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1.
Sci Rep ; 14(1): 5971, 2024 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472297

RESUMO

Recent biological surveys of ancient inselbergs in southern Malawi and northern Mozambique have led to the discovery and description of many species new to science, and overlapping centres of endemism across multiple taxa. Combining these endemic taxa with data on geology and climate, we propose the 'South East Africa Montane Archipelago' (SEAMA) as a distinct ecoregion of global biological importance. The ecoregion encompasses 30 granitic inselbergs reaching > 1000 m above sea level, hosting the largest (Mt Mabu) and smallest (Mt Lico) mid-elevation rainforests in southern Africa, as well as biologically unique montane grasslands. Endemic taxa include 127 plants, 45 vertebrates (amphibians, reptiles, birds, mammals) and 45 invertebrate species (butterflies, freshwater crabs), and two endemic genera of plants and reptiles. Existing dated phylogenies of endemic animal lineages suggests this endemism arose from divergence events coinciding with repeated isolation of these mountains from the pan-African forests, together with the mountains' great age and relative climatic stability. Since 2000, the SEAMA has lost 18% of its primary humid forest cover (up to 43% in some sites)-one of the highest deforestation rates in Africa. Urgently rectifying this situation, while addressing the resource needs of local communities, is a global priority for biodiversity conservation.


Assuntos
Borboletas , Animais , Biodiversidade , África Oriental , Répteis , Florestas , África do Sul , Filogenia , Mamíferos
2.
Mol Phylogenet Evol ; 182: 107747, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36849095

RESUMO

Cladogenic diversification is often explained by referring to climatic oscillations and geomorphic shifts that cause allopatric speciation. In this regard, southern Africa retains a high level of landscape heterogeneity in vegetation, geology, and rainfall patterns. The legless skink subfamily Acontinae occurs broadly across the southern African subcontinent and therefore provides an ideal model group for investigating biogeographic patterns associated with the region. A robust phylogenetic study of the Acontinae with comprehensive coverage and adequate sampling of each taxon has been lacking up until now, resulting in unresolved questions regarding the subfamily's biogeography and evolution. In this study, we used multi-locus genetic markers (three mitochondrial and two nuclear) with comprehensive taxon coverage (all currently recognized Acontinae species) and adequate sampling (multiple specimens for most taxa) of each taxon to infer a phylogeny for the subfamily. The phylogeny retrieved four well-supported clades in Acontias and supported the monophyly of Typhlosaurus. Following the General Lineage Concept (GLC), many long-standing phylogenetic enigmas within Acontias occidentalis and the A. kgalagadi, A. lineatus and A. meleagris species complexes, and within Typhlosaurus were resolved. Our species delimitation analyses suggest the existence of hidden taxa in the A. occidentalis, A. cregoi and A. meleagris species groups, but also suggest that some currently recognized species in the A. lineatus and A. meleagris species groups, and within Typhlosaurus, should be synonymised. We also possibly encountered "ghost introgression" in A. occidentalis. Our inferred species tree revealed a signal of gene flow, which implies possible cross-over in some groups. Fossil evidence calibration dating results showed that the divergence between Typhlosaurus and Acontias was likely influenced by cooling and increasing aridity along the southwest coast in the mid-Oligocene caused by the opening of the Drake Passage. Further cladogenesis observed in Typhlosaurus and Acontias was likely influenced by Miocene cooling, expansion of open habitat, uplifting of the eastern Great Escarpment (GE), and variation in rainfall patterns, together with the effect of the warm Agulhas Current since the early Miocene, the development of the cold Benguela Current since the late Miocene, and their co-effects. The biogeographic pattern of the Acontinae bears close resemblance to that of other herpetofauna (e.g., rain frogs and African vipers) in southern Africa.


Assuntos
Especiação Genética , Lagartos , Animais , Filogenia , África Austral , Ecossistema , Lagartos/genética , Filogeografia
3.
G3 (Bethesda) ; 13(2)2023 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-36524354

RESUMO

Allotetraploid genomes have two distinct genomic components called subgenomes that are derived from separate diploid ancestral species. Many genomic characteristics such as gene function, expression, recombination, and transposable element mobility may differ significantly between subgenomes. To explore the possibility that subgenome population structure and gene flow may differ as well, we examined genetic variation in an allotetraploid frog-the African clawed frog (Xenopus laevis)-over the dynamic and varied habitat of its native range in southern Africa. Using reduced representation genome sequences from 91 samples from 12 localities, we found no strong evidence that population structure and gene flow differed substantially by subgenome. We then compared patterns of population structure in the nuclear genome to the mitochondrial genome using Sanger sequences from 455 samples from 183 localities. Our results provide further resolution to the geographic distribution of mitochondrial and nuclear diversity in this species and illustrate that population structure in both genomes corresponds roughly with variation in seasonal rainfall and with the topography of southern Africa.


Assuntos
Genoma , Metagenômica , Animais , Xenopus laevis/genética , Genômica , África Austral , Evolução Molecular , Filogenia
4.
Zootaxa ; 5124(4): 401-430, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35391113

RESUMO

Here we provide the first phylogenetic analysis that include Afrogecko ansorgii and a detailed morphological comparison with other species of leaf-toed geckos. For this purpose, we used two mitochondrial (16S, ND2) and four nuclear (RAG1, RAG2, CMOS, PDC) genes to produce a robust phylogenetic reconstruction. This allowed us to show that A. ansorgii is not related as previously believed to circum-Indian Ocean leaf-toed geckos and is rather more closely related to other Malagasy leaf-toed geckos. Additionally, we explore and compare osteological variation in A. ansorgii skulls through High Resolution X-ray Computed Tomography with previously published material. This allowed us to describe herein a new genus, Bauerius gen. nov., and additionally provide a detailed redescription of the species (including the first description of male material), supplementing the limited original description and type series, which consisted of only two females.


Assuntos
Lagartos , Angola , Animais , Núcleo Celular/genética , Lagartos/genética , Masculino , Mitocôndrias , Filogenia
5.
Zookeys ; 1127: 91-116, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36760357

RESUMO

We here describe a new species of feather-tailed leaf-toed gecko, Kolekanos, from southern Benguela Province, Angola, based on morphological and osteological evidence, supported by phylogenetic analysis of mitochondrial data. The new species adds to the rapidly growing and newly-recognised endemic biodiversity of Angola, doubling the number of Kolekanos species, breaking the pattern observed within other closely-related African members of a clade of circum-Indian Ocean leaf-toed geckos - Ramigekko, Cryptactites and Afrogecko - all of which are presently monotypic. The new species is easily distinguished from K.plumicaudus, based on spine-like (as opposed to feather-like) scales on the margins of the original tail. Phylogenetic analyses also recovered the new taxon as monophyletic, with a well-supported sister relationship to K.plumicaudus, from which it differs by a substantial 24.1% NADH-dehydrogenase subunit 2 mitochondrial gene uncorrected p-distance.

6.
Zookeys ; 1121: 97-143, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36760759

RESUMO

African Shovel-snout snakes (Prosymna Gray, 1849) are small, semi-fossorial snakes with a unique compressed and beak-like snout. Prosymna occur mainly in the savanna of sub-Saharan Africa. Of the 16 currently recognised species, four occur in Angola: Prosymnaambigua Bocage, 1873, P.angolensis Boulenger, 1915, P.frontalis (Peters, 1867), and P.visseri FitzSimons, 1959. The taxonomical status and evolutionary relationships of P.angolensis have never been assessed due to the lack of genetic material. This species is known to occur from western Angola southwards to Namibia, and eastwards to Zambia, Botswana and Zimbabwe. The species shows considerable variation in dorsal colouration across its range, and with the lower ventral scales count, an 'eastern race' was suggested. In recent years, Prosymna material from different parts of Angola has been collected, and with phylogenetic analysis and High Resolution X-ray Computed Tomography, the taxonomic status of these populations can be reviewed. Strong phylogenetic evidence was found to include the angolensis subgroup as part of the larger sundevalli group, and the existence of three phylogenetic lineages within the angolensis subgroup were identified, which each exhibit clear morphological and colouration differences. One of these lineages is assigned to the nominotypical P.angolensis and the other two described as new species, one of which corroborates the distinct eastern population previously detected. These results reinforce that a considerable part of Angolan herpetological diversity is still to be described and the need for further studies.


ResumoAs cobras-de-focinho-de-pá africanas (Prosymna) são pequenas cobras semi-fossoriais com um focinho único, achatado e em forma de bico, que ocorrem principalmente na savana da África subsaariana. Das 16 espécies actualmente reconhecidas, quatro existem em Angola: Prosymnaambigua Bocage, 1873, P.angolensis Boulenger, 1915, P.frontalis (Peters, 1867), e P.visseri FitzSimons, 1959. O estatuto taxonómico e as relações evolutivas de P.angolensis nunca foram avaliados devido à falta de material genético. A espécie ocorre desde o oeste de Angola, para sul até a Namíbia, e para este em direcção à Zâmbia, Botswana e Zimbábue. Na sua área de ocorrência, esta espécie tem variação principalmente na coloração dorsal, e com base no menor número de escamas ventrais, foi sugerida a existência de uma raça oriental. Recentemente foi amostrado material de Prosymna de várias partes de Angola, e com recurso a análises filogenéticas e a tomografia computadorizada de raios-X de alta resolução, foi possível rever o estatuto taxonómico destas populações. Encontrámos fortes evidências filogenéticas para incluir o subgrupo angolensis como parte do grupo sundevalli. Revelámos a existência de três linhagens filogenéticas no subgrupo angolensis. Atribuímos uma dessas linhagens ao P.angolensis nominotípico, e descrevemos as outras duas como espécies novas, uma das quais corrobora a população oriental previamente detectada. Estes resultados reforçam a ideia de que uma parte considerável da diversidade herpetológica angolana está ainda por descrever, e a necessidade de mais estudos.

7.
Zootaxa ; 5032(1): 1-46, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34811145

RESUMO

The genus Pedioplanis reaches its northernmost limit in western Angola, where it is represented by three species, Pedioplanis benguelensis, P. haackei and P. huntleyi. The taxonomic status of P. benguelensis remains problematic, mainly due to the vague original description and the loss of the original type material. Here we provide a revision of the Angolan representatives of the genus, with the description of a new species, Pedioplanis serodioi sp. nov., from the lowlands of southwestern Angola. Phylogenetic analyses using a combination of mitochondrial (16S and ND2) and nuclear (RAG-1) markers, as well as morphological data, support the recognition of the new species. For purposes of nomenclatural stability, we designate a neotype for P. benguelensis and provide motivation to correct the spelling of the specific epithet to benguelensis. The clarification of the status of P. benguelensis and the description of a new species contribute to a better understanding of the taxonomy and biogeography of the genus Pedioplanis, as well as the general biogeographic context of southwestern Angola, adding to the growing evidence in favor of the recognition of this region as a hotspot of lizard diversity and endemism. An updated key to the genus is also provided.


Assuntos
Lagartos , Animais , Núcleo Celular , Lagartos/genética , Mitocôndrias , Filogenia
8.
Mol Phylogenet Evol ; 161: 107152, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33741534

RESUMO

Phylogenetic relationships of sub-Saharan African natricine snakes are understudied and poorly understood, which in turn has precluded analyses of the historical biogeography of the Seychelles endemic Lycognathophis seychellensis. We inferred the phylogenetic relationships of Seychelles and mainland sub-Saharan natricines by analysing a multilocus DNA sequence dataset for three mitochondrial (mt) and four nuclear (nu) genes. The mainland sub-Saharan natricines and L. seychellensis comprise a well-supported clade. Two maximally supported sets of relationships within this clade are (Limnophis,Natriciteres) and (Afronatrix,(Hydraethiops,Helophis)). The relationships of L. seychellensis with respect to these two lineages are not clearly resolved by analysing concatenated mt and nu data. Analysed separately, nu data best support a sister relationship of L. seychellensis with (Afronatrix,(Hydraethiops,Helophis)) and mt data best support a sister relationship with all mainland sub-Saharan natricines. Methods designed to cope with incomplete lineage sorting strongly favour the former hypothesis. Genetic variation among up to 33 L. seychellensis from five Seychelles islands is low. Fossil calibrated divergence time estimates support an overseas dispersal of the L. seychellensis lineage to the Seychelles from mainland Africa ca. 43-25 million years before present (Ma), rather than this taxon being a Gondwanan relic.


Assuntos
Colubridae/genética , Evolução Molecular , Filogenia , Filogeografia , África Subsaariana , Animais , Análise de Sequência de DNA , Seicheles
9.
Zootaxa ; 5081(3): 301-332, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-35391006

RESUMO

A new species of red toad, from the previously monotypic genus Schismaderma, is described. The new species was found in Malanje Province, and seems endemic to central Angola, occurring approximately 500 km west of the closest known records of Schismaderma carens. Unusual adult colouration and geographical distance to remaining S. carens populations suggested specific differentiation. In an integrative approach, we compared the red toads from central Angola with S. carens from across the entire range, including molecular data, morphology of adults and tadpoles, and male advertisement calls. Phylogenetic analysis based on mitochondrial (12S, 16S, COI) and nuclear (CXCR4, RAG1) markers, retrieved the Angolan clade as monophyletic, and revealed intra-specific substructuring among the remaining Schismaderma. Genetic distances supported specific differentiation of the central Angolan material compared with other S. carens. Adults from the new Angolan species have bolder ventral patterning and smaller body size than S. carens. No obvious differences were detected between the tadpoles and the advertisement calls of the two Schismaderma species. This discovery adds to the knowledge of the herpetofauna of the Angolan Miombo woodlands, a poorly understood ecoregion, and likely more biodiverse than previously assumed. The result of past river basin dynamics in central Angola likely led to the evolution of this new species of Schismaderma.


Assuntos
Bufonidae , Rios , Angola , Animais , Bufonidae/genética , Larva/genética , Masculino , Filogenia
10.
Zookeys ; 979: 133-160, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33192134

RESUMO

Recent molecular phylogenetic work has found that Breviceps Merrem, 1820 comprises two major clades, one of which, the B. mossambicus group, is widely distributed across southern sub-Saharan Africa. This group is notable for harboring abundant cryptic diversity. Of the four most recently described Breviceps species, three are members of this group, and at least five additional lineages await formal description. Although Breviceps has long been known to occur in Angola, no contemporary material has been collected until recently. The three most widespread taxa, B. adspersus, B. mossambicus, and B. poweri, may all occur in Angola, but accurate species assignment remains challenging given the rampant morphological similarity between these taxa, and, until recently, the lack of genetic resources. Phylogenetic, morphological, and acoustic analyses of recently collected samples from disparate localities within Angola provide evidence for an undescribed species that is sister to B. poweri. The new species can be diagnosed from its sister taxon by lacking pale spots along the flanks, a pale patch above the vent, and a short, dark band below the nares (all present in B. poweri). Additionally, the male advertisement call differs from the three other Breviceps that might occur in Angola in having both a longer interval between consecutive calls and a higher average dominant frequency. We here describe this lineage as a distinct species, currently only known from Angola, and discuss the presence of other Breviceps taxa within Angola.


ResumoInvestigações moleculares recentes revelaram que o género Breviceps Merrem, 1820, é composto por duas linhagens principais, uma das quais, o grupo B. mossambicus, é amplamente distribuído na região sul da África subsaariana. Este grupo é notável por albergar uma abundante diversidade críptica. Das quatro espécies de Breviceps recentemente descritas, três pertencem a este grupo, e pelo menos outras cinco linhagens adicionais aguardam a sua descrição formal. Apesar de o género ser conhecido de Angola desde há muito tempo, só muito recentemente foram colhidos novos espécimes. Os três taxa mais amplamente distribuídos, B. adspersus, B. mossambicus e B. poweri podem todos, porventura, ocorrer em Angola, no entanto a correta identificação destas espécies têm sido problemática devido às semelhanças morfológicas extremas entre este taxa, e, até muito recente, a completa ausência de material genético. Análises filogenéticas, morfológicas e acústicas dos espécimes recentemente colhidos em diferentes locais de Angola apontam para a existência de uma espécie nova para a ciência, irmã de B. poweri. A nova espécie pode ser diferenciada do seu táxon irmão pela falta de marcas pálidas nos flancos, mancha pálida acima do ventre e pequena banda negra abaixo do nariz (presentes em B. poweri). Para além destas características, o chamamento dos machos difere das outras três espécies de Breviceps que podem ocorrer em Angola por ter um maior intervalo entre chamamentos consecutivos e uma maior frequência média dominante. Descrevemos aqui esta linhagem como uma espécie distinta, atualmente apenas conhecida de Angola, e discutimos a presença de outras espécies de Breviceps em Angola.

11.
Zootaxa ; 4576(1): zootaxa.4576.1.1, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31715772

RESUMO

The Port Elizabeth Museum herpetology collection contains 407 type specimens, representing 70 primary and 55 secondary squamate types. The type series comprise 93 African taxa (84 lizards and 9 snakes), of which 75 are still regarded as valid. It is the third largest primary reptile type collection in Africa. This is the first catalogue of this important African squamate type collection. It provides the original name, original publication date, journal volume number and pagination, reference to illustrations, current name, museum collection number, type locality, and notes on the status of all types and important additional non-type material mentioned in historical descriptions. Photographs of all primary types, as well as original illustrated material are provided.


Assuntos
Lagartos , Animais , Museus , Serpentes , África do Sul
12.
Zootaxa ; 4646(3): zootaxa.4646.3.6, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31717005

RESUMO

A new species of tree snake Dipsadoboa montisilva Branch, Conradie Tolley sp. nov. (Serpentes: Colubridae) is described from the 'sky islands' of Mount Mabu and Mount Ribáuè in northern Mozambique. Features of scalation, colour, body form and habitat distinguish the new species from other Dipsadoboa. This is supported by a phylogenetic analysis using one mitochondrial marker (cytochrome b) that shows the new Mozambican species is divergent from other sampled Dipsadoboa, including D. flavida and D. aulica, the only congeners known to occur in Mozambique. Morphologically, the new Dipsadoboa forms part of the D. werneri-shrevei complex from east and southeast Africa, but differs in having higher subcaudal counts, a different temporal pattern and only two supralabials entering the orbit. Phylogenetically, it occurs in a clade with D. shrevei and D. werneri. The status of D. shrevei in East Africa is reassessed, particularly in terms of the poorly-known Dipsadoboa shrevei kageleri from northern Tanzania. It is morphologically well defined from D. shrevei shrevei and utilises a different habitat. Although based on limited genetic data, it appears to be well-defined from typical D. shrevei and is accordingly raised to specific status. The only Tanzanian record for typical D. shrevei from Mtene, Rondo Plateau in southeast Tanzania is well isolated from the species' range to the west (e.g. Zambia, Angola) and the published scalation features, particularly ventral counts, do not fully accord with D. shrevei. The Rondo Plateau population is treated as Dipsadoboa incerta sedis, and because we return D. shrevei to its binomial status, we can no longer consider D. shrevei as occurring in Tanzania. Biogeographically, the Rondo Plateau population may have a stronger affinity to the new Mozambican species. The discovery of isolated populations of the new species in mid-altitude forest remnants on Mt Mabu and Mt Ribáuè emphasizes the high conservation importance of the Mozambique forest 'sky islands' from which numerous other endemic new species have been recently discovered. These species are impacted by ongoing habitat destruction through slash and burn clearing for subsistence agriculture.


Assuntos
Colubridae , Angola , Animais , Florestas , Ilhas , Moçambique , Filogenia , Tanzânia , Zâmbia
13.
Syst Biol ; 68(6): 859-875, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31140573

RESUMO

Theory predicts that sexually dimorphic traits under strong sexual selection, particularly those involved with intersexual signaling, can accelerate speciation and produce bursts of diversification. Sexual dichromatism (sexual dimorphism in color) is widely used as a proxy for sexual selection and is associated with rapid diversification in several animal groups, yet studies using phylogenetic comparative methods to explicitly test for an association between sexual dichromatism and diversification have produced conflicting results. Sexual dichromatism is rare in frogs, but it is both striking and prevalent in African reed frogs, a major component of the diverse frog radiation termed Afrobatrachia. In contrast to most other vertebrates, reed frogs display female-biased dichromatism in which females undergo color transformation, often resulting in more ornate coloration in females than in males. We produce a robust phylogeny of Afrobatrachia to investigate the evolutionary origins of sexual dichromatism in this radiation and examine whether the presence of dichromatism is associated with increased rates of net diversification. We find that sexual dichromatism evolved once within hyperoliids and was followed by numerous independent reversals to monochromatism. We detect significant diversification rate heterogeneity in Afrobatrachia and find that sexually dichromatic lineages have double the average net diversification rate of monochromatic lineages. By conducting trait simulations on our empirical phylogeny, we demonstrate that our inference of trait-dependent diversification is robust. Although sexual dichromatism in hyperoliid frogs is linked to their rapid diversification and supports macroevolutionary predictions of speciation by sexual selection, the function of dichromatism in reed frogs remains unclear. We propose that reed frogs are a compelling system for studying the roles of natural and sexual selection on the evolution of sexual dichromatism across micro- and macroevolutionary timescales.


Assuntos
Anuros/classificação , Filogenia , Pigmentação , África , Animais , Anuros/fisiologia , Evolução Biológica , Feminino , Masculino , Caracteres Sexuais
14.
Mol Phylogenet Evol ; 136: 183-195, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30965125

RESUMO

Trachylepis (Mabuyinae) includes ∼80 species of fully-limbed skinks found primarily in Africa and Madagascar, but a robust species-level phylogeny for this genus is lacking and this impedes studies on a wide-range of topics from biogeography to character evolution. Trachylepis and its close relatives (which together form the Mabuya group or Mabuyinae) are notable in that they have undergone multiple transitions and remarkable specializations in their reproductive modes. A Trachylepis phylogeny will be particularly useful for investigating reproductive evolution, because it includes species that exhibit oviparity, viviparity, and bimodal parity (species with both oviparous and viviparous populations). We sequenced DNA at four mitochondrial and five nuclear loci for 67 (∼84% of) Trachylepis species to infer a phylogeny for this genus. We performed stochastic character mapping of parity mode under a variety of parity mode transition models to infer ancestral parity mode states and the number and type of parity mode transitions. We recovered a strongly supported phylogeny of Trachylepis that is generally consistent with earlier phylogenetic studies. The best-fit model of reproductive mode evolution supports an oviparous ancestor for Trachylepis, and supports at least three viviparity to oviparity transitions. We compared parity mode evolution under the overall best-fit model (no constraints on parity mode transitions) to the best-fit model among the subset of models that assume viviparity to oviparity transitions are impossible. Our results support a model of reproductive evolution that allows for reversibility from viviparity to oviparity, a process that is not generally accepted. Alternatively, the best-fit model of evolution among the set of models that eliminate reversals from viviparity to oviparity suggests that bimodal reproduction may have persisted for millions of years within multiple lineages.


Assuntos
Lagartos/classificação , Filogenia , África , Animais , Sequência de Bases , Feminino , Loci Gênicos , Geografia , Lagartos/genética , Madagáscar , Reprodução/fisiologia , Especificidade da Espécie , Processos Estocásticos , Temperatura
15.
PLoS One ; 14(4): e0214889, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30995262

RESUMO

Atractaspidines are poorly studied, fossorial snakes that are found throughout Africa and western Asia, including the Middle East. We employed concatenated gene-tree analyses and divergence dating approaches to investigate evolutionary relationships and biogeographic patterns of atractaspidines with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). We sampled 91 individuals from both atractaspidine genera (Atractaspis and Homoroselaps). Additionally, we used ancestral-state reconstructions to investigate fang and diet evolution within Atractaspidinae and its sister lineage (Aparallactinae). Our results indicated that current classification of atractaspidines underestimates diversity within the group. Diversification occurred predominantly between the Miocene and Pliocene. Ancestral-state reconstructions suggest that snake dentition in these taxa might be highly plastic within relatively short periods of time to facilitate adaptations to dynamic foraging and life-history strategies.


Assuntos
Viperidae/classificação , Viperidae/genética , Estruturas Animais/anatomia & histologia , Estruturas Animais/fisiologia , Animais , Citocromos b/genética , Evolução Molecular , Genes Mitocondriais , Genes RAG-1 , Genes mos , NADH Desidrogenase/genética , Filogenia , Comportamento Predatório , RNA Ribossômico 16S/genética , Fatores de Tempo , Viperidae/fisiologia
16.
Mol Phylogenet Evol ; 130: 357-365, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30366085

RESUMO

The African green and bush snakes of the genus Philothamnus currently comprises 21 species and three subspecies and occurs throughout sub-Saharan Africa. The genus has been the subject of previous taxonomic revisions based on traditional morphological characters and limited genetic assessment, and may not reflect their evolutionary history. Indeed, previous findings based on phylogenetics show discordant results of interspecific relationships and question the monophyly of the genus, although taxon sampling has been limited to date. We investigated phylogenetic affinities within Philothamnus with more inclusive genetic and geographical sampling, with the aim of better understanding their evolutionary history, so that future taxonomic revision of Philothamnus can be better informed. Species relationships were examined within a phylogenetic context and sampling included 133 ingroup samples from 16 taxa. Phylogenies were constructed in Bayesian and likelihood frameworks using three mitochondrial (16S, cyt b and ND4) and two nuclear (c-mos and RAG1) markers. Competing hypotheses relating to the monophyly of the genus were tested with a Shimodaira-Hasegawa test. To examine species boundaries, Bayesian General Mixed Yule-Coalescent Model and multi-rate Poisson Tree Processes analyses were conducted. In addition, a barcoding approach was used to further clarify species-level relationships by comparing frequency distributions between intra- and interspecific sequence divergence. The genus was recovered as monophyletic; however, species-delimitation results suggest that the current taxonomy does not reflect the evolutionary history of this group. For example, Philothamnus s. semivariegatus is paraphyletic, with at least four distinct clades. Philothamnus carinatus consists of two cryptic (sister) lineages from Central and West Africa that are deeply divergent, suggesting a long history of isolation between those regions. Furthermore, the subspecies P. n. natalensis and P. n. occidentalis show strong support for species-level divergence, which reflects their morphological and ecological differences. Accordingly, we elevate P. occidentalisnov. comb. to a full species. A fully informed taxonomic revision of these taxa will require additional morphological and ecological data for corroboration, but it seems that the morphological characters (e.g. scalation, dentition) used to describe these species to date are labile within and between species. This most likely has clouded our understanding of the species boundaries within the genus. Our phylogeny and species-delimitation analyses should provide a sounder framework for taxonomy, but may also prove useful toward understanding the morphological adaptations of these species to their respective habitats.


Assuntos
Colubridae/genética , Variação Genética , África Ocidental , Animais , Teorema de Bayes , Geografia , Funções Verossimilhança , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie
17.
Zootaxa ; 4706(2): zootaxa.4706.2.3, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-32230541

RESUMO

Historically Panaspis wahlbergi (Smith, 1849) has been the only assignable species present in Kenya. Recent studies have shown that it comprises multiple cryptic species and the nominal species is now restricted to southern Africa. Newly collected mitochondrial data (16S rRNA) helped to resolve the status of the Kenyan populations, which revealed the presence of two distant related species. Pairwise distances show average 5.87% differences between the two Kenyan species, and 3.58-5.27% and 8.62-9.15% to nominal P. wahlbergi and P. maculicollis Jacobsen Broadley, 2000 respectively. Ablepharus massaiensis Angel, 1924 was described from the Maasai plains near Nairobi, but has long been considered a junior synonym of P. wahlbergi. We herein resurrect Panaspis massaiensis comb. nov. as a valid species and describe a new species, Panaspis tsavoensis sp. nov. from the Tsavo Conservation Area in south-eastern Kenya. Morphological examinations of specimens reveal minor differences from each other as well as nominal forms of P. wahlbergi and P. maculicollis. Panaspis massaiensis comb. nov. shares with the P. wahlbergi group a white ventrolateral stripe but can be distinguished by the presence of 26 midbody scale rows versus 24. Panaspis tsavoensis sp. nov. on the other hand, lacks the white ventrolateral stripe, most similar to the P. maculicollis group but differs in that P. maculicollis breeding males have a black patch on the neck with diagonal rows of white spots. Panaspis massaiensis comb. nov. is widespread in the Kenyan and northern Tanzanian highlands, isolated dryland montane forests and rocky hills, while P. tsavoensis sp. nov. occur in the expansive arid lowlands of Tsavo Conservation Area and should be present in similar arid lowlands in northern Kenya as well as in adjacent Tanzania.


Assuntos
Lagartos , Animais , Quênia , Masculino , Filogenia , RNA Ribossômico 16S
18.
Zootaxa ; 4429(1): 89-106, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-30313280

RESUMO

The African genus of fossorial legless lizards (Acontias Cuvier) currently comprises 26 species and subspecies. In a recent study on the two disjunct populations of Acontias breviceps Essex, the presence of cryptic species was discovered. Here, we increase the sampling size and describe these disjunct populations from the Mpumalanga Escarpment of South Africa as new species. The new species differ from congeners based on a combination of factors, including the number of midbody, ventral, and subcaudal scale counts, ventral pigmentation, allopatric distributions, and genetic divergences. The new species are genetically distant from nominal A. breviceps, with which it shares overall pigmentation and scalation. The new description adds to the growing number of Mpumalanga escarpment endemic reptiles, and highlights the area as a biodiversity hotspot. The use of vertebral counts as a distinguishing character between species is briefly discussed.


Assuntos
Lagartos , Filogenia , Animais , Biodiversidade , África do Sul
19.
Zootaxa ; 4379(2): 177-198, 2018 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-29689983

RESUMO

A new species of African reed frog (genus Hyperolius Rapp, 1842) is described from the Coastal Forests of the Eastern Africa Biodiversity Hotspot in northeastern Mozambique. It is currently only known from less than ten localities associated with the Mozambican coastal pans system, but may also occur in the southeastern corner of Tanzania. Phylogenetic reconstructions using the mitochondrial 16S marker revealed that it is the sister taxon of Hyperolius mitchelli (>5.6% 16S mtDNA sequence divergence) and forms part of a larger H. mitchelli complex with H. mitchelli and H. rubrovermiculatus. The new species is distinguished from other closely related Hyperolius species by genetic divergence, morphology, vocalisation, and dorsal colouration.


Assuntos
Anuros , Animais , DNA Mitocondrial , Florestas , Moçambique , Filogenia , Tanzânia
20.
Mol Phylogenet Evol ; 127: 288-303, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29551523

RESUMO

Members of the snake subfamily Aparallactinae occur in various habitats throughout sub-Saharan Africa. The monophyly of aparallactine snakes is well established, but relationships within the subfamily are poorly known. We sampled 158 individuals from six of eight aparallactine genera in sub-Saharan Africa. We employed concatenated gene-tree analyses, divergence dating approaches, and ancestral-area reconstructions to infer phylogenies and biogeographic patterns with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). As a result, we uncover several cryptic lineages and elevate a lineage of Polemon to full species status. Diversification occurred predominantly during the Miocene, with a few speciation events occurring subsequently in the Pliocene and Pleistocene. Biogeographic analyses suggested that the Zambezian biogeographic region, comprising grasslands and woodlands, facilitated radiations, vicariance, and dispersal for many aparallactines. Moreover, the geographic distributions of many forest species were fragmented during xeric and cooler conditions, which likely led to diversification events. Biogeographic patterns of aparallactine snakes are consistent with previous studies of other sub-Saharan herpetofauna.


Assuntos
Clima Desértico , Lagartos/anatomia & histologia , Lagartos/classificação , Filogenia , Filogeografia , África Subsaariana , Animais , DNA Mitocondrial/genética , Funções Verossimilhança , Lagartos/genética , Serpentes/anatomia & histologia , Serpentes/genética
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