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Background Occidozyga shiwandashaensis was recently discovered from Guangxi Province of China. Hylarana latouchii is a widespread species in southern China, including Hong Kong and Taiwan. Both species are expected to be found in the border areas between Vietnam and China; however, no records of these frogs have been documented from Vietnam so far. New information We record two species of amphibians for the first time from Vietnam, namely Occidozyga shiwandashaensis from Bac Giang Province and Hylarana latouchii from Hai Phong City and Quang Ninh Province in northern Vietnam. Morphologically, the Vietnamese representatives of O. shiwandashanensis resemble the type series from China. The specimens of H. latouchii from Vietnam slightly differ from the type series from China by having a larger size (SVL 48.6-51.7 mm in males, SVL 58.4 mm in the females vs. 36.0-40.0 mm in males, 42.0-53.0 mm in females). Genetic distances between the Vietnamese records and the type specimens of O. shiwandashanensis from China varied from 0 to 1.5% (16S gene). Genetic divergences between the Vietnamese records and H. latouchii from the type locality were 2.0-2.6% (16S gene). In addition, morphological data and natural history notes of the aforementioned species are provided, based on the new records from Vietnam. [ABSTRACT FROM AUTHOR]

We describe a new species of microhylid frog of the genus Synapturanus from the lower Putumayo basin in Loreto, Perú. Specimens inhabited the soils of stunted pole forests growing on peat. The new species is distinguished from other species of Synapturanus through morphology, genetics, and acoustic characteristics. This species differs from most nominal congeners by having a head flat in lateral view (vs convex in the rest of species), a characteristic only shared by S. rabus and S. salseri. The new species can be distinguished from S. rabus and S. salseri by a combination of morphological characters and by having an advertisement call with a note length of 0.05-0.06 seconds (vs 0.03 seconds in S. rabus) and a dominant frequency ranging from 1.73 to 1.81 kHz (vs 1.10-1.47 kHz in S. salseri). Principal component analyses of 12 morphological characters and three acoustic variables further support differences between the new species and its described and undescribed congeners. [ABSTRACT FROM AUTHOR]

A summary of the main features of the ilium and associated muscles is presented in Appendix B, and additional information on frog ilial musculature is summarized in Appendix C. The characters used to assess and compare the ilia were taken, or adapted, from those used by authors when describing new fossil frog taxa (e.g. [19]; [30]; [15]; [3]; [17]). The VSA was noted as being larger than 90° in the majority of anurans by [23], but in this survey close to a third (28%) of the southern African anuran ilia have a VSA of less than 90°, suggesting that this was an over-estimation, at least in the case of the southern African taxa. For the position of the DT relative to the acetabulum, the two most common categories for the majority of taxa are category 2 (posterior to the acetabulum) or category 3 (proximal portion of dorsal prominence at same level as acetabulum). [Extracted from the article]

Developmental instability provides a powerful monitoring tool to detect threats prior to population declines. Consequently, assessing the level of developmental instability by measuring fluctuating asymmetry (FA) of bilaterally symmetrical traits in association with environmental stress has become increasingly attractive. However, many studies failed in detecting a clear connection of FA to environmental stressors. Some of these may have suffered from large measurement error (ME) or the use of inappropriate methods. Here, we compared measurement accuracy and FA outcome from manual calliper measurements with those from non-destructive micro-3D-computed tomography (µCT) based skeletal measurements. Amphibians are assumed to be ideal models for measuring fluctuating asymmetry due to their sensitivity to environmental stress. For our study, we chose two bilateral, metric traits (femur and radio--ulna length) of the European Common Frog, Rana temporaria. Calliper measurements revealed meaningful FA estimates (i.e., FA exceeded ME) for radio-- ulna length only. In contrast, µCT-based measurements delivered meaningful FA estimates for both traits. ME was about twice as high for calliper measurements compared to µCT-based measurements, resulting in inflated levels of FA. Using callipers, we observed higher ME for femur measurements than for radio--ulna, meaning that ME strongly depended on the respective trait. When using µCT, however, we observed comparable ME between both traits. Our study revealed that analyses of developmental instability using manual measurements should be treated with caution. For smaller vertebrates we recommend skeletal measurements with µCT as a valuable alternative due to its greater reliability, thereby allowing for multi-trait analyses with equal accuracy. [ABSTRACT FROM AUTHOR]

Ecomorphology is the association between an organism's morphology and its ecology. Larval anuran amphibians (tadpoles) are classified into distinct ecomorphological guilds based upon morphological features and observations of their ecology. The extent to which guilds comprise distinct morphologies resulting from convergent evolution, the degree of morphological variability within each guild, and the degree of continuity in shape between guilds has not previously been examined in a phylogenetically informed statistical framework. Here, we examine tadpole ecomorphological guilds at a macroevolutionary scale by examining morphological diversity across the Australian continent. We use ecological data to classify species to guilds, and geometric morphometrics to quantify body shape in the tadpoles of 188 species, 77% of Australian frog diversity. We find that the ecomorphological guilds represented by Australian species are morphologically distinct, but there is substantial morphological variation associated with each guild, and all guilds together form a morphological continuum. However, in a phylogenetic comparative context, there is no significant difference in body shape among guilds. We also relate the morphological diversity of the Australian assemblage of tadpoles to a global sample and demonstrate that ecomorphological diversity of Australian tadpoles is limited with respect to worldwide species. Our results demonstrate that general patterns of ecomorphological variation are upheld in Australian tadpoles, but tadpole body shape is more variable and possibly generalist than generally appreciated. Ecomorphological guilds act as a proxy for studying assemblages of aquatic environments and modelling ecosystems. Here we study guilds of tadpoles sampled from all species of Australia to understand whether body shape can be an indicator of guild. We find that some guilds have distinct body shapes but all guilds together form a morphological continuum suggesting tadpole body shape is more variable than generally appreciated. [ABSTRACT FROM AUTHOR]

The taxonomic status of some of New Zealand's endemic and threatened leiopelmatid frogs has been debated for decades. Clarifying this uncertainty is vital to their conservation, especially given the risk of extinction of cryptic taxa. We re-examined leiopelmatid diversity through multivariate analyses of the skeletal and external morphology of extinct and extant Leiopelma to determine morphological differentiation. Our results suggest that the morphological distinction between extinct taxa is greater than in modern extant taxa. While size ranges of postcranial elements overlapped within extant species, maxillae shape discriminated some extant taxa. We confirm the morphological distinctiveness of the extinct taxa recognized to date but identify latitudinal and altitudinal variation in postcranial element size and shape within the widespread Leiopelma markhami and L. waitomoensis, which suggest possible post-human extinction of cryptic taxa. Furthermore, the lack of morphological and osteological differentiation between L. archeyi and the insular extant L. hamiltoni and L. pakeka leads us to question the taxonomic distinctiveness of these three taxa. Future genetic research using modern and ancient DNA is recommended to enable species limits within Leiopelma to be tested in more detail to provide an evidence-based assessment for their conservation management. [ABSTRACT FROM AUTHOR]

Based on morphological and phylogenetic analyses (16S rRNA mtDNA), two new species of the genus Leptobrachella are described from southern China, namely L. yunkaiensis Wang, Li, Lyu & Wang, sp. n. from Dawuling Forest Station of Guangdong Province and L. wuhuangmontis Wang, Yang & Wang, sp. n. from Mt. Wuhuang of Guangxi Province. To date, the genus Leptobrachella contains 68 species, among which 13 species are known from China. The descriptions of the two new species further emphasize that the species diversity of the genus Leptobrachella from China is still highly underestimated and requires further investigations. [ABSTRACT FROM AUTHOR]

Background: Quantifying morphological diversity across taxa can provide valuable insight into evolutionary processes, yet its complexities can make it difficult to identify appropriate units for evaluation. One of the challenges in this field is identifying the processes that drive morphological evolution, especially when accounting for shape diversification across multiple structures. Differential levels of co-varying phenotypic diversification can conceal selective pressures on traits due to morphological integration or modular shape evolution of different structures, where morphological evolution of different modules is explained either by co-variation between them or by independent evolution, respectively. Methods: Here we used a 3D geometric morphometric approach with x-ray micro CT scan data of the skull and bones of forelimbs and hindlimbs of representative species from all 21 genera of the ancient Australo-Papuan myobatrachid frogs and analysed their shape both as a set of distinct modules and as a multi-modular integrative structure. We then tested three main questions: (i) are evolutionary patterns and the amount and direction of morphological changes similar in different structures and subfamilies?, (ii) do skulls and limbs show different levels of integration?, and (iii) is morphological diversity of skulls and limbs shaped by diet, locomotion, burrowing behavior, and ecology?. Results: Our results in both skulls and limbs support a complex evolutionary pattern typical of an adaptive radiation with an early burst of phenotypic variation followed by slower rates of morphological change. Skull shape diversity was phylogenetically conserved and correlated with diet whereas limb shape was more labile and associated with diet, locomotion, and burrowing behaviour. Morphological changes between different limb bones were highly correlated, depicting high morphological integration. In contrast, overall limb and skull shape displayed semi-independence in morphological evolution, indicating modularity. Conclusions: Our results illustrate how morphological diversification in animal clades can follow complex processes, entailing selective pressures from the environment as well as multiple trait covariance with varying degrees of independence across different structures. We suggest that accurately quantifying shape diversity across multiple structures is crucial in order to understand complex evolutionary processes. [ABSTRACT FROM AUTHOR]

Although primarily terrestrial, cane toads ( Rhinella marina) sometimes climb near-vertical surfaces (tree-trunks, cliffs, fences) during foraging or dispersal activities. We scored climbing ability (in laboratory trials) of 288 cane toads from four regions in Australia, plus two sites on the island of Hawai'i. We found strong divergence in climbing ability associated not only with sex and relative limb length, but also population of origin. Within each population, longer-limbed individuals (and hence, males rather than females) were better climbers, although the geographical divergence in climbing ability remained significant even when sex and limb length were included in multivariate regression models. The geographical difference in climbing ability (but not morphology) disappeared when the progeny were raised in captivity under identical conditions, without climbing opportunities. Although influenced by morphology, climbing ability in wild-caught cane toads appears to be driven primarily by local environmental conditions that facilitate and/or reward arboreal activity. [ABSTRACT FROM AUTHOR]

The Eurasian Pelophylax esculentus hybridogenetic complex, including Pelophylax ridibundus (R), P. lessonae (L), and their hybrid P. kl. esculentus (E), is considered to be one of the most complicated animal hemiclonal systems. It has been attracting the attention of evolutionary and molecular biologists as well as ecologists for decades. Despite the considerable number of studies describing population structure, reproductive modes, and distribution of the species complex, data on the rarely observed REL scenario, i.e., the presence of all three species at one site, are lacking. This study compared the morphological (morphometry, external morphology) and ecological (diet) profiles of all three species from a REL complex population located in the northwestern part of Croatia (Bjelovar-Bilogora County). In terms of external morphology, the species varied interspecifically, but some features, for example, the yellow or green femoral coloration found in P. ridibundus, had not been expected. All three species exhibited a strong predilection for terrestrial prey, but interspecific differences were noticed. This paper aims to provide a better and more comprehensible insight into the ecological relationships of the REL complex, allowing comparisons with other study areas across Europe. [ABSTRACT FROM AUTHOR]

Animals from different clades but subject to similar environments often evolve similar body shapes and physiological adaptations due to convergent evolution, but this has been rarely tested at the transcontinental level and across entire classes of animal. Australia's biome diversity, isolation and aridification history provide excellent opportunities for comparative analyses on broad-scale macroevolutionary patterns. We collected morphological and environmental data on eighty-four (98%) Australian hylid frog species and categorized them into ecotypes. Using a phylogenetic framework, we tested the hypothesis that frogs from the same ecotype display similar body shape patterns: (i) across all the Australian hylids, and (ii) through comparison with a similar previous study on 127 (97%) Australian myobatrachid species. Body size and shape variation did not follow a strong phylogenetic pattern and was not tightly correlated with environment, but there was a stronger association between morphotype and ecotype. Both arboreal and aquatic frogs had long limbs, whereas limbs of fossorial species were shorter. Other terrestrial species were convergent on the more typical frog body shape. We quantified the strength of morphological convergence at two levels: (i) between fossorial myobatrachid and hylid frogs, and (ii) in each ecomorph within the hylids. We found strong convergence within ecotypes, especially in fossorial species. Ecotypes were also reflected in physiological adaptations: both arboreal and cocooned fossorial frogs tend to have higher rates of evaporative water loss. Our results illustrate how adaptation to different ecological niches plays a crucial role in morphological evolution, boosting phenotypic diversity within a clade. Despite phylogenetic conservatism, morphological adaptation to repeatedly emerging new environments can erase the signature of ancestral morphotypes, resulting in phenotypic diversification and convergence both within and between diverse clades. [ABSTRACT FROM AUTHOR]

Body shape is predicted to differ among species for functional reasons and in relation to environmental niche and phylogenetic history. We quantified morphological differences in shape and size among 98.5% of the 129 species and all 21 genera of the Australo-Papuan endemic myobatrachid frogs to test the hypothesis that habitat type predicts body shape in this radiation. We tested this hypothesis in a phylogenetic context at two taxonomic levels: across the entire radiation and within the four largest genera. Thirty-four external measurements were taken on 623 museum specimens representing 127 species. Data for seven key environmental variables relevant to anurans were assembled for all Australian-distributed species based on species' distributions and 131,306 locality records. The Australo-Papuan myobatrachid radiation showed high diversity in adult body size, ranging from minute (15 mm snout-vent length) to very large species (92 mm), and shape, particularly sin relative limb length. Five main morphological and environmental summary variables displayed strong phylogenetic signal. There was no clear relationship between body size and environmental niche, and this result persisted following phylogenetic correction. For most species, there was a better match between environment/habitat and body shape, but this relationship did not persist following phylogenetic correction. At a broad level, species fell into three broad groups based on environmental niche and body shape: 1) species in wet habitats with relatively long limbs, 2) species in arid environments with relatively short limbs (many of which are forward or backward burrowers) and 3) habitat generalist species with a conservative body shape. However, these patterns were not repeated within the four largest genera − Crinia, Limnodynastes, Pseudophryne and Uperoleia. Each of these genera displayed a highly conservative anuran body shape, yet individual species were distributed across the full spectrum of Australian environments. Our results suggest that phylogenetic legacy is important in the evolution of body size and shape in Australian anurans, but also that the conservative body plan of many frogs works well in a wide variety of habitats. [ABSTRACT FROM AUTHOR]