Craniomandibular Variation in the Taxonomically Problematic Gerbil Genus <Emphasis Type="Italic">Gerbillus</Emphasis> (Gerbillinae,Rodentia): Assessing the Influence of Climate,Geography, Phylogeny,and Size

The taxonomy of Gerbillus, the most speciose gerbil genus, is highly debated. Of particular contention is the relationship of Dipodillus to Gerbillus; some consider it to be a closely related genus, while others synonymize it with Gerbillus—either with or without recognizing it as a subgenus. The main objective of this study is to test the validity of common taxonomic groupings within the Gerbillus-Dipodillus species complex, which was achieved by using geometric morphometrics to examine cranial and mandibular variation in 34 out of the 52 Gerbillus-Dipodillus species. Craniomandibular size and shape were highly correlated, indicating strong allometric patterns in shape variation. The common taxonomic groups were significantly different in craniomandibular size and shape, yet they did overlap considerably in morphospace. A notable exception was the extreme divergence of Monodia (G. mauritaniae) from all other species in the occlusal view of the mandible. Morphospace overlap is likely a consequence of both phylogenetic history and environmental adaptation. Only the ventral cranium was associated with climate, particularly in areas related to resource acquisition. Geographic distance was not significantly associated with craniomandibular morphometric distance, and the groups overlapped greatly in their geographic range. Cranial and mandibular regions differed in discrimination power—the ventral cranium had among the highest, while the dorsal cranium and the occlusal mandible had the lowest. Craniomandibular regions varied in association with climate, phylogeny, and size—previous studies suggest this difference may be a consequence of different genetic controls for shape variation.     

Molecular systematics of gerbils and deomyines (Rodentia: Gerbillinae,Deomyinae) and a test of desert adaptation in the tympanic bulla

Recent molecular studies in gerbils found multiple instances of discordance between molecular and morphological phylogenies. In this study, we analyse the largest molecular data set to date of gerbils and their sister group the deomyines to estimate their phylogenetic relationships. Maximum‐likelihood and Bayesian analyses were largely concordant, and both generally had high levels of node support. For gerbils, the results were generally concordant with previous molecular phylogenies based on allozymes, chromosomes, DNA/DNA hybridization and DNA sequences, and discordant with morphological phylogenies. None of the traditional gerbil tribes and subtribes were monophyletic. In addition, paraphyly was found in the genera Gerbillus, Gerbilliscus and Meriones as well as in five subgenera within Dipodillus, Gerbillurus and Meriones. Short branches separating taxa in small clusters within Dipodillus and Meriones suggest synonymy. Within deomyines, all genera and subgenera were monophyletic; however, two species groups within Acomys appear to contain synonymous taxa. We also find support for the discordance between molecular and morphological phylogenies in gerbils being partly due to convergent adaptations to arid environments, primarily in the suite of traits associated with inflation of the tympanic bullae. Relative bullar size does appear to be a desert adaptation and is correlated with aridity independent of phylogeny. Further, it varies more strongly along bioclimatic clines than between binary habitat classifications (desert versus mesic).     

Integrative taxonomy of a poorly known Sahelian rodent, Gerbillus nancillus (Muridae,Gerbillinae)

Aridification processes that affected the Sahelian area of West Africa during the last decades have induced significant changes in plant and animal communities of this region. In rodents, the genus Gerbillus characteristic of North African and Asian arid habitats has been affected by this climatic and environmental trends. Several species of this genus showed a southward range expansion in recent years into the Sahelian bioclimatic zone. Recent sampling in several localities of West Africa (Mali, Niger and Senegal) enabled us to collect numerous specimens of small gerbils. An integrative study of these samples using molecular, morphological and cytogenetical methods revealed that many of them were attributable to Gerbillus nancillus, a secretive and poorly known species. Gerbillus nancillus appears characterized by a well differentiated karyotype with 2n = 56 chromosomes, and to represent a unique genetic lineage within this genus. Body and skull measurements of G. nancillus were compared with those of the morphologically similar Gerbillus henleyi, which provided diagnostic clues between them. These new data significantly expand the distribution area of G. nancillus, which now ranges from Sudan in the East to Senegal in the West. G. nancillus is here reported from numerous new localities in Niger and Mali, and for the first time in Senegal, which raises questions about the origin of its presence and the colonization routes it followed to get there. We also show that G. henleyi and G. nancillus are sympatric and apparently often syntopic in the sub-Saharan part of the distribution of G. henleyi.     

Molecular phylogeny and biogeography of Malagasy frogs of the genus Gephyromantis

The genus Gephyromantis is a clade within the Malagasy-Comoroan family Mantellidae composed of rainforest frogs that live and breed to varying degrees independently from water. Based on DNA sequences of five mitochondrial and five nuclear genes we inferred the phylogeny of these frogs with full taxon coverage at the species level. Our preferred consensus tree from a partitioned Bayesian analysis of 5843 base pairs of 51 nominal and candidate species supports various major clades within the genus although the basal relationships among these remain unresolved. The data provide strong evidence for the monophyly of the subgenera Gephyromantis (after exclusion of Gephyromantis klemmeri), Laurentomantis, Vatomantis, and Phylacomantis. Species assigned to the subgenus Duboimantis belong to two strongly supported clades of uncertain relationships. G. klemmeri, previously in the subgenus Gephyromantis, was placed with high support sister to the Laurentomantis clade, and the Laurentomantis + G. klemmeri clade was sister to Vatomantis. A reconstruction of ancestral distribution areas indicates a diversification of several subgenera in the northern biogeographic regions of Madagascar and the dispersal out of northern Madagascar for several clades.     

Phylogenetic relationships among species of the Neotropical genus Graomys (Rodentia: Cricetidae): contrasting patterns of skull morphometric variation and genetic divergence

Subtle differences of external traits characterize species of rodents in the Neotropical genus Graomys. On the other hand, the species differ markedly in chromosome number. In the present study, we evaluate the possible evolutionary forces involved in the evolution of the genus by assessing the degree of intra‐ and interspecific genetic and morphological variation. A phylogenetic analysis demonstrates the existence of at least three species with high levels of genetic distance (10%), which diverged between 1 and 1.5 Mya. Neither Graomys griseoflavus, nor Graomys chacoensis present marked phylogeographical structure. Regarding morphological characters, these species show shape differences in the skull that could be attributable to differences in the local conditions they inhabit, being more marked in G. griseoflavus than in G. chacoensis. The skull shape of G. chacoensis could have evolved under genetic drift, whereas evidence reported in the present study indicates that this character could be under selective pressures in G. griseoflavus. Reconstruction of the ancestral area suggests that G. griseoflavus originated in the central Monte desert, whereas G. chacoensis originated in the Chaco ecoregion surrounding the austral extreme of the Yungas rainforest. Subsequently, both species would have undergone demographic and geographical expansions almost simultaneously, starting approximately 150 000–175 000 years ago. The complex evolutionary history of the genus could be partly explained by the decoupling of morphological, karyological and molecular traits.     

Molecular evolution of tephritid fruit flies in the genus Bactrocera based on the cytochrome oxidase I gene

Fruit flies of the genus Bactrocera (Diptera: Tephritidae) are one of the major economically important insects in Asia and Australia. Little attention has been given to analyses of molecular phylogenetic relationships among Bactrocera subgenera. By using mitochondrial cytochrome oxidase I gene (COI) sequences, the phylogenetic relationships among four subgenera, Asiadacus, Bactrocera, Hemigymnodacus, and Zeugodacus, were investigated. Nucleotide diversity within subgenera ranged from 11.7 to 12.4%, and the net divergence among subgenera ranged from 11.2 to 15.7%. Phylogenetic trees calculated from both maximum parsimony and neighbor-joining phylogenetic analysis methods were highly congruent in terms of tree topologies. Phylogenetic analysis of mitochondrial COI sequences suggests that tephritid fruit fly species, which attack cucurbit plants, that is, Asiadacus, Hemigymnodacus and Zeugodacus, were more closely related to each other than to fruit fly species of the subgenus Bactrocera, which attack plants of numerous families. Our data supports previous classification of Bactrocera based on morphological characters. However, the phylogenetic tree showed the polyphyletic of fruit flies in subgenus Zeugodacus. Possible causes of speciation among fruit flies species in this genus were also discussed.     

Revision of the pale-bellied Micronycteris Gray, 1866 (Chiroptera,Phyllostomidae) with descriptions of two new species

The systematics and taxonomy of the Neotropical genus Micronycteris are not yet resolved; previous studies evidenced paraphyletic relationships, a number of potential undescribed species, and inadequate diagnostic characters. This revision focuses on the pale-bellied members of the genus using phylogenetic and morphometric tools, an increased sample size with all recognized taxa, and an expanded geographic coverage relative to prior studies. For the genetic analyses (n = 166), four molecular markers were concatenated, one mitochondrial (cytb), one nuclear (Fgb-I7), and two Y-chromosomal (DBY5 and DBY7). In the Bayesian and maximum likelihood analyses, the recognized subgenera Schizonycteris, Leuconycteris, Xenoctenes, and Micronycteris were recovered as monophyletic. The pale-bellied subgenera, Schizonycteris and Leuconycteris, were not sister clades; thus, venter coloration was not monophyletic. Leuconycteris was sister to the dark-bellied Micronycteris, and Schizonycteris was sister to the rest of the genus. Micronycteris schmidtorum was genetically defined for the first time, and it was determined all previous phylogenetic studies used a misidentified M. minuta from Bolivia. Our results showed a sister relationship between M. schmidtorum and M. brosseti, which redefines Leuconycteris. The subgenus Schizonycteris was also redefined, and it presented two well-supported clades from Central America and western Ecuador that are described as new species. Results are supported by a multivariate morphometric analyses (n = 114), karyological, and morphological comparisons. The taxonomic implications are discussed and emended diagnoses presented for the pale-bellied subgenera and for M. schmidtorum.     

Aspergillus yunnanensis,a new and rare species in the Aspergillus section Jani

Aspergillus is a monophyletic genus comprising the subgenera Aspergillus, Circumdati, Cremei, Fumigati, Nidulantes and Polypaecilum. The subgenus Circumdati contains many economically important species and mycotoxin producers. Section Jani was recently introduced with morphological and molecular support. In the present study, two strains isolated from farmland soil were assigned in section Jani based on multi-locus phylogenetic analyses but showed low similarity with existing species. Further morphological observation found they had wider vesicles and conidia connections which were different from the known species. Based on phylogenetic and morphological data, Aspergillus yunnanensis was introduced as the third species in section Jani. Members in section Jani are rarely distributed, this is the first report of this section in China.     

New insights into the pollen morphology of the genus Gunnera (Gunneraceae)

Pollen grains from ten species of Gunnera, chosen to represent the six different subgenera in the genus, were examined using light and scanning electron microscopy. The aim of the study was to explore characters that have the potential to define different types of pollen within Gunnera and to study the evolution of these characters in light of the phylogeny of the genus. According to our results, there are three main types of pollen in the examined species of Gunnera. Type 1, unique for the South American species G. herteri (subgenus Ostenigunnera), is characterised by an imperfect reticulum with sinuous undulating-creasted muri. A reticulum with equidimensional polygonal lumina is typical for the plesiomorphic type of pollen (type 2) present in subgenera Gunnera, Misandra and Panke. Lastly, pollen grains of subgenera Pseudogunnera and Milligania are characterised by a reticulum with lumina of variable shape and size (type 3). In G. macrophylla (subgenus Pseudogunnera), the lumina in the apocolpia are of a different shape and size from the lumina in the mesocolpia (type 3a), while in G. dentata, G. monoica and G. cordifolia (subgenus Milligania), the lumina are identical in the apocolpium and the mesocolpium (type 3b).

The identification of pollen types will possibly allow the interpretation of the different specimens of Tricolpites reticulatus, the fossil species believed to be allied to the extant Gunnera.

In addition to the revision on the pollen of Gunnera, a brief comparison between the pollen of this genus and its sister group Myrothamnus is reported.     

Sesquiterpene lactones and systematics of the genus Artemisia

The sesquiterpene lactones isolated from species in the genus Artemisia have been reviewed in an attempt to better understand the phylogeny and systematics of the four sections (subgenera), Abrotanum, Absinthium, Dracunculus and Seriphidium, proposed by Besser in 1829. The absence of hair on the receptacle is the only morphological characteristic separating species of Abrotanum from the species of Absinthium. There are no chemical characteristics segregating the species in these two subgenera since both produce eudesmanolides and guaianolides that are identical or biosynthetically similar. This suggests that the two subgenera could be combined into one (Artemisia) as proposed by Poljakov. The subgenus Seriphidium is composed of two geographical groups, one in the Old World and the other in the New World. The Old World species almost exclusively produce sesquiterpene lactones in the eudesmanolide class whereas the New World species (section Tridentatae) produce eudesmanolides and guaianolides, many of the latter being identical or structurally related to the sesquiterpene lactones in New World Abrotanum species. The chemical data in conjunction with geographic distributions suggest that the subgenus Seriphidium is polyphyletic and that the section Tridentatae originated from Abrotanum. Consequently, the Tridentate should be recognized as a subgenus separate and distinct from the Old World Seriphidium. There was insufficient information from the subgenus Dracunculus for interpretation.     

Towards a revision of the South American genus Praocis Eschscholtz (Coleoptera,Tenebrionidae), with estimation of the diversity of each subgenus

A review of the subgenera of the South American genus Praocis Eschscholtz (Pimeliinae: Praociini) is presented. Praocis comprises 77 species and 8 subspecies arranged in nine subgenera distributed in arid lands from Central Peru and Bolivia to the Southern part of Patagonia in Chile and Argentina. For each subgenus of Praocis: Praocis Eschscholtz, Mesopraocis Flores & Pizarro-Araya, subgen. n., Anthrasomus Guérin-Méneville, Filotarsus Gay & Solier, Postpraocis Flores & Pizarro-Araya, subgen. n., Hemipraocis Flores & Pizarro-Araya, subgen. n., Orthogonoderes Gay & Solier, Praonoda Flores & Pizarro-Araya, subgen. n., and Praocida Flores & Pizarro-Araya, subgen. n., we present a diagnosis using new and constant characters of adult morphology such as clypeal configuration, length and proportion of antennomeres 9, 10 and 11, arrangement of apical tomentose sensory patches on antennomeres 10 and 11, anterior margin of prosternum, lateral margin of elytron, ventral surface of profemora, and shape of protibiae. An identification key for the nine subgenera of Praocis is presented. Type species are designated for the five new subgenera; for Mesopraocis: Praocis calderana Kulzer, for Postpraocis: Praocis pentachorda Burmeister, for Hemipraocis: Praocis sellata Berg, for Praonoda: Praocis bicarinata Burmeister, for Praocida: Praocis zischkai Kulzer, and for the previously described subgenus Orthogonoderes: Praocis subreticulata Gay & Solier. The current number of species and the estimated number of species to be described are presented. The distribution ranges of the subgenera, including new records from collections and recent expeditions, are given. Habitat preferences and a discussion of the biogeography of the genus are also presented.     

The morphology of the larval stages of three species (Arrenurus mediorotundatus Thor, 1898; Arrenurus conicus Piers 1894; and Arrenurus cylindratus Piers, 1896) of the Megaluracarus subgenus (Acari: Hydrachnidia: Arrenuridae)

The morphology of the larval stages of three species (Arrenurus mediorotundatus, Arrenurus conicus and Arrenurus cylindratus) belonging to the Megaluracarus subgenus is described. Particular attention is paid to the common characters of the three species in which they differ from the other species belonging to the other subgenera. These are: the shape of the excretory pore plate, the shape of the dorsal plate, the length of coxal plate II medial margin and the C1-CpI, C4-CpIII distances. Other characters differ between the three species also. These are: the shape of the dorsal plate, the shape of coxal plate III, the shape of excretory pore plate and the presence or absence of secondary setae of the IFe3 setae.     

Ornamentation of achene silica walls and its contribution to the systematics of <Emphasis Type="Italic">Eleocharis</Emphasis> (Cyperaceae)

Micromorphology of the achene surface of 26 Brazilian species of Eleocharis was studied by scanning electron microscopy in order to evaluate its usefulness in the taxonomy of the genus. The results point out two patterns of cell organization according to silica structures of achenes. The first corresponds to a group of species (group A) that have small to medium cells arranged vertically. The second is found in those species (group B) with medium to large cells arranged horizontally. These data were useful in separating species of Eleocharis subgenus Scirpidium and E. subgenus Limnochloa (group B) from E. subgenus Eleocharis (group A). However, group A shows considerable variation in silica wall arrangement. Eleocharis squamigera, previously considered as part of E. subgenus Eleocharis, shows features rather similar to those of Scirpidium, confirming recent phylogenies. The subgenus Limnochloa was clearly distinguished from others by achenes with large cells (over 55 μm width), presence of crenate or repand anticlinal walls, and some orifices near the wall in some species. The silica wall ornamentation seems to be a useful morphological tool for studying relationships between subgenera and distinguishes Limnochloa from the other subgenera.     

Molecular phylogeny of the subgenus Holothuria (Selenkothuria) Deichmann, 1958 (Holothuroidea: Aspidochirotida)

The subgenus Selenkothuria comprises 12 species of tropical shallow water sea cucumbers that share morphological features, such as rods in the body wall and tube feet, modified tentacles for suspension feeding, and cryptic colours. The taxonomic status of this taxon has been controversial, but currently it is accepted as a subgenus of the genus Holothuria. Phylogenetic analyses of mitochondrial genes [cytochrome c oxidase subunit 1 (COI), 16S RNA] of ten species of Selenkothuria and related subgenera showed the polyphyly of this subgenus; monophyly was rejected by a likelihood ratio test. A geographical split divides the species of this subgenus into three different groups: one Indo‐West‐Pacific (IWP) group and two American groups. The IWP group is more closely related to Holothuria (Semperothuria) cinerascens and to other subgenera such as Roweothuria, Holothuria, and Vaneyothuria, whereas the two American groups are more closely related to each other and to some species of the subgenus Halodeima. These results suggest multiple parallel originations and diversification of ossicle morphology within the subgenus Selenkothuria. The current scheme of subgenera for the genus Holothuria is not supported, suggesting the need for a new classification. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 109–120.     

Molecular phylogenetic analyses indicate paraphyly of the genus Hybomys (Rodentia: Muridae): Taxonomic implications

Widely distributed in Guineo‐Congolian forests, the genus Hybomys is represented by two species complexes (univittatus and trivirgatus), each restricted to one distinct forest block. In the last revision, these two species complexes were considered as distinct subgenera (Hybomys and Typomys). Previous morphological and karyological studies identified an important divergence between these two subgenera and raised the question of their taxonomic status (subgenus or genus). The number of species within this genus is also a matter of discussion: nine forms were described but only six (H. badius, H. basilii, H. lunaris, H. planifrons, H. trivirgatus, and H. univitttatus) are currently recognized as distinct species, the three others (H. pearcei, H. eisentrauti, and H. rufocanus) being considered as synonyms. The monophyly of the genus and its species have never been previously investigated with DNA sequence data. In this study, we combined mitochondrial and nuclear data (for a total of 3,264 nucleotide characters) to test the monophyly of Hybomys and to assess the specific status of H. eisentrauti and H. rufocanus. Our results highlight the paraphyly of the genus: members of the H. univittatus species complex appeared closely related to the genera Stochomys and Dephomys; representatives of H. trivirgatus are the sister clade of the node grouping Stochomys, Dephomys and member of the H. univittatus species complex. Combined with previous morphological findings, our results suggest that Typomys and Hybomys should be considered as two distinct genera. Based on tree topology and genetic distances, we propose to consider H. rufocanus as a valid species, distinct from H. univittaus, and to consider H. badius and H. eisentrauti as junior synonyms of H. rufocanus.     

A MORPHOLOGICAL AND MOLECULAR STUDY OF AUSTRAL SARGASSUM (FUCALES,PHAEOPHYCEAE) SUPPORTS THE RECOGNITION OF PHYLLOTRICHA AT GENUS LEVEL,WITH FURTHER ADDITIONS TO THE GENUS SARGASSOPSIS1

Sargassum subgenus Phyllotricha currently includes seven species restricted to Australian and New Zealand coasts. A recent study of Cystoseira and other Sargassaceae genera based on mitochondrial 23S DNA and chloroplast‐encoded psbA sequences resulted in the most widely distributed species of subgenus Phyllotricha, Sargassum decurrens, being transferred to the reinstated monospecific Sargassopsis Trevisan. The fate of the residual six Phyllotricha species, however, was not considered. The present study examines these Phyllotricha species, alongside other Sargassum subgenera, Sargassopsis, Sirophysalis trinodis (formerly Cystoseira trinodis) and the New Zealand endemic Carpophyllum Greville, using morphological evidence and the molecular phylogenetic markers cox3, ITS‐2 and the rbcL–S spacer. Our results suggest both the genus Sargassum and Sargassum subgenus Phyllotricha are polyphyletic as currently circumscribed. Four S. subgen. Phyllotricha species, i.e. S. sonderi, S. decipiens, S. varians and S. verruculosum, form a monophyletic group sister to the genus Carpophyllum, and S. peronii is genetically identical to S. decurrens with regard to all three loci. We propose the resurrection of the genus Phyllotricha Areschoug, with type species Phyllotricha sonderi, and include the new combinations Phyllotricha decipiens, Phyllotricha varians and Phyllotricha verruculosum. Sargassum peronii, S. heteromorphum and S. kendrickii are transferred to Sargassopsis and Sargassum peronii is considered a synonym of Sargassopsis decurrens.     

New and little known crickets of the subfamily phalangopsinae (Orthoptera, Gryllidae): 3. Indonesia, the Philippines, and Seychelles

Two new subgenera and eight new species of the subfamily Phalangopsinae are described from Sulawesi, Supiori, Mindoro, Palawan, Sumatra, and Cousin islands. Two former subgenera, Longizacla and Brevizacla, are considered as genera. The new synonymy for a subgenus of the genus Luzonogryllus is established. Diagnostic characters and systematic position of some taxa are discussed.     

A review of the genus <Emphasis Type="Italic">Deporaus</Emphasis> (Coleoptera,Rhynchitidae) from the Russian fauna: 1. Subgenera <Emphasis Type="Italic">Pseudapoderites</Emphasis> and <Emphasis Type="Italic">Japonodeporaus</Emphasis>

The genus Deporaus from the Russian fauna is revised. Four species (D. pacatus, D. azarovae, D. septentrionalis, and D. hartmanni) of the subgenera Pseudapoderites and Japonodeporaus are found. Keys to the subgenera and to the species of the subgenus Pseudapoderites are given. The genus Deporaus, subgenera Pseudapoderites and Japonodeporaus, and four species are redescribed. The distribution of these species in Russia is discussed.     

Molecular phylogenetics and biogeography provide insights into the subgeneric classification of Wiedemannia Zetterstedt (Diptera: Empididae: Clinocerinae)

The subgenera of Wiedemannia are poorly defined and, as such, most recently described species are not assigned to a subgenus or have been assigned to a subgenus without explanation. In this study we perform a molecular phylogenetic analysis to elucidate relationships within the genus Wiedemannia. We sequenced two mitochondrial (cytochrome oxidase c subunit I and cytochrome β) and two nuclear (carbomoylphosphate synthase domain of rudimentary and elongation factor‐1α) gene fragments to reconstruct phylogenetic relationships among the subgenera Chamaedipsia, Eucelidia, Philolutra, Pseudowiedemannia, Roederella and Wiedemannia (s.s.) using both Bayesian inference and maximum likelihood approaches. The genus was found to be monophyletic, but most of the subgenera were not. We propose eliminating the present subgeneric division altogether. Molecular dating using a log‐normal clock model and calibration with fossil species indicated that Wiedemannia diversified about 48 Ma, while there was still land connectivity between Europe and Asia with North America. Wiedemannia has a near‐worldwide distribution apart from the Australasian and Neotropical regions and Antarctica, with greatest species richness in the western Palaearctic, especially the Mediterranean region. Molecular phylogenetics support more recent morphological studies. The subgenera of Wiedemannia are invalid and rejected. Biogeographical data suggest potential hotspots, and the current distribution is discussed.