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Until recently, all papillated specimens of Pareledone were ascribed to the species Pareledone charcoti (Joubin, 1905), of which P. aurorae (Berry, 1917) was considered a junior synonym. Re-examination of the papillated type material of Pareledone, coupled with extensive fishing over several years off the Antarctic Peninsula, has led to a revision of this position. Seven new species of papillated Pareledone are identified from the Antarctic Peninsula region. They are identified by subtle taxonomic characters, such as the morphology and placement of their papillae, although traditional indices often fail to separate the species. Whilst apparently sympatric, there is some evidence of niche separation of these species with respect to depth. A key is provided for their identification.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 75−108.  相似文献   

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Analysis of ecological characters on phylogenetic frameworks has only recently appeared in the literature, with several studies addressing patterns of niche evolution, generally over relatively recent time frames. In the present study, we examined patterns of niche evolution for a broad radiation of American blackbird species (Family Icteridae), exploring more deeply into phylogenetic history. Within each of three major blackbird lineages, overlap of ecological niches in principal components analysis transformed environmental space varied from high to none. Comparative phylogenetic analyses of ecological niche characteristics showed a general pattern of niche conservatism over evolutionary time, with differing degrees of innovation among lineages. Although blackbird niches were evolutionarily plastic over differing periods of time, they diverged within a limited set of ecological possibilities, resulting in examples of niche convergence among extant blackbird species. Hence, an understanding of the patterns of ecological niche evolution on broad phylogenetic scales sets the stage for framing questions of evolutionary causation, historical biogeography, and ancestral ecological characteristics more appropriately.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 869–878.  相似文献   

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The genus Melaloncha Brues is defined and groundplan character states established based on outgroup comparison with Phalacrotophora Enderlein and Melittophora Brues. Major groupings within Melaloncha are recognized, and two subgenera are established: Udamochiras Enderlein (type species M. colossia (Enderlein)) and Melaloncha s.s. (type species M. pulchella Brues). Subgenus Udamochiras is revised and 42 species are recognized, including the following 33 new to science: M. anaticula , M. angustifrons , M. apicula , M. aprica , M. basella , M. biseta , M. brevicarina , M. carinata , M. compressicauda , M. exigua , M. falcata , M. flavilata , M. hamata , M. hansoni , M. horologia , M. individa , M. lobata , M. maculifrons , M. parkeri , M. paxilla , M. premordica , M. rhampha , M. rhypopoda , M. rostrata , M. sinuosa , M. spatula , M. spicula , M. triangularis , M. trua , M. valeria , M. vargasi , M. villosa , M. woodi . Melaloncha simillima Borgmeier is removed from synonymy with M. piliapex Borgmeier and reinstated as a separate species; lectotypes are designated for both.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 1−42  相似文献   

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Shell outlines of 202 extant cytheroidean ostracods were analysed in dorsal, lateral, and posterior views by elliptic Fourier analysis. The results obtained confirm that the exterior morphology is related to ecological factors as well as phylogenetic constraints. Phytal species living on tall seagrass and benthic species burrowing in sediments are characterized and differentiated from the species crawling on sediments by the presence of slender shells with tapered venters. With reference to reconstruction of ancestral state of outline traits on the molecular phylogeny, the hypothetical ancestor of cytheroidean ostracods is presumed to have had an average-shaped shell. Morphological plasticity of the shell outline was observed in many families. The phytal species living on tall seagrass appear to have evolved convergently with species from other habitats, acquiring slim shell outlines during the Cenozoic period. The present analysis also reveals the phylogenetic constraints on the morphological evolution of the Trachyleberididae in their adaptation to a burrowing habit.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 810–821.  相似文献   

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Ornithogalum chetikianum Uysal, Ertugrul & Dural sp. nov. (Liliaceae) is described and illustrated from Anatolia, Turkey. The species grows on alpine steppe and stony places in Bozkır (C4 Konya province) in South Anatolia. It is closely related to O. nutans L. and O. demirizianum Malyer & M.Koyuncu, an endemic confined to South Anatolia. Diagnostic morphological characters are discussed. Notes are also presented on the ecology, biogeography and conservation status of the new species.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 501–504.  相似文献   

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A new species, Achetaria latifolia V.C.Souza, is described and illustrated. It is characterized by its broadly ovate leaves, indument of stems and leaves of noncapitate hairs, and pubescent capsule. Achetaria latifolia is known only in the coastal dune-area of Cabo Frio region, Rio de Janeiro State, Brazil.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 73–75.  相似文献   

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Two new Pauridiantha species (Pauridiantheae, Rubiaceae) from Gabon are described and illustrated. Pauridiantha pleiantha is characterized by a combination of entirely glabrous stems, stipules with a narrow base, and large inflorescences. Pauridiantha smetsiana is characterized by entirely glabrous stems, narrow, early deciduous stipules, leaves red-tinged when dry, and small inflorescences. The two new species, especially P. smetsiana , close the morphological gap between Commitheca and Pauridiantha in combining typical Commitheca characters, such as glabrous stems and a narrow stipular base, with Pauridiantha characters, such as eucamptodromous venation. A detailed morphological comparison (including ovary structure, seed morphology, exotesta anatomy, and pollen morphology) between the two genera is given; in conclusion, Commitheca is relegated to the synonymy of Pauridiantha . The necessary new specific combinations are provided.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 105–117.  相似文献   

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Viola muliensis Y.S. Chen & Q.E. Yang, a new species of Viola L. (Violaceae) from Sichuan, China, is described and illustrated. Viola muliensis is endemic to Muli County, south-western Sichuan. This new species has yellow flowers with very short spurs and belongs to subsection Brevicalcaratae W. Beck., section Dischidium Ging. It is distinguished from other related species by having pedatipartite leaves.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 365–368.  相似文献   

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In order to investigate parasitoids of the genus Cotesia (Hymenoptera: Braconidae), larvae of a speciose group of butterflies, the tribe Melitaeini (Lepidoptera: Nymphalidae), were collected from several sites in Catalonia, northern Spain, a region that harbours ten out of the 20 European species of Melitaeini. New information on the natural history of the butterflies is presented, and the structure of their communities and patterns of larval parasitism are described. On the basis of mtDNA sequence data (COI gene), microsatellite data (ten loci) and behavioural experiments, we recognize seven biologically distinct species of Cotesia parasitizing the Melitaeini communities within this relatively small geographical area. In particular, the notional species C. melitaearum and C. acuminata each represents a series of cryptic species with narrow host associations. The possibility of direct competition among the parasitoids and/or indirect interactions between butterflies mediated by Cotesia parasitoids is explored.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 45–65.  相似文献   

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This paper offers a new biotic interaction hypothesis for the Cambrian 'explosion' of mineralized, benthic, metazoan diversity. It proposes that organic-mineral composite structures (e.g. shells and muscle lever-arms) originated in Proterozoic lineages of primary larva-like, but reproductively competent, pelagic bilaterians because mineralization was both mechanically and energetically favourable, not because it provided armour against predation. Increased strength and rigidity of composite structures permitted growth to sizes incompatible with a continued pelagic existence, while the increased density resulting from massive mineralization facilitated settlement into, and stability in, a nutrient-rich, Proterozoic benthic zone that offered new ecological opportunities. Because evolutionary success is recognized by the formation of recoverable fossils, which requires large, enduring populations, successful lineages are those that responded to the new opportunities by achieving broad niche occupancy through the evolution of metamorphosis to larger, mineralized 'adult' body forms with more efficient food-collecting apparatus and higher fecundity. Niche modification (e.g. reef and shell-bed formation) by early mineralized benthic settlers may have increased the likelihood of further successful settlement, leading to the appearance of a period of 'explosive' increase in benthic, mineralized, metazoan diversity. Predator-prey arms races may then have followed, causing early faunal turnover and possible selection for improved armour.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 483–490.  相似文献   

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A new species of Viola (Violaceae) from north-western Yunnan, China, is described and illustrated. Viola dimorphophylla Y. S. Chen & Q. E. Yang sp. nov. is endemic to Zhongdian County, north-western Yunnan, and is very easily distinguishable from all other Chinese species of the genus by having obviously dimorphic leaves, with the basal ones being long petiolate, undivided and widely cordate, and the cauline ones sessile, linear and verticillate.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 115–119.  相似文献   

15.
A new ostracod, Loxoconcha kamiyai sp. nov. in the Family Loxoconchidae, is described from the Pleistocene Omma Formation of Japan. Its geological and geographical distributions suggest that this species was once endemic to the Japan Sea, where it would have evolved until the Pliocene. Since the early Pleistocene, this species would have become extinct within this marginal sea during glacial maxima, probably due to its narrower salinity tolerances and geographical distributions than those of extant species inhabiting the euryhaline environments in other seas. The distributional patterns of pore systems in this species strongly suggest its closest phylogenetic affinities to a living species, Loxocorniculum mutsuense . These two species show a unique adult sexual dimorphism in the anterior element of the hingement. Taking the female hingement morphology as a standard, the male hingement can be explained in terms of heterochrony, i.e. paedomorphosis. Sexual hingement dimorphism with paedomorphosis occurs in only one phylogenetic group of the genus Loxoconcha , which is distinguished by the ontogenetic distributional patterns of pore systems. This morphology may represent relict primitive characters of ancient ostracods and could be an important character for evaluating the history of sexual dimorphism in ostracods since the Palaeozoic.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 239–251.  相似文献   

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Astragalus rahiminejadii , a new species endemic to Iran, is described and illustrated. This species, which belongs to section Astragalus , is confined to the western part of Iran (Prov. Kermanshah) and is known only from a single population. Seed testa morphology as viewed under the scanning electron microscope is discussed and photomicrographs are provided. In addition, the geographical distribution and ecology of the species belonging to this section are discussed.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 363–368.  相似文献   

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The patterns of adaptive radiations in ancient lakes provide valuable clues to mechanisms of speciation and adaptation. In contrast to vertebrate radiations, for instance in fishes or finches, invertebrate species flocks have been largely neglected. While the increase in molecular data narrows this gap, the anatomical basis for interpreting these data against the background of evolutionary hypotheses is still widely lacking. Here we evaluate anatomical findings in the live‐bearing pachychilid freshwater gastropod Tylomelania, which has radiated extensively in ancient lakes in the Indonesian island, Sulawesi; we have aimed at reconciling these data with recently obtained molecular phylogenetic evidence. Discovered more than a century ago, the speciose and phenotypically diverse species flock with 34 currently described taxa was only occasionally cited as an example of adaptive radiation in ancient lakes, while anatomical data were entirely lacking. Our study of anatomical characters reveals very low qualitative variation at the species level. Thus, contrary to earlier views we suggest the existence of a single monophyletic lineage endemic to this island. The most conspicuous feature of Tylomelania is its uterine brooding strategy, i.e. retaining eggs and embryos in the pallial oviduct. This is unique among South‐East Asian pachychilids. Within the uterine brood pouch the offspring is surrounded by considerable amounts of nutritive material produced by a very large albumin gland, and the embryos are produced continuously. The shelled juveniles of some species are the largest known so far in viviparous gastropods, measuring almost 2 cm in length when hatching. This combination of reproductive features in Tylomelania, characterized by a high amount of maternal investment, is considered to be ovoviviparous, rendering its brooding strategy unique also among other gastropods. In addition, our data reject a previously assumed close relationship to other South‐East Asian pachychilids and instead suggest the North Australian Pseudopotamis as sister group to Tylomelania. These findings have significant consequences for the phylogenetic interpretation of morphological characters of Tylomelania in an evolutionary and biogeographical context, leading to the hypothesis that the common ancestor of both genera originated somewhere on the northern Australian continental margin. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85 , 513–542.  相似文献   

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Chromosome study of the fern genus Cyrtomium (Dryopteridaceae)   总被引:1,自引:0,他引:1  
Cyrtomium (Dryopteridaceae) is an Asiatic genus comprising about 40 species characterized by having anastomosing veins that form areolae with included veinlets. Twelve chromosome counts representing 11 taxa were made in the present study. The chromosome numbers of six species endemic to China are reported for the first time: C. uniseriale , 2 n  = 164; C. guizhouense , 2 n  = 82; C. shingianum , n  = 82, 2 n  =  c .164; C. chingianum , 2 n  = 164; C. urophyllum , 2 n  = 82 and C. aequibasis , 2 n  = 123. The results were used to show that (1) C. uniseriale should be reduced to varietal status under C. balansae ; (2) subseries Balansana is not closely related to any other Cyrtomium species and should be separated from Cyrtomium ; and (3) C. guizhouense and C. lonchitoides are basal groups when subseries Balansana is not considered. These results were also supported by morphology. A high level of differentiation is a distinct characteristic in Cyrtomium . The genus has two reproductive types: sexual and apogamous. Sexual species are distributed mostly in China. Southwestern China is a modern diversity centre of Cyrtomium , with 80.6% of known species occurring there. Many species are endemic, most of which are sexual tetraploids or apogamous triploids. Both the apogamous reproductive type and polyploid species are adaptions to limestone habitats.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 221–228.  相似文献   

19.
A new species Swartzia trimorphica Mansano & A. L. Souza (Leguminosae, Papilionoideae, Swartzieae) from the Amazonian Brazil, is described and illustrated. The new species is notable and distinct from all the other species of Swartzia by its highly unusual trimorphic stamens, while the other species have either an isomorphic or a dimorphic androecium. The new species is included in the section and subsection Swartzia , ser. Orthostylae based on its bracteolate pedicels, the cauligerous inflorescences, lateral style and the relative size of the ovary compared to the style. The atypically small gynoecium in the material suggests the possibility that flowers may be functionally unisexual. Field observations and more collections are needed to resolve this question.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 235–238.  相似文献   

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