pronounced when the alternative approaches are of a mathematical nature or are implemented by compu...
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We describe a new species of Colostethus from moderate elevations of Cuchilla los Picachos, a spur of the eastern slopes of the Cordillera Oriental of Colombia (Departamento de Caqueta ´). The new species is a small, diurnal, forest dweller characterized, in part, by lacking sexual dimorphism in ventral coloration; the throat, chest, and anterior b...
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Scientific discovery requires both abstract, theoretically defined concepts and discovery operations formed by sets of rules that permit the empirical detection of instances of those concepts. In this paper, I examine the ontological status of discovery operations and the tests employed to evaluate them in evolutionary biology. Attention is drawn t...
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By use of the technique of direct optimization the phylogenetics of the cis-Andean lizard genus Tropidurus were examined on the basis of both molecular (ca. 1.04 kb of sequences from 12S rDNA, valine tDNA, and 16S rDNA) and morphological (93 characters) data. Although equal weighting of all parsimony cost functions logically must maximize descripti...
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Colostethus trilineatus (Boulenger, 1883) is widespread in the lowlands of Amazonian Peru and Ecuador. It is characterized, in part, by small size, gray throat and Finger III strongly swollen in adult males, and an advertisement call of 10 notes with emphasized frequencies at 4920–6040 Hz. Material examined revealed extensive variation in dorsal, v...
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Based on characters of external morphology, scutellation, and osteology, we describe a new species of Synophis from the Pacific versant of the Cordillera Occidental of Colombia. Assignment of this species to Synophis is tentative, pending a reassessment of nothopsin relationships. Some natural history notes are reported for the new species. /// Con...