The subgenus Mantidactylus is a group of frogs endemic to Madagascar, including the largest anuran species on the island. Although these frogs are common and widely distributed, their taxonomy remains unclear. Two species are currently recognised, M. grandidieri and M. guttulatus, with another available name, Rana pigra, considered to be a synonym of M. grandidieri. However, molecular studies have suggested the presence of several cryptic species within the group. Additionally, due to the lack of prominent morphological features, allocating the available names to evolutionary lineages has proven challenging. In the present study, we take a first step towards solving these problems by using fragments of the 16S mitochondrial gene and RAG1 nuclear gene from all over the range of the subgenus to describe its genetic diversity. We also use a newly designed target enrichment laboratory protocol to sequence three mitochondrial fragments from five name-holding museum specimens (as old as 120 years) in order to determine to which lineages the existing names should be applied. The study of the 16S mitochondrial gene revealed 7 geographically separated lineages, distinct enough to be considered candidate species. Out of the five museum specimens analysed, four successfully yielded DNA sequences and could be attributed to one of the aforementioned lineages. Therefore, the name Mantidactylus grandidieri should be applied to the populations from North-Eastern Madagascar, while M. guttulatus refers to populations from inland localities along the Eastern coast of the island. On the other hand, the holotype of Rana pigra did not yield enough genetic material to allow definitive identification. While our data were not sufficient to assess the status of the four lineages distributed along the Eastern coast, the populations from North-Western Madagascar were highly distinct on both the mitochondrial and nuclear markers. We thus describe them as a new species, M. radaka sp. nov. http://www.zoobank.org/urn:lsid:zoobank.org:pub:1EDDAF0D-FE37-490A-B09E-E136A0C5CB35

Background: Understanding the causes underlying heterogeneity of molecular evolutionary rates among lineages is a long-standing and central question in evolutionary biology. Although several earlier studies showed that modern frogs (Neobatrachia) experienced an acceleration of mitochondrial gene substitution rates compared to non-neobatrachian relatives, no further characterization of this phenomenon was attempted. To gain new insights on this topic, we sequenced the complete mitochondrial genomes and nine nuclear loci of one pelobatoid (Pelodytes punctatus) and five neobatrachians, Heleophryne regis (Heleophrynidae), Lechriodus melanopyga (Limnodynastidae), Calyptocephalella gayi (Calyptocephalellidae), Telmatobius bolivianus (Ceratophryidae), and Sooglossus thomasseti (Sooglossidae). These represent major clades not included in previous mitogenomic analyses, and most of them are remarkably species-poor compared to other neobatrachians. Results: We reconstructed a fully resolved and robust phylogeny of extant frogs based on the new mitochondrial and nuclear sequence data, and dated major cladogenetic events. The reconstructed tree recovered Heleophryne as sister group to all other neobatrachians, the Australasian Lechriodus and the South American Calyptocephalella formed a clade that was the sister group to Nobleobatrachia, and the Seychellois Sooglossus was recovered as the sister group of Ranoides. We used relative-rate tests and direct comparison of branch lengths from mitochondrial and nuclear-based trees to demonstrate that both mitochondrial and nuclear evolutionary rates are significantly higher in all neobatrachians compared to their non-neobatrachian relatives, and that such rate acceleration started at the origin of Neobatrachia. Conclusions: Through the analysis of the selection coefficient (ω) in different branches of the tree, we found compelling evidence of relaxation of purifying selection in neobatrachians, which could (at least in part) explain the observed higher mitochondrial and nuclear substitution rates in this clade. Our analyses allowed us to discard that changes in substitution rates could be correlated with increased mitochondrial genome rearrangement or diversification rates observed in different lineages of neobatrachians.

A recent paper proposing taxonomic changes in the South American snake genus Eunectes Wagler, 1830 (anacondas) is analysed. This paper raises an unusually high number of taxonomic and nomenclatural problems. The work does not rely on an explicit species concept, the analysis of the molecular data based on three mitochondrial genes is shown to be unreliable, and the validity of the ‘clades’ proposed in this work is questioned. The nomen proposed for a purported new species is a nomen nudum (nomenclaturally unavailable), and the designation of a ‘lectotype’ for the nominal species Eunectes murinus (Linnaeus, 1758) is invalid. We provide a review of the nomenclatural status of 18 nominal species (including four unavailable ones) once or still now referred to the genus Eunectes, we identify their ‘types’ (nomen-bearing specimens), we designate five lectotypes, which are all specimens figured and briefly described in ancient publications, and we explain the rationale behind this action, which will allow the subsequent designation as neotypes of recently collected specimens associated with precise type localities and molecular data. We show that the generic nomen Eunectes Wagler, 1830 does not apply to the taxonomic genus accommodating anacondas but, this nomen having been used for these giant and spectacular snakes for about 200 years and being well-known even outside the field of taxonomy, we argue that its traditional use should be maintained through an action of the International Commission of Zoological Nomenclature using its plenary power. Finally, we provide various recommendations regarding nomenclatural actions and publications presenting them.

We revise the frogs of the genus Raorchestes from Myanmar and Thailand based on data of external morphology, bioacoustics, and molecular genetics. The results of this integrative study provide evidence for the recognition of seven species, two of which we describe as new: Raorchestes mindat sp. nov. from Mindat District, Chin State, western Myanmar, and Raorchestes leiktho sp. nov. from Hpa-an District, Kayin State, southeastern Myanmar. The other species that we recognize in Myanmar and Thailand are R. cangyuanensis, R. huanglianshan, R. longchuanensis, R. menglaensis, and R. parvulus. We have compared the external morphology of the lectotype and four paralectotypes of Ixalus parvulus Boulenger, 1893 with the species of the Raorchestes parvulus group currently recognized from South-east Asia. Although the type series of Ixalus parvulus is morphologically most similar to specimens of R. cangyuanensis from Thailand, we refrain from formally synonymizing these two taxa until genetic data for I. parvulus are available that would allow this hypothesis to be tested. Thus, R. parvulus remains an enigmatic taxon still only known from the original type series. As now defined, R. cangyuanensis is distributed across most of Myanmar except for the Malayan Peninsula, and also in adjacent Yunnan Province, China, and adjacent northeastern Bangladesh. Raorchestes longchuanensis occurs in northwestern Thailand as well as in eastern Myanmar and western Yunnan, China. Raorchestes menglaensis ranges from southern Yunnan, China, across Thailand, Laos, and Cambodia to northern Western Malaysia. Raorchestes huanglianshan is distributed in southern Yunnan, China, and northwestern Thailand. Often two, at some places even three species of this genus occur sympatrically (e.g., R. leiktho sp. nov., R. longchuanensis and R. parvulus near Leiktho, Kayin State, Myanmar; R. longchuanensis and R. huanglianshan at Doi Inthanon). We provide new bioacoustic data for R. longchuanensis, R. menglaensis, and R. leiktho sp. nov., and compare these with data of R. cangyuanensis and R. rezakhani.