Sweet or salty? The origin of freshwater gastrotrichs (Gastrotricha,Chaetonotida) revealed by molecular phylogenetic analysis

Chaetonotidae is the most diverse and widely distributed family of the order Chaetonotida (Gastrotricha) and includes both marine and freshwater species. Although the family is regarded as a sister taxon to the exclusively marine Xenotrichulidae, the type of environment, marine or freshwater, where Chaetonotidae originated is still not known. Here, we reconstructed the phylogeny of the family based on molecular sequence data and mapped both morphological and ecological characters to determine the ancestral environment of the first members of the family. Our results revealed that the freshwater genus Bifidochaetus is the earliest branching lineage in the paraphyletic Chaetonotidae (encompassing Dasydytidae and Neogosseidae). Moreover, we reconstructed Lepidochaetus-Cephalionotus clade as a monophyletic sister group to the remaining chaetonotids, which supports Kisielewski's morphological based hypothesis concerning undifferentiated type of body scales as a most primary character in Chaetonotidae. We also found that reversals to marine habitats occurred independently in different Chaetonotidae lineages, thus marine species in the genera Heterolepidoderma, Halichaetonotus, Aspidiophorus and subgenera Chaetonotus (Schizochaetonotus) or Chaetonotus (Marinochaetus) should be assumed as having secondarily invaded the marine environment. Character mapping revealed a series of synapomorphies that define the clade that includes Chaetonotidae (with Dasydytidae and Neogosseidae), the most important of which may be those linked to reproduction.     

Systematics of Amaryllidaceae based on cladistic analysis of plastid sequence data

Cladistic analyses of plastid DNA sequences rbcL and trnL-F are presented separately and combined for 48 genera of Amaryllidaceae and 29 genera of related asparagalean families. The combined analysis is the most highly resolved of the three and provides good support for the monophyly of Amaryllidaceae and indicates Agapanthaceae as its sister family. Alliaceae are in turn sister to the Amaryllidaceae/Agapanthaceae clade. The origins of the family appear to be western Gondwanaland (Africa), and infrafamilial relationships are resolved along biogeographic lines. Tribe Amaryllideae, primarily South African, is sister to the rest of Amaryllidaceae; this tribe is supported by numerous morphological synapomorphies as well. The remaining two African tribes of the family, Haemantheae and Cyrtantheae, are well supported, but their position relative to the Australasian Calostemmateae and a large clade comprising the Eurasian and American genera, is not yet clear. The Eurasian and American elements of the family are each monophyletic sister clades. Internal resolution of the Eurasian clade only partially supports currently accepted tribal concepts, and few conclusions can be drawn on the relationships of the genera based on these data. A monophyletic Lycorideae (Central and East Asian) is weakly supported. Galanthus and Leucojum (Galantheae pro parte) are supported as sister genera by the bootstrap. The American clade shows a higher degree of internal resolution. Hippeastreae (minus Griffinia and Worsleya) are well supported, and Zephyranthinae are resolved as a distinct subtribe. An Andean clade marked by a chromosome number of 2n = 46 (and derivatives thereof) is resolved with weak support. The plastid DNA phylogenies are discussed in the context of biogeography and character evolution in the family.     

Phylogenetic relationships within the South American fish family Anostomidae (Teleostei,Ostariophysi, Characiformes)

Analysis of a morphological dataset containing 152 parsimony‐informative characters yielded the first phylogenetic reconstruction spanning the South American characiform family Anostomidae. The reconstruction included 46 ingroup species representing all anostomid genera and subgenera. Outgroup comparisons included members of the sister group to the Anostomidae (the Chilodontidae) as well as members of the families Curimatidae, Characidae, Citharinidae, Distichodontidae, Hemiodontidae, Parodontidae and Prochilodontidae. The results supported a clade containing Anostomus, Gnathodolus, Pseudanos, Sartor and Synaptolaemus (the subfamily Anostominae sensu Winterbottom) albeit with a somewhat different set of relationships among the species within these genera. Anostomus as previously recognized was found to be paraphyletic and is split herein into two monophyletic components, a restricted Anostomus and the new genus Petulanos gen. nov. , described herein. Laemolyta appeared as sister to the clade containing Anostomus, Gnathodolus, Petulanos, Pseudanos, Sartor and Synaptolaemus. Rhytiodus and Schizodon together formed a well‐supported clade that was, in turn, sister to the clade containing Anostomus, Gnathodolus, Laemolyta, Petulanos, Pseudanos, Sartor and Synaptolaemus. Anostomoides was sister to the clade formed by these nine genera. Leporinus as currently defined was not found to be monophyletic, although certain clades within that genus were supported, including the species with subterminal mouths in the former subgenus Hypomasticus which we recognize herein as a genus. Abramites nested in Leporinus, and Leporellus was found to be the most basal anostomid genus. The presence of cis‐ and trans‐Andean species in Abramites, Leporellus, Leporinus and Schizodon, all relatively basal genera, suggests that much of the diversification of anostomid species pre‐dates the uplift of the Andean Cordilleras circa 11.8 million years ago. Several important morphological shifts in anostomid evolution are illustrated and discussed, including instances of convergence and reversal. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 70–210.     

Molecular phylogeny of fungus gnats (Diptera: Mycetophilidae) revisited: position of Manotinae,Metanepsiini, and other enigmatic taxa as inferred from multigene analysis

The phylogeny of selected genera from four subfamilies of fungus gnats (Diptera: Mycetophilidae) – Manotinae, Leiinae, Sciophilinae and Gnoristinae (including Metanepsiini) – is reconstructed based on the combined analysis of five mitochondrial (12S, 16S, COI, COII, cytB) and two nuclear (28S, ITS2) gene markers. Results of the different analyses all support Manotinae as a monophyletic group, with Leiinae as the sister group. Allactoneura DeMeijere is nested in the monophyletic and strongly supported clade of Leiinae. The tribe Metanepsiini is revealed as paraphyletic and the genera Metanepsia Edwards and Chalastonepsia Søli do not appear to be closely related. The genera Docosia Winnertz, Ectrepesthoneura Enderlein, Novakia Strobl and Syntemna Winnertz were placed with a group of genera included traditionally in the Gnoristinae. The monophyly of Dziedzickia Johannsen and Phthinia Winnertz is not supported. The genera of Sciophilinae (excluding Paratinia Mik but including Eudicrana Loew) form a monophyletic group in the Bayesian model.     

MULTIGENE ANALYSES OF PHOTOSYNTHETIC EUGLENOIDS AND NEW FAMILY,PHACACEAE (EUGLENALES)1

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.     

Molecular Phylogeny of Tribe Theeae (Theaceae s.s.) and Its Implications for Generic Delimitation

Tribe Theeae, which includes some economically important and widely grown plants, such as beverage tea and a number of woody ornamentals, is the largest member of the Theaceae family. Using five genomic regions (chloroplast: atpI-H, matK, psbA5''R-ALS-11F, rbcL; nuclear: LEAFY) and 30 species representing four of the five genera in this tribe (Apterosperma, Camellia, Polyspora, and Pyrenaria s.l.), we investigated the phylogeny of Theeae and assessed the delimitation of genera in the tribe. Our results showed that Polyspora was monophyletic and the sister of the three other genera of Theeae investigated, Camellia was paraphyletic and Pyrenaria was polyphyletic. The inconsistent phylogenetic placement of some species of Theeae between the nuclear and chloroplast trees suggested widespread hybridization between Camellia and Pyrenaria, Polyspora and Parapyrenaria. These results indicate that hybridization, rather than morphological homoplasy, has confused the current classification of Theeae. In addition, the phylogenetic placement and possible allies of Laplacea are also discussed.     

Evolutionary relationships in the Asteraceae tribe Inuleae (incl. Plucheeae) evidenced by DNA sequences of ndhF; with notes on the systematic positions of some aberrant genera

The phylogenetic relationships between the tribes Inuleae sensu stricto and Plucheeae are investigated by analysis of sequence data from the cpDNA gene ndhF. The delimitation between the two tribes is elucidated, and the systematic positions of a number of genera associated with these groups, i.e. genera with either aberrant morphological characters or a debated systematic position, are clarified. Together, the Inuleae and Plucheeae form a monophyletic group in which the majority of genera of Inuleae s.str. form one clade, and all the taxa from the Plucheeae together with the genera Antiphiona, Calostephane, Geigeria, Ondetia, Pechuel-loeschea, Pegolettia, and Iphionopsis from Inuleae s.str. form another. Members of the Plucheeae are nested with genera of the Inuleae s.str., and support for the Plucheeae clade is weak. Consequently, the latter cannot be maintained and the two groups are treated as one tribe, Inuleae, with the two subtribes Inulinae and Plucheinae. The genera Asteriscus, Chrysophthalmum, Inula, Laggera, Pentanema, Pluchea, and Pulicaria are demonstrated to be non-monophyletic. Cratystylis and Iphionopsis are found to belong to the same clade as the taxa of the former Plucheeae. Caesulia is shown to be a close relative of Duhaldea and Blumea of the Inuleae-Inulinae. The genera Callilepis and Zoutpansbergia belong to the major clade of the family that includes the tribes Heliantheae sensu lato and Inuleae (incl. Plucheeae), but their exact position remains unresolved. The genus Gymnarrhena is not part of the Inuleae, but is either part of the unresolved basal complex of the paraphyletic Cichorioideae, or sister to the entire Asteroideae.     

A molecular phylogeny of celtidaceae and ulmaceae (Urticales) based onrbcL Nucleotide sequences

On the basis of 1,290 bp sequences of the chloroplast generbcL, a molecular phylogeny of seven of nine genera of the Celtidaceae and four of six genera of the Ulmaceae was produced. These data were analyzed together with some other urticalean genera using three methods (i.e., maximum parsimony, maximum likelihood, and neighbor joining methods). Maximum likelihood topology among 18 trees obtained indicated that the Urticales are monophyletic with its common clade splitting basally into two: one leading to a line comprisingAmpelocera (traditionally placed in Celtidaceae) and Ulmaceae, and the other leading to a line comprising the remaining genera of Celtidaceae, Moraceae, and other Urticales. Ulmaceae, to whichAmpelocera is a sister group, are monophyletic, as supported by many lines of morphological evidence. In contrast to Ulmaceae, the monophyly of Celtidaceae (excludingAmpelocera) was not supported, and resolution of relationships of Celtidaceae with other Urticales, as well as of those within the family, is left for future study.     

Evolution of green lacewings (Neuroptera: Chrysopidae): an anchored phylogenomics approach

A phylogeny of green lacewings (Neuroptera: Chrysopidae) using anchored hybrid enrichment data is presented. Using this phylogenomic approach, we analysed 137 kb of sequence data (with < 10% missing) for 82 species in 50 genera of Chrysopidae under Bayesian and maximum likelihood criteria. We recovered a strongly supported tree topologically congruent with recently published phylogenies, especially relationships amongst higher‐level groups. The subfamily Nothochrysinae was recovered as paraphyletic, with one clade sister to the rest of Chrysopidae, and the second clade containing the nominal genus (Nothochrysa Navás) as sister to the subfamily Apochrysinae. Chrysopinae was recovered as a monophyletic with the monobasic Nothancylini tribe n. sister to the rest of the subfamily. Leucochrysini was recovered sister to Belonopterygini, and Chrysopini was rendered paraphyletic with respect to Ankylopterygini. Divergence times and diversification estimates indicate a major shift in rate in ancestral Chrysopini at the end of the Cretaceous, and the extensive radiation of Chrysopinae, the numerically dominant clade of green lacewings, began in the Mid‐Paleogene (c. 45 Ma).     

Genetic diversity and phylogenetic position of the subclass Astomatia (Ciliophora) based on a sampling of six genera from West African oligochaetes (Glossoscolecidae, Megascolecidae), including description of the new genus Paraclausilocola n. gen

To more confidently assess phylogenetic relationships among astome ciliates, we obtained small subunit (SSU) rRNA sequences from nine species distributed in six genera and three families: Almophrya bivacuolata, Eudrilophrya complanata, Metaracoelophrya sp. 1, Metaracoelophrya sp. 2, Metaracoelophrya intermedia, Metaradiophrya sp., Njinella prolifera, Paraclausilocola constricta n. gen., n. sp., and Paraclausilocola elongata n. sp. The two new species in the proposed new clausilocolid genus Paraclausilocola n. gen. are astomes with no attachment apparatus, two files of contractile vacuoles, and an arc-like anterior suture that has differentiations of thigmotactic ciliature on the anterior ends of the left kineties of the upper surface. Phylogenetic analyses were undertaken using neighbor-joining, Bayesian inference, maximum likelihood, and maximum parsimony. The nine species of astomes formed a strongly supported clade, showing the subclass Astomatia to be monophyletic and a weakly supported sister clade to the scuticociliates. There were two strongly supported clades within the astomes. However, genera assigned to the same family were found in different clades, and genera assigned to the same order were found in both clades. Thus, astome taxa appear to be paraphyletic when morphology is used to assign species to genera.     

Phylogeny of Mesoamerican freshwater mussels and a revised tribe‐level classification of the Ambleminae

Evolutionary and ecological hypotheses of the freshwater mussel subfamily Ambleminae are intensely geographically biased—a consequence of the complete exclusion of Mesoamerican taxa in phylogenetic reconstructions of the clade. We set out to integrate a portion of the Mesoamerican freshwater mussel assemblage into existing hypotheses of amblemine classification and evolution by generating a molecular phylogeny that includes four previously unsampled Mesoamerican genera and nine species endemic to that region. Given the traditionally hypothesized affinity to Nearctic mussels and the understanding that classification should reflect common ancestry, we predicted that (a) Mesoamerican genera would be recovered as members of the recognized tribes of the Ambleminae, and (b) genera would be supported as monophyletic. The mutilocus phylogeny (COI + 28S + 16S) reported herein does not fully support either of those hypotheses. Neither Cyrtonaias nor Psorula were supported as monophyletic and we predict several other Mesoamerica genera are also non‐monophyletic. The reconstructed phylogeny recovered four independent lineages of Mesoamerican freshwater mussels and these clades are distributed across the phylogeny of the Ambleminae, including the tribe Quadrulini (Megalonaias), Lampsilini (two lineages: Cyrtonaias explicata/Sphenonaias microdon, and Pachynaias), and a previously unrecognized, exclusively Mesoamerican and Rio Grande clade consisting of the genera Psoronaias, Psorula and Popenaias. The latter clade possesses several morphological characteristics that distinguish it from its sister taxon, tribe Lampsilini, and we recognize this newly identified Mesoamerican clade as a fifth tribe of the Ambleminae attributable to the Popenaiadini Heard & Guckert, 1970. This revised classification more completely recognizes the suprageneric diversity of the Ambleminae.     

The gastropod–crustacean connection: towards the phylogeny and evolution of the parasitic copepod family Splanchnotrophidae

Amongst the most significant metazoan taxa associated with gastropod molluscs is the endoparasitic copepod family Splanchnotrophidae. Currently it contains five genera with highly modified morphology and exclusively infesting nudibranch and sacoglossan sea slug hosts. The present study is a first approach towards reconstructing their phylogeny and evolution. Cladistic analysis of 109 morphological characters including 24 known splanchnotrophid species resulted in a fully resolved strict consensus tree that is discussed in morphological, functional, and geographical frameworks. Alternative topologies are also explored. Originating from paraphyletic Philoblennidae, the Splanchnotrophidae emerge as sister group to the genus Briarella. Unique synapomorphies, such as the bizarre body shapes and successive reduction of mouthparts, are discussed as adaptive traits to endoparasitism that evolved only once within copepods infesting shell‐less heterobranch gastropods. The ancestrally Indo‐Pacific Splanchnotrophidae split up into a clade of the still Indo‐Pacific genera Ceratosomicola and Arthurius, sister to a clade composed of the monophyletic amphi‐American genus Ismaila and European Splanchnotrophus emerging from paraphyletic Lomanoticola. Although initial radiation of Briarella and Splanchnotrophidae is likely to have involved chromodoridid nudibranch hosts, later phylogenies of parasites and their hosts are incongruent; intriguingly, host shifts from nudibranch to only distantly related sacoglossan species occurred at least two times independently. Such remarkable ecological plasticity is assumed to have driven splanchnotrophid diversification. Topological hypotheses and historical biogeographical and evolutionary scenarios inferred herein can be tested by future molecular research. © 2013 The Linnean Society of London     

Analysis of Ribosomal RNA Genes Suggests That Trypanosomes Are Monophyletic

To further investigate the phylogeny of protozoa from the order Kinetoplastida we have sequenced the small subunit (SSU) and a portion of the large subunit (LSU) nuclear rRNA genes. The SSU and LSU sequences were determined from a lizard trypanosome, Trypanosoma scelopori and a bodonid, Rhynchobodo sp., and the LSU sequences were determined from an insect trypanosomatid, Crithidia oncopelti, and a bodonid, Dimastigella trypaniformis. Contrary to previous results, in which trypanosomes were found to be paraphyletic, with Trypanosoma brucei representing the earliest-diverging lineage, we have now found evidence for the monophyly of trypanosomes. Addition of new taxa which subdivide long branches (such as that of T. brucei) have helped to identify homoplasies responsible for the paraphyletic trees in previous studies. Although the monophyly of the trypanosome clade is supported in the bootstrap analyses for maximum likelihood at 97% and maximum parsimony at 92%, there is only a small difference in ln-likelihood value or tree length between the most optimal monophyletic tree and the best suboptimal paraphyletic tree. Within the trypanosomatid subtree, the clade of trypanosomes is a sister group to the monophyletic clade of the nontrypanosome genera. Different groups of trypanosomes group on the tree according to their mode of transmission. This suggests that the adaptation to invertebrate vectors plays a more important role in the trypanosome evolution than the adaptation to vertebrate hosts. Received: 5 July 1996 / Accepted: 26 September 1996     

Therps16 intron and the phylogeny of theRubioideae (Rubiaceae)

The phylogeny of the subfamilyRubioideae (Rubiaceae) was estimated from sequence variation in therps16 intron (cpDNA) in 143 ingroup and 5 outgroup taxa. The analysis largely confirms a recent one based onrbcL sequences, but branch support is often much stronger. Three of the traditional subfamilies are supported,Rubioideae, Cinchonoideae s. str., andIxoroideae s. l. while there is no support forAntirheoideae. TheRubioideae are the sister group of all otherRubiaceae and comprise the tribesAnthospermeae, Coccocypseleae, Cruckshanksieae, Coussareeae, Gaertnereae, Hedyotideae, Knoxieae, Morindeae, Ophiorrhizeae, Paederieae, Pauridiantheae, Perameae, Psychotrieae, Rubieae, Spermacoceae, Theligoneae, andUrophylleae. TheHamelieae andHillieae belong to theCinchonoideae. Rachicallis andSiemensia should be transferred from theHedyotideae to theCinchonoideae. ThePauridiantheae, Urophylleae, Ophiorrhizeae, andRaritebe form the basalmost subclade of theRubioideae. The second basalmost clade consists of the generaLasianthus andPerama. The third basalmost clade consists of the tribesCoussareeae, Coccocypseleae andCruckshanksieae, and the generaDeclieuxia andHindsia. The tribesKnoxieae, Anthospermeae, Argostemmateae, Paederieae, Theligoneae, Rubieae, Hedyotideae, andSpermacoceae are members of one clade. TheKnoxieae are monophyletic ifOtiophora, Otomeria, andPentas are included. The tribeAnthospermeae is supported as monophyletic, but its subtribes are not. ThePaederieae, together withTheligonum, form a paraphyletic grade basal to theRubieae. TheHedyotideae, includingSchismatoclada, form a grade at the base of theSpermacoceae. TheGaertnereae are monophyletic and distinct from thePsychotrieae. TheMorindeae are monophyletic and includeDamnacanthus andMitchella. Schradera is the sister group of theMorindeae. ThePsychotrieae are monophyletic when theGaertnereae, Lasianthus, andDeclieuxia are excluded. The recognition of a subtribeHydnophytineae leaves the rest of thePsychotrieae paraphyletic.Psychotria is paraphyletic with respect to all other genera of the tribe. Approximately 50 genera are here classified for the first time based on molecular data.     

Editorial note

Phylogenetic analyses of the Dasyaceae based on sequence analysis of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) and 42 morphological characters are presented. Comparative sequence analysis confirms the general view of the Ceramiaceae as a primitive, paraphyletic group giving rise to the Rhodomelaceae, Delesseriaceae and Dasyaceae within the monophyletic Ceramiales. On the basis of both data sets, the Heterosiphonia-like genera (Heterosiphonia, Colacodasya and Dasyella) are the most primitive members of the Dasyaceae, whereas the Dasya-like genera (Dasya, Pogonophorella, Eupogodon and Rhodoptilum) and Thuretia and Dictyurus are of more recent origin. On the basis of morphological data only, Thuretia and Dictyurus form a sister group to Heterosiphonia, and Eupogodon is monophyletic whereas Dasya and Heterosiphonia are not. Primary radial symmetry has arisen once in the Dasya clade but is secondarily obscured in some species by heavy, asymmetrical cortication that gives the appearance of bilateral symmetry. This is illustrated by species of Eupogodon and Rhodoptilum.     

Phylogeny and morphological evolution of tribe Menispermeae (Menispermaceae) inferred from chloroplast and nuclear sequences

The Menispermaceae family contains ca. 72 genera with 450 species that are almost entirely tropical. Its phylogeny at the tribal level has never been examined using molecular data. Here we used DNA sequences of the chloroplast matK gene and trnL-F regions, and the nuclear ITS region to study the delimitation and position of the tribe Menispermeae within the family and its subtribal monophyletic groups. Family-wide phylogenetic analyses of the chloroplast data produced two strongly supported clades. The first clade contains two subclades: Coscinieae including Arcangelisia and Anamirta, and Tinosporeae sensu lato including Fibraureae, supported by morphological characters, such as traits of the cotyledon, stylar scar and embryo. The second clade consists of the tribes Menispermeae sensu DC. and Tiliacoreae Miers. All our analyses surprisingly recognized that tribe Menispermeae is not monophyletic unless tribe Tiliacoreae is included, suggesting that characters of cotyledon and stylar scar are very important for the infrafamilial classification, and that endosperm presence vs. absence was over-emphasized in traditionally tribal division of the family. Our topologies indicate a secondary loss of endosperm. The monophyly of two subtribes of the tribe Menispermeae, Stephaniinae and Cissampelinae, is supported by the cpDNA and ITS data, as well as by morphological characters, including aperture types and shapes, and colpal membrane features of pollen grains, and sepal number of male flowers. The Cocculinae was recognized as a paraphyletic group containing the remaining genera of the tribe Menispermeae.     

PHYLOGENY OF THE EUGLENOID LORICATE GENERA TRACHELOMONAS AND STROMBOMONAS (EUGLENOPHYTA) INFERRED FROM NUCLEAR SSU AND LSU rDNA1

Previous studies using the nuclear SSU rDNA and partial LSU rDNA have demonstrated that the euglenoid loricate taxa form a monophyletic clade within the photosynthetic euglenoid lineage. It was unclear, however, whether the loricate genera Trachelomonas and Strombomonas were monophyletic. In order to determine the relationships among the loricate taxa, SSU and LSU nuclear rDNA sequences were obtained for eight Strombomonas and 25 Trachelomonas strains and combined in a multigene phylogenetic analysis. Conserved regions of the aligned data set were used to generate maximum‐likelihood (ML) and Bayesian phylogenies. Both methods recovered a strongly supported monophyletic loricate clade with Strombomonas and Trachelomonas species separated into two sister clades. Taxa in the genus Strombomonas sorted into three subclades. Within the genus Trachelomonas, five strongly supported subclades were recovered in all analyses. Key morphological features could be attributed to each of the subclades, with the major separation being that all of the spine‐bearing taxa were located in two sister subclades, while the more rounded, spineless taxa formed the remaining three subclades. The separation of genera and subclades was supported by 42 distinct molecular signatures (33 in Trachelomonas and nine in Strombomonas). The morphological and molecular data supported the retention of Trachelomonas and Strombomonas as separate loricate genera.     

Life on the fly: phylogenetics and evolution of the helicopter damselflies (Odonata,Pseudostigmatidae)

Ingley, S.J., Bybee, S.M., Tennessen, K.J., Whiting, M.F. & Branham, M.A. (2012). Life on the fly: phylogenetics and evolution of the helicopter damselflies (Odonata, Pseudostigmatidae). —Zoologica Scripta, 41, 637–650. Helicopter damselflies (Odonata: Pseudostigmatidae) form a relatively small, yet highly specialized group of odonates, including the largest extant odonate (wingspan of ～190 mm). Pseudostigmatids are found throughout Central and South America, with the exception of one species that is found exclusively in East Africa. Pseudostigmatids oviposit exclusively in phytotelmata and forage on orb‐weaver spiders, which they pluck from webs. Pseudostigmatids also exhibit unique forms of both broad and narrow wings. Although the ecology of these behaviours and morphological features have been studied, their phylogenetic origins and evolutionary history are unknown. Here, we examine the origins of pseudostigmatid wing forms, oviposition in phytotelmata and spider feeding within a modern phylogenetic context, testing for single origins of each character. Phylogenetic analyses are based on 59 morphological characters and ～5 kb of sequence data. Our findings include a well‐supported monophyletic Pseudostigmatidae and Coryphagrion grandis as sister to the Neotropical genera. The genus Mecistogaster is paraphyletic, with Pseudostigma nested within the clade. The genus Microstigma is supported as monophyletic and forms a sister group relationship to the clade of Megaloprepus and Anomisma. The sister group relationship to Pseudostigmatidae is less clear. On the basis of this phylogenetic analysis, we propose three new tribes (Coryphagrionini, Microstigmatini and Mecistogastrini). As Pseudostigmatidae is monophyletic, the behaviour of gleaning spiders from webs appears to derive from a single origin. There are two origins of broad wings within Pseudostigmatidae. Oviposition in phytotelmata most certainly evolved multiple times within Coenagrionoidea. These findings provide new insights into pseudostigmatid evolution that can be used to generate hypotheses regarding behaviour and morphological adaptation in this unique and threatened group of damselflies.     

Interrelationships of the Gastrotricha and their place among the Metazoa inferred from 18S rRNA genes

The phylum Gastrotricha includes about 700 species. They are small worm‐like organisms abundant among marine and freshwater meiobenthos. In spite of their ubiquity, diversity and relative abundance, phylogenetic relationships of these animals remain enigmatic due to the conflicting results of morphological and molecular cladistic analyses. Also unclear are the alliances within the phylum. In order to best estimate the position of Gastrotricha among the Metazoa and to shed some light on the ingroup phylogenetic relationships, small subunit (SSU) ribosomal DNA (rDNA) from 15 species of Chaetonotida (eight genera) and 28 species of Macrodasyida (26 genera) were included in an alignment of 50 metazoan taxa representing 26 phyla. Of the gastrotrich SSU rDNA sequences, eight are new and, along with published sequences represent eight families, including the five marine most speciose. Gastrotricha were resolved within a monophyletic Lophotrochozoa as part of a clade including Micrognathozoa, Rotifera and Cycliophora. The Gnathostomulida were sister to this clade. Nodal support was low for all of these relationships except the grouping of the Micrognathozoa, Rotifera and Cycliophora. Bayesian inference resolved the Gastrotricha as monophyletic with weak nodal support; the Macrodasyida were resolved as paraphyletic with many basal nodes poorly supported. Within the Chaetonotida, the monotypic Multitubulatina Neodasys was found in alliance with the macrodasyidan Urodasys while all the Paucitubulatina were found to form a single, well‐supported clade, with Musellifer as the most basal member. Among the more densely sampled Macrodasyida the Lepidodasyidae and Macrodasyidae were each found to be polyphyletic while monophyly was well supported for the Turbanellidae and Thaumastodermatidae. The congruence of our results with those of the cladistic analysis based on morphological traits provides confidence about the value of each dataset, and calls for widening of the research to include additional taxa of particular phylogenetic significance such as the Dactylopodolidae, Diuronotus, Heteroxenotrichula and Draculiciteria. The study highlights the problems in working with small species, the need for voucher specimens and the confused taxonomic status and membership of various gastrotrich families.