On the marine sister groups of the freshwater crabs (Crustacea: Decapoda: Brachyura)

Freshwater crab sister group relationships with marine eubrachyuran families were investigated. A morphology-based cladistic analysis was conducted on representatives of the freshwater crab families Deckeniidae, Gecarcinucidae, Parathelphusidae, Potamidae, Potamonautidae, Pseudothelphusidae, and Trichodactylidae using a disparate assemblage of marine heterotreme and thoracotreme brachyurans as possible sister groups. The monophyly of the freshwater crabs sensu lato is falsified. The family Trichodactylidae and the marine portunid subfamily Carcininae form basal groups within the superfamily Portunoidea. The monophyly of the Pseudothelphusidae and the Paleotropical freshwater crab families is supported, and this clade is the sister group of the Thoracotremata (Gecarcinidae, Grapsidae s.l., and Ocypodoidea). The origin, groundplan, and diversification of freshwater crabs are discussed in the context of previously published scenarios of their evolution.     

Molecular phylogeny of Eastern Pacific porcelain crabs, genera Petrolisthes and Pachycheles, based on the mtDNA 16S rDNA sequence: phylogeographic and systematic implications

Porcelain crabs, genera Petrolisthes and Pachycheles, are diverse and abundant members of the eastern Pacific near-shore decapod crustacean community. Morphology-based taxonomic analyses of these crabs have determined groupings of affiliated species, but phylogenetic relationships remain unknown. We used sequence data from the mitochondrial 16S rRNA gene of 46 species of eastern Pacific porcelain crabs to perform phylogenetic analyses by distance and parsimony methods. Our results are used to compare the taxonomic significance of morphological and molecular characters, to examine sequence divergence rates of crab 16S rRNA genes, and to analyze the phylogeographic history of these crabs. Our phylogenetic trees indicate that the genus Petrolisthes is divided into two main clades, reflecting morphological features. One clade contains primarily tropical species, and the other contains species from throughout the eastern Pacific, as well as species in the genera Allopetrolisthes and Liopetrolisthes. Phylogenetic trees of Pachycheles suggest an antitropical distribution; north and south temperate species form one clade and tropical species form a second clade. Sequence divergence rates of the 16S rRNA gene from three pairs of geminate species can be used to date divergence times, and we discuss porcelain crab phylogeographic patterns in relation to paleogeographic events.     

The enigmatic monotypic crab plover Dromas ardeola is closely related to pratincoles and coursers (Aves, Charadriiformes, Glareolidae)

The phylogenetic placement of the monotypic crab plover Dromasardeola (Aves, Charadriiformes) remains controversial. Phylogenetic analysis of anatomical and behavioral traits using phenetic and cladistic methods of tree inference have resulted in conflicting tree topologies, suggesting a close association of Dromas to members of different suborders and lineages within Charadriiformes. Here, we revisited the issue by applying Bayesian and parsimony methods of tree inference to 2,012 anatomical and 5,183 molecular characters to a set of 22 shorebird genera (including Turnix). Our results suggest that Bayesian analysis of anatomical characters does not resolve the phylogenetic relationship of shorebirds with strong statistical support. In contrast, Bayesian and parsimony tree inference from molecular data provided much stronger support for the phylogenetic relationships within shorebirds, and support a sister relationship of Dromas to Glareolidae (pratincoles and coursers), in agreement with previously published DNA-DNA hybridization studies.     

Global diversity of crabs (Crustacea: Decapoda: Brachyura) in freshwater

An assessment of the global freshwater crab diversity is presented. A total of 1,476 species in 14 families are currently known from all zoogeographical regions (except Antarctica), including 1,306 species in eight exclusively freshwater families (Pseudothelphusidae, Trichodactylidae, Potamonautidae, Deckeniidae, Platythelphusidae, Potamidae, Gecarcinucidae and Parathelphusidae). Estimates of true freshwater crab diversity including likely numbers of undescribed taxa suggest that the field remains largely in a “discovery” phase. Main ideas on the origins, diversification, and phylogeny of true freshwater crabs are briefly discussed. The economic importance of freshwater crabs is also highlighted. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

Phylogenetics of the brachyuran crabs (Crustacea: Decapoda): the status of Podotremata based on small subunit nuclear ribosomal RNA

The true crabs, the Brachyura, are generally divided into two major groups: Eubrachyura or 'advanced' crabs, and Podotremata or 'primitive' crabs. The status of Podotremata is one of the most controversial issues in brachyuran systematics. The podotreme crabs, best recognised by the possession of gonopores on the coxae of the pereopods, have variously been regarded as mono-, para- or polyphyletic, or even as non-brachyuran. For the first time, the phylogenetic positions of the podotreme crabs were studied by cladistic analysis of small subunit nuclear ribosomal RNA sequences. Eight of 10 podotreme families were represented along with representatives of 17 eubrachyuran families. Under both maximum parsimony and Bayesian Inference, Podotremata was found to be significantly paraphyletic, comprising three major clades: Dromiacea, Raninoida, and Cyclodorippoida. The most 'basal' is Dromiacea, followed by Raninoida and Cylodorippoida. Notably, Cyclodorippoida was identified as the sister group of the Eubrachyura. Previous hypotheses that the dromiid crab, Hypoconcha, is an anomuran were unsupported, though Dromiidae as presently composed could be paraphyletic. Topologies constrained for podotreme monophyly were found to be significantly worse (P < 0.04) than unconstrained topologies under Templeton and S-H tests. The clear pattern of podotreme paraphyly and robustness of topologies recovered indicates that Podotremata as a formal concept is untenable. Relationships among the eubrachyurans were generally equivocal, though results indicate the majoids or dorippoids were the least derived of the Eubrachyura. A new high level classification of the Brachyura is proposed.     

Phylogeny of the freshwater crabs of the Western Ghats (Brachyura,Gecarcinucidae)

The Western Ghats mountain range in India is a biodiversity hotspot for a variety of organisms including a large number of endemic freshwater crab species and genera of the family Gecarcinucidae. The phylogenetic relationships of these taxa, however, have remained poorly understood. Here, we present a phylogeny that includes 90% of peninsular Indian genera based on mitochondrial 16S rRNA and nuclear histone H3 gene sequences. The subfamily Gecarcinucinae was found to be paraphyletic with members of two other subfamilies, Liotelphusinae and Parathelphusinae, nesting within. We identify a well‐supported clade consisting of north Indian species and one clade comprising mostly south Indian species that inhabit the southern ‘sky islands’ of the Western Ghats. Relationships of early diverging genera, however, were resolved with low support. This study also includes newly sampled material from an isolated mountain plateau in the northern part of the Western Ghats, representing a new species of Gubernatoriana, which we describe here as Gubernatoriana basalticola sp. n. The new species is immediately distinguished from its congeners and the related genera Ghatiana and Inglethelphusa by its carapace and cheliped morphology, which are unique among Indian freshwater crabs. This study highlights the urgent need for continued faunistic studies to assess the true diversity of gecarcinucid crabs on the Indian subcontinent, to fully understand the basal phylogenetic relationships within the freshwater crab family Gecarcinucidae, and to evaluate the conservation threat status and biogeography of the montane freshwater crabs of the Western Ghats.     

Phylogeny of Myrmeleontiformia based on larval morphology (Neuropterida: Neuroptera)

The suborder Myrmeleontiformia is a derived lineage of lacewings (Insecta: Neuroptera) including the families Psychopsidae, Nemopteridae, Nymphidae, Ascalaphidae and Myrmeleontidae. In particular, Myrmeleontidae (antlions) are the most diverse neuropteran family, representing a conspicuous component of the insect fauna of xeric environments. We present the first detailed quantitative phylogenetic analysis of Myrmeleontiformia, based on 107 larval morphological and behavioural characters for 36 genera whose larvae are known (including at least one representative of all the subfamilies of the suborder). Four related families were used as outgroups to polarize character states. Phylogenetic analyses were conducted using both parsimony and Bayesian methods. The reconstructions resulting from our analyses corroborate the monophyly of Myrmeleontiformia. Within this clade, Psychopsidae are recovered as the sister family to all the remaining taxa. Nemopteridae (including both subfamilies Nemopterinae and Crocinae) are recovered as monophyletic and sister to the clade comprising Nymphidae + (Myrmeleontidae + Ascalaphidae). Nymphidae consist of two well‐supported clades corresponding to the subfamilies Nymphinae and Myiodactylinae. Our results suggest that Ascalaphidae may not be monophyletic, as they collapse into an unresolved polytomy under the Bayesian analysis. In addition, the recovered phylogenetic relationships diverge from the traditional classification scheme for ascalaphids. Myrmeleontidae are reconstructed as monophyletic, with the subfamilies Stilbopteryginae, Palparinae and Myrmeleontinae. We retrieved a strongly supported clade comprising taxa with a fossorial habit of the preimaginal instars, which represents a major antlion radiation, also including the monophyletic pit‐trap building species.     

Generic-level relationships within the ant subfamily Dolichoderinae (Hymenoptera: Formicidae)

A cladistic analysis was undertaken to determine relationships among extant genera of the ant subfamily Dolichoderinae. Twenty-one of the twenty-two currently recognized genera within the subfamily were examined using 104 morphological characters. A single fully resolved, most-parsimonious tree was found when a combination of ordered and unordered characters was used. When all characters were coded as unordered, seventy most-parsimonious trees were found. The following results were found with both character coding methods. Leptomyrmex was placed basal to the remainder of the subfamily and the monophyletic sets Dolichoderus + Liometopum + Axinidris + Tapinoma + Technomyrmex, Froggattella + Iridomyrmex + Ochetellus + Papyrius + Philidris + Turneria , and Bothriomyrmex + Dorymyrmex + Forelius + Loweriella were suggested. The genera Linepithema and Doleromyrma showed a small amount of instability in moving between neighbouring sister groups when the character coding method changed. The genera Anillidris and Anonychomyrma were difficult to place as they showed major differences in their positions between the two character coding methods.     

Evolution of Afrotropical freshwater crab lineages obscured by morphological convergence

We use sequence data derived from six DNA gene loci to examine evolutionary and biogeographic affinities among all freshwater crab families. With an emphasis on the Afrotropical fauna that includes Africa, Madagascar, and the Seychelles, we test the proposed Gondwanan cladogenesis of the group. Phylogenetic results demonstrate that contemporary distribution patterns of freshwater crab lineages are incongruent with the expected area cladogram of continental fragmentation. Instead, our phylogenetic estimate and divergence time estimation indicate a post-Gondwanan, early Cretaceous cladogenesis for freshwater crabs implying that the acquisition of a freshwater lifestyle was achieved more recently. A dispersal hypothesis as opposed to vicariance appears to best explain the contemporary distribution pattern of this group. However, our results do not explicitly disprove a Gondwanan origin for the Afrotropical freshwater crabs. Alarmingly, these results suggest that most of the currently recognized freshwater crab families are unreliable taxonomic groupings since virtually no Afrotropical freshwater crab families formed monophyletic units thus obscuring inferred biogeographic relationships. Convergence in characters associated with the terminal segment of the mandibular palp is clearly a pervasive obstacle in the taxonomy of this group.     

An investigation into the application of the Wagner parsimony method in synecology

Synecological analyses are usually based on typological, phenetic and cladistic methods. The disadvantages of these techniques are shown. The application of the Wagner parsimony method to synecology is considered. All the methods need some prerequisites, viz. definitions of localities and characters (the most simple one being the presence/absence of taxa); the choice of taxonomic level of taxa; their autochthony. The application of Wagner parsimony needs a new terminology. The congruence of any environmental condition, including freshwater monitoring indices, can be tested on parsimonious trees. The Wagner parsimony method not only provides various indices (tree length, CI, HI, RC, RI) which allow the comparison of trees but also minimal trees which are direct tools in synecology.     

The subfamilies and tribes of the family Bovidae

In this paper 112 skeletal characters in 27 living species of bovids are used in cladistic and phenetic analyses of the relationships among the tribes in the family. Consideration and modification of the cladistic analysis leads to the conclusion that bovids cluster around four foci in ascending evolutionary sequence: Boselaphini and allies; Antilopini and some Neotragini; the Caprinae; and a group of African antelopes containing Aepyceros , Alcelaphini, Reduncini and Hippotragini. This conclusion is quite closely compatible with the phenetic distance analysis of the same data, provided die latter is read as if primitive or early bovids share more similarities than divergently advanced ones and hence associate more closely. Given the primitiveness of Boselaphini and allies, the crucial finding is that Caprinae link with African antelopes and that Antilopini are more remote. Cladistic and phenetic analyses of 32 characters in 12 extinct bovid species produce similar groupings, but also throw doubt on the classification of Aepyceros , Reduncini and Hippotragini alongside Alcelaphini within a clade of African antelopes. As a result of these two sets of studies, of living and of extinct bovids, minimal alterations are proposed to the arrangement of bovid tribes. In addition, Saiga is placed in the Antilopini, and, with less assurance, Pelea in the Neotragini, Aepyceros in the Alcelaphinae, and Pantholops in the Caprinae. The contribution of the fossil record to understanding bovid evolution is considered.     

A cladistic analysis of the nomadine bees (Hymenoptera: Apoidea)

Abstract. This study compares the results of Rozen's cladistic analysis of the larvae of fifteen genera of cleptoparasitic bees in the subfamily Nomadinae with an independent data set of adult characters for the same genera. Adult characters exhibited considerably higher levels of homoplasy and poorer resolution of cladistic relationships, with multiple equally parsimonious cladograms. However, comparison of a Nelson consensus tree based on adult characters with the cladogram based on larval characters reveals three components consistently supported in both analyses (the tribes Epeolini and Ammobatini, and Neopasites + Neolarra) , one component supported only by adult characters (Isepeolus + Protepeolus) , and one terminal component supported only by larval characters (Nomada + Ammobatini), as well as several more inclusive groupings based on larval characters that are difficult to compare with the adult consensus tree because it shows so much less resolution. When adult and larval characters are combined in a single data matrix, the resulting cladogram closely resembles the cladogram based on larval characters alone, although levels of homoplasy are considerably higher than in the larval analysis.
A preliminary analysis of adult characters for thirty-four genera in the Nomadinae also exhibited high levels of homoplasy and very large numbers of equally parsimonious cladograms. Nevertheless, certain consistent monophyletic groupings, most notably the Epeolini and Ammobatini, were also supported in this analysis. The one currently recognized tribe whose monophyly has received no support from any analysis is the Nomadini.
The relevance of these phylogenetic hypotheses to our understanding of host associations and variable features of egg morphology and oviposition behaviour in nomadine bees is briefly discussed.     

Molecular phylogeny, character evolution, and biogeography of the grammitid fern genus Lellingeria (Polypodiaceae)

? Premise of the study: The recognition of monophyletic genera for groups that have high levels of homoplastic morphological characters and/or conflicting results obtained by different studies can be difficult. Such is the case in the grammitid ferns, a clade within the Polypodiaceae. In this study, we aim to resolve relationships among four clades of grammitid ferns, which have been previously recovered either as a polytomy or with conflicting topologies, with the goal of circumscribing monophyletic genera. ? Methods: The sampling included 89 specimens representing 61 species, and sequences were obtained for two genes (atpB and rbcL) and four intergenic spacers (atpB-rbcL, rps4-trnS, trnG-trnR, and trnL-trnF), resulting in a matrix of 5091 characters. The combined data set was analyzed using parsimony, likelihood, and Bayesian methods. Ninety-six morphological characters were optimized onto the generated trees, using the parsimony method. ? Key results: Lellingeria is composed of two main clades, the L. myosuroides and the Lellingeria s.s. clades, which together are sister to Melpomene. Sister to all three of these is a clade with two species of the polyphyletic genus Terpsichore. In the L. myosuroides clade, several dispersal events occurred between the neotropics, Africa, and the Pacific Islands, whereas Lellingeria s.s. is restricted to the neotropics, with about 60% of its diversity in the Andes. ? Conclusions: Overall, our results suggest that Lellingeria is monophyletic, with two clades that are easily characterized morphologically and biogeographically. Morphological characters describing the indument are the most important to define the clades within the ingroup. A small clade, previously considered in Terpsichore, should be recognized as a new genus.     

Clade stability and the addition of data: A case study from erigonine spiders (Araneae: Linyphiidae, Erigoninae)

This study presents a new phylogeny of erigonine spiders with emphasis on genera from the Neotropics. Thirty‐nine exemplar taxa representing mostly Neotropical genera were added to a global sample of 31 erigonine and 12 outgroup exemplar taxa analyzed in a previous study. These 82 taxa were coded for 176 (172 informative) mostly morphological characters. Eighty‐one characters were identical to or modified from the 73 (67 informative) characters included in a previous study; the remaining 95 characters are new. The complete data set includes 70 erigonine exemplars representing 65 genera, seven nonerigonine linyphiid exemplars, and five exemplars representing four araneoid families in the outgroup. Cladistic analysis resulted in a single most parsimonious tree (L =904, CI = 0.23, RI = 0.58; uninformative characters excluded: L = 900, CI = 0.23). This paper explores the implications of the new topology for the evolution of several characters of interest in erigonine evolution. The phylogeny implies that the desmitracheate condition is a synapomorphy of erigonines, with a reversal to the haplotracheate condition in one large clade within Erigoninae. We infer that the loss of the paracymbium in Neotropical erigonines occurred twice and may have progressed by different evolutionary pathways. Our phylogeny differs markedly from the previous cladistic hypothesis of erigonine relationships. We investigate how the addition of characters and taxa (alone and together) have altered the earlier hypothesis of erigonine phylogeny. We conclude that topological changes from the previous study to the current one are largely the result of adding and modifying characters, not adding taxa. Continuous Jackknife Function (CJF) analysis predicts that the inclusion of additional character data will continue to imply changes in the relationships among taxa in our analysis.     

Phenetic and cladistic relationships among tenebrionid beetles (Coleoptera)

Abstract. The higher classification of Tenebrionidae is analysed using numerical phenetic, numerical cladistic and traditional Hennigian methods. In all, eighty characters are examined for about 335 taxa; definitive analyses are made on combinations of eighteen to seventy characters for thirty-three OTUs. At lower levels of relationship (genera and closely related tribes) phenetic and cladistic classifications are shown to be congruent, but at higher levels (tribes and subfamilies) there is marked discordance with phenetic results being more stable. A consensus classification is more similar to the Hennigian cladogram than is any single computer generated cladogram. Two main tribal groups – the Lagrioid and Tenebrionoid groups – are suggested which differ in defensive glands, female anatomy, wing and mouthpart morphology, larval characters and other features. The Tenebrionoid group consists of three main subdivisions – the tenebrionine, coelometopine and diaperine lineages. Changes in classificatory position are recommended for eighty-seven genera and tribes (listed in Appendix E) and implied for numerous others.     

Classification of the family Plectonemertidae (Nemertea): a phenetic comparison

A phenetic classification based on overall morphological similarity between the species in the family Plectonemertidae (genera Plectonemertes, Campbellonemertes, Potamonemertes, Leptonemertes, Katechonemertes, Argonemertes, Anliponemertes, and Acteonemertes ) was undertaken and the result compared with a cladistic and an evolutionary classification. Similarity between species was computed by Gower's general coefficient of similarity and various techniques were used to find patterns in the similarity matrix: single-linkage, average-linkage, and complete-linkage clustering, together with principal coordinate analysis. Although the explicit aim of phenetics is not to estimate the phylogeny, the classification based on overall similarity still portrays phylogeny better than an intuitive assessment of morphological similarity, as judged by the cladistic analysis. The classification does not support the previously proposed hypothesis that the two freshwater genera Campbellonemertes and Potamonemertes have descended from a terrestrial ancestor.     

Implications of morphological phylogenetics for the placement of the generaAdenocaulon andEriachaenium (Asteraceae)

Adenocaulon andEriachaenium are two problematic genera because their tribal and subfamilial placement in Asteraceae is uncertain. Previous cladistic analyses based on molecular data undertaken to analyze the relationships within Asteraceae, placeAdenocaulon in the tribe Mutisieae (Cichorioideae). This paper investigates cladistic relationships amongAdenocaulon andEriachaenium and tribes of subfamilies Cichorioideae and Asteroideae using morphological data. Thirty-eight characters were scored across 52 genera selected as exemplar taxa to represent the current classification system. In the analysis (one tree, length = 86, c.i. = 0.55, r.i. = 0.64)Adenocaulon andEriachaenium are sister taxa and appear as an isolated clade nested in Cichorioideae. A new, tentative position among the tribes of the paraphyletic Cichorioideae is proposed for these two isolated genera.     

Cladistics and the comparative morphology of linyphiid spiders and their relatives (Araneae, Araneoidea, Linyphiidae)

This paper provides the first quantitative cladistic analysis of linyphiid morphology. Classical and novel homology hypotheses for a variety of character systems (male and female genitalia, somatic morphology, spinneret silk spigot morphology, etc.) are critically examined and studied within a phylogenetic context. Critical characters have been illustrated. A sample of linyphiid taxa (nine genera in four subfamilies), five species of Pimoa (Pimoidae), and two other araneoid families (Tetragnathidae and Araneidae, represented by Tetragnatha and Zygiella , respectively) were used to study the implications of the phylogeny of Pimoidae for the systematics of linyphiids. The phylogenetic relationships of these 16 exemplar taxa, as coded for the 47 characters studied, were analysed using numerical cladistic methods. In the preferred cladogram Pimoidae and Linyphiidae are sister groups, Stemonyphantinae are sister group to the remaining linyphiids, and Mynogleninae are sister group to the clade composed of Erigoninae plus Linyphiinae. These results agree with the relationships recently proposed by Wunderlich, except by finding erigonines as the sister group to linyphiines rather than to mynoglenines.