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1.
A new genus of palaeomacromiid dragonflies, Curviarculia , based on Curviarculia delicata sp. nov. and Curviarculia lamasi sp. nov., is erected from the upper Paleocene Maíz Gordo Formation of north–western Argentina. Phylogenetic relationships within Palaeomacromiidae are discussed, leading to a new family diagnosis.  相似文献   

2.
A new family of dragonflies, Palaeomacromiidae, based on Palaeomacromia multicellulata gen. et sp. nov., is described from the Late Paleocene Maíz Gordo Formation of north-western Argentina. The present discovery demonstrates that the present knowledge of the Early Cenozoic insect fauna of the Neotropical region remains very poor.  相似文献   

3.
A new family of damselflies, based on Latibasalia elongata gen. et sp. nov. and L. quispeae gen. et sp. nov., is erected from the Upper Palaeocene Maíz Gordo Formation, north-western Argentina. Latibasaliidae fam. nov. can be included in the Zygoptera: Caloptera: Eucaloptera: Amphipterygida: Amphipterygoidea. Its phylogenetic relationships within the clade Eucaloptera Bechly, 1996 are discussed. Within Amphipterygoidea, Latibasaliidae could be closely related to Pseudolestidae or to the 'thaumatoneurid' genera Petrolestes and Congqingia because they share the absence of secondary antenodal crossveins of first and second rows and the absence of antesubnodal crossveins. These characters could be potential synapomorphies of these taxa but they are somewhat homoplastic within the Zygoptera.  相似文献   

4.
A new genus and species of “libellulid” dragonfly, Austrolibellula noroestenia nov. gen., nov. sp., of the group Italoansida BECHLY, 1996, is described. The specimen comes from the Maíz Gordo Formation (late Paleocene) that crops out in northwestern Argentina. Its phylogenetic relationships within Cavilabiata BECHLY, 1996 are discussed.  相似文献   

5.
The lower slope of the drowned Alpine Adnet Reef was recolonized in Hettangian time by sponge communities of hexactinellid (hexactinosid and lyssacinosid) taxa and a few demosponges. Special taphonomic processes caused an excellent preservation of these sponges. The preservation allows to define several growth forms and to study original spicule configurations of the mainly non-rigid skeletons. Sponge faunas of presumably similar associations are known from adjacent basins, but only by isolated spicules of completely collapsed specimens. In Adnet the sponges are embedded in biodetrital limestones of the Schnöll Formation. Orientation and distribution of the sponges reflect autochthonous faunas that have been mixed with dislocated individuals by local water currents. The predominance of erect sponge types indicates intermediate sedimentation rates and/or occasional high-energy events. Sponge types and community structures are comparable with those ones from Middle Paleozoic mud mounds. Several hiatuses, mostly characterized by ferromanganese crusts have been kept free of sponge settlement. Carbon stable isotopes of the sponge-rich sequence show a small negative δ13Ccarb excursion that covers the period from Lower Hettangian to Lower Sinemurian.This revised version was published online in May 2005 because several displayed passages had been inadvertently deleted in the original published version.  相似文献   

6.
不同水稻品种对虫害胁迫的生理响应   总被引:15,自引:0,他引:15  
陈威  周强  李欣  何国锋 《生态学报》2006,26(7):2161-2166
以褐飞虱-水稻为模式,研究虫害胁迫下植物的化学防御生理生态特征,测定了可溶性糖含量、叶绿素含量、光合速率、蒸腾速率、气孔导度以及细胞间隙二氧化碳浓度、防御酶的时间变化特征.结果表明,经虫害诱导,不同品种水稻可溶性糖含量降低;同时,光合速率以及叶绿素含量也相应下降;蒸腾速率、气孔导度和细胞间隙二氧化碳浓度的变化不显著。虫害对水稻叶片多酚氧化酶、过氧化物酶和脂氧合酶均具有诱导作用.这种诱导作用具有时间效应,且不同品种诱导作用不一致.  相似文献   

7.
Abstract:  The partial, articulated skeleton of a pleurodiran turtle from the Nova Olinda Member of the Crato Formation (Araripe Basin) of north-east Brazil displays an impression of the outline of the soft tissues surrounding the left hind limb. The external mould of the soft tissue surface preserves only the gross morphology of the limb although the outline of the limb is well defined. It appears to be an external mould of the limb's surface, which formed prior to the decay of the integument. The limb skeleton is mostly fully articulated. This style of preservation is comparable with the mouldic preservation found in such famous fossils as the feathered Archaeopteryx specimens of the Solnhofen limestone. Although soft-tissue preservation is occasionally encountered in the Crato Formation, this is the first documented occurrence of mouldic preservation of body outline reported for this Konservat-Lagerstätten. The new specimen is referred to the pelomedusoid Araripemys and represents a new species, A. arturi sp. nov., which is described here.  相似文献   

8.
2005年吴江市褐飞虱后期特大发生原因及其防治对策   总被引:6,自引:0,他引:6  
2005年褐飞虱Nilaparvata lugens(Stal)在吴江市稻区后期特大发生。在总结其发生特点的基础上,分析特大发生的原因,主要与后期成虫迁入量大、气候及苗情适宜、褐飞虱对吡虫啉产生高水平的抗药性、残留基数高以及用药质量差等因素有关,最后提出了积极开展综合防治、加强监测以及科学使用农药等治理措施。  相似文献   

9.
Abstract:  Soft-tissue preservation of the hind gut, or anal sac, in the tegmen of Tubulusocrinus (gen. nov.) doliolus (Wright) from the Mississippian (Visean, Asbian) Pittenweem Formation at St Andrews, Scotland, is the first of its kind known in crinoids; it sheds important new light on the nature of the cladid tegmen. Many cladid crinoids had a calcite-plated anal sac that may have functioned like a chimney to prevent fouling of the ambulacra. The tubular, uncalcified anal sac of Tubulusocrinus may have functioned like a hose by pointing down current between the arms to avoid fouling of the ambulacra. Its smaller size may also have required less energy to produce than a heavy-plated sac. The hind gut is apparently preserved by haematite replacement, which was probably altered from original authigenic pyrite that formed soon after catastrophic burial.  相似文献   

10.
11.
A new species of Planthopper, Nogodina chiapaneca sp. nov. from the Mexican Chiapas amber (southeast Mexico) is described. The new species belongs to Nogodinidae: Nogodinini: Nogodinina. This is the second nogodinid species described from Mexican amber. Both species belong to Nogodinina, a taxon with a Neotropical distribution. The only recent species of Nogodina, N. reticulata, ranges from Honduras to Brazil and is unknown from Mexico yet.  相似文献   

12.
A list of Hemiptera Fulgoromorpha (planthoppers) of Iran is provided, based primarily on literature records from 1902 to the present. In total 15 families and 235 species are recorded, with taxonomic details. Distribution data in Iran are given. Iranissus ephedrinus Dlabola, 1980 is transferred from Issidae to Nogodinidae. To resolve nomenclatural difficulty the following new combinations in Issidae are given: Iranodus dumetorus (Dlabola, 1981), Iranodus khatunus (Dlabola, 1981) and Iranodus repandus (Dlabola, 1981). Due to published generic synonomy the following are new combinations: Duilius seticulosus (Lethierry, 1874), Duilius tamaricis (Puton & Lethierry, 1887), Duilius tamaricicola (Dubovsky, 1966) and Duilius v-atrum (Dlabola, 1985).  相似文献   

13.
The nature of organic material and the environment in which it is deposited exert a major influence on the extent to which biomacromolecules are preserved in the fossil record. The role of these factors is explored with a particular focus on the cuticle of arthropods and leaves. Preservation of the original chemistry of arthropod cuticles is favoured by their thickness and degree of sclerotization, and the presence of biominerals. Decay and burial in terrestrial as opposed to marine, and anoxic rather than oxygenated conditions, likewise appear to enhance preservation. The most important factor in the long-term preservation of the chemistry of both animal and plant cuticles, however, is diagenetic alteration to an aliphatic composition. This occurs even in amber, which encapsulates the fossil, eliminating almost all external factors. Some plants contain an original decay-resistant macromolecular aliphatic component but this is not the case in arthropods. It appears that the aliphatic components of many plant as well as animal fossils may be the result of diagenetic polymerization. Selective preservation as a result of decay resistance may explain the initial survival of organic materials in sediments, but in many cases longer-term preservation relies on chemical changes. Selective preservation is only a partial explanation for the origin of kerogen.  相似文献   

14.
Three-dimensional preservation of arthropod soft integument occurs in Middle Cambrian sediments of the Georgina Basin, western Queensland, Australia. The beds are referred to the Monastery Creek Phosphorite Formation, Gowers Formation, Inca Shale Formation and Devon-court Limestone Formation. The finds include arthropod type-A larvae previously described by Müller & Walossek and several complete appendages, possibly of early Palaeozoic 'ostracodes', as well as indeterminable cuticular remains. The Australian sediments were in part deposited under high water-energy conditions, whereas previously known occurrences of three-dimensional soft-integument preservation have been from environments of lower water energy. Such preservation may thus be more widespread in the Early Paleozoic than hitherto known. □ Phosphatization, arthropods, type-A larvae, appendages, Middle Cambrian, Geogina Basin, Australia, three-dimensional preservation.  相似文献   

15.
A survey of threecornered alfalfa hopper, Spissistilus festinus (Say) (Hemiptera: Membracidae), damage in 60 South Carolina peanut, Arachis hypogaea L., fields showed that 89 and 58% of plants had feeding girdles during 2003 and 2004, respectively. Use of a foliar insecticide for other target pests reduced hopper damage. Hopper damage was not affected by sampling distance from the field edge; therefore, injury was adequately assessed at 10 m from field borders. In-furrow insecticide choice, planting date, soil texture, previous crop, or tillage did not measurably affect girdling. Subsequent field experiments demonstrated a cultivar effect on threecornered alfalfa hopper injury, with the standard runner-type cultivar ('Georgia Green') more susceptible than the standard Virginia-type ('NC-V11'). More than 50% of stem girdling occurred on the basal quarter (first five internodes) of the plant. Most feeding occurred on secondary branches of main and lateral stems. Weekly sampling of seven grower fields showed that adult hoppers colonize peanut during June and produce two generations on peanut. Only low levels of plant girding were observed in June, but plant girdling increased gradually through late July, when girdling markedly increased contemporary with peak populations of first generation nymphs and adults. A second increase in plant girdling, observed in early September, coincided with the second generation of nymphs on peanut. Foliar treatments at 45- 60 d after planting (DAP) were most effective in suppressing injury. Granular chlorpyrifos treatment also suppressed hopper injury. There was no yield response to insecticide treatments at the hopper injury levels in these tests (up to six girdles per plant). Although the economic injury level (EIL) for this pest has not been defined, our data indicate that a critical interval for monitoring hopper activity is the first 3 wk of July, before the occurrence of significant injury. Where growers have a consistent risk of economic injury, applying foliar treatment in mid-July would be most effective in suppressing damage.  相似文献   

16.
The mid‐Cretaceous greenhouse period in the southern Patagonia Argentina (Austral Basin) is represented by the Mata Amarilla Formation. It is composed of three informal sections which were deposited in littoral and continental environments. The boundary between the lower and middle sections of the Mata Amarilla Formation shows a drastic reduction in accommodation/sediment supply (A/S) ratio, interpreted as a forced regressive surface. This surface is characterized by a well‐developed palaeosol, associated with the extensive preservation of a podocarp‐dominated fossil forest over a vast area (more than 5400 km2). Sedimentological and palaeopedological analyses, in conjunction with forest structure, tree density and growth ring analyses, indicate that the mid‐Cenomanian forced regression can be distinguished as a non‐uniform surface developed over a short period of time. This sequence boundary is recognized through a heterogeneous regional surface, delimited in the western part of the study area by an erosional surface generated by a large lateral channel migration recorded by sheet‐like channel deposits with transported logs. By comparison, towards the eastern part of the study area, it appears as a paraconformity bounded by a very mature vertic Alfisol, which may have taken 40–100 ky to develop, and the preservation of a fossil forest in life position with a minimum age of 337 years. It is concluded that the extensive presence of these fossil forests at the same stratigraphic level in a vast region respond to changes in A/S ratio in a forced regressive surface at basin scale.  相似文献   

17.
《Palaeoworld》2016,25(3):431-443
A cervical vertebra preserved at the famous and productive Cleveland-Lloyd Dinosaur Quarry in the Upper Jurassic Morrison Formation of Utah is that of an Apatosaurus, a sauropod dinosaur genus not previously recognized at the site and the first new dinosaur taxon identified at the site in years. The presence of Apatosaurus at a mudstone site dominated by other taxa, both theropod and sauropod, suggests a pattern of preservation within the Morrison Formation in which sites in fine-grained sediments yield dramatically uneven relative abundances of dinosaurs, with variable dominant taxa by site, compared with more time-averaged and attritional coarse-grained channel sandstone deposits. In addition, the continued demonstration of the wide-spread occurrence and abundance of Apatosaurus within the Morrison Formation, and the absence of its clade among diplodocid faunas on other continents, suggest that this group may have been endemic to North America during the Late Jurassic and that it may have originated there, though this is far from clear.  相似文献   

18.
Occurrence, preservation and evidence of plant–insect interactions in the leaf deposits of the early Miocene Geumgwangdong Formation are described, and the taphonomy and palaeoenvironmental implications are interpreted. The Geumgwangdong leaf beds are tuffaceous lacustrine deposits consisting mainly of thin-bedded sediments, including shale. Deposition was dominated through the vertical aggradation of fine-grained sediments by suspension sedimentation, rather than by the fluvial deposition of coarse-grained sediments. The majority of the fossil leaves were preserved by compression rather than merely preserved as impressions. The Geumgwangdong leaf deposits can be characterised as a wind-transported, dysaerobic, deep-water, lake taphofacies with some influence of water-transport. The fossil flora of the Geumgwandong Formation consists of 64 taxa belonging to 27 families and 43 genera. The dominant taxa were Metasequoia, Fagus, Betula, Quercus, Acer, Zelkova, and Leguminosae, which is comparable to the Early Miocene cool–temperate Aniai-type Flora of north-east Japan. The similarity between the lake settings of the Geumgwangdong Formation and the Aniai Coal-bearing Formation might have been a factor in the development of similar plant–fossil assemblages. Although traces of insect damage in the fossil leaves of the Geumgwangdong Formation were commonly observed, more than 90% of the damaged leaves showed a low level of diversity and degree of insect damage (< 10%), which is indicative of a cool–temperate palaeoclimatic condition. Despite latitudinal differences and geographic separation, the development of similar floras in the Geumgwangdong Formation of south-east Korea and the Aniai Coal-bearing Formation of north-east Japan during the early Miocene could have been influenced by the incipient NW–SE sea-floor spreading that resulted in the opening of the East Sea (Sea of Japan), which might have enabled floral migration between the two regions. This study provides useful data for understanding not only the taphonomy and palaeoenviroments of the leaf deposits, but also the spatial development of the flora resulting from palaeogeographic changes driven by tectonic movement during the early Miocene in Far East Asia.  相似文献   

19.
Thirty-one specimens of a small megasporangiate lycopsid cone referable to the genus Porostrobus Nathorst and abundant associated dispersed megaspores have been collected from Early Pennsylvanian strata in the Allied Stone Company quarry, Milan, Illinois. Based on other elements in the flora, the deposit is considered to be part of the Morrowan Caseyville Formation and probably of Namurian age. This is the first reported occurrence of Porostrobus in North America and the cones are recognized as a new species, P. nathorstii. The environment of deposition indicates that the cones may have been transported from the parent plant prior to preservation. Cones are preserved as coalified compressions measuring 15–36 mm long by 2.5–7 mm wide, and are characterized by an apical tuft of leaves up to 20 mm long. Sporophylls are spirally arranged on a narrow cone axis, lack a heel or keel, and have a long distal lamina. Sporangia contain a single functional megaspore tetrad. Mature megaspores are 750–1, 150 μm in diameter, have prominent trilete sutures raised to form a gula, and have numerous branched hairs confined to an equatorial band. Megaspores correspond to the dispersed form Setosisporites praetextus (Zerndt) Potonie and Kremp. Porostrobus nathorstii is the only species of the genus described to date that is monosporangiate.  相似文献   

20.
Additional vertebrates and ostracods from the bituminous shale of the Khao Loc Formation at Tong Vai, Ha Giang Province, northern Vietnam, corroborate its correlation with the upper part of the Xishancun (Xiaxishancun) Formation and the lower part of the Xitun and Lianhuashan formations of South China, and its Middle to Late Lochkovian age. The variations in morphology and ornamentation of the galeaspid Polybranchiaspis liaojaoshanensis from Tong Vai are discussed and regarded as possibly size and growth-related. A new acanthothoracid placoderm with a very deep dorsal process is described from Tong Vai and the specific distinction between the antiarchs Minicrania lissa from Tong Vai and M. lirouyii from Yunnan is supported by additional characters. Petalichthyid placoderms are recorded from this locality for the first time, and the skull of a juvenile youngolepidid sarcopterygian is described. Eurypterid fragments and a phyllocarid crustacean are also recorded from the Khao Loc Formation. A new species of the chonetid brachiopod genus Tulynetes, endemic to northern Vietnam, is described from the Pragian Mia Le Formation at Cu Le, Bac Kan Province, a new locality which yields a large diversity of taxa with outstanding preservation.  相似文献   

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