Phylogeography and diversification of an Amazonian understorey hummingbird: paraphyly and evidence for widespread cryptic speciation in the Plio‐Pleistocene

Straight‐billed Hermit Phaethornis bourcieri inhabits the understorey of upland terra firme forest throughout most of the Amazon basin. Currently, two allopatric taxa regarded as subspecies are recognized: P. b. bourcieri and P. b. major. However, the validity, interspecific limits and evolutionary history of these taxa are not yet fully elucidated. We use molecular characters to propose a phylogenetic hypothesis for populations and taxa grouped under Phaethornis bourcieri. Our results showed that P. bourcieri is part of the ‘Ametrornis’ clade, along with Phaethornis philippii and Phaethornis koepckeae, and that the subspecies major is more closely related to the latter two species than to populations grouped under nominate bourcieri. Our phylogenetic hypotheses recovered three main reciprocally monophyletic clades under nominate bourcieri separated by the lower Negro River and the Branco River or the Branco–Negro interfluve (clades B and C) and the upper Amazon (Solimões) or lower Marañon/Ucayali Rivers (clades C and D). Based on multi‐locus phylogeographic and population genetics approaches, we show that P. b. major is best treated as a separate species, and that P. b. bourcieri probably includes more than one evolutionary species, whose limits remain uncertain. The diversification of the ‘Ametrornis’ clade (P. bourcieri, P. philippii and P. koepckeae) is centred in the Amazon and appears to be closely linked to the formation of the modern Amazon drainage during the Plio‐Pleistocene.     

New insights into the systematics of Malagasy mongoose‐like carnivorans (Carnivora,Eupleridae, Galidiinae) based on mitochondrial and nuclear DNA sequences

The Malagasy carnivorans (Eupleridae) comprise seven genera and up to ten species, depending on the authority, and, within the past decades, two new taxa have been described. The family is divided into two subfamilies, the Galidiinae, mongoose‐like animals, and the Euplerinae, with diverse body forms. To verify the taxonomic status of Galidiinae species, including recently described taxa, as well as some recognized subspecies, we studied intrageneric genetic variation and structure, using both mitochondrial and nuclear markers. Our results suggest the recognition of four species in the Galidiinae, rendering each genus monospecific. We propose to recognize three subspecies in Galidia elegans (G. e. dambrensis, G. e. elegans, and G. e. occidentalis), two subspecies in Mungotictis decemlineata (M. d. decemlineata and M. d. lineata), and two subspecies in Galidictis fasciata (G. f. fasciata and G. f. grandidieri, the latter was recently described as a distinct species). Our results indicate also that Salanoia durrelli should be treated as a junior synonym of Salanoia concolor. Low levels of intraspecific divergence revealed some geographical structure for the Galidiinae taxa, suggesting that environmental barriers have isolated certain populations in recent geological time. All taxa, whether at the species or subspecies level, need urgent conservation attention, particularly those with limited geographical distributions, as all are threatened by forest habitat degradation.     

Molecular and morphological evidences reveal a cryptic species in the Vinaceous Rosefinch Carpodacus vinaceus (Fringillidae; Aves)

Wu, H.‐C., Lin, R.‐C., Hung, H.‐Y., Yeh, C.‐F., Chu, J.‐H., Yang, X.‐J., Yao, C.‐J., Zou, F.‐S., Yao, C.‐T., Li, S.‐H. & Lei, F.‐M. (2011). Molecular and morphological evidences reveal a cryptic species in the Vinaceous Rosefinch Carpodacus vinaceus (Fringillidae; Aves). —Zoologica Scripta, 40, 468–478. The Vinaceous Rosefinch (Carpodacus vinaceus) is endemic in East Asia with two recognized subspecies –C. v. vinaceus, distributed along the eastern edge of the Tibetan Plateau and the Himalayas, and C. v. formosanus, restricted to Taiwan’s Central Mountain Range. As reflected in a controversial taxonomic history, this vastly disjunctive distribution pattern suggests that the subspecies, having been isolated from each other for a long time, might have diverged, challenging the current taxonomic treatment and calling for possible species delimitation. Sequences of two mitochondrial fragments (mtDNA) and two Z‐linked nuclear loci (zDNA) were used to reconstruct the intraspecific phylogeny of C. vinaceous. The mtDNA tree shows that the two subspecies of the vinaceous rosefinch form two exclusively monophyletic clades. All but one zDNA sequences from the nominate subspecies and C. v. formosanus also formed exclusively monophyletic clades (the exceptional zDNA sequence from C. v. vinaceous formed a weakly supported clade with two outgroup species). Moreover, by conducting quantitative comparisons of morphometric traits and male plumage coloration, we found that the two subspecies exhibit distinguishable morphological differences. All the evidence therefore suggests that C. v. formosanus is a cryptic species and that its taxonomic status should be restored to full species. Molecular dating suggests that the two sibling rosefinches split 1.7 ± 0.2 million years ago, providing a point estimate for the historical connectivity of biota between eastern Tibet‐Himalayas and montane Taiwan.     

Conserved shell disguises diversity in Mesodontrachia land snails from the Australian Monsoon Tropics (Gastropoda: Camaenidae)

We comprehensively revise the taxonomy of the camaenid genus Mesodontrachia Solem, 1985, which is endemic to the Victoria River District and East Kimberley in the north‐western Australian Monsoon Tropics based on comparative analyses of key morphological features and mitochondrial DNA sequences. We examined newly collected samples from several collection sites spread over nearly 20 000 km² of mostly inaccessible land, which represented all three currently known and three previously undescribed species. All species were initially identified as members of Mesodontrachia based on their similar, putatively typical shell. However, Mesodontrachia as so delimited was polyphyletic in a mitochondrial phylogeny with respect to several other camaenid genera from NW Australia. Contrary to the shell, we found considerable variation in the penial anatomy that was consistent with the mtDNA differentiation. To retain monophyletic taxa, we propose a revised taxonomy whereby Mesodontrachia is maintained as a monotypic taxon. In addition, four genera (Nodulabium, Ototrachia, Pseudomesodontrachia and Vincentrachia) and three species (P. gregoriana, O. compressa and N. solidum) are newly described. The shell of all these taxa is highly conserved and of little taxonomic utility. Shell similarity is attributed to a similar life style in a similar and harsh environment.     

Unreported yet massive deforestation driving loss of endemic biodiversity in Indian Himalaya

Deforestation is a primary driver of biotic extinctions in the tropics. The impacts of deforestation in tropical biodiversity hotspots are of particular concern because these regions contain high concentrations of globally endemic species. However, the effects of large-scale deforestation on native biotas within the biodiversity hotspot of Himalaya remain poorly documented. Here we report on an alarming trend of deforestation in the Indian Himalaya and project the likely consequential extinctions of endemic taxa (species and subspecies) by 2100 across a broad range of taxonomic groups, including gymnosperms, angiosperms, fishes, amphibians, reptiles, birds, and mammals. With the current level of deforestation, by 2100 only about 10% of the land area of the Indian Himalaya will be covered by dense forest (>40% canopy cover)—a scenario in which almost a quarter of the endemic species could be wiped out, including 366 endemic vascular plant taxa and 35 endemic vertebrate taxa. We also show that inaccurate reporting of forest cover data by governmental institutions can result in underestimations of the biological impacts of deforestation, as well as potential miscalculations in land-use decisions (e.g., the construction of hydroelectric dams). Large-scale conservation efforts, including forest protection and reforestation, are urgently needed to avoid the impending deforestation-driven biodiversity losses in the Himalaya.     

Quantitative comparison of taxa and taxon concepts in the diatom genus Fragilariopsis: a case study on using slide scanning,multiexpert image annotation,and image analysis in taxonomy1

Semiautomated methods for microscopic image acquisition, image analysis, and taxonomic identification have repeatedly received attention in diatom analysis. Less well studied is the question whether and how such methods might prove useful for clarifying the delimitation of species that are difficult to separate for human taxonomists. To try to answer this question, three very similar Fragilariopsis species endemic to the Southern Ocean were targeted in this study: F. obliquecostata, F. ritscheri, and F. sublinearis. A set of 501 extended focus depth specimen images were obtained using a standardized, semiautomated microscopic procedure. Twelve diatomists independently identified these specimen images in order to reconcile taxonomic opinions and agree upon a taxonomic gold standard. Using image analyses, we then extracted morphometric features representing taxonomic characters of the target taxa. The discriminating ability of individual morphometric features was tested visually and statistically, and multivariate classification experiments were performed to test the agreement of the quantitatively defined taxa assignments with expert consensus opinion. Beyond an updated differential diagnosis of the studied taxa, our study also shows that automated imaging and image analysis procedures for diatoms are coming close to reaching a broad applicability for routine use.     

New insights into and limitations of the molecular phylogeny in the taxon-rich land snail genus Montenegrina (Mollusca: Gastropoda: Clausiliidae)

Rock-dwelling gastropods are usually patchily distributed in limestone habitats, presumably have low active and passive dispersal ability and often represent narrow-ranged endemic taxa. Their current taxonomy is predominantly shell morphology based, and it remains unknown whether the morphologically differentiated and geographically separated populations represent phylogenetic clades. In this study, we analysed the hyperdiverse, terrestrial door snail genus Montenegrina. Based on the current taxonomy defined by shell morphology, it contains 29 species and 106 subspecies distributed in the Balkan region. The constructed phylogenetic tree using three mitochondrial markers was used to test whether it agrees with the current taxonomy. In this comprehensive tree, about half of the species and subspecies are monophyletic. Some of the paraphylies could be reasonably resolved by taxonomic changes; that is, some subspecies should be reassigned or raised to species level. Other incongruencies probably arose due to introgression even between distant clades. The histone genes turned out to be unsuitable for elucidating the phylogeny of Montenegrina. In the species-delimitation tests, considerably more molecular operational taxonomic units were delimited than the number of presently described species. The present data indicate that (a) shell morphology-based taxonomy and taxon recognition can be problematic in such a large and morphologically highly variable genus; (b) the potential error due to incomplete sampling presents a problem in a genus as variable as Montenegrina; (c) multi-locus analyses should be conducted to arrive at a better basis for species delimitation; and (d) integrative approaches including genetic as well as morphological/anatomical data from a comprehensive geographic sample are necessary.     

Radiation and speciation of spider monkeys,genus Ateles,from the cytogenetic viewpoint

The chromosomes of 22 animals of four subspecies of the genus Ateles (A. paniscus paniscus, A. p. chamek, A. belzebuth hybridus, and A. b. marginatus) were compared using G/C banding and NOR (nucleolar organizer region) staining methods. The cytogenetic data of Ateles in the literature were also used to clarify the phylogenetic relationships of the species and subspecies and to infer the routes of radiation and speciation of these taxa. Chromosomes 6 and 7 that showed more informative geographic variation and the apomorphic form 4/12, exclusively in A. p. paniscus, are the keys for understanding the evolution, radiation, and specification of the Ateles taxa. The ancestral populations of the genus originated in the southwestern Amazon Basin (the occurrence area of A. paniscus chamek) and spread in the Amazon Basin and westward, crossing the Andes and colonizing Central America and northwesternmost regions of South America. The evolutionary history of the northern South American taxa is interpreted using the model of biogeographical evolution postulated by Haffer [Science 185:131–137, 1969]. Ateles paniscus paniscus is the genetically most differentiated form and probably derives from A. belzebuth hybridus. Based on the karyotype differences, the populations of Ateles can be divided into four different group. These findings indicate the necessity of a more coherent taxonomic arrangement for the taxa of Ateles. Am. J. Primatol. 42:167–178, 1997. © 1997 Wiley-Liss, Inc.     

Two new species of Huberia (Melastomataceae: Merianieae) from Brazil

Two new Brazilian species of the genusHuberia,H. carvalhoi andH. consimilis, are described, discussed, and illustrated.Huberia carvalhoi is endemic to Bahia;H. consimilis has a wider distribution, with disjunct populations in Pernambuco, Bahia, and Rio de Janeiro. A key is provided to the three Bahia taxa with some comments on the taxonomic affinities of the two new species.     

Morphological convergence and molecular divergence: the taxonomic status of Sceloporus serrifer (squamata,phrynosomatidae) subspecies

Martínez‐Méndez, N., Mejía, O., Rocha‐Gómez, A. & Méndez‐De La Cruz, F. R. (2012) Morphological convergence and molecular divergence: the taxonomic status of Sceloporus serrifer (squamata, phrynosomatidae) subspecies. —Zoologica Scripta, 41, 97–108. The systematics of the subspecies included in Sceloporus serrifer has undergone several taxonomic and nomenclatural rearrangements. This species previously comprised two recognized subspecies, Sceloporus serrifer serrifer and Sceloporus serrifer prezygus, which inhabit contrasting habitats. In this study, we re‐evaluate the taxonomic status of both subspecies using molecular and morphological evidence. Sceloporus serrifer serrifer was recovered as a paraphyletic group, whereas S. s. prezygus was recovered as a polyphyletic group. The molecular results indicate the existence of two independent lineages that diverged at least 1.29 Myr, with the populations currently recognized as S. s. prezygus from the Cuchumatanes Mountains representing a secondary invasion of S. s. serrifer from the lowlands. The lack of meristic differences among the highland populations of different species suggests convergence in similar environments achieved by two different lineages.     

Genome-wide nuclear data confirm two species in the Alpine endemic land snail Noricella oreinos s.l. (Gastropoda,Hygromiidae)

The Austrian endemic land snail species Noricella oreinos (formerly Trochulus oreinos) occurs in the Northeastern Calcareous Alps at high elevations. Two morphologically highly similar subspecies N. o. oreinos and N. o. scheerpeltzi have been described. First analyses of mitochondrial and nuclear marker sequences indicated a high genetic divergence between them. In the present study, we aimed to assess gene flow between the two subspecies which should help to re-evaluate their taxonomic status. Sequence data and amplified fragment length polymorphism (AFLP) markers of 255 Noricella specimens covering the whole distribution range were analyzed. A clear geographic separation was found within the potential contact zone, the Haller Mauern mountain range. Samples of all western sites were part of the clade representing N. o. scheerpeltzi and almost all samples from the eastern sites clustered with N. o. oreinos. However, within two sampling sites of the eastern Haller Mauern, a few individuals possessed a COI sequence matching the N. o. oreinos clade whereas at the ITS2 locus they were heterozygous possessing the alleles of both taxa. Contrary to the ITS2 results indicating historical and/or ongoing hybridization, AFLP analyses of 202 individuals confirmed a clear separation of the two taxa congruent with the mitochondrial data. Although they occur on the same mountain range without any physical barrier, no indication of ongoing gene flow between the two taxa was found. Thus, we conclude that the two taxa are separate species N. oreinos and N. scheerpeltzi.     

Molecular phylogeny of Central and South American slider turtles: implications for biogeography and systematics (Testudines: Emydidae: Trachemys)

We analyse phylogeny, systematics and biogeography of slider turtles (Trachemys spp.) using sequence data of four mitochondrial genes (3242 bp) and five nuclear loci (3396 bp) of most South American and southern Central American taxa and representatives of northern Central American, West Indian and North American slider species (16 species and subspecies) and allied North American species (genera Chrysemys, Deirochelys, Graptemys, Malaclemys, Pseudemys). By applying maximum likelihood, relaxed molecular clock and ancestral range analyses, we provide evidence for two successive colonizations of South America by slider turtles. In addition, we show that the current species delineation of Central and South American slider turtles is incorrect. Our data suggest that Trachemys grayi is a distinct polytypic species that embraces, besides the nominotypical subspecies, T. g. emolli and T. g. panamensis. Trachemys ornata is also polytypic with the subspecies T. o. ornata, T. o. callirostris, T. o. cataspila, T. o. chichiriviche and T. o. venusta. Moreover, T. adiutrix should be regarded as a subspecies of T. dorbigni. All studied Trachemys species are inferred to have originated in the Late Miocene to Early Pliocene. The ancestor of the two subspecies of T. dorbigni colonized South America most probably prior to the establishment of the land bridge connecting Central and South America, whereas the two South American subspecies of T. ornata represent a younger independent immigration wave from Central America.     

Cranial and chromosomal geographic variation in manatees (Mammalia: Sirenia: Trichechidae) with the description of the Antillean manatee karyotype in Brazil

We employed landmark‐based 3D geometric morphometrics to assess cranial size and shape diversification in Trichechus manatus and T. inunguis to compare it with patterns among all manatee taxa (T. manatus latirostris, T. m. manatus, T. inunguis and T. senegalensis), and to analyse geographic variation within American manatee populations, using a sample of 189 skulls. Chromosome G‐ and C‐banding techniques were performed in T. m. manatus from Brazil. All taxa were statistically discriminated by skull shape. Trichechus m. manatus and T. m. latirostris have larger skulls than T. inunguis. A morphological discontinuity was noted within T. m. manatus, with the Brazilian population south of the Amazon discriminated from the T. m. manatus Caribbean and T. m. latirostris USA populations. Specimens from Suriname and Guyana had a skull shape more similar to the one from the Caribbean population. The Brazil Antillean manatee population exhibited morphological differences similar in magnitude to those found between the Amazonian and African species. Additionally, structural chromosome differences were detected between that population (chromosome pair 4 is metacentric and 10 is submetacentric) and manatees from Puerto Rico and Florida. Based on such morphological discontinuity and chromosomal divergence, we hypothesize that the Amazon River mouth may be acting as a reproductive barrier for the T. m. manatus population in Brazil, thus indicating that its taxonomic status and conservation strategies need an urgent reassessment.     

Taxonomy of cryptic species in the Cyornis rubeculoides complex in the Indian subcontinent

Taxa classified as subspecies may in fact be cryptic species. We assessed the taxonomic status of the Blue-throated Flycatcher Cyornis rubeculoides complex in India, which consists of several forms with similar plumages and song. We used mitochondrial and nuclear DNA, plumage traits, and detailed song analysis to ascertain the taxonomic status of the different forms. The molecular data identified three primary clades: (1) in the west Himalayan foothills, (2) at higher elevations in the northeast hill states of Meghalaya, Nagaland and Mizoram, and (3) at lower elevations in the northeastern hills of Meghalaya and the east Himalayas of Arunachal Pradesh. The western clade represents nominate C. rubeculoides rubeculoides. The high-elevation eastern clade was considered to be C. rubeculoides rogersi, because it included a sample from this subspecies from near the type locality in southwest Myanmar. These two sister clades had an estimated divergence time of 1.5 million years (my). The low-elevation east clade has previously been assigned to C. rubeculoides, but we showed it is closely related to the Hainan Blue Flycatcher Cyornis hainanus, formerly thought to breed only further east, with an estimated divergence time of only ~0.8 my. This clade may represent a subspecies of C. hainanus or, given reports of widespread sympatry with C. hainanus in Thailand, a distinct species, Cyornis dialilaemus. However, more research is advocated, including molecular data, from the area of overlap. Songs were remarkably similar across all taxa. In playback experiments, C. r. rubeculoides in the west responded to all taxa. This is in agreement with recent work demonstrating that song differences and responses to songs are not always a good indicator of the progress of reproductive isolation.     

Integrative taxonomy of the Rhinolophus macrotis complex (Chiroptera,Rhinolophidae) in Vietnam and nearby regions

The taxonomic status of Rhinolophus macrotis sensu lato (s.l.) in Vietnam and adjacent territories remains problematic. To address this issue, we performed an integrated study of morphological, acoustic, and genetic characters of R. macrotis s.l. specimens and compared these with sympatric species within the philippinensis group (R. marshalli, R. paradoxolophus, and R. rex). Our results reveal that in addition to a cryptic species of R. macrotis previously found in Jiangxi and Jingmen, China, R. macrotis s.l. in continental Asia includes three further species, namely R. cf. siamensis, R. cf. macrotis, and R. cf. macrotis “Phia Oac.” These four taxa are distinguished from genuine R. macrotis in Nepal and R. siamensis in Thailand by their morphological and/or genetic features. Further taxonomic evaluation of the subspecies of R. macrotis s.l. is needed to determine their affinities with recently recognized cryptic species and to possibly describe new taxa. Our results also show that interspecific divergences in mitochondrial DNA sequences (Cytb and COI genes) among taxa within the philippinensis group (particularly between R. cf. siamensis/R. cf. macrotis and R. rex/R. paradoxolophus) are significantly lower than those of other morphological groups in the genus. These phylogenetic patterns might be explained by recent allopatric speciation or ancient introgression events among ancestors of the taxa during the Pleistocene. However, further investigations including genetic analyses of nuclear genes are needed to test the latter hypothesis.     

Delimitation of sympatric Palaemon (Decapoda,Palaemonidae) species of the Laguna Madre,Mexico

Grass shrimps Palaemon mundusnovus, P. pugio and P. vulgaris sympatrically inhabit in the Laguna Madre, Mexico. They exhibit very close morphological similarity and overlap in their diagnostic characteristics, which has hindered certainty in their identification and has raised doubt regarding their taxonomic validity. In this work, we analyse intra‐ and interspecific morphometric and meristic variability through a multivariate analysis, and we determine the molecular variation using mitochondrial sequences of the 12S, 16S and COX1 genes to confirm the validity of the three taxa as having distinct lineages or to recognize a smaller number of species with phenotypic plasticity. Our results corroborate the taxonomic validity of the three species; however, there is intraspecific plasticity, interspecific overlap of characteristics and greater morphological and molecular similarity between the species P. mundusnovus and P. pugio, whereas P. vulgaris was better delimited. These species form a monophyletic group but the phylogenetic relationship obtained is discussed. Telson length was the primary variable in the principal components analysis, whereas the length of the propodus of the second pereiopod was the best discriminant. The range of variation reported in the characteristics linked to the rostrum is extended, and its influence on the separation of these species is recognized. The joint application of multivariate analysis from morphological variables and molecular tools is recommended to clarify the taxonomic status of species featuring close morphological similarity and sympatric distribution.     

Correction to: An update and reassessment of fern and lycophyte diversity data in the Japanese Archipelago

The fern and lycophyte flora of Japan comprising 721 native taxa (including subspecies and varieties) plus 371 interspecific hybrids was reassessed using a nearly comprehensively sampled distribution map at 10 km resolution vouchered by 216,687 specimens, up-to-date cytotaxonomic information covering 74% of the taxa, and an rbcL sequence dataset covering 97.9% of the taxa. Spatial distribution of species richness and phylogenetic diversity was visualized. Apomixis was observed in 11.0% of the native taxa whose reproductive modes are known. The number of sexually reproducing polyploid taxa (n = 199) is less than sexual diploids (n = 241), and 30 of them are evidently allopolyploid, in contrast with the low number of possible autopolyploids (n = 4). Apomictic taxa were found to have smaller latitudinal ranges than sexual taxa or taxa with multiple reproductive modes. A morphological character dataset in Lucid format is provided for taxonomic identification of the native taxa.

     

Diversification in the South American Pampas: the genetic and morphological variation of the widespread Petunia axillaris complex (Solanaceae)

Understanding the spatiotemporal distribution of genetic variation and the ways in which this distribution is connected to the ecological context of natural populations is fundamental for understanding the nature and mode of intraspecific and, ultimately, interspecific differentiation. The Petunia axillaris complex is endemic to the grasslands of southern South America and includes three subspecies: P. a. axillaris, P. a. parodii and P. a. subandina. These subspecies are traditionally delimited based on both geography and floral morphology, although the latter is highly variable. Here, we determined the patterns of genetic (nuclear and cpDNA), morphological and ecological (bioclimatic) variation of a large number of P. axillaris populations and found that they are mostly coincident with subspecies delimitation. The nuclear data suggest that the subspecies are likely independent evolutionary units, and their morphological differences may be associated with local adaptations to diverse climatic and/or edaphic conditions and population isolation. The demographic dynamics over time estimated by skyline plot analyses showed different patterns for each subspecies in the last 100 000 years, which is compatible with a divergence time between 35 000 and 107 000 years ago between P. a. axillaris and P. a. parodii, as estimated with the IMa program. Coalescent simulation tests using Approximate Bayesian Computation do not support previous suggestions of extensive gene flow between P. a. axillaris and P. a. parodii in their contact zone.