Relationships, classification and evolution of Scleranthus (Caryophyllaceae) as inferred from analysis of morphological characters

Study of floral anatomy, micromorphology, palynology and onotogeny has revealed new characters for phylogenetic analysis in the genus Scleranthus . Cladistic analysis of these characters, along with those previously available, suggests that the genus consists of Eurasian/Mediterranean and Australasian sister clades. Gynoecial morphology and development are closely similar in all species, suggesting the genus is monophyletic despite its disjunct northern and southern hemisphere distribution. Variation in pollen:ovule ratios and their implications for the evolution of Scleranthus species are also discussed and it is concluded that a range of breeding strategies intermediate between autogamy and xenogamy exists in the genus. Single-stamened species of Scleranthus are likely to be obligate autogams, despite their comparatively high pollen:ovule ratios in relation to autogamic species of other genera.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 15–29.     

Phyllanthus section Choretropsis (Euphorbiaceae) in Brazil

Section Choretropsis genus Phyllanthus (Euphorbiaceae) is formed by plants whose branches are modified into phylloclades. Despite the suitable characteristics of phylloclades within the Phyllanthus genus, the systematics of these species are poorly understood. Morphological data are presented here to allow future revision of this taxonomic group. The section is represented by nine species distributed in South America, eight of them endemic to Brazil. Our taxonomic studies distinguish the species and propose the synonymization of nine varieties of P. klotzschianus and two varieties of P. flagelliformis based on vegetative and reproductive characters. The diversity of branching and the morphology of phylloclades are discussed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 131–164.     

Integrative taxonomy reveals cryptic Amazonian species of Pristimantis (Anura: Strabomantidae)

Hypotheses on the taxonomic status of two Bolivian Pristimantis with taxonomic problems are assessed by an integrative taxonomic approach that integrates three independent lines of evidence: external morphology, prezygotic reproductive barriers (advertisement calls) and reciprocal monophyly (phylogenetic analyses of partial 16S mtDNA sequences). Central Andean Bolivian populations previously assigned to either P. peruvianus or P. dundeei, and lowland Amazonian populations from southern Peru and northern Bolivia previously considered P. peruvianus do not correspond to these species. Indeed, multivariate analyses of qualitative and quantitative morphological and bioacoustic characters, and phylogenetic analyses support the hypothesis that they represent different, previously unknown, cryptic lineages. They are herein described as new species. The former is a sibling species of P. fenestratus that inhabits the Amazonian and semideciduous forests of the Andean foothills in central Bolivia. The latter is sibling to the Andean species P. danae and is parapatric to it in the Amazonian lowland forests and adjacent foothills of northern Bolivia, southern Peru and adjacent Brazil. Most species of Neotropical frogs, and especially Pristimantis, have been described by using external qualitative morphological characters only. An extended integrative taxonomic approach, as exemplified herein, may lead to the discovery of many other cryptic and sibling lineages that would increase the species numbers of tropical areas. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 97–122.     

Quantification of sexual dimorphism in Asellus aquaticus (Crustacea: Isopoda) using outline approaches

A marked sexual dimorphism is often observed in arthropods species in which males perform precopulatory mate guarding. It is generally thought to reflect the influence of sexual selection. Until now, sexual dimorphisms associated with mate guarding have mainly been qualitatively described. However, assessing the effects of sexual selection on sexual dimorphims requires a preliminary quantitative assessment of differences in morphology between sexes. Using Fourier analyses, we tested if morphological dimorphisms could be quantitatively assessed in the isopod Asellus aquaticus . In addition, we checked whether sexual dimorphism in shape was exclusively related to mate guarding through considering characters that are not, a priori , implicated in mating behaviour. To assess the potential role of sexual selection in shaping morphology, we then examined how dimorphic characters could influence males' pairing success. Three characters (pleotelson, paraeopods 4 and 5) differed significantly in shape between males and females. In addition, two characters (pleotelson and paraeopods 4) differed in shape between guarding males and non-guarding males, with the latter being closer in shape to females. This suggests that sexual selection may be partly responsible for the observed morphological divergence between sexes in A. aquaticus .  © 2002 The Linnean Society of London, Biological Society of the Linnean Society , 2002, 77 , 523–533.     

Development, phylogeny, and taxonomy of Bostrycapulus (Caenogastropoda: Calyptraeidae), an ancient cryptic radiation

Calyptraeid gastropods are well know for the taxonomic difficulties caused by their simple, phenotypically variable shells. In this paper I demonstrate that what was previously considered to be a single species, Crepidula aculeata , is an ancient (3–15 Myr) cryptic species complex made up of at least eight species, and that this group should be placed in the genus Bostrycapulus . Despite the difficulty in finding diagnostic adult shell and anatomical features upon which species can be unambiguously identified, DNA sequences, protoconch morphology, embryonic morphology and developmental characters clearly differentiate these eight species. A single species with direct development and nurse eggs is present in the South Atlantic, and a species with planktotrophic development occurs in the equatorial Pacific. The species from Japan, Australia, Florida, the Pacific coasts of Mexico and Central America, and the Cape Verde Islands all have direct development. Most of these species are separated by > 15% divergence in COI sequence data. The fossil record of Bostrycapulus goes back to the Miocene, which agrees with genetic estimates of divergences within the genus ranging from 3 to 15 Mya. Surprisingly, these ancient species differ only slightly in morphology from each other and genetic differentiation does not correlate with geographical distance. I revise the genus Bostrycapulus on the basis of differences in adult morphology, embryonic morphology, mode of development, protoconch morphology, and DNA sequence data. I also describe four new species ( B. pritzkeri sp. nov., B. odites sp. nov., B. latebrus sp. nov. and B. urraca sp. nov. ) and remove three others ( B. gravispinosus , B. calyptraeformis , and B.  cf. tegulicius ) from synonymy with B. aculeatus .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 75−101.     

Paeonia (Paeoniaceae) in the Caucasus

The taxonomy of the genus Paeonia in the Caucasus has been controversial, with recognized species varying in number from one to 13. The taxonomic history of Paeonia in this area is reviewed (including an analysis of the characters used by previous authors) based on extensive field observations, population sampling and critical examination of a large number of herbarium specimens. The results show that Paeonia may be divided into three groups. The P. intermedia group is known from only a single population. In the P. tenuifolia group, all the characters used for distinguishing the three previously recognized species were found to be polymorphic. In the P. daurica group, petal colour, shape and size of leaflets, and indumentum of leaflets and carpels were used to distinguish nine species, but these characters were found to be polymorphic or continuous in variation, and thus can only be used for infraspecific classification. Thus, three species are recognized: P. intermedia , P. tenuifolia and P. daurica . The last species is further divided into five subspecies: sspp. coriifolia , wittmanniana , mlokosewitschii , macrophylla and tomentosa stat. nov .  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143 , 135–150.