首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Dr. Andrej Ernst 《Facies》2000,43(1):79-102
Summary Permian bryozoan faunas from the Lower Permian sequences of the Carnic Alps (UpperPseudoschwagerina Formation and Trogkofel Formation) and from some other Permian units of the NW-Tethys (Sicily, Tunisia) include cystoporid, trepostomid, fenestellid, rhabdomesid, and timanodictyid taxa. Fenestellids and cystoporids species dominate. The Lower Permian bryozoan fauna of the Carnic Alps displays close relations to faunas of Sakmarian-Artinskian age of the Russian Platform and Pamir as well as of the Lower Permian of Australia. Bryozoans from Permian sequences of Sicily and Tunisia display relations to the Permian faunas of Indonesia and Australia.  相似文献   

2.
The foraminiferal faunas and biostratigraphic correlation of the Tethyan uppermost Permian (Dzhulfian and Dorashamian) provide important paleogeographic and tectonic data for the interpretation of the Palaeofusulina-bearing terranes in East and Southeast Asia. These interpretations have a significant bearing on understanding Japanese pre-Cretaceous tectonostratigraphic and micropaleontologic data, as well as the geodynamic evolution of the Japanese Palaeofusulina-bearing terranes. The Tethyan foraminiferal fauna in the uppermost Permian is characterized by the occurrence of provincial and endemic schubertellid genera, and the absence of neoschwagerinids and verbeekinids which had characterized the rapidly evolving Middle Permian Tethyan marine faunas until their extinction at the end of the Midian. Difficulties in world-wide correlation of the uppermost Permian have resulted because of different geographic faunal compositions and the geographic patterns of extinction of Permian marine faunas. The Palaeofusulina fauna is one of the most reliable indicators of the uppermost Permian. Its presence or absence serves as paleogeographic constraints on East and Southeast Asian terranes. For example, the absence of Palaeofusulina fauna and the presence of late Midian Lepidolina multiseptata faunas in the Lhasa Terrane in Tibet and the Wolya Terrane in Sumatra (the third continental sliver north of Gondwana) are important, particularly, for identifying the rift–drift–collision process of the Gondwana-affinity terranes. They suggest a Late Permian separation of the two terranes from Gondwana. Tethyan Palaeofusulina occur in the latest Permian tropical to subtropical latitudinal belt and along with other geologic data assist in paleogeographic reconstructions and in interpreting the possible movement and emplacement of the Palaeofusulina-bearing terranes such as the Maizuru, South Kitakami–Kurosegawa and Chichibu terranes in Japan. They reveal that: (1) the Upper Permian Maizuru Group was deposited on the eastern continental margin of South China; (2) the occurrence of the Lower Permian Cathaysian flora and a number of geologic data in the South Kitakami–Kurosegawa suggest an arc–trench system setting and the Late Permian deposition in a shallow open-marine environment in proximity to South China; (3) foraminiferal biogeograpic data and the reconstructed oceanic plate stratigraphy in the Chichibu Terrane constrain the location of the Chichibu Seamount Chains to the western part of the Panthalassan domain, as they moved westwards against the Cathaysian Continent until their Jurassic accretion.  相似文献   

3.
The main aim of this paper is to review Middle Permian through Middle Triassic continental successions in European. Secondly, areas of Middle–Late Permian sedimentation, the Permian–Triassic Boundary (PTB) and the onset of Triassic sedimentation at the scale of the westernmost peri-Tethyan domain are defined in order to construct palaeogeographic maps of the area and to discuss the impact of tectonics, climate and sediment supply on the preservation of continental sediment.At the scale of the western European peri-Tethyan basins, the Upper Permian is characterised by a general progradational pattern from playa-lake or floodplain to fluvial environments. In the northern Variscan Belt domain, areas of sedimentation were either isolated or connected to the large basin, which was occupied by the Zechstein Sea. In the southern Variscan Belt, during the Late Permian, either isolated endoreic basins occurred, with palaeocurrent directions indicating local sources, or basins underwent erosion and/or there was no deposition. These basins were not connected with the Tethys Ocean, which could be explained by a high border formed by Corsica–Sardinia palaeorelief and even parts of the Kabilia microplate. The palaeoflora and sedimentary environments suggest warm and semi-arid climatic conditions.At the scale of the whole study area, an unconformity (more or less angular) is observed almost everywhere between deposits of the Upper Permian and Triassic, except in the central part of the Germanic Basin. The sedimentation gap is more developed in the southern area where, in some basins, Upper Permian sediment does not occur. The large sedimentary supply, erosion and/or lack of deposition during the Late Permian, as well as the variable palaeocurrent direction pattern between the Middle–Late Permian and the Early Triassic indicate a period of relief rejuvenation during the Late Permian. During the Induan, all the intra-belt basins were under erosion and sediment was only preserved in the extra-belt domains (the northern and extreme southern domains). In the northern domain (the central part of the Germanic Basin), sediment was preserved under the same climatic conditions as during the latest Permian, whereas in the extreme southern domain, it was probably preserved in the Tethys Ocean, implying a large amount of detrital components entering the marine waters. Mesozoic sedimentation began in the early Olenekian; the ephemeral fluvial systems indicate arid climatic conditions during this period. Three distinct areas of sedimentation occur: a northern and southern domain, separated by an intra-belt domain. The latter accumulated sediments during the Early–Middle Permian and experienced erosion and/or no-deposition conditions between the Middle–Late Permian and the beginning of Mesozoic sedimentation, dated as Anisian to Hettangian. At the top of the Lower Triassic, another tectonically induced, more or less angular unconformity is observed: the Hardegsen unconformity, which is dated as intra-Spathian and is especially found in the North European basins. This tectonic activity created new source areas and a new fluvial style, with marine influences at the distal part of the systems. During the Anisian and Ladinian, continental sedimentation was characterised by a retrogradational trend. In other words, the fluvial system evolved into fluvio-marine environments, attesting to a direct influence of the Tethys Ocean in the southern and northern domains. Both at the end of the Olenekian (Spathian) and during the Anisian, the presence of palaeosols, micro- and macrofloras indicate less arid conditions throughout this domain.  相似文献   

4.
Two new species of the family Spilapteridae, Homaloneura brauckmanni sp. nov. and Baeoneura desperata sp. nov. are described from the Lower Permian insect bearing deposits of the Vorkuta Coal Basin. For Vorkutoneura variabilis Sinitshenkova, 1977 (Spilapteridae), the imaginal forewing and nymphal hindwings are described for the first time. The dictyoneuridan assemblage does not agree with the existing dating of these deposits as Late Permian, as the insect assemblage suggests an Early Permian age.  相似文献   

5.
值此黄汲清先生100周年冥诞之际,我们深切地感念先生对后学的奖掖提携,十分钦敬先生早年在我国二叠系学术园地里的辛勤耕耘和丰硕成果。令人感动的是先生以耄耋之年,仍然关注和督促着我国二叠系的研究,并且在二叠系“三分”和下界国际化的认识回归中作出无人可以替代的重大贡献。  相似文献   

6.
The Carboniferous and Permian of the Baoshan block consist of three major depositional sequences: a Lower Carboniferous carbonate sequence, a Lower Permian siliciclastic sequence, and a Middle Permian carbonate sequence. These three sequences were interrupted by two major regressive events: first, the Namurian Uplift ranging in age from Serpukovian to Gzhelian, and second, the Post-Sakmarian Regression occurring probably at Artinskian time in the Baoshan block, although the precise time interval of the latter event is still unclear. The Baoshan block is characterized by warm-water, highly diverse and abundant faunas during the Early Carboniferous, by cold-water and low diversity faunas during the Early Permian, and by possibly warm-water but low diversity faunas during the Middle Permian. The Sweetognathus bucaramangus conodont fauna constrains the upper boundary of the diamictite-bearing siliciclastic deposits (Dingjiazhai Formation) to the Sakmarian to early Artinskian, as well as the eruption of the rifting basalts (Woniusi Formation) to, at least, the post-early Artinskian. Paleozoogeographically, affiliation of the faunas in the Baoshan block changed from Eurasian in the Early Carboniferous, to Peri-Gondwanan in the Early Permian, and to Marginal Cathaysian/Cimmerian in the Middle Permian. Cimmerian blocks have more or less comparable geohistory to one another in the Carboniferous and Permian. During the Middle Permian, the eastern Cimmerian blocks such as Sibumasu (s.s), Baoshan, and Tengchong are not far from the palaeoequator, but apparently more distant than the western Cimmerian blocks based on the presence or absence of some index taxa such as the fusulinaceans Eopolydiexodina and Neoschwagerina, and the corals Thomasiphyllum and Wentzellophyllum persicum.  相似文献   

7.
Bone microanatomy appears to track changes in various physiological or ecological properties of the individual or the taxon. Analyses of sections of the tibia of 99 taxa show a highly significant (P 相似文献   

8.
Y. Ezaki 《Palaeontology》2000,43(2):199-217
Scleractinian corals are the most important constituents of modern coralgal reefs. For many years, it was thought that they first appeared in the Middle Triassic and subsequently underwent explosive radiation. However, abundant scleractinian-like corals with ancestral morphological traits have recently been recovered from Middle Permian sponge reefs in China, which not only confirms a role in Permian reef ecology but also suggests a possible Palaeozoic origin for the group. Two species of a new Permian scleractiniamorph genus from China are described herein as Houchangocyathus wangi gen. et sp. nov. and Houchangocyathus yaoi gen. et sp. nov. Putative Palaeozoic Scleractinia may have evolved over a substantial time interval and diverged into stem lineages by the end of the Permian. These forms evolved within both the rigid framework of their basic body plan and the morphological constraints characteristic of each lineage. The Middle Permian development of calcisponge reefs was closely related to habitat expansion, which would have provided an ideal dwelling for scleractinian-like corals and enhanced their chances of fossilization. Such scleractiniamorphs disappeared at the end-Permian extinction, but may have survived as progenitors of Triassic Scleractinia.  相似文献   

9.
滇西保山地区石炭纪、二叠纪古动物地理演化   总被引:14,自引:0,他引:14  
探讨滇西保山地块晚古生代Ting类、有孔虫、珊瑚、牙形刺、腕足类等动物群的古生物地理属性,根据牙形刺和Ting类化石,确定长期争论的丁家寨组的时代为Artinskian期,小型单体珊瑚Cyathaxonia动物群可出现在从早石炭世到二叠纪的多种沉积环境中,不一定指示冷水冈瓦纳型。根据沉积特征及对环境特别敏感的珊瑚和Ting类动物群的分布特点,结合全球构造事件,恢复保山地块的古地理演化模式。早石炭世  相似文献   

10.
In the present paper, we discuss the evolution of an upper Permian anagenetic lineage of polycystine radiolarians belonging to the genus Albaillella. This genus is characterized by increasing curvature of the shell during the upper Permian and the trend is reversed (proteromorphic retrogradation) in the Lower Triassic with the sudden appearance of forms that are homeomorphic to the earliest Permian representative of the genus. These primitive-looking forms are derived from their immediate ancestors by retrograde evolution, a phenomenon which has been described as proteromorphosis.  相似文献   

11.
Permian fusulinoidean faunas occur in mainly four stratigraphic levels in the Baoshan Block of West Yunnan and the Sibumasu Block of Southeast Asia, which constituted part of the eastern Cimmerian Continent. The oldest fauna, from the upper part of the Dingjiazhai Formation in the Baoshan Block, consists of Pseudofusulina, Eoparafusulina, and a new boultoniid genus, and is assignable to the Yakhtashian (=Artinskian). The second one, which occurs in the basal part of the Ratburi Limestone and its equivalent strata in the Sibumasu Block, is represented by Monodiexodina, and is probably referable to the Bolorian (=Kungurian). The third fauna, composed of Eopolydiexodina, Rugososchwagerina, Yangchienia, Chusenella, Jinzhangia, and several other genera, is dated to the Murgabian (=Wordian), and occurs in the lower part of the Shazipo and Daaozi formations in the Baoshan Block and the main part of the Ratburi Limestone in the Sibumasu Block. The youngest fauna of probably Dzhulfian (=Wuchiapingian) age is found in the upper part of the Ratburi Limestone, and contains Nanlingella, Reichelina, Codonofusiella?, and a few staffellid genera. A smaller foraminiferal genus, Shanita, found from the upper part of the Ratburi Limestone and the upper part of the Shazipo Formation is also an important element of the foraminiferal assemblage near the Midian-Dzhulfian (=Capitanian-Wuchiapingian) boundary in the Baoshan and Sibumasu blocks.In the eastern Cimmerian Continent, low generic diversity throughout the Permian and the paucity of Tethys-characterizing neoschwagerinid and verbeekinid genera during Middle Permian time are two remarkable features of the Permian fusulinoidean faunas. In the Cimmerian Continent, the generic diversity of Permian fusulinoidean faunas in space and time gradually increases from the Early Permian to late Middle Permian as well as from the eastern Cimmerian areas to western ones. The temporal increase of the generic diversity can be explained by the northward drift of the Cimmerian Continent during Permian time. In contrast, the lower generic diversity of the eastern Cimmerian Permian fusulinoidean faunas against western ones is possibly due to an oblique arrangement of the continent to paleolatitude. Thus, the western Cimmerian Continent was more proximal to the tropical Tethyan domain than its eastern part. In addition, the Middle Permian Cimmerian paleobiogeographic region is likely to be subdivided into two subregions, the western Tethyan Cimmerian and the eastern Gondwanan Cimmerian, based on the distribution pattern of verbeekinid and neoschwagerinid fusulinoideans and overall generic diversity. The scarce occurrence or total absence of these essentially Tethys-indicating fusulinoideans in the Baoshan and Sibumasu blocks suggests that the eastern Cimmerian Continent was still far from the equatoro-tropical Cathaysian domain and was probably in a warm temperate or subtropical zone until the end of the Permian. The eastern Cimmerian areas finally migrated into a tropical zone by the Late Triassic judging from well-developed Carnian sponge-coral buildups in the Chaiburi Formation in the Sibumasu Block.  相似文献   

12.
所讨论的“板状水螅”是一类分类位置尚有争议的化石,为华蓥山地区上二叠统生物礁的主要造礁生物之一。这里描述了3属3种.其中包括2新属和3新种.它们是Pseudopalaeoaplysinahuayingensis,Phragmorphaasiatica和Cnidoporatuberculosa。  相似文献   

13.
对鲁西晚古生代含煤岩系以及华北各地石炭、二叠系孢粉组合中已经发现的Sinulatisporites一属的时空分布进行详细研究,结果表明:其时空分布仅限于华夏植物区的北方亚区,在时间上始于早二叠世早期(太原组),灭绝于中二叠世中、晚期,可视为鲁西乃至华北地区早二叠世晚期、中二叠世早期中期华夏植物区北方亚区的典型分子。其母体植物可能为一种喜湿热的真蕨植物或种子蕨植物。该属产出层位稳定,延续时间较短,在月门沟统山西组、石盒子统下石盒子组含量丰富,又常产出于月门沟统山西组的主要含煤岩段及其上部石盒子统下石盒子组的砂、泥岩段,故可作为二叠系划分和对比煤层的重要依据。  相似文献   

14.
Cranial morphology of Permian and Triassic Therocephalia of Eastern Europe is revised. The Therocephalia are regarded as an order of the subclass Eutherapsida of the class Theromorpha. Phylogenetic relationships are reconsidered and a tentative taxonomic scheme of the order is proposed. Biomorph evolution of East European Therocephalia from the Middle Permian to the Middle Triassic are discussed.  相似文献   

15.
Uniquely preserved pollen was extracted from intestines of fossil insects from the Lower Permian of the Urals. A species of Hypoperlidae, an extinct family ancestral to bark-lice, bugs and plant-hoppers, and two species of Grylloblatida, a predominantly Permian group with a few extant representatives related to stoneflies, contain protosaccate taeniate grains of several pollen genera well known as dispersed microfossils and occasionally found in sporangia of conifers, peltasperms and glossopterids. This is so far the earliest direct evidence of pollinivory, a major factor of plant-insect coevolution. The partly digested pollen grains reveal infratectal reticulum and other structural details of evolutionary significance. It is suggested that the peculiar taeniate pollen of worldwide distribution in the Permian might simultaneously evolve in several groups of Paleozoic seed plants in relation to pollinivory that, by altering the rnicropyle load and thereby the pollen/ovule ratio, could also affect ovuliferous structures. Thus pollinivory might impel rapid diversification of gymnosperms in the Permian. The pollinivorous Hypoperlidae, which have evolved in the direction of ovulivory, might initiate insect pollination in the process.  相似文献   

16.
Dicynodont therapsids have been known from the Upper Permian of Eastern Europe since the beginning of the twentieth century, but the phylogenetic relationships of these taxa have not been examined cladistically. Here we present the results of a phylogenetic analysis that includes eight Permian dicynodonts from Russia as well as 18 taxa best known from southern Africa. Our results do not conflict with much of the established picture of Permian dicynodont phylogeny, but are consistent with several novel hypotheses. Most importantly, our analysis suggests that the genus Dicynodon is paraphyletic, and we question its use in correlating widely separated basins. However, we cannot strongly reject a monophyletic Dicynodon . Our results also indicate that the closest Permian relatives of Kannemeyeria lived in Russia, suggesting a Laurasian origin for the lineage that includes this important Triassic taxon. The phylogeny presented here also suggests a Laurasian origin for several other dicynodont clades, but a Gondwanan origin is equally likely given the data at hand. Regardless of where these groups originated, there appears to be some endemism among Late Permian dicynodont faunas. Although our understanding of dicynodont phylogeny is improving, this study emphasizes the disparity in sampling of the dicynodont record between Gondwana and Laurasia and the need for a large scale phylogenetic analysis of Permian and Triassic dicynodonts.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 139 , 157−212.  相似文献   

17.
Summary The roles of Permian colonial corals in forming organic reefs have not been adequately assessed, although they are common fossils in the Permian strata. It is now known that colonial corals were important contributors to reef framework during the middle and late Permian such as those in South China, northeast Japan, Oman and Thailand. A coral reef occurs in Kanjia-ping, Cili County, Hunan, South China. It is formed by erect and unscathed colonies ofWaagenophyllum growing on top of one anotherin situ to form a baffle and framework. Paleontological data of the Cili coral reef indicates a middle to late Changhsing age (Late Permian), corresponding to thePalaeofusulina zone. The coral reef exposure extends along the inner platform margin striking in E-S direction for nearly 4 km laterally and generally 35 to 57 m thick. The Cili coral reef exhibits a lateral differentiation into three main reef facies; reef core facies, fore-reef facies, and marginal slope facies. The major reef-core facies is well exposed in Shenxian-wan and Guanyin-an sections where it rests on the marginal slope facies. Colonial corals are dispersed and preserved in non-living position easward. Sponges become major stabilizing organisms in the eastern part of Changhsing limestone outcrop in Kanjia-ping, but no read sponge reefs were formed. Coral reefs at Cili County in Human are different distinctly from calcisponge reefs in South China in their palaeogeography, lithofacies development, organic constitutuents, palaeoecology and diagenesis. The Cili coral reef also shows differences in age, depositional facies association, reef organisms and diagenesis from coral reefs in South Kitakami of Japan, Khorat Plateau of Thailand, and Saih Hatat of Oman. Although some sponge reefs and mounds can reach up to the unconformable Permian/Triassic boundary, coral reef at Kanjia-ping, Cili County, is the latest Permian reef known. This reef appears to had been formed in a palaeoenvironment that is different from that of the sponge reefs and provides an example of new and unique Permian reef type in South China, and could help us to: 1) understand the significance of colonial corals in Permian carbonate buildups; 2) evaluate the importance of coral community evolution prior to the collapse of reef ecosystems at the Permian/Triassic boundary; 3) better understand the effects of the biotic extinction events in Palaeotethys realm; 4) look for environmental factors that may have controlled reefs through time and space, and 5) provide valuable data for the study of Permian palaeoclimate and global evolutionary changes of Permian reefs and reef community.  相似文献   

18.
A small brachiopod fauna is described from the carbonate rocks of the basal Shazipo Formation of the Baoshan Block, western Yunnan, south-west China, including significant new ventral and dorsal internal morphological features of Cryptospirifer omeishanensis Huang. This fauna is regarded as Wordian (Middle Guadalupian, Middle Permian) because of the presence of Cryptospirifer omeishanensis Huang and associated fusulinids ( Neoschwagerina craticulifera Zone). Palaeobiogeographically, the brachiopod fauna is of considerable interest because of its admixed nature characterized by typical warm-water Cathaysian elements intermingled with temperate Peri-Gondwanan taxa. This in turn is interpreted to indicate that the Baoshan Block may have been situated in an intermediate palaeogeographical position between Gondwanaland to the south and Cathaysia to the north during the Mid Permian and, as such, it probably furnished an important 'stepping stone' for the dispersal of Mid Permian eastern Tethyan marine invertebrate taxa (e.g. Cryptospirifer ) to the western Tethys.  相似文献   

19.
Analysis of a large database of the stratigraphic distribution of fusulinacean Foraminifera reveals an Early Permian event of significant decline of species diversity in South China. Data from Late Carboniferous to Early Permian sections without apparent unconformity in southwest China were evaluated to determine if the apparent pattern of species disappearance was caused by bias in fossil preservation associated with Early Permian sea-level changes. Statistical analysis suggests that the Early Permian event started in the Late Sakmarian with a significant drop of species diversity in the Robustoschwagerina ziyunensis Zone and continued through the Pamirina darvasica Zone of the Artinskian and into the Brevaxina dyhrenfurthi Zone of the Early Kungarian, resulted in a total loss of about 40% species diversity in the fusulinacean fauna. The Early Permian event is the most extensive bioevent in the history of fusulinacean Foraminifera at the species level although it is less significant at the generic level. Because a similar faunal change has been found among the fusulinacean assemblages in North America and in various regions of Tethys, this event may represent a major faunal turn-over in response to the Early Permian changes in sea level and could be of a global nature. Previous recognition of this event was hampered by Early Permian unconformities in North America and other regions of Tethys.  相似文献   

20.
We describe the first known occurrence of a Permian shark specimen preserving two temnospondyl amphibians in its digestive tract as well as the remains of an acanthodian fish, which was ingested by one of the temnospondyls. This exceptional find provides for the first time direct evidence of a vertebrate three-level food chain in the fossil record with the simultaneous preservation of three trophic levels. Our analysis shows that small-sized Lower Permian xenacanthid sharks of the genus Triodus preyed on larval piscivorous amphibians. The recorded trophic interaction can be explained by the adaptation of certain xenacanthids to fully freshwater environments and the fact that in these same environments, large temnospondyls occupied the niche of modern crocodiles. This unique faunal association has not been documented after the Permian and Triassic. Therefore, this Palaeozoic three-level food chain provides strong and independent support for changes in aquatic trophic chain structures through time.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号