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1.
The age and geographical distribution of fossil cercopithecids in China   总被引:2,自引:0,他引:2  
Cercopithecids did not arrive in China until the latest Tertiary, relatively late in their evolutionary history. Cercopithecines are represented in the Chinese fossil record by two genera,Procynocephalus andMacaca, both of which made their appearance in the Late Pliocene or Early Pleistocene, but only one of which,Macaca, was widely distributed throughout the Quaternary and remains in the country today. The much less well known genusProcynocephalus disappeared from China in the late Early Pleistocene, but is of considerable interest because it appears to have been part of a radiation of large terrestrial cercopithecines that extended throughout portions of southern and eastern Asia. Colobines are poorly represented in the fossil record of China. Aside from a few scattered occurrences ofRhinopithecus in the Middle and Late Pleistocene records of southern China, the subfamily is represented by only one other intriguing specimen. This is the large and nearly complete mandible now classified as «Megamacaca lantianensis» from the Gongwangling locality of Lantian, Shaanxi Province. The specimen was retrieved from sediments of late Early Pleistocene age and was associated with elements of a typical southern,Ailuropoda — Stegodon fauna. The distribution of cercopithecids, especiallyMacaca, in China followed the southern and eastern retreat of subtropical habitats during the course of the Pleistocene.  相似文献   

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Fossil scorpions are among the oldest terrestrial arthropods known from the fossil record. They have a worldwide distribution and a rich fossil record, especially for the Paleozoic. Fossil scorpions from Mesozoic and Cenozoic deposits are usually rare (except in amber-deposits). Here, we describe the only fossil scorpion from the Early to Middle Eocene Pesciara Lagerstätte in Italy. Eoeuscorpius ceratoi gen. et sp. nov. is probably a genus and species within the family Euscorpiidae. This may be the first fossil record of the Euscorpiidae, which are so far only known from four extant genera. Eoeuscorpius ceratoi gen. et sp. nov. was found in the “Lower Part” of the Pesciara Limestone, which is actually dated Late Ypresian stage (between 49.5 and 49.7 Ma). Besides a possible pseudoscorpion, the here-described fossil scorpion is the second arachnid species known from the Bolca Locality.  相似文献   

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Collections from French Guiana, Amazonian Brazil, and Colombia taken in the last 20 years include new species in the following genera:Duroia, Pagamea, Psychotria, Randia, Retiniphyllum, Rudgea, Sabicea, Sipanea, andSphinctanthus. Twenty-one new species are described and five are illustrated.  相似文献   

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Seeds of 39 species representing all native genera and sections of New WorldAntirrhineae were examined with the Scanning Electron Microscope and Light Microscope. Based on seed shape and surface ornamentation, seven morphological categories are recognized: cristate, tetracostate, foveolate, tumid tuberculate/cristate, circumalate, medusiform, and a miscellaneous category. Most sections and/or generic categories can be characterized by a single morphological type, althoughMaurandya s.l. has several distinctive seed types included within present generic boundaries. The cristate seed type is believed to be the “primitive type” from which the medusiform and tumid tuberculate/cristate types have developed. The tumid tuberculate/cristate type presumably gave rise to the circumalate, tetracostate, and foveolate patterns. The miscellaneous category (represented byLinaria andKickxia) may be phyletically remote from the other New World types. Seeds of the New WorldAntirrhineae mostly seem to be adapted for water dispersal although some adaptations for wind dispersal (e.g. wings, light weight) are evident. Free-hand sections and seed coat clearings indicate that circumalate seeds are of two different anatomical patterns; such structural diversity may be found in the other seed types.  相似文献   

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An assemblage of earliest Silurian (Llandovery, Rhuddanian) fossils from South Kazakhstan (Ak-Kerme Peninsula, Lake Balkhash) contains solitary rugose corals (Calostylis denticulata, Streptelasma? sp., and Cystipaliphyllum sp.) and the demosponge Calycocoelia typicalis, which are described here. This assemblage occurs with previously described brachiopods and constitutes a post extinction survival fauna; such faunas are poorly known and this study fills a gap in our knowledge. All three genera of Rugosa were transitional across the Ordovician–Silurian boundary and are also reported from other parts of Kazakhstan, Uzbekistan, and Tajikistan during the Llandovery. Streptelasma had already been present in Kazakhstan during the Ordovician, while during the Rhuddanian Calostylis immigrated from Baltica or China, and Cystipaliphyllum from the Australian part of Gondwana. Demosponges are rare during the Llandovery but probably had a cosmopolitan distribution. Calycocoelia typicalis marks the first Rhuddanian record of lithistid demosponges, and the first record of Silurian demosponges from Kazakhstan.  相似文献   

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The general morphology of cuticle-lined internal genitalia and oviduct is analyzed in intact females of the phytophagous mites, Loboquintus subsquamatus and Trisetacus cf bagdasariani (Acari: Eriophyoidea) using tetramethylrhodamine B isothiocyanate-phalloidin, three anaesthetics (magnesium sulphate, lidocaine and CO2-enriched water) and confocal laser scanning microscopy (CLSM). This is the first protocol adopted for CLSM studying musculature of mites. Revision of the previous terminology of eriophyoid internal genitalia from Nuzzaci and Alberti (Eriophyoid mites: their biology, natural enemies and control. World crop pests 6. Elsevier, Amsterdam, pp 101–150, 1996) resulted in the refinement of the terms “distal oviduct”, “genital chamber” and “spermatheca”. Relative position of the elements of cuticle-lined internal genitalia is discussed and a generalized 3D model and animation (available on-line as supplementary material) of eriophyoid genital apparatus are provided. The wall of eriophyoid oviduct contains strong longitudinal muscles attached to the cuticle genital chamber with folded walls. When the egg is being extruded by contraction of the oviduct muscles, it forms lobes corresponding to the internal topography of the oviduct and genital chamber; these lobes invaginate inward from the gonopore, resulting in the “flower-shaped” figures rarely observed in slide-mounted mites. Gnathosomal muscles (cheliceral muscles and extrinsic muscles of palps) and opisthosomal muscles D1 of Loboquintus mites are attached to the three posterior depressions near the rear prodorsal shield margin. Prospects of CLSM approach for studying different aspects of mite morphology are briefly discussed.  相似文献   

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Of the many types of freshwater bodies across Iceland (e.g., lakes, springs, rivers, and ponds), greater effort has been invested in researching the freshwater Crustacea (Cladocera, Copepoda) of more permanent, larger, and deeper water bodies than on smaller or more ephemeral sites. To address this, we described the fauna of 12 shallow freshwater bodies distributed from the coast to the central highlands of Iceland. We identified 16 species in 11 genera belonging to six families of Cladocera, and 12 species in eight genera belonging to four families of Copepoda. Five of the species we identified (Alona werestschagini, Cyclops vicinus, Daphnia cristata, Diacyclops abyssicola, and Heterocope borealis) represent new distribution records for Iceland, increasing the number of species now known from this region to 34 Cladocera and 38 Copepoda taxa. Additionally, we discuss the taxonomy of some species with doubtful taxonomical status. Six crustacean taxocenes are described, each characterized by the dominance of different taxa, with bottom sediment characteristics best explaining species assemblage structure. We evaluated the relationships between Icelandic Cladocera and Copepoda faunas and those of the adjacent Svalbard, Faroe, and Shetland Islands, Greenland, and the mainland Norway. The taxonomic composition of the Icelandic fauna is dominated by widely distributed Holarctic, and secondarily Palaearctic and Nearctic species, and is more similar to the faunas of the major North Atlantic islands (64.2–71.8 % similarity) than it is to that of continental Norway.  相似文献   

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Scanning electron microscopy was used to examine foliar surface features such as cuticular patterns, epicuticular wax, and trichome types in species ofAlnus, Betula, Carpinus, Corylus, andOstrya. Six trichome types are recognized in this survey, four non-glandular (acicular, filiform, aduncate, subulate) and two glandular (stipitate gland and peltate scale). The distribution of these trichomes among the genera supports the recognition of two tribes, Betuleae (Alnus andBetula) and Coryleae (Carpinus, Corylus, andOstrya). Trichome morphology can be an important supportive taxonomic character in determining evolutionary relationships.  相似文献   

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Combinations of DNA-binding fluorescent dyes and counterstains that enhance selectivity and contrast in primary stain fluorescence were used to differentiate types of C-bands in the genus Warramaba. Chromomycin A3 (in conjunction with two A-T binding counterstains), which identifies chromosome segments enriched in G-C base pair clusters, stains only a minority of the C-bands in Warramaba species, but these include all those known to contain 18S + 26S rRNA cistrons and most of those containing 5S rRNA genes. DAPI/actinomycin D fluorescent staining is positive for a very few bands, including two (in the Standard phylad of W. virgo) that are at or adjacent to sites containing 5S rRNA cistrons. One of the latter regions is also positively stained by DAPI/distamycin A which, in addition, highlights some centromeric bands. The fluorescent staining patterns of the Standard and Boulder-Zanthus phylads of W. virgo are significantly different, confirming their independent origin by hybridization between different races of the ancestral species “P169” and “P196”.  相似文献   

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The dominating rhizosphere fungi of broad bean (Vicia faba Linn.) variety “Giza 1”, and cotton (Gossypium barbadense Linn.) variety “Giza 47”, were grown in liquid medium. After 10 days, filtrates were obtained and sterilized by filtration through sintered-glass filter. Plants were grown in sterile sand which was supplemented with nutrient solution. Every plant was irrigated with fungal filtrate, unconsumed medium, and water. The filtrates of the rhizosphere fungi of both broad bean and cotton stimulated plant growth.  相似文献   

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Temporal variations in the different morphological forms observed during growth of the pleomorphicHyphomicrobium T37 have been quantified by the use of a “Population Index” (P i). This index relates the “Cell Number” (CN) in each “Colony-Forming Unit” (CFU) to the total number of CFU's at any particular time. Such measurements have proved of value in explaining the nature of an observed pseudo-log phase in swarmer-inoculated cultures and of a discontinuity in the log phase of growth.  相似文献   

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Marine sponges contain dense and diverse microbial communities, which are renowned as a source of bioactive metabolites. The biological activities of sponge-microbe natural products span a broad spectrum, from antibacterial and antifungal to antitumor and antiviral applications. However, the potential of sponge-derived compounds has not been fully realized, due largely to the acknowledged “supply issue.” Most bacteria from environmental samples have resisted cultivation on artificial growth media, and cultivation of sponge-associated bacteria has been a major focus in the search for novel marine natural products. One approach to isolate so-called “uncultivable” microorganisms from different environments is the diffusion growth chamber method. Here, we describe the first application of diffusion growth chambers for the isolation of cultivable and previously uncultivated bacteria from sponges. The study was conducted by implanting diffusion growth chambers in the tissue of Rhabdastrella globostellata reef sponges. In total, 255 16S rRNA gene sequences were obtained, with phylogenetic analyses revealing their affiliations with the Alpha- and Gammaproteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes. Fifteen sequences represented previously uncultivated bacteria belonging to the Bacteroidetes and Proteobacteria (Alpha and Gamma classes). Our results indicate that the diffusion growth chamber approach can be successfully applied in a natural, living marine environment such as sponges.  相似文献   

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