Late Cretaceous Vicariance in Gondwanan Amphibians

Overseas dispersals are often invoked when Southern Hemisphere terrestrial and freshwater organism phylogenies do not fit the sequence or timing of Gondwana fragmentation. We used dispersal-vicariance analyses and molecular timetrees to show that two species-rich frog groups, Microhylidae and Natatanura, display congruent patterns of spatial and temporal diversification among Gondwanan plates in the Late Cretaceous, long after the presumed major tectonic break-up events. Because amphibians are notoriously salt-intolerant, these analogies are best explained by simultaneous vicariance, rather than by oceanic dispersal. Hence our results imply Late Cretaceous connections between most adjacent Gondwanan landmasses, an essential concept for biogeographic and palaeomap reconstructions

Phylogeny and classification of fejervaryan frogs (Anura: Dicroglossidae)

Systematics and classification of Asian frogs of the genus Fejervarya and related genera (family Dicroglossidae; hereafter referred to as fejervaryan frogs) have been the subject of intensive debates in the past few years. We complement previous phylogenetic studies with analyses of concatenated sequences from 14 nuclear loci and mitochondrial gene fragments, totaling 12,752 nucleotides for 46 species representing all major lineages and relevant outgroups. We find strong support for two major clades within Fejervarya: a South Asian clade and a Southeast Asian clade. Previously, South Asian species have been hypothesized to constitute a separate genus, Zakerana (currently considered a junior synonym of Fejervarya), and also include species previously described as members of the genus Minervarya. Although parsimony and species tree analyses found support for the monophyly of Fejervarya as currently understood, partitioned Bayesian inference and unpartitioned Maximum Likelihood analyses of concatenated sequences recovered Southeast Asian species as a clade sister to the genus Sphaerotheca, albeit with low nodal support. We discuss the advantages and disadvantages of alternative classification schemes in light of previously proposed criteria for naming supraspecific taxa. The current single-genus taxonomy would impart desirable economy of nomenclatural change, and morphological diagnosability. However, other taxon naming criteria such as support for monophyly, temporal framework for diversification, and biogeographic regionalism would support a contrasting two-genus alternative. Because new species of Fejervarya are increasingly being discovered and described, and because a single-genus classification (Fejervarya) will remain controversial, given ambiguous support for its inferred monophyly, we propose recognizing two genera: Southeast Asian Fejervarya, and South Asian Minervarya. This classification results in two genera whose monophyly is strongly supported, respectively, and unlikely to be challenged by future analyses. Accordingly, we transfer all species of the South Asian clade to the genus Minervary

Figure 1. Bayesian consensus phylogram for 167 in Phylogenetic position of the poorly known montane cascade frog Amolops monticola (Ranidae) and description of a new closely related species from Northeast India

Figure 1. Bayesian consensus phylogram for 167 taxa representing members of the genus Amolops and five outgroup species, based on 2001 bp of concatenated mitochondrial DNA (16S, COI, and ND2 genes). Voucher numbers and associated details are referenced in Table S1. Bayesian posterior probabilities (BPP) and RAxML bootstrap support (BS) values>50% are denoted above and below the branches, or separated by an oblique (/) mark, respectively. Black vertical bars beside the terminal nodes indicate Amolops species recognised based on Bayesian and ML inferences; grey bars and open rectangles indicate putative species delimited in the bPTP analysis with support values of>90% or <90%, respectively. The genus comprises eight major species groups following Wu et al. (2020), as indicated with coloured bars on the extreme right and corresponding circles on the internal and terminal nodes. Four subgroups are observed within the focal Amolops monticola group. Illustrations representing species groups were prepared based on published photographs.Published as part of Patel, Naitik G., Garg, Sonali, Das, Abhijit, Stuart, Bryan L. & Biju, S.D., 2021, Phylogenetic position of the poorly known montane cascade frog Amolops monticola (Ranidae) and description of a new closely related species from Northeast India, pp. 1403-1440 in Journal of Natural History 55 (21-22) on page 1410, DOI: 10.1080/00222933.2021.1946185, http://zenodo.org/record/546937

Figure 7 in Phylogenetic position of the poorly known montane cascade frog Amolops monticola (Ranidae) and description of a new closely related species from Northeast India

Figure 7. (a) Distribution map of all known members of the Amolops monticola species group found in India; (b) inset rectangle enlarged to show the type locality of Amolops monticola 'Darjeeling' and the rediscovered locality in south Sikkim. An asterisk (*) after the species name indicates members whose type locality is in India. A question mark (?) indicates a doubtful record. Geographical coordinates and their source information are referenced in Table S2.Published as part of Patel, Naitik G., Garg, Sonali, Das, Abhijit, Stuart, Bryan L. & Biju, S.D., 2021, Phylogenetic position of the poorly known montane cascade frog Amolops monticola (Ranidae) and description of a new closely related species from Northeast India, pp. 1403-1440 in Journal of Natural History 55 (21-22) on page 1423, DOI: 10.1080/00222933.2021.1946185, http://zenodo.org/record/546937

A unique mating strategy without physical contact during fertilization in Bombay Night Frogs (Nyctibatrachus humayuni) with the description of a new form of amplexus and female call

Anurans show the highest diversity in reproductive modes of all vertebrate taxa, with a variety of associated breeding behaviours. One striking feature of anuran reproduction is amplexus. During this process, in which the male clasps the female, both individuals’ cloacae are juxtaposed to ensure successful external fertilization. Several types of amplexus have evolved with the diversification of anurans, and secondary loss of amplexus has been reported in a few distantly related taxa. Within Nyctibatrachus, a genus endemic to the Western Ghats of India, normal axillary amplexus, a complete loss of amplexus, and intermediate forms of amplexus have all been suggested to occur, but many species remain unstudied. Here, we describe the reproductive behaviour of N. humayuni, including a new type of amplexus. The dorsal straddle, here defined as a loose form of contact in which the male sits on the dorsum of the female prior to oviposition but without clasping her, is previously unreported for anurans. When compared to known amplexus types, it most closely resembles the form of amplexus observed in Mantellinae. Furthermore, we prove that, opposed to the situation in most anurans, male semen release happens before egg deposition. We hypothesize that the male ejaculates on the female’s dorsum and that sperm subsequently runs from her back and hind legs before fertilizing the eggs. A second feature characterizing anuran breeding is the advertisement call, mostly produced solely by males. Despite recent descriptions of several new Nyctibatrachus species, few studies have explored their vocal repertoire. We describe both the male advertisement call and a female call for N. humayuni. The presence of a female call has not been reported within Nyctibatrachidae, and has been reported in less than 0.5% of anuran species. Altogether, our results highlight a striking diversity and several unique aspects of Nyctibatrachus breeding behaviour

Late Cretaceous vicariance in Microhylidae and Natatanura.

<div><p>(<b>A</b>) Molecular timetree (TK method, all calibration points except G <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000074#pone.0000074-1" target="_blank">[12]</a>).</p> <p>Horizontal colored bars and lines at internal nodes (Standard deviation and 95% credibility interval, respectively) indicate vicariance events reconstructed by DIVA-analyses, and interpreted as follows: orange: Australia <–> Indo-Madagascar; yellow: Africa <–> South America; blue: Africa <–> Indo-Madagascar; purple: Madagascar <–> India (Seychelles); green: S. America-Antarctica <–> Indo-Madagascar (the intervening Kerguelen Plateau being involved).</p> <p>The latter splits in our timetree are interpreted as vicariance events between the Kerguelen plateau and Antarctica or Indo-Madagascar <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000074#pone.0000074-1" target="_blank">[12]</a>.</p> <p>The branches denoting the latest colonization of Eurasia, as reconstructed by DIVA, are indicated by an asterisk.</p> <p>Numbers at terminals correspond to taxon numbers in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000074#pone-0000074-g001" target="_blank">figure 1</a>. (<b>B</b>) Late Cretaceous Gondwana, with indication of corresponding geological break-ups.</p> <p>Abbreviations: AF = Africa, MA = Madagascar, IN = India, EU = Eurasia, SA = South America, AN = Antarctica, AU = Australia-New Guinea, KP = Kerguelen Plateau.</p></div

Data from: The impact of anchored phylogenomics and taxon sampling on phylogenetic inference in narrow-mouthed frogs (Anura, Microhylidae)

Despite considerable progress in unravelling the phylogenetic relationships of microhylid frogs, relationships among subfamilies remain largely unstable and many genera are not demonstrably monophyletic. Here, we used five alternative combinations of DNA sequence data (ranging from seven loci for 48 taxa to up to 73 loci for as many as 142 taxa) generated using the anchored phylogenomics sequencing method (66 loci, derived from conserved genome regions, for 48 taxa) and Sanger sequencing (seven loci for up to 142 taxa) to tackle this problem. We assess the effects of character sampling, taxon sampling, analytical methods and assumptions in phylogenetic inference of microhylid frogs. The phylogeny of microhylids shows high susceptibility to different analytical methods and datasets used for the analyses. Clades inferred from maximum-likelihood are generally more stable across datasets than those inferred from parsimony. Parsimony trees inferred within a tree-alignment framework are generally better resolved and better supported than those inferred within a similarity-alignment framework, even under the same cost matrix (equally weighted) and same treatment of gaps (as a fifth nucleotide state). We discuss potential causes for these differences in resolution and clade stability among discovery operations. We also highlight the problem that commonly used algorithms for model-based analyses do not explicitly model insertion and deletion events (i.e. gaps are treated as missing data). Our results corroborate the monophyly of Microhylidae and most currently recognized subfamilies but fail to provide support for relationships among subfamilies. Several taxonomic updates are provided, including naming of two new subfamilies, both monotypic

Molecular systematics of caeciliid caecilians (Amphibia: Gymnophiona) of the Western Ghats, India

Together, Indian plus Seychelles caeciliid caecilian amphibians (Gymnophiona) constitute approximately 10 of the extant species of this order. A molecular phylogenetic analysis of all but one (or two) nominal species (16, in five genera) is presented based on mitochondrial (12S, 16S, cytb, cox1) and nuclear (RAG1) sequence data. Results strongly support monophyly of both Seychelles and peninsular Indian caeciliids, and their sister-group status. Within the Indian caeciliids, Indotyphlus and Gegeneophis are monophyletic sister genera. The phylogenetic position of Gegeneophis ramaswamii, Gegeneophis seshachari, and Gegeneophis carnosus are not well resolved, but all lie outside a well-supported clade of most northern Western Ghats Gegeneophis (madhavai, mhadeiensis, goaensis, danieli/nadkarnii). Most nominal species of Indian caeciliid are diagnosed by robust haplotype clades, though the systematics of G. carnosus-like forms in northern Kerala and southern Karnataka requires substantial further investigation. For the most part, Indian caeciliid species comprise narrowly distributed, allopatric taxa with low genetic diversity. Much greater geographic genetic diversity exists among populations referred to G. seshachari, such that some populations likely represent undescribed species. This, the first phylogenetic analysis of Indian caeciliids, generally provides additional support for recent increases in described species (eight since 1999), and a framework for ongoing taxonomic revision. © 2011 Elsevier Inc