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1.

Background

The Astrophorida (Porifera, Demospongiae p) is geographically and bathymetrically widely distributed. Systema Porifera currently includes five families in this order: Ancorinidae, Calthropellidae, Geodiidae, Pachastrellidae and Thrombidae. To date, molecular phylogenetic studies including Astrophorida species are scarce and offer limited sampling. Phylogenetic relationships within this order are therefore for the most part unknown and hypotheses based on morphology largely untested. Astrophorida taxa have very diverse spicule sets that make them a model of choice to investigate spicule evolution.

Methodology/Principal Findings

With a sampling of 153 specimens (9 families, 29 genera, 89 species) covering the deep- and shallow-waters worldwide, this work presents the first comprehensive molecular phylogeny of the Astrophorida, using a cytochrome c oxidase subunit I (COI) gene partial sequence and the 5′ end terminal part of the 28S rDNA gene (C1-D2 domains). The resulting tree suggested that i) the Astrophorida included some lithistid families and some Alectonidae species, ii) the sub-orders Euastrophorida and Streptosclerophorida were both polyphyletic, iii) the Geodiidae, the Ancorinidae and the Pachastrellidae were not monophyletic, iv) the Calthropellidae was part of the Geodiidae clade (Calthropella at least), and finally that v) many genera were polyphyletic (Ecionemia, Erylus, Poecillastra, Penares, Rhabdastrella, Stelletta and Vulcanella).

Conclusion

The Astrophorida is a larger order than previously considered, comprising ca. 820 species. Based on these results, we propose new classifications for the Astrophorida using both the classical rank-based nomenclature (i.e., Linnaean classification) and the phylogenetic nomenclature following the PhyloCode, independent of taxonomic rank. A key to the Astrophorida families, sub-families and genera incertae sedis is also included. Incongruences between our molecular tree and the current classification can be explained by the banality of convergent evolution and secondary loss in spicule evolution. These processes have taken place many times, in all the major clades, for megascleres and microscleres.  相似文献   

2.
Freshwater sponges include six extant families which belong to the suborder Spongillina (Porifera). The taxonomy of freshwater sponges is problematic and their phylogeny and evolution are not well understood. Sequences of the ribosomal internal transcribed spacers (ITS1 and ITS2) of 11 species from the family Lubomirskiidae, 13 species from the family Spongillidae, and 1 species from the family Potamolepidae were obtained to study the phylogenetic relationships between endemic and cosmopolitan freshwater sponges and the evolution of sponges in Lake Baikal. The present study is the first one where ITS1 sequences were successfully aligned using verified secondary structure models and, in combination with ITS2, used to infer relationships between the freshwater sponges. Phylogenetic trees inferred using maximum likelihood, neighbor-joining, and parsimony methods and Bayesian inference revealed that the endemic family Lubomirskiidae was monophyletic. Our results do not support the monophyly of Spongillidae because Lubomirskiidae formed a robust clade with E. muelleri, and Trochospongilla latouchiana formed a robust clade with the outgroup Echinospongilla brichardi (Potamolepidae). Within the cosmopolitan family Spongillidae the genera Radiospongilla and Eunapius were found to be monophyletic, while Ephydatia muelleri was basal to the family Lubomirskiidae. The genetic distances between Lubomirskiidae species being much lower than those between Spongillidae species are indicative of their relatively recent radiation from a common ancestor. These results indicated that rDNA spacers sequences can be useful in the study of phylogenetic relationships of and the identification of species of freshwater sponges.  相似文献   

3.
4.
Molossidae is a large (roughly 100 species) pantropically distributed clade of swift aerially insectivorous bats for which the phylogeny remains relatively unknown and little studied compared with other speciose groups of bats. We investigated phylogenetic relationships among 62 species, representing all extant molossid genera and most of the subgenera, using 102 morphological characters from the skull, dentition, postcrania, external morphology, tongue, and penis, based on direct observation and literature reports. Both parsimony and Bayesian analyses were used in phylogenetic reconstruction. Our analysis supports two main clades of molossids, both of which mingle Old World and New World taxa. One clade is comprised of Mormopterus,Platymops, Sauromys, Neoplatymops, Molossops, Cynomops, Cheiromeles, Molossus, and Promops. The other clade includes Tadarida, Otomops, Nyctinomops, Eumops, Chaerephon, and Mops. The position of Myopterus with respect to these two groups is unclear. As in other recent analyses, we find that several genera do not appear to be monophyletic (e.g. Tadarida, Chaerephon, and Molossops sensu lato). We recommend that the subgenera of Molossops sensu lato and Austronomus be recognized at the generic level. We conclude that much more data are needed to investigate lower level problems (generic monophyly and relationships within genera) and to resolve the higher‐level branching pattern of the family.  相似文献   

5.
Abstract Nuclear-encoded SSU rDNA sequences have been obtained from 64 strains of conjugating green algae (Zygnemophyceae, Streptophyta, Viridiplantae). Molecular phylogenetic analyses of 90 SSU rDNA sequences of Viridiplantae (inciuding 78 from the Zygnemophyceae) were performed using complex evolutionary models and maximum likelihood, distance, and maximum parsimony methods. The significance of the results was tested by bootstrap analyses, deletion of long-branch taxa, relative rate tests, and Kishino–Hasegawa tests with user-defined trees. All results support the monophyly of the class Zygnemophyceae and of the order Desmidiales. The second order, Zygnematales, forms a series of early-branching clades in paraphyletic succession, with the two traditional families Mesotaeniaceae and Zygnemataceae not recovered as lineages. Instead, a long-branch Spirogyra/Sirogonium clade and the later-diverging Netrium and Roya clades represent independent clades. Within the order Desmidiales, the families Gonatozygaceae and Closteriaceae are monophyletic, whereas the Peniaceae (represented only by Penium margaritaceum) and the Desmidiaceae represent a single weakly supported lineage. Within the Desmidiaceae short internal branches and varying rates of sequence evolution among taxa reduce the phylogenetic resolution significantly. The SSU rDNA-based phylogeny is largely congruent with a published analysis of the rbcL phylogeny of the Zygnemophyceae (McCourt et al. 2000) and is also in general agreement with classification schemes based on cell wall ultrastructure. The extended taxon sampling at the subgenus level provides solid evidence that many genera in the Zygnemophyceae are not monophyletic and that the genus concept in the group needs to be revised.  相似文献   

6.
A cladistic analysis was conducted to test the monophyly of Eschweilera and Lecythis as well as to examine the relationships of these two genera and their close relatives Bertholletia and Corythophora. The study included 86 species, representing all four genera and covering the range of taxonomic and morphological variation in the genera. The data matrix included 49 parsimony-informative characters derived from vegetative, floral, fruit, and seed morphology and anatomy. The results based on the consensus of all most parsimonious trees indicate that Bertholletia, Corythophora, Eschweilera, and Lecythis form a clade supported by brachyparacytic stomata, the absence of pedicels (with subsequent reversals in several clades), a two or four-locular ovary, the presence of an aril, and the absence of cotyledons. Within the clade, the monophyly of Corythophora is supported by the presence of inflorescence scales and the absence of nectar. Eschweilera is monophyletic only if E. congestiflora and E. simiorum are excluded. The monophyly of Eschweilera is supported by the presence of a two-locular ovary. Lecythis is not monophyletic, but sections Corrugata, Pisonis, and Poiteaui are monophyletic. Three species of section Lecythis are more closely related to Eschweilera, and other species of section Lecythis along with Bertholletia excelsa remain as unresolved.  相似文献   

7.
Despite the well-supported Macroscelidea phylogeny proposed at the end of the 1960s, several systematic arrangements have been suggested in the last 20 years, raising doubts about the phylogeny of the Macroscelidinae; sengi inter-specific relationships are still debated to this day. The main issue of concern involves the supposed Elephantulus diphyly. To solve this persisting debate about sengi phylogeny, we examined the cranium ventral surface of 13 species using geometric morphometric techniques and neighbour-joining algorithms. This study supported the idea that the ventral side of the sengi cranium has the potential to provide important signals for reconstructing the Macroscelidea phylogeny. The phylogenetic signals seemed to differentiate between two major clades in the sengi radiation. In the first clade, the two monospecific genera (Petrodromus and Macroscelides), the two African Horn species (Elephantulus revoilii and E. rufescens), and the only North African species (E. rozeti) were clustered together. The second clade includes the remnant south-central African Elephantulus species. Our results were in agreement with both mitochondrial and nuclear data, confirmed that there is no Elephantulus monophyly and highlighted the close relationship between Petrodromus and E. rozeti. It appears that all the soft-furred sengi species are organised in two evolutionary lines: an old monophyletic clade, comprising only Elephantulus species, and a new polyphyletic clade, including P. tetradactylus, M. proboscideus, and E. rozeti. This requires a taxonomic and nomenclatural rearrangement within Macroscelidinae, where the phylogenetic position of the remnant 4 (of 12) Elephantulus species has yet to be fully defined.  相似文献   

8.
Despite their role in marine systems, Sergestidae remain one of the most poorly understood families amongst planktonic shrimps with regard to phylogeny. Recent morphological and phylogenetic revisions of a number of sergestid genera have disentangled classificatory problems and emphasized the importance of reproductive structures for the taxonomy and phylogeny of the Sergestidae. Only three genera, Acetes, Peisos, and Sicyonella, remain unrevised phylogenetically. We undertook a phylogenetic analysis of these groups based on 124 morphological characters (120 binary, four multistate). Eighteen new characters were based on scanning electron microscopy studies of the clasping organ and petasma. The phylogenetic analysis revealed statistically supported monophyly of the clades Sicyonella and Acetes + Peisos. We combine Peisos and Acetes into a monophyletic genus Acetes, give emended diagnoses and keys to all species of Sicyonella and Acetes, and discuss morphological trends within these genera. We present maps of geographical distribution for all valid species of Acetes. © 2015 The Linnean Society of London  相似文献   

9.
Bayesian and maximum‐likelihood (ML) analyses of the combined multigene data (nuclear SSU rDNA, and plastid SSU and LSU rDNA) were conducted to evaluate the phylogeny of photosynthetic euglenoids. The combined data set consisted of 108 strains of photosynthetic euglenoids including a colorless sister taxon. Bayesian and ML analyses recovered trees of almost identical topology. The results indicated that photosynthetic euglenoids were divided into two major clades, the Euglenaceae clade (Euglena, Euglenaria, Trachelomonas, Strombomonas, Monomorphina, Cryptoglena, Colacium) and the Phacaceae clade (Phacus, Lepocinclis, Discoplastis). The Euglenaceae clade was monophyletic with high support and subdivided into four main clades: the Colacium, the Strombomonas and Trachelomonas, the Cryptoglena and Monomorphina, and the Euglena and Euglenaria clades. The genus Colacium was positioned at the base of the Euglenaceae and was well supported as a monophyletic lineage. The loricate genera (Strombomonas and Trachelomonas) were located at the middle of the Euglenaceae clade and formed a robust monophyletic lineage. The genera Cryptoglena and Monomorphina also formed a well‐supported monophyletic clade. Euglena and the recently erected genus Euglenaria emerged as sister groups. However, Euglena proxima branched off at the base of the Euglenaceae. The Phacaceae clade was also a monophyletic group with high support values and subdivided into three clades, the Discoplastis, Phacus, and Lepocinclis clades. The genus Discoplastis branched first, and then Phacus and Lepocinclis emerged as sister groups. These genera shared a common characteristic, numerous small discoid chloroplasts without pyrenoids. These results clearly separated the Phacaceae clade from the Euglenaceae clade. Therefore, we propose to limit the family Euglenaceae to the members of the Euglena clade and erect a new family, the Phacaceae, to house the genera Phacus, Lepocinclis, and Discoplastis.  相似文献   

10.
Haukisalmi, V., Wickström, L. M., Henttonen, H., Hantula, J. & Gubányi, A. (2004). Molecular and morphological evidence for multiple species within Paranoplocephala omphalodes (Cestoda, Anoplocephalidae) in Microtus voles (Arvicolinae). —Zoologica Scripta, 33, 277–290. The present study was designed to test the hypothesis that the anoplocephalid cestode Paranoplocephala omphalodes (Hermann, 1783), a Holarctic parasite of Microtus voles, is a complex of host‐specific species, rather than a single host‐generalist species, using uni‐ and multivariate morphometrics and DNA sequence data from the mitochondrial cytochrome oxidase I gene. The phylogenetic methods applied to the mtDNA sequence data showed consistently that the cestodes morphologically recognizable as P. omphalodes include four well‐supported monophyletic groups, representing at least three distinct, largely host‐specific species. Multivariate morphometrics (discriminant analysis) successfully distinguished the four main mtDNA clades of P. omphalodes‐like cestodes. The true P. omphalodes is shown to be a parasite of Microtus arvalis, M. agrestis and Clethrionomys glareolus in Europe. Microtus oeconomus harbours two host‐specific, allopatric and possibly conspecific clades, one with a Holarctic and another with an (eastern) Beringian (Alaskan) distribution. The eastern Beringian endemic M. miurus is also parasitized with a host‐specific, morphologically divergent species of Paranoplocephala. The cestode clades recognized in M. oeconomus and M. miurus represent 2–3 undescribed species. Molecular phylogenetic analyses supported the monophyly of the ‘northern clade’ of Paranoplocephala spp., an assemblage including P. kalelai from Clethrionomys spp., P. macrocephala from Microtus spp. and all clades of P. omphalodes‐like cestodes except those representing the true P. omphalodes from Europe. The intra‐ and interspecific phylogeny within the northern clade is compared tentatively with the known evolutionary history of the hosts.  相似文献   

11.
A phylogenetic analysis based on 58 morphological characters including 18 species representing 14 genera over the 15 currently known in Darnini (Hemiptera: Membracidae) confirms the monophyly of this tribe. This result is particularly supported by the presence of cucullate setae on the ventral side of the femora. Two sister clades are inferred: the clade Funkhouseriana+ which groups four genera (Aspona, Cyphotes, Funkhouseriana, Taunaya) and exhibits a ‘bird dropping’ habitus and all other genera which exhibit a ‘dewdrop’ like habitus (Alobia, Darnis, Dectonura, Hebetica, Hebeticoides, Leptosticta, Ochrolomia, Stictopelta) or a ‘thorny’ habitus (Alcmeone, Sundarion). In the ‘dewdrop’ habitus, only the clade Ochrolomia+ is retained as a monophyletic unit. According to these results, pronotal shapes and habitus have evolved independently in each monophyletic unit and each one seems correlated with a particular type of mimicry strategy. According to the strategy, characters involved are different, a priori independent; moreover, they look coordinated regarding to the mimicry function they serve. The various evolutionary scenarios are discussed in relation to the phylogeny, and particularly in correlation with the non-gregarious behavior of these membracids, also coherent with their mimicry strategy.  相似文献   

12.
13.
The present molecular systematic and phylogeographic analysis is based on sequences of cytochrome c oxidase subunit 1 (cox1) (mtDNA) and 28S ribosomal DNA and includes 59 isolates of cestodes of the genus Anoplocephaloides Baer, 1923 s. s. (Cyclophyllidea, Anoplocephalidae) from arvicoline rodents (lemmings and voles) in the Holarctic region. The emphasis is on Anoplocephaloides lemmi (Rausch 1952) parasitizing Lemmus trimucronatus and Lemmus sibiricus in the northern parts of North America and Arctic coast of Siberia, and Anoplocephaloides kontrimavichusi (Rausch 1976) parasitizing Synaptomys borealis in Alaska and British Columbia. The cox1 data, 28S data and their concatenated data all suggest that A. lemmi and A. kontrimavichusi are both non‐monophyletic, each consisting of two separate, well‐defined clades, that is independent species. As an example, the sister group of the clade 1 of A. lemmi, evidently representing the ‘type clade’ of this species, is the clade 1 of A. kontrimavichusi. For A. kontrimavichusi, it is not known which one is the type clade. There is also fairly strong evidence for the non‐monophyly of Anoplocephaloides dentata (Galli‐Valerio, 1905)‐like species, although an earlier phylogeny suggested that this multispecies assemblage may be monophyletic. The results suggest a deep phylogenetic codivergence of Lemmus spp. and A. lemmi, primarily separating the two largely allopatric host and parasite species at the Kolyma River in east Siberia. There are also two allopatric sublineages within each main clade/species of A. lemmi and Lemmus, but the present distributions of the sublineages within the eastern L. trimucronatus and clade 1 of A. lemmi are not concordant. This discrepancy may be most parsimoniously explained by an extensive westward distributional shift of the easternmost parasite subclade. The results further suggest that the clade 1 of A. kontrimavichusi has diverged through a host shift from the precursor of L. trimucronatus to S. borealis.  相似文献   

14.
Euptychiina is the most species‐rich subtribe of Neotropical Satyrinae, with over 450 known species in 47 genera (14 monotypic). Here, we use morphological characters to examine the phylogenetic relationships within Euptychiina. Taxonomic sampling included 105 species representing the majority of the genera, as well as five outgroups. A total of 103 characters were obtained: 45 from wing pattern, 48 from genitalia and 10 from wing venation. The data matrix was analysed using maximum parsimony under both equal and extended implied weights. Euptychiina was recovered as monophyletic with ten monophyletic genera, contrasting previous DNA sequence‐based phylogenies that did not recover the monophyly of the group. In agreement with sequence‐based hypotheses, however, three main clades were recognized: the ‘Megisto clade’ with six monophyletic and three polyphyletic genera, the ‘Taygetis clade’ with nine genera of which three were monophyletic, and the ‘Pareuptyhia clade’ with four monophyletic and two polyphyletic genera. This is the first morphology‐based phylogenetic hypothesis for Euptychiina and the results will be used to complement molecular data in a combined analysis and to provide critical synapomorphies for clades and genera in this taxonomically confused group.  相似文献   

15.
Aim To determine the origin and diversification of monachine seals using a phylogenetic framework. Methods Molecular sequence data from three mitochondrial genes (cyt b, ND1 and 12S), and one nuclear marker (an intron from the α‐lactalbumin gene) were examined from all extant species of monachine seals. Maximum likelihood and partitioned Bayesian inference were used to analyse separate and combined (mitochondrial + nuclear) data sets. Divergence times were estimated from the resultant phylogeny using nonparametric rate smoothing as implemented by the program r8s. Results Mirounga, Monachus and the Lobodontini form three well‐supported clades within a monophyletic Monachinae. Lobodontini + Mirounga form a clade sister to Monachus. Molecular divergence dates indicate that the first split within the Monachinae (Lobodontini + Mirounga clade and Monachus) occurred between 11.8 and 13.8 Ma and Mirounga, Monachus and the Lobodontini originated 2.7–3.4, 9.1–10.8 and 10.0–11.6 Ma, respectively. Main conclusions Two main clades exist within Monachinae, Monachus and Lobodontini + Mirounga. Monachus, a warm water clade, originated in the North Atlantic and maintained the temperate water affinities of their ancestors as they diversified in the subtropic regions of the Northern Hemisphere. The cold‐water clade, Lobodontini + Mirounga, dispersed southward to the cooler climates of the Southern Hemisphere. The Lobodontini continued south until reaching the Antarctic region where they diversified into the present‐day fauna. Mirounga shows an anti‐tropical distribution either reflective of a once cosmopolitan range that was separated by warming waters in the tropics or of transequatorial dispersal.  相似文献   

16.
Phylogenetic relationships of (19) serpulid taxa (including Spirorbinae) were reconstructed based on 18S rRNA gene sequence data. Maximum likelihood, Bayesian inference, and maximum parsimony methods were used in phylogenetic reconstruction. Regardless of the method used, monophyly of Serpulidae is confirmed and four monophyletic, well-supported major clades are recovered: the Spirorbinae and three groups hitherto referred to as the Protula-, Serpula-, and Pomatoceros-group. Contrary to the taxonomic literature and the hypothesis of opercular evolution, the Protula-clade contains non-operculate (Protula, Salmacina) and operculate taxa both with pinnulate and non-pinnulate peduncle (Filograna vs. Vermiliopsis), and most likely is the sister group to Spirorbinae. Operculate Serpulinae and poorly or non-operculate Filograninae are paraphyletic. It is likely that lack of opercula in some serpulid genera is not a plesiomorphic character state, but reflects a special adaptation.  相似文献   

17.
The phylogenetic relationships of the tribe Rhingiini and the genus Cheilosia (Diptera, Syrphidae) were investigated using morphological and molecular characters. The genus Cheilosia is one of the most diverse lineages of hoverflies (Syrphidae). The mitochondrial protein coding gene cytochrome c oxidase subunit I (COI), and the D2‐3 region of the nuclear 28S rRNA gene were chosen for sequencing, and morphological characters were scored for both adults and immature stages. The combined dataset included 56 ingroup taxa. The datasets were analyzed separately and in conjunction, using both static and dynamic alignment under the parsimony criterion. The aim of the study was to assess the phylogenetic relationships of the tribe Rhingiini, and to explore if the subgenera of Cheilosia were supported as monophyletic clades. Results showed that the monophyly of subtribes of Rhingiini remained ambiguous, especially due to unstable phylogenetic placements of the genera Portevinia and Rhingia. We recovered most subgenera of Cheilosia as monophyletic clades. Dynamic alignment, using the optimization alignment program POY, always recovered more parsimonious topologies under all parameter weighting schemes, than did parsimony analyses using static alignment and analyzed with NONA.  相似文献   

18.
A molecular phylogenetic study of selected species of three sub-genera of the genusCordyceps was undertaken, along with representatives of the generaAkanthomyces, Aschersonia, Gibellula, Hymenostilbe, Hypocrella, Nomuraea andTorrubiella, to examine their inter-relationship. Phylogenetic analyses of the data indicated that the Clavicipitaceae form a monophyletic group within the Hypocreales, while the monophyly ofCordyceps was not supported. Four clades were identified:Cor. militaris/Cor. pseudomilitaris; Cor. iranginesis/Cor. sphecocephala; Cor. intermedia/Cor. capitata; andCor. cylindrica/Nom. atypicola. The sub-genusNeocordyceps was shown to be monophyletic while the sub-generaEucordyceps andOphiocordyceps do not form monophyletic groups. The genusHypocrella appeared monophyletic, and radiated after the formation of the generaCordyceps, andTorrubiella. Akanthomyces arachnophilus andGi. pulchra, anamorphs ofTorrubiella species, formed a distinct clade that was separate from one formed by the scale insect pathogens,To. luteorostrata andPaecilomyces cinnamomeus, suggesting that this genus may be polyphyletic.  相似文献   

19.
Aktipis, S. W., Boehm, E. & Giribet, G. (2010). Another step towards understanding the slit‐limpets (Fissurellidae, Fissurelloidea, Vetigastropoda, Gastropoda): a combined five‐gene molecular phylogeny. —Zoologica Scripta, 40, 238–259. Fissurellids, commonly known as slit or keyhole limpets, are limpet‐shaped gastropods that typically possess a hole, slit or notch in their bilaterally symmetrical shells and usually occur on rocky marine substrates. Competing classifications for Fissurellidae have been circumscribed using various morphological characters such as radular, shell and mantle features; two to five different subfamilies have been recognized. Although fissurellid species are frequently included in larger vetigastropod phylogenies, relatively few phylogenetic studies of the group have been performed. This study presents a phylogenetic investigation of the relationships amongst slit‐limpets in the vetigastropod superfamily Fissurelloidea, representing the first molecular phylogeny of this clade. In this study, the monophyly of Fissurelloidea and Fissurellidae varied depending on the analytical method used, but clades compatible with the subfamilies Diodorinae and Fissurellinae were recovered with high bootstrap support in all analyses. Species traditionally classified in Emarginulinae formed two groups identified in this study as Hemitominae (Puncturella, Cranopsis and Hemitoma) and Emarginulinae sensu stricto (Emarginula, Montfortula, Tugali, Scutus and Nannoscutum), but Hemitominae was only monophyletic in the maximum likelihood analysis. The results of this study contradict traditional fissurellid classifications as well as theories about the evolution of key fissurellid shell characters. The placement of Puncturella, Cranopsis and Hemitoma sister to all remaining fissurellids suggests that the presence of an anteriorly placed foramen or notch is plesiomorphic, and that an anterior notch or slit evolved multiple times in Fissurellidae.  相似文献   

20.
Eremias, or racerunners, is a widespread lacertid genus occurring in China, Mongolia, Korea, Central Asia, Southwest Asia and Southeast Europe. It has been through a series of taxonomic revisions, but the phylogenetic relationships among the species and subgenera remain unclear. In this study, a frequently studied region of the mitochondrial 16S rRNA was used to (i) reassess the phylogenetic relationships of some Eremias species, (ii) test if the viviparous species form a monophyletic group, and (iii) estimate divergence time among lineages using a Bayesian relaxed molecular-clock approach. The resulting phylogeny supports monophyly of Eremias sensu Szczerbak and a clade comprising Eremias, Acanthodactylus and Latastia. An earlier finding demonstrating monophyly of the subgenus Pareremias is corroborated, with Eremias argus being the sister taxon to Eremias brenchleyi. We present the first evidence that viviparous species form a monophyletic group. In addition, Eremias przewalskii is nested within Eremias multiocellata, suggesting that the latter is likely a paraphyletic species or a species complex. Eremias acutirostris and Eremias persica form a clade that is closely related to the subgenus Pareremias. However, the subgenera Aspidorhinus, Scapteira, and Rhabderemias seem not to be monophyletic, respectively. The Bayesian divergence-time estimation suggests that Eremias originated at about 9.9 million years ago (with the 95% confidence interval ranging from 7.6 to 12 Ma), and diversified from Late Miocene to Pleistocene. Specifically, the divergence time of the subgenus Pareremias was dated to about 6.3 million years ago (with the 95% confidence interval ranging from 5.3 to 8.5 Ma), which suggests that the diversification of this subgenus might be correlated with the evolution of an East Asian monsoon climate triggered by the rapid uplift of the Tibetan Plateau approximately 8 Ma.  相似文献   

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