Biostratigraphy and sedimentary evolution of Late Miocene and Pliocene continental deposits of the Granada Basin (southern Spain)

The Late Miocene and Pliocene continental sediments in the Granada Basin (southern Spain) have yielded large amounts of fossil small mammals in 37 localities from 11 sections. The aim of this paper is to integrate faunistic, stratigraphic, and sedimentary criteria to unravel the geological history of the continental infilling of the basin. The palaeontological study has led to a detailed biozonation on the basis of rodents, which helps to correlate in detail the different sedimentary units found in the basin, and to follow the changes of the different sedimentary systems and their palaeogeographical evolution through time. Combination of the proposed biostratigraphy and the reinterpretation of the magnetostratigraphic analyses of the Barranco del Purcal section allows us to assign an absolute age slightly older than 5.23 Ma to the Turolian–Ruscinian boundary (MN13‐MN14).     

Historical biogeography of the arid‐adapted velvet ant Sphaeropthalma arota (Hymenoptera: Mutillidae) reveals cryptic species

Aim To investigate the phylogeographic patterns among populations of the wide‐ranging velvet ant Sphaeropthalma arota to (1) examine the biogeographic patterns within this species, and (2) associate major genetic divergences to historical vicariance events in order to gain insight into the processes that drove diversification in arid‐adapted organisms. Location Western North America. Methods Phylogenetic relationships were determined by analysing the two ribosomal DNA internal transcribed spacers (ITS1 and ITS2) in Mr Bayes . Divergence dates were estimated for major nodes using two different molecular dating analyses: a penalized likelihood approach to rate smoothing using the program r8s , and a Bayesian MCMC averaging approach to rate smoothing using the program beast . Both analyses were calibrated using fossils from Dominican amber. Haplotype networks were estimated using tcs . Ecological niche models (ENMs) were developed using six bioclimatic variables from the WorldClim data set in the program Maxent . Results The phylogenetic reconstructions indicate that S. arota can be split into four deeply divergent lineages that probably represent distinct species. No morphological characters were found that can be used to identify these four species, making the S. arota species complex the first documented cryptic species complex in the family Mutillidae. Ecological niche models provide estimated distributions, which indicate that each of the four species inhabits a distinct niche. Divergence date estimates suggest that major diversification events occurred in the late Neogene. Main conclusions Sphaeropthalma arota is composed of four genetically distinct species that cannot be distinguished morphologically based on current methods. We suggest that the members of this group be identified as the S. arota species complex. Major diversification events in this species complex can be linked to late Neogene mountain building and aridification events, specifically the uplift of the mountain ranges in southern California and the expansion of the Bouse Sea.     

A maximum likelihood approach to generate hypotheses on the evolution and historical biogeography in the Lower Volga Valley regions (southwest Russia)

The evolution of the diverse flora in the Lower Volga Valley (LVV) (southwest Russia) is complex due to the composite geomorphology and tectonic history of the Caspian Sea and adjacent areas. In the absence of phylogenetic studies and temporal information, we implemented a maximum likelihood (ML) approach and stochastic character mapping reconstruction aiming at recovering historical signals from species occurrence data. A taxon-area matrix of 13 floristic areas and 1018 extant species was constructed and analyzed with RAxML and Mesquite. Additionally, we simulated scenarios with numbers of hypothetical extinct taxa from an unknown palaeoflora that occupied the areas before the dramatic transgression and regression events that have occurred from the Pleistocene to the present day. The flora occurring strictly along the river valley and delta appear to be younger than that of adjacent steppes and desert-like regions, regardless of the chronology of transgression and regression events that led to the geomorphological formation of the LVV. This result is also supported when hypothetical extinct taxa are included in the analyses. The history of each species was inferred by using a stochastic character mapping reconstruction method as implemented in Mesquite. Individual histories appear to be independent from one another and have been shaped by repeated dispersal and extinction events. These reconstructions provide testable hypotheses for more in-depth investigations of their population structure and dynamics.     

A new genus (Chardinomys) of murid rodent (Mammalia,Rodentia) from the neogene of China,and comments on its biogeography

Three murid specimens from the late Neogene ofChina are described, one as the new taxon Chardinomys, which is most closely related to Orientalomys. The Orientalomys-Chardinomys complex was widely distributed over the Palearctic region during the late Neogene. Cf. Rattus occurring with the Orientalomys-Chardinomys complex in China suggests South Asian influence in the eastern Palearctic during the late Neogene.     

Convergence in the distribution patterns of Europe’s plants and mammals is due to environmental forcing

Aim Our aims were to test: (1) the extent to which vascular plant associations are related in space to mammalian associations, and (2) whether the plant associations are more closely related than the mammalian associations to climate and to a published environmental stratification of Europe. Location Europe, as defined by the following boundaries: 11° W, 32° E, 71° N and 35° N. Methods The analysis is based on presence/absence records of mammal species and plant species with a resolution of 50 km × 50 km. The similarity of the overall spatial structure was tested using a partial Mantel test while controlling for the effect of geographical proximity. To further identify the main spatial components in the datasets, we used k‐means clustering and principal components analysis. The resulting geographical patterns were compared with one another, with climate variables and with the environmental stratification of Europe. Results The clustering of the plant data forms coherent areas that can be interpreted as reflections of floristic regions that are controlled to a large extent by climate and topography. In terms of the correlation between distance matrices, the relationship between plants and mammals is relatively strong. The relationships between mammals and climate, and between plants and climate, are more complex but always statistically significant. There is no evidence that the plant clusters are more closely related than the mammalian clusters to climate, although plant clusters are closer to environmental data than to climate. Main conclusions The clustering patterns of mammals and plants form groups that agree with one another in their spatial extent. The forcing of floristic patterns into coherent entities appears mainly to be caused by climatic variables (temperature, temperature range and rainfall), mediated by elevation differences. The formation of individual plant clusters is also related to species numbers and to local and regional floristic differences. The close correlation between the floristic and faunal patterns suggests that the mammal and plant distributions are controlled by the same environmental variables, although the extent to which the mammals are controlled directly by climate or through the influence of vegetation requires more detailed study.     

The biogeography and historical ecology of Lobelia urens L.(r)(the heath lobelia) in southern England

This paper examines the past and present ecology and biogeography of Lobelia urens L. (the heath lobelia) which is threatened with extinction in southern England. A survey of the historical and documentary evidence of the distribution of the species is presented. Historical records exist for nineteen sites in the south but nowhere else in England. The status of L. urens is in decline in Britain with ten populations having been lost this century. The six remaining sites have been surveyed to describe the phytosociology of L. urens communities and the variability of the environmental factors controlling its distribution. A total of ninety-five quadrats containing 122 species were recorded and analysed using two-way indicator species analysis. Canonical correspondence analysis was used to assess the correlations between twenty-eight environmental variables and the floristic variation in the ninety-five quadrats. These were reduced to sixteen variables for the final analysis. L. urens is shown to be a member of rough, grass-heath communities (NVC M25 and W23) dominated by Molinia caerulea and situated on seasonally waterlogged, moderately acidic, nutrient-poor soils. The species is suited to both cyclical and sporadic soil disturbance regimes. The final discussion argues that existing populations will only be maintained and expansion of the species distribution occur, if conservationists prevent woodland succession in L. urens sites and periodically disturb the ground in locations where the species survives at present and also where it has been observed in the recent past. This link between historical ecology and present-day conservation management would appear very important. Further demographic and experimental work is needed to explore these predictions and their implications for the future conservation management of L. urens .     

Gliridae (Rodentia,Mammalia) with a simple dental pattern: a new genus and new species from the European Early and Middle Miocene

A new genus of Gliridae, Simplomys gen. nov. is proposed. It contains glirids with a simplified dental pattern from the European Early and Middle Miocene. Simplomys gen. nov. includes several species originally described as Pseudodryomys such as Simplomys simplicidens, Simplomys robustus, Simplomys julii, and Simplomys aljaphi. In addition, a new species, Simplomys meulenorum sp. nov. , is proposed from the Spanish Miocene. The species of this genus share not only a very reduced and simplified dental morphology, but also unique dental proportions that clearly separate them from any other genera of Gliridae. Simplomys gen. nov. is recorded in most of the fossil faunas from the Early and Middle Miocene of the Iberian Peninsula, and shows the maximum diversity in this area during Mammal Neogene Zones MN 3 and MN 4. The genus has been also recorded in other European countries such as France, Germany, and Switzerland, conferring to this very characteristic taxon an important role for biochronological correlations within the European continent. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 157 , 622–652.     

Phylogeny, biogeography, and host-plant association in the subfamily Apaturinae (Insecta: Lepidoptera: Nymphalidae) inferred from eight nuclear and seven mitochondrial genes

The subfamily Apaturinae consists of 20 genera and shows disjunct distributions and unique host-plant associations. Most genera of this subfamily are distributed in Eurasia South-East Asia and Africa, whereas the genera Doxocopa and Asterocampa are distributed mainly in South America and North America, respectively. Although the Apaturinae larvae mainly feed on the Cannabaceae, those of the genus Apatura are associated with Salix and Populus (Salicaceae), which are distantly related to the Cannabaceae. Here, we infer the phylogeny of Apaturinae and reconstruct the history of host shifting and of colonization in the New World. We analyzed 9761 bp of nuclear and mitochondrial DNA sequence data, including the genes encoding EF1a, Wg, ArgK, CAD, GAPDH, IDH, MDH, RpS5, COI, COII, ATPase8, ATPase6, COIII, ND3, and ND5 for 12 apaturine genera. We also inferred the phylogeny with six additional genera using mitochondrial sequence data alone. Within the Apaturinae, two major clades are recovered in all the datasets. These clades separate the New World genera, Doxocopa and Asterocampa, indicating that dispersal to the New World occurred at least twice. According to our divergence time estimates, these genera originated during the Early Oligocene to the Early Miocene, implying that they migrated across the Bering Land Bridge rather than the Atlantic Land Bridge. The temporal estimates also show that host shifting to Salix or Populus in Apatura occurred more than 15 million years after the divergence of their host plants. Our phylogenetic results are inconsistent with the previously accepted apaturine genus groups and indicate that their higher classification should be reconsidered.     

Morphotypic variability of masticatory surface pattern of molars in the recent and Pleistocene Lemmus and Myopus (Rodentia,Cricetidae) of Europe and Western Siberia

In this article, we present the results of morphological study, applying multivariate statistical analysis, of seven samples of recent Lemmini species (Lemmus lemmus, L. sibiricus, Myopus schisricolor) and eight samples of the ancient Siberian lemmings from the Middle and Late Pleistocene localities, mainly in northeastern Europe. On the basis of studying variability of masticatory surface pattern of molars, 24 morphotypes have been described. The differences in morphotypes frequencies were found between the recent Myopus and Lemmus and between the two Norwegian lemming samples. There are some indications of an evolutionary trend in molar morphology of the Siberian lemmings of the Middle, Late Pleistocene, and the recent of Eastern Europe. The distinctions, at least, between the Middle Pleistocene and modern lemmings exceed a species level.     

Patterns in the morphological variation of Zonorchis and Skrjabinus (Trematoda: Dicrocoelidae) from small mammals in Malaysia.

A collection of dicroceolid flukes from rats, squirrels and Tupaia in Malaysia is found to be morphologically heterogeneous. Cluster analysis on the basis of three selected body ratios distinguishes two major types comprising highly diverse Skrjabinus from rats, and homogenous Zonorchis from callosciurid squirrels. Tupaia harbours flukes of both genera. Analysis of variance of flukes from rats, demonstrates marked uniformity among worms within individual hosts. Possible effects of allometric growth are investigated by plotting each chosen dimension against body length for the two major groups of worms. Prominent changes are noted only in the relative size of testis in Skrjabinus from rats. Patterns of morphology are discussed in relation to host ecology and distribution.     

A new species of lesser panda Parailurus (Mammalia,Carnivora) from the Pliocene of Transbaikalia (Russia) and some aspects of ailurine phylogeny

A new species of the lesser panda, Parailurus baikalicus sp. nov., from the Pliocene of Transbaikalia is described. In contrast to the European taxa P. anglicus and P. hungaricus, it retains a primitive occlusal pattern of M¹-M², with a concave buccal outline, small mesostyle on M¹, and undeveloped styles on M². At the same time, the Transbaikalian panda is more advanced than other representatives of Parailurus in the upper molars with a reduced lingual cingulum and an enlarged paraconule, which is partially (M¹) or completely (M²) separated from the protocone. This combination of primitive and advanced characters points to the separation of the Asian branch at the earliest stages of the genus development. The Transbaikalian lesser panda may represent a terminal form of this phylogenetic lineage.     

Adding new pieces to the Azadinium (Dinophyceae) diversity and biogeography puzzle: Non-toxigenic Azadinium zhuanum sp. nov. from China,toxigenic A. poporum from the Mediterranean,and a non-toxigenic A. dalianense from the French Atlantic

The marine planktonic dinophyceaen genus Azadinium is a primary source of azaspiracids, but due to their small size its diversity may be underestimated and information on its biogeography is still limited. A new Azadinium species, A. zhuanum was obtained from the East China Sea and Yellow Sea of China by incubating surface sediments. Five strains were established by isolating single germinated cells and their morphology was examined with light microscopy and scanning electron microscopy. Azadinium zhuanum was characterized by a plate pattern of Po, cp, X, 4′, 2a, 6′′, 6C, 5S, 6′′′, 2′′′′, by a distinct ventral pore at the junction of Po, the first and fourth apical plates, and a conspicuous antapical spine. Moreover, Azadinium poporum was obtained for the first time from the Mediterranean by incubating surface sediment collected from Diana Lagoon (Corsica) and a new strain of Azadinium dalianense was isolated from the French Atlantic. The morphology of both strains was examined. Small subunit ribosomal DNA (SSU rDNA), large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer (ITS) sequences were obtained from cultured strains. In addition, LSU sequences were obtained by single cell sequencing of two presumable A. poporum cells collected from the French Atlantic. Molecular phylogeny based on concatenated SSU, LSU and ITS sequences revealed that A. zhuanum was closest to A. polongum. French A. poporum from Corsica (Mediterranean) and from the Atlantic showed some genetic differences but were nested within one of the A. poporum ribotypes together with other European strains. Azadinium dalianense from France together with the type strain of the species from China comprised a well resolved clade now consisting of two ribotypes. Azaspiracid profiles were analyzed for the cultured Azadinium strains using LC–MS/MS and demonstrate that the Mediterranean A. poporum strain produced AZA-2 and AZA-2 phosphate with an amount of 0.44 fg cell⁻¹. Azadinium zhuanum and A. dalianense did not produce detectable AZA. Results of the present study support the view of a high diversity and wide distribution of species belonging to Azadinium. The first record of AZA-2 producing A. poporum from the Mediterranean suggests that this species may be responsible for azaspiracid contaminations in shellfish from the Mediterranean Sea.     

The introduction to Japan of the Titan barnacle,Megabalanus coccopoma (Darwin, 1854) (Cirripedia: Balanomorpha) and the role of shipping in its translocation

The Titan Acorn barnacle, Megabalanus coccopoma, a native of the tropical eastern Pacific, has become established in the western Atlantic (Brazil and the northern Gulf of Mexico to the Carolinas), northwestern Europe and the western Indian Ocean (Mauritius), and therefore its dispersal capabilities are well known. This study reports its introduction to Japan and confirms its occurrence in Australia. In an attempt to determine the source of this introduction, phylogeographic techniques, involving cytochrome c oxidase I sequences of various widely separate populations of M. rosa and M. volcano, were utilized. No significant genetic differentiation or haplotype patterns between widely separated populations of each of the three species were found. Lack of such differentiation indicates recent geographical isolation and thus negates a null hypothesis predicting that the occurrence of one of more of these species in Australia was natural.     

Systematics of the Rhinella margaritifera complex (Anura,Bufonidae) from western Ecuador and Panama with insights in the biogeography of Rhinella alata

The Rhinella margaritifera species group consists of 17 species of toads distributed in tropical and subtropical South America and eastern Central America. The identity of some of its species is poorly understood and there are numerous undescribed cryptic species. Among them, the status of Rhinella margaritifera is one of the most problematic. Its range includes lowland rainforests separated by the Andes, the Chocoan rainforest to the west and the Amazonian rainforest to the east. This distribution is puzzling because the Andes are an old and formidable barrier to gene flow and therefore should generate vicariant speciation between disjunct lowland populations. Herein we clarify the taxonomy of populations of the Rhinella margaritifera complex from Central America and the Chocó region of South America. The morphological and genetic variation of Rhinella margaritifera was examined from 39 populations from Chocó, 24 from the upper Amazon region of Ecuador, and 37 from Panama, including the holotype of the Panamanian Rhinella alata. Phylogenetic analyses were performed based on mitochondrial genes 12S rRNA, 16S rRNA, and cytochrome c oxidase I (COI) and the nuclear gene Tyrosinase (Tyr). The genetic and morphological data show that Panamanian and Chocoan populations are conspecific. In the phylogeny, populations from Chocó and Panama form a well-supported clade. The morphology of the holotype of Rhinella alata falls within the variation range of Panamanian and Chocoan populations. Based on all this evidence, we assign the populations from western Ecuador and Panama to Rhinella alata and demonstrate that the unusual distribution pattern of “Rhinella margaritifera” on both sides of the Andes was an artifact of incorrectly defined species boundaries.     

Identifying freshwater mussels (Unionoida) and parasitic glochidia larvae from host fish gills: a molecular key to the North and Central European species

Freshwater mussels (order Unionoida) represent one of the most severely endangered groups of animals due to habitat destruction, introduction of nonnative species, and loss of host fishes, which their larvae (glochidia) are obligate parasites on. Conservation efforts such as habitat restoration or restocking of host populations are currently hampered by difficulties in unionoid species identification by morphological means. Here we present the first complete molecular identification key for all seven indigenous North and Central European unionoid species and the nonnative Sinanodonta woodiana, facilitating quick, low-cost, and reliable identification of adult and larval specimens. Application of this restriction fragment length polymorphisms (RFLP) key resulted in 100% accurate assignment of 90 adult specimens from across the region by digestion of partial ITS-1 (where ITS is internal transcribed spacer) polymerase chain reaction (PCR) products in two to four single digestions with five restriction endonucleases. In addition, we provide protocols for quick and reliable extraction and amplification of larval mussel DNA from complete host fish gill arches. Our results indicate that this new method can be applied on infection rates as low as three glochidia per gill arch and enables, for the first time, comprehensive, large-scale assessments of the relative importance of different host species for given unionoid populations.     

Postglacial dispersal of the European rabbit (Oryctolagus cuniculus) on the Iberian peninsula reconstructed from nested clade and mismatch analyses of mitochondrial DNA genetic variation

Nested clade analysis was applied to cytochrome b restriction site data previously obtained on 20 natural populations of the European rabbit across the Iberian Peninsula to test the hypothesis of postglacial dispersal from two main refugia, one in the northeast and the other in the southwest. Apart from historical fragmentation that resulted in geographic discontinuity of two distinct mitochondrial DNA (mtDNA) clades A and B, patterns of haplotype genetic variability have been shaped mostly by restricted gene flow via isolation by distance. The distribution of tip versus interior haplotypes suggests that dispersal occurred from both the southwestern and northeastern groups. Dispersal from the southwest had a north and northwest direction, whereas from the northeast it had mostly a western and southern orientation, with subsequent overlap in a southeastern-northwestern axis across the Iberian Peninsula. The analysis of the pairwise mismatch distribution of a 179-181-bp fragment of the mtDNA control region, for seven of those populations, further supports the idea that major patterns of dispersal were in the direction of central Iberia. Additionally, rabbit populations do not show signs of any significant loss of genetic diversity in the recent past, implying that they maintained large population sizes and structure throughout the ice ages. This is congruent with the fact that the Iberian Peninsula was itself a glacial refugium during Quaternary ice ages. Nonetheless, climatic oscillations of this period, although certainly milder than in northern Europe, were sufficient to affect the range distributions of Iberian organisms.