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1.
ANNA I. ANTOSHKINA 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2008,41(2):163-171
The continuous Upper Ashgill–Sheinwoodian carbonate succession in the most eastern Kozhym River area in the Subpolar Urals comprises the Yaptikshor (Rawtheyan), Kamennaya baba (Hirnantian), Ruchej and Manyuku (Llandovery–?Sheinwoodian) formations. The facies of the deep subtidal Yaptikshor Fm. mark an abrupt sea‐level rise following emergence of the Bad’ya reef (Rawtheyan). Carbonate breccias at the base of the Kamennaya baba Fm. correlate with the beginning of the Hirnantian glaciation and change upwards towards the Ordovician–Silurian boundary with the development of light‐grey massive boundstone/packstone shoal deposits. An abrupt change in facies to the Rhuddanian–Aeronian Ruchej Fm. continental slope environment marked the start of a long‐term sea‐level rise. The uppermost Aeronian–?Sheinwoodian is represented by submarine canyon carbonate conglobreccias of the Manyuku Fm. unconformably underlying the Balban’yu reef. The rapid facies changes at the base of the Hirnantian and at the Ordovician–Silurian boundary were of global eustatic origin. In contrast, the abrupt changes in the Rawtheyan and the formation of the Manyuku Fm. conglobreccias were of local or regional origin associated with tectonics. They were followed by the start of a regional transgression (Yaptikshor Fm.) and a global transgression marked by the initiation of the Balban’yu Reef in the Sheinwoodian. 相似文献
2.
The late Gorstian to early Ludfordian hemipelagic succession of the south‐eastern part of the Prague Synform preserves a rich fossil record dominated by 28 species of planktic graptoloids associated with pelagic myodocopid ostracods, pelagic and nektobenthic orthocerid cephalopods, epibyssate bivalves, nektonic phyllocarids, rare dendroid graptolites, brachiopods, crinoids, trilobites, sponges and macroalgae. Faunal dynamics have been studied with particular reference to graptolites. The early Ludfordian leintwardinensis graptolite extinction Event manifests itself as a stepwise turnover of a moderate diversity graptolite fauna rather than an abrupt destruction of a flourishing biota. The simultaneous extinction of the spinose saetograptids Saetograptus clavulus, Saetograptus leintwardinensis and the rare S. sp. B. at the top of the S. leintwardinensis Zone was preceded by a short‐term acme of S. clavulus. Cucullograptus cf. aversus and C. rostratus vanished from the fossil record in the lower part of the Bohemograptus tenuis Biozone. No mass proliferation of Bohemograptus has been observed in the postextinction interval. Limited indigenous speciation gave rise to Pseudomonoclimacis kosoviensis and Pseudomonoclimacis cf. dalejensis. Egregiograptus (the only novel element of cryptic origin) made its earliest occurrence in association with the latest cucullograptids. A postextinction graptolite assemblage of moderate diversity, composed for the most part of long‐ranging taxa, persisted through the middle and upper tenuis Biozone until new rediversification in the Neocucullograptus inexpectatus Biozone. Unlike the graptoloids, the planktic, epiplanktic, nektonic and nektobenthic shelly fauna did not suffer significant extinction in the early Ludfordian. The Gorstian–Ludfordian boundary is placed at the lowest occurrence of S. leintwardinensis in spite of the very modest graptolite record available from the Ludfordian GSSP where no graptolites occur below the basal bed of the Lower Leintwardine Formation. Elsewhere, the Gorstian–Ludfordian boundary has been placed at the base of the Saetograptus linearis Biozone which has been considered roughly correlative with the leintwardinensis Biozone. Indeed, our morphometric study places the worldwide biozonal index species S. linearis in synonymy with S. leintwardinensis and thus considerably enhances the biostratigraphical utility of the latter index species. Pseudomonoclimacis antiqua sp. nov. is described. 相似文献
3.
《Comptes Rendus Palevol》2014,13(3):147-155
The Rheic Ocean was a major oceanic domain between Baltica, Laurentia, Perunica and Gondwana in Ordovician-Silurian times. The cosmopolitan nepiomorphian bivalves Praecardioidei Newell, 1965 and Antipleuroidei Kříž, 2007 are characteristic of the Silurian of Perunica, peri-Gondwana, and Baltica, and occur also in Laurentia and Siberia. The Bohemian-type bivalve Cardiolinka Kříž, 1981 (Nepiomorphia Kříž, 2007, Cardiolidae Hoernes, 1884), from the Late Silurian of the Bahar-1 well core, has been found for the first time in southeastern Turkey. The strata containing the species Cardiolinka bohemica (Barrande, 1881) occur in the middle part of the Dadaş Formation in the interior Petroleum District X-Siirt of the northern parts of the Arabian Plate. The cosmopolitan species C. bohemica was until now known from the Latest Ludlow to Pridoli of the Prague Basin, France, Carnic Alps, Sardinia, East European Platform (Poland), eastern Serbia, Moesian Platform, and Arctic Canada. The new surprising subsurface data on C. bohemica in Diyarbakır-Bismil area (southeastern Turkey) therefore represent another piece of evidence in favour of strong faunistic affinity between Perunica, peri-Gondwanan Europe and the northern Gondwana margin. 相似文献
4.
This paper investigates a time interval within the Late Ludfordian (Late Silurian), involving changes in faunal composition
(the Lau Event), a major positive carbon isotope excursion (CIE), and contemporaneous sea-level changes in remote palaeo-basins.
Based on the Silurian strata of Gotland (Sweden), we integrate sequence stratigraphy, carbon isotope stratigraphy, and platform-scale
palaeoecological changes associated with this turbulent time period in Earth history. Three depositional sequences (sequences
Nos. 1–3), including two separate periods of forced regression (falling stage systems tracts, FSSTs) are identified from outcrop
and drillcore studies. The sequence stratigraphical framework is interpreted to reflect glacio-eustatic sea-level changes.
The CIE starts at the onset of the initial FSST (sequence No. 1), just below the last appearance datum of the conodont Polygnathoides siluricus. The values increase through the ensuing lowstand and transgressive systems tracts (LST and TST) of sequence No. 2 and peak
in the following highstand systems tract (HST). A second forced regression (FSST of sequence No. 2) took place in the lower Ozarkodina snajdri Zone. δ13C data are scarce from these siliciclastic strata, but inferably remain high. The δ13C values increase within the LST and earliest TST of sequence No. 3, before a decreasing trend starts within the early TST.
δ13C values return to pre-excursion levels within the ensuing HST. The CIE is closely associated with an increase in stromatolites
(mats and oncoids) across a wide range of depths and sedimentary environments, and correlations to other basins indicate a
global increase in cyanobacterial activity. A drastic decline in level-bottom benthic faunas during the FSST of sequence No.
2 is, however, interpreted as a local response to the progradation of a delta complex (the Burgsvik Sandstone). Biological
carbonate production replenishes rapidly within the TST of sequence No. 3, succeeding a thin LST dominated by reworked siliciclastics
and chemically precipitated carbonates (ooids). The detailed relationship between the CIE and sea-level change presented herein
is not fully consistent with previous reports on the CIEs associated with the lower Silurian Ireviken and Mulde events, respectively.
Based on our facies analysis and sequence stratigraphical interpretation, two main mechanisms are suggested as responsible
for the Late Ludfordian CIE: (1) a change in the riverine C-weathering flux towards the 13C end member following glacio-eustatically induced subaerial exposure of carbonate platforms throughout the tropics, and,
(2) increased photosynthetic activity by benthic cyanobacteria exaggerating the δ13C values of precipitated carbonates. 相似文献
5.
Eric A. Rickart Danilo S. Balete Rebecca J. Rowe Lawrence R. Heaney 《Diversity & distributions》2011,17(3):530-541
Aim Island faunas, particularly those with high levels of endemism, usually are considered especially susceptible to disruption from habitat disturbance and invasive alien species. We tested this general hypothesis by examining the distribution of small mammals along gradients of anthropogenic habitat disturbance in northern Luzon Island, an area with a very high level of mammalian endemism. Location Central Cordillera, northern Luzon Island, Philippines. Methods Using standard trapping techniques, we documented the occurrence and abundance of 16 endemic and two non‐native species along four disturbance gradients where habitat ranged from mature forest to deforested cropland. Using regression analysis and AICc for model selection, we assessed the influence of four predictor variables (geographic range, elevational range, body size and diet breadth) on the disturbance tolerance of species. Results Non‐native species dominated areas with the most severe disturbance and were rare or absent in mature forest. Native species richness declined with increasing disturbance level, but responses of individual species varied. Elevational range (a measure of habitat breadth) was the best predictor of response of native species to habitat disturbance. Geographic range, body size and diet breadth were weakly correlated. Main conclusions The endemic small mammal fauna of northern Luzon includes species adapted to varying levels of natural disturbance and appears to be resistant to disruption by resident alien species. In these respects, it resembles a diverse continental fauna rather than a depauperate insular fauna. We conclude that the long and complex history of Luzon as an ancient member of the Philippine island arc system has involved highly dynamic ecological conditions resulting in a biota adapted to changing conditions. We predict that similar responses will be seen in other taxonomic groups and in other ancient island arc systems. 相似文献
6.
Irini Papanicolopulu 《Ocean Development & International Law》2013,44(4):381-398
This article points out some of the issues that may arise during the delimitation of maritime boundary in a sea area where coastal states have proclaimed various maritime zones. Issues considered include delimitation in the presence of overlapping or coincident zones, the role of existing boundaries, use of all-purpose maritime boundaries, and the delimitation of future zones. Special reference is made to the Mediterranean Sea where coastal states have advanced various claims consisting of zones sometimes different from the ones provided for in the 1982 United Nations Convention on the Law of the Sea. 相似文献
7.
Audrey J. Geffen Jon Albretsen Bastian Huwer Richard D. M. Nash 《Journal of fish biology》2021,99(2):569-580
Lemon sole Microstomus kitt is a commercially valuable flatfish species that occurs in shelf waters around the northeast Atlantic. Only the most basic life-history information is available for the North Sea. Spawning is generally assumed to occur between early May and October, with a peak between May and August. Lemon sole larvae have been found in the water column in the northern North Sea in winter during standard surveys. Larvae captured in November/December 2016 and January/February 2017 using the International Council for the Exploration of the Seas standard 2 m Midwater Ring trawls (MIK) were analysed to gain a better understanding of the pelagic early life-history stages of lemon sole, especially in relation to the timing of spawning and the dispersal of overwintering larvae. Larval age was estimated from sagittal otolith primary increment counts. The larvae caught in November/December ranged in nominal age from 4 to 45 days post-hatching which suggests that spawning continues into late October and November. Most, but not all, of the larvae caught in January/February were post metamorphosis, and the difference in age between the two sampling dates was consistent with the elapsed time between samplings. The estimated hatching dates confirm that lemon sole spawning extends into late autumn in the northern North Sea, with overwintering larvae in all developmental stages. Drift modelling of eggs and larvae released at historically documented spawning grounds in the northern North Sea suggests that these grounds are also the source for all of the larvae sampled during the 2016–2017 surveys. 相似文献
8.
Kathrin Affeld Susan Worner Raphael K. Didham Jon Sullivan Rosa Henderson Jagoba Malumbres Olarte 《New Zealand journal of zoology.》2013,40(2):177-202
Abstract The range of microhabitats and microclimatic conditions provided by epiphytes has been linked to the high diversity of invertebrates in many forest canopies worldwide, but comparably little is known about the invertebrate fauna in this habitat in New Zealand. This study compiled an inventory of the invertebrate fauna of epiphyte mats in the canopy of northern rata (Myrtaceae: Metrosideros robusta A. Cunn.) at two study sites on the West Coast of the South Island. A total of 242 069 invertebrate specimens was collected over one year, representing 4 phyla, 9 classes and more than 160 families, 225 genera and 446 species. At least 10 new species and 3 new genera were identified, while 5 species were recorded outside their known geographical range. Epiphyte mats provided habitat for an invertebrate fauna, highly diverse and abundant both taxonomically and functionally, dominated in terms of abundance by Acari, Collembola and Hymenoptera (largely ants), and in terms of feeding guilds by epiphyte grazers and ants. As the first inventory of this taxonomic depth and breadth compiled for New Zealand forest epiphyte habitats, this study provides important baseline data for the conservation of biodiversity in New Zealand's indigenous forests. 相似文献
9.
The biogeographical affinities of the fauna in episodically filled salt lakes: A study of Lake Eyre South,Australia 总被引:8,自引:8,他引:0
Lake Eyre South, a large and normally dry playa in central Australia, filled with water in January 1984. Water persisted until January 1985. Salinity rose between these dates from 25 to > 270. Monthly observations on the fauna were made to determine if it consisted of widely dispersed species, and thus to test the assumption that episodically filled salt lakes are unimportant as evolutionary loci for the fauna of salt lakes. It was concluded that most species in the lake were indeed widely dispersed. Particularly common components of the fauna were: Craterocephalus eyresii (Steindachner) (fish), an undescribed species of Diacypris (ostracod), Moina baylyi Forró (cladoceran), Tanytarsus barbitarsis Freeman (chironomid), Parartemia minuta Geddes (anostracan), and Microcyclops platypus (Kiefer) (copepod). 相似文献
10.
One of the great underlying assumptions made by all scientists utilizing primate models for their research is that the optimal nutritional status and health of the animals in use has been achieved. That is, no nutrient deficiency or excess has compromised their health in any detectable way. To meet this assumption, we rely on the National Research Council's (NRC's) nutritional recommendations for nonhuman primates to provide accurate guidance for proper dietary formulations. We also rely on feed manufacturers to follow these guidelines. With that in mind, the purpose of this commentary is to discuss three related points that we believe have significant ramifications for the health and well being of captive primates as well as for their effective use in biomedical research. First, our laboratory has shown that most experimental primates are likely in a state of hypervitaminosis A. Second, it is apparent that many primate diets are providing vitamin A at levels higher than the NRC's recommendation. Third, the recommendation itself is based on inadequate information about nutrient needs and is likely too high, especially when compared with human requirements. Am. J. Primatol. 71:813–816, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
11.
Carina Donne Maurine Neiman James D. Woodell Martin Haase Gerlien Verhaegen 《Molecular ecology》2020,29(18):3446-3465
Non‐native invasive species are threatening ecosystems and biodiversity worldwide. High genetic variation is thought to be a critical factor for invasion success. Accordingly, the global invasion of a few clonal lineages of the gastropod Potamopyrgus antipodarum is thus both puzzling and has the potential to help illuminate why some invasions succeed while others fail. Here, we used SNP markers and a geographically broad sampling scheme (N = 1617) including native New Zealand populations and invasive North American and European populations to provide the first widescale population genetic assessment of the relationships between and among native and invasive P. antipodarum. We used a combination of traditional and Bayesian molecular analyses to demonstrate that New Zealand populations harbour very high diversity relative to the invasive populations and are the source of the two main European genetic lineages. One of these two European lineages was in turn the source of at least one of the two main North American genetic clusters of invasive P. antipodarum, located in Lake Ontario. The other widespread North American group had a more complex origin that included the other European lineage and two New Zealand clusters. Altogether, our analyses suggest that just a small handful of clonal lineages of P. antipodarum were responsible for invasion across continents. Our findings provide critical information for prevention of additional invasions and control of existing invasive populations and are of broader relevance towards understanding the establishment and evolution of asexual populations and the forces driving biological invasion. 相似文献
12.
《L'Anthropologie》2022,126(1):102974
Prehistoric sites testifying to human presence older than one million years in Europe are rare, and in the current state of knowledge, the oldest of them have been dated to around 1.4–1.5 Ma. The Vallonnet cave at Roquebrune-Cap-Martin in the Alpes-Maritimes, on the Mediterranean border, is one of the oldest sites in France to have yielded evidence of human activity: a lithic assemblage of about a hundred pieces and traces of butchery on bones of an Epivillafranchian fauna. The archaeological levels of this small cave were recently dated between 1.1 and 1.2 Ma by U-Pb correlated with paleomagnetic data. The site was occupied alternately by large carnivores that used it as a den or a lair, and by hominins that stayed there briefly in bivouac. The lithic remains are mainly percussion tools, shaped pebbles, flakes and cores, whose raw materials are local, or even semi-local, and on the whole not very diversified with mainly limestone, and to a lesser extent sandstone, quartzite, flint and quartz. This assemblage is attributed to a Mode 1 technology (Oldowayen), among which macro-tools (hammerstones, shaped and fractured pebbles) are found alongside rarer elements resulting from debitage operating chains aimed at producing sharp-edged flakes, very rarely retouched. The bipolar-on-anvil flaking technique could be identified from the characteristics of some artifacts. Several refitting flakes on shaped pebbles or percussion tools attest to knapping and percussion activities in the cave. Hominins consumed the remains of large herbivore carcasses, as attested by the presence of cutting and fracturing marks on some bones. The presence of a freshwater source in the immediate vicinity, and the knapping and butchering activities here therefore document the subsistence behavior of Lower Pleistocene human groups, certainly in competition with the carnivores present. 相似文献
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14.
Dmitry A. Ruban 《Geobios》2010,43(3):355
A palaeontological record of the Northern Caucasus provides new data to evaluate the influence of the Permian/Triassic mass extinction on brachiopod communities. The study region is currently located in the southwest of Russia; it laid on the northern margin of the Palaeo-Tethys Ocean during the late Paleozoic-early Mesozoic. A total of 168 genera and 36 superfamilies are known from the Changhsingian-Bajocian deposits of this region. The total diversity of brachiopods was very high in the Changhsingian (57 genera and 19 superfamilies), but these organisms disappeared entirely at the Permian/Triassic boundary. Three genera and three superfamilies existed in the Induan, but brachiopods perished again in the Olenekian. A recovery began in the Anisian, but the Changhsingian diversity was never reached again. No genera crossed the Permian/Triassic boundary, whereas 4 superfamilies became able to do this. Ambocoelioidea was a “dead clade walking” and went extinct in the Induan, whereas three other superfamilies (Dialasmatoidea, Rhynchonelloidea, and Wellerelloidea) were more successful. Survivors included no less than 20% of genera during the entire Induan-Bajocian time interval. The Changhsingian-Anisian interval is dominated by just one type of facies in the studied region, which may explain differences in the post-extinction diversity patterns between the Northern Caucasus, South China, and other parts of the World. Use of the alternative Triassic time scale does not change the absolute duration of the post-extinction stress (5.1 myr), whereas it highlights higher rates for the Anisian recovery (appearance of 0.9 superfamilies and 2.8 genera per myr). 相似文献
15.
G. Besnard B. Khadari M. Navascués M. Fernández-Mazuecos A. El Bakkali N. Arrigo D. Baali-Cherif V. Brunini-Bronzini de Caraffa S. Santoni P. Vargas V. Savolainen 《Proceedings. Biological sciences / The Royal Society》2013,280(1756)
The location and timing of domestication of the olive tree, a key crop in Early Mediterranean societies, remain hotly debated. Here, we unravel the history of wild olives (oleasters), and then infer the primary origins of the domesticated olive. Phylogeography and Bayesian molecular dating analyses based on plastid genome profiling of 1263 oleasters and 534 cultivated genotypes reveal three main lineages of pre-Quaternary origin. Regional hotspots of plastid diversity, species distribution modelling and macrofossils support the existence of three long-term refugia; namely the Near East (including Cyprus), the Aegean area and the Strait of Gibraltar. These ancestral wild gene pools have provided the essential foundations for cultivated olive breeding. Comparison of the geographical pattern of plastid diversity between wild and cultivated olives indicates the cradle of first domestication in the northern Levant followed by dispersals across the Mediterranean basin in parallel with the expansion of civilizations and human exchanges in this part of the world. 相似文献
16.
北方农牧交错区农业生态系统生产力对气候波动的响应——以准格尔旗为例 总被引:2,自引:0,他引:2
气候变化对区域生态系统结构和功能有重大影响。以中国北方农牧交错区的准格尔旗为例,利用气象和《统计年鉴》数据,采用数理统计方法分析准格尔旗1961—2009年降水量、平均气温的波动特征,计算出该地区1961—2009年农业生态系统NPP值和主要农作物的气候产量,论述了准格尔旗农业生态系统生产力对气候波动的响应。结果表明:(1)降水量和平均气温的年际、年内波动均显著。(2)准格尔旗农业生态系统生产力呈现阶段性地波动上升趋势。排除社会、科技等影响,气候生产力对气候波动表现出较强的敏感性,是作物气候生态适应的结果。(3)中国北方雨养旱作区,粮食气候产量受降水量年际波动(特别是7、8月)显著影响;谷子、糜黍、玉米、薯类、大豆和油料等农作物的气候产量与降水量年际波动呈显著正相关;谷子、糜黍的气候产量与生长季降水量年内波动呈显著负相关。集水型生态农业是北方农牧交错区生态环境友好的农业发展模式。(4)谷子、糜黍、薯类、大豆和油料等农作物的气候产量与6、7、8月平均气温年际波动呈显著负相关;生长季平均气温年内波动对谷子、糜黍、大豆和油料等农作物的气候产量有显著负面影响。因此,需要综合采取工程、生物和农业措施,将气候变化对主要农作物气候产量的不利影响降到最低。 相似文献
17.
Cesare Ravazzi Marta Donegana Elisa Vescovi Enrico Arpenti Marco Caccianiga Petra Kaltenrieder Laurent Londeix Stefano Marabini Stefano Mariani Roberta Pini Gian Battista Vai Lucia Wick 《Vegetation History and Archaeobotany》2006,15(4):357-371
We describe a new palaeobotanical site at Bubano quarry on the easternmost Po plain, northern Italy. Pollen and macrofossils from river and marsh sediments demonstrate the occurrence of Picea in a Pinus sylvestris forest growing in a radius of some tens of kilometres south of the sedimentation place, at the beginning of the Late-glacial interstadial. The Late-glacial and Holocene history of Picea in the northern Apennines is reconstructed on the basis of the palaeobotanical record. The sharp climatic continentality increase eastwards across the northern Apennines from the Tyrrhenian to the Adriatic coast is considered significant for the survival of Picea during the Late-glacial. The most critical phase of survival is related to the moisture changes and consequent Abies competition associated with the last glacial-interglacial transition and the early Holocene. The residual spruce populations expanded during the middle Holocene. The history of Picea in the northern Apennines is a case of ineffective interglacial spread of tree populations from pre-existing stands of LGM (Last Glacial Maximum) and Late-glacial age. 相似文献
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Murray J Fletcher 《Australian Journal of Entomology》2008,47(2):107-120
Abstract A key to the genera of Ricaniidae occurring in Australia is provided along with an annotated checklist of the described species in each genus. Taxonomic changes include transfer of Privesa pronotalis Distant to Aprivesa Melichar as Aprivesa pronotalis (Distant) comb. nov. and transfer of Busas Jacobi to the Tropiduchidae: Gaetuliini. Ricania fusconebulosa Lallemand and R. pedicellata Jacobi are both transferred to the genus Euricania Melichar as Euricania fusconebulosa (Lallemand) comb. nov. and Euricania pedicellata (Jacobi) comb. nov. Epithalamium moirae sp. nov. is described from Western Australia. The known Australian Ricaniidae fauna includes 29 species in 10 genera. 相似文献
20.
Improvement of recovery rates is crucial for the supply chain management of waste cooking oil-to-biofuel conversion. This paper constructs a dynamic game model between biofuel enterprises and recyclers to compare the recycling modes and recycling rate decisions of waste cooking oil-to-biofuel conversion in China and Japan. Results demonstrate that: (1) the recovery rate of Chinese mode with recyclers as price leader is not necessarily lower than that of Japanese mode theoretically, indicating that the collection-storage-transportation integrated mode in several cities led by Chinese government may not be the optimal choice. (2) The subsidies for recyclers have insignificant impact on recovery rate, while the subsidies for biofuel enterprises can significantly improve the recovery rate. (3) Decreasing difficulty coefficient and expanding the market size can greatly improve the recovery rate. Therefore, reforming the beneficiary of subsidies, improving the recycling infrastructure, implementing strict technical and administrative control and creative sales policy of biofuel finished products may benefit the recovery rate in China. 相似文献