The Pattern and Evolution of the Permian Palaeobiogeography and Tectonic Palaeogeography in Jilin and Heilongjiang Orogenic Belt

The orogenic belt locates between the North China plate and Siberia plate. The Permian palaeobiogeography and tectonic palaeogeography changed quickly and clearly. The line from Changchun to Yanji is an important palaeobiogeographic provincing line,which may be the collission suture belt of the North China plate and north middle massifs. The orogenic belt has been divided into 2 regions: the North middle massif region and the North Margin of North China plate, the pattern and evolution of Permian palaeobiogeography in the present area were discussed and the Permian biota mixture and its significants were analysed. Then, Based on the above,the Permian tectonic palaeogeography of the orogenic belt is reconstructed.

Middle Permian palaeobiogeography study in East Kunlun,A'nyêmaqên and Bayan Har

Three regions can easily be identified in the study area according to the Middle Permian palaeobiogeographic distribution of biota, they are the southern slope of East Kunlun, A’nyêmaqên and Bayan Har. Biotic constitution and ecology in the southern slope of East Kunlun and Bayan Har are very similar. Both the diversity and abundance of organisms in these two areas are very high and reefs are widely developed. However, biotic diversity and abundance in A’nyêmaqên which is between the above two areas are obviously low. Differentiation of palaeo- biogeographic distribution in these areas should be due to the baring of A’nyêmaqên ocean in the time of Middle Permian. Middle Permian radiolarian chert and thick abyssal red ooze are widely spread in A’nyêmaqên, implying that the A’nyêmaqên ocean had a great scale in size. Vast scale of deep ocean basin became an impassable gulf for some of the benthos, and as a result, only part of the organisms could have the chance to get to the isolated islands situated in ocean basin. Small living space and hard conditions in the islands further limited the abundance and diversity of biota. Tectonic background reflected by the geochemical study of basalt in the three areas is coupling well enough with the palaeobiogeographic division.

The first record of freshwater plesiosaurian from the Middle Jurassic of Gansu, NW China, with its implications to the local palaeobiogeography

Plesiosaurs are one of the common groups of aquatic reptiles in the Mesozoic,which mainly lived in marine environments.Freshwater plesiosaurs are rare in the world,especially from the Jurassic.The present paper reports the first freshwater plesiosaur,represented by four isolated teeth from the Middle Jurassic fluviolacustrine strata of Qingtujing area,Jinchang City,Gansu Province,Northwest China.These teeth are considered to come from one individual.The comparative analysis of the corresponding relationship between the body and tooth sizes of the known freshwater plesiosaur shows that Jinchang teeth represent a small-sized plesiosaurian.Based on the adaptive radiation of plesiosaurs and the palaeobiogeographical context,we propose a scenario of a river leading to the Meso-Tethys in the Late Middle Jurassic in Jinchang area,which may have provided a channel for the seasonal migration of plesiosaurs.

Coevolution of global brachiopod palaeobiogeography and tectonopalaeogeography during the Carboniferous

The global brachiopod palaeobiogeography of the Mississippian is divided into three realms, six regions, and eight provinces, while that of the Pennsylvanian is divided into three realms, six regions, and nine provinces. On this basis,we examined coevolutionary relationships between brachiopod palaeobiogeography and tectonopalaeogeography using a comparative approach spanning the Carboniferous. The appearance of the Boreal Realm in the Mississippian was closely related to movements of the northern plates into middle–high latitudes. From the Mississippian to the Pennsylvanian, the palaeobiogeography of Australia transitioned from the Tethys Realm to the Gondwana Realm,which is related to the southward movement of eastern Gondwana from middle to high southern latitudes. The transition of the Yukon–Pechora area from the Tethys Realm to the Boreal Realm was associated with the northward movement of Laurussia, whose northern margin entered middle–high northern latitudes then. The formation of the six palaeobiogeographic regions of Mississippian and Pennsylvanian brachiopods was directly related to "continental barriers", which resulted in the geographical isolation of each region. The barriers resulted from the configurations of Siberia, Gondwana, and Laurussia, which supported the Boreal, Tethys, and Gondwana realms, respectively. During the late Late Devonian–Early Mississippian, the Rheic seaway closed and North America(from Laurussia) joined with South America and Africa(from Gondwana), such that the function of "continental barriers" was strengthened and the differentiation of eastern and western regions of the Tethys Realm became more distinct. In the Barents Ocean tectonic domain during the Pennsylvanian, the brachiopods on the northern margin of the Barents Ocean formed the Verkhoyansk–Taymyr Province, while those on the southern margin formed the Yukon–Pechora Province. The Mongolia–Okhotsk Province was formed by brachiopods of the Mongolia–Okhotsk Ocean tectonic domain. The Northern Margin of the Palaeo-Tethys Ocean Province and the Southern Margin of the Palaeo-Tethys Ocean Province were formed, respectively, by brachiopods on the northern and southern margins of the Palaeo-Tethys Ocean tectonic domain. South China and Southeast Asia were dissociated from the major continental blocks mentioned above, and formed the South China Province.

Uneven Distribution of Pseudotormentus De Wever et Caridroit(Radiolaria,Protozoa):Provincialism of a Permian Planktonic Microorganism

The Permian planktonic distribution is not well known,in contrast to other fossil distributions of nekton and benthos.Radiolaria are representative microfossils of plankton in the Permian palaeocean.This study compares both correlated radiolarian occurrences（Pseudotormentus De Wever et Caridroit and Quadriremis Nazarov et Ormiston） in literature data from the Pacific Rim and quantitative data from the Liuhuang and Gujingling sections in South China.Pseudotormentus distributions are concentrated in the Panthalassa,whereas Quadriremis occurrences are distributed over both the Panthalassa and the Palaeotethys.The uneven distribution of Pseudotormentus seems to have been controlled by a difference in the oceanic basins,indicating the presence of faunal differences in Permian planktonic microorganisms between the Panthalassa and the Palaeotethys.In other words,this study infers the provincialism of Permian planktonic microorganisms.The uneven distribution is explainable by a hypothesis that Pseudotormentus was strongly affected by a Panthalassan equatorial current.

Addressing the Chengjiang conundrum: A palaeoecological view on the rarity of hurdiid radiodonts in this most diverse early Cambrian Lagerstatte

Over one hundred arthropod fossil species have been described from the famous Chengjiang Lagerst?tte(South China, Cambrian Stage 3, ca. 518 Ma) including a diverse assemblage of radiodonts–a group containing Anomalocaris and its relatives. These iconic stem-group euarthropods include some of the largest animals of the time, and some are known from hundreds of specimens. A longstanding conundrum has been the rarity or absence of hurdiids from Cambrian Series 2 Lagerst?tten like Chengjiang. This is because radiodonts are generally common in such deposits and the oldest radiodont ever discovered is a hurdiid. Furthermore, this family displays the widest geographic and temporal ranges of all radiodont families, and the highest diversity. Here we document the first hurdiid frontal appendages from Chengjiang, which display unique features within the family and may provide insights for understanding the character evolution of hurdiid appendages. The palaeoenvironmental distribution of hurdiids suggests that the rarity of hurdiids in Chengjiang may be due to a preference for deeper water environments,and the later success of this family from the Wuliuan onwards may relate to their ability to tolerate cooler water temperatures than other radiodont families. The palaeogeographical, palaeoenvironmental, and stratigraphical patterns observed in hurdiids maybe caused in part by the limited distributions of Konservat-Lagerst?tten in the Cambrian as well.

The most northerly record of the sirenian <i>Protosiren</i>and the possible polyphyletic evolution of manatees and dugongs

Newly discovered remains of the early Middle Eocene (Lutetian) sirenian Protosiren (Protosirenidae) in shark tooth rich conglomerates from a coastal delta environment northwest of the European Rhenish Massif at Fürstenau (northwestern Germany), represent the most northerly occurrence of this genus whose global distribution was generally restricted to warm waters. Its presence of the remains so far north can be explained by seasonal inflow of warm Tethys surface water into the cool, upwelling-influenced, basin. The existence of two discrete centers of sirenian evolution can be explained by the opening of the Atlantic and the upwelling that separated the North American warm water faunal province from those of Africa and Eurasia. A slightly modified evolutionary model is presented in which the oldest Early Eocene manatee sirenians evolved in the Caribbean of Central America. Protosiren, however, appears to have developed polyphyletically along the African coastline of the Tethys, and represents the oldest known dugong ancestor. Younger (Oligocene) European sirenian skeletons of Halitherium and Anomotherium are included in the phylostratigraphic model in which sirenians had generally reduced their teeth by 28 Ma as an adaptation for feeding on sea-plants (macroalgae/seagrass). Teeth from early megatooth sharks, which preyed on sirenians, have been recorded from shallow marine Eocene and Oligocene coastlines of the southern proto-North Sea Basin, and shark bite marks have been found on sirenian skeletons.

Evolution of white and megatooth sharks, and evidence for early predation on seals, sirenians, and whales

The early white shark Carcharodon Smith, 1838 with the fossil Carcharodon auriculatus (Blainville, 1818) and the extinct megatooth shark Otodus Agassiz, 1843 with species Otodus sokolovi (Jaeckel, 1895) were both present in the European proto North Sea Basin about 47.8 - 41.3 m.y. ago (Lutetian, early Middle Eocene), as well as in the Tethys realm around the Afican-Eurasian shallow marine habitats. Both top predators developed to be polyphyletic, with possible two different lamnid shark ancestors within the Early Paleocene to Early Eocene timespan with Carcharodon (white shark line-age) and Otodus (megatooth shark lineage). Their sawblade teeth developed during the early Paleogene as the result of adaptation to feeding on various marine new rising mammals, coinciding with three main waves of evolutionary emergence of seals, sirenians, and whales in parallel with the evolution of these large predatory sharks. Megatooth sharks specialized in hunting whales and sirenians only on the coastal shelves of warm oceans and disappeared globally in the Pleistocene due to climate change and ocean cooling. The cold-water adapted early white sharks have survived until the present day with body temperate change adaptation in warm to temperate oceans and are proposed to have specialized on coastal seal hunting already50 m.y. ago.

Triassic integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

Rocks of the Qinghai-Tibetan Plateau(QTP)host abundant Triassic fossils.So far,the well established marine fossil sequences based on ammonoids,conodonts,bivalves,brachiopods,radiolarians,and terrestrial spora-pollen sequence have become standard for biostratigraphic correlation of the QTP.For much of Triassic time,the QTP occupied a marine setting as suggested by the dominance of marine deposits.The main sedimentary types represented in the Triassic successions include littoral to shallow marine clastic rocks,shallow marine carbonate platform carbonates,bathyal to abyssal slope carbonates intercalated with clastic and siliceous deposits,coal-bearing clastic strata contained within paralic facies deposits,and littoral and terrestrial volcaniclastic rocks.These deposits are organized into four stages in ascending order:(1)Early Triassic deposits that record marine transgression,including extensive shallow marine carbonate platform strata.(2)Middle Triassic Ladinian to Late Triassic Carnian deposits,including thin-bedded limestone,fine clastics,and siliceous rocks,that accumulated at greater depths than underlying Early Triassic strata and reflect the peak of the transgression.Magmatic activity appears to have occurred in some areas during this stage.(3)Late Triassic Norian deposits that record the onset of marine regression as suggested by the widespread occurrence of platform carbonates.It is noteworthy that stage 3 deposits of the Qin-Qi-Kun area in the northernmost region of the QPT is dominated by terrestrial strata and displays evidence of local erosion.(4)Late Triassic Rhaetian littoral and shallow marine clastic and coal-bearing deposits that preserve the record of continued marine regression continued.The Indus-Yarlungzangbo Suture Zone(IYSZ)appears to have been the rifting axis during Triassic time as suggested by sedimentary facies trends that reflect deepening to south and north.Thus,the Himalaya Block to the south of the IYSZ was part of the passive margin of Gondwana whereas the north side of the IYSZ,including the Gangdis(or Lhasa)and South Qiangtang blocks,belonged to the passive margin of Eurasia.The similarity of rocks of the Bangongco-Nujiang Suture Zone(BNSZ)to the north of the IYSZ with those of the Gangdis Block to the south and the South Qiangtang Block to the north does not support the contention that the BNSZ was a rift axis during Triassic time.Results of palaeobiological research also suggest that the IYSZ rather than BNSZ was a biogeographic boundary during the Triassic.Early and Middle Triassic break-up of Pangea was accompanied on the QTP by rifting along the IYSZ.The expression of crustal shortening induced by the Indosinian Orogeny on the QTP is largely a change of sedimentary facies induced by Late Triassic uplift.Deposits of the Gangdis to South Qiangtang regions of the QTP record a transition from shallow marine carbonate platform deposits to littoral and paralic coal-bearing strata.Moreover,the stratigraphic succession of the Qin-Qi-Kun area preserves a transition from littoral clastic deposits to terrestrial facies and local erosion.

Ordovician integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Ordovician rocks on the Qinghai-Tibetan Plateau represent the oldest non-metamorphic strata,and are critical to understanding the history of regional geology and biotic evolution of the entire plateau.Strata of Floian,Darriwilian,Sandbian,Katian and Hirnantian are represented in the plateau with a hiatus of variable duration occurring underneath the basal Ordovician across the area.Five stratigraphical regions,including the Himalaya,Gangdise-Zayu,Qiangtang-Qamdo,Songpan-Garze,and Karakoram-Kunlun-Altun,are differentiated for the Ordovician strata,which are correlated with their equivalents in the Sibumasu,Indochina,Qaidam-Qilian,Tarim-Tianshan,and the Yangtze(western margin)stratigraphical regions.On the QinghaiTibetan Plateau,graptolites,conodonts,and cephalopods are the most common and useful fossils for the Ordovician biostratigraphy.The Ordovician biotas of the Qinghai-Tibetan Plateau bear some distinguishable palaeobiogeographical signatures,among which the cephalopods are characterized by the flourishing actinocerids of North China affinity in the Early-Middle Ordovician,and by the thriving lituitids and orthocerids of South China affinity in the Middle-Late Ordovician.Fossil occurrences and their palaeobiogeographical evolution provide critical evidence bearing on the reconstruction of the geological history of the Qinghai-Tibetan Plateau and surrounding terranes in northeastern peri-Gondwana.The stratigraphical successions of the Cambrian-Ordovician transition in the Himalaya and Lhasa and nearby Sibumasu terranes were significantly affected by the Kurgiakh Orogeny,which resulted in the extensive unconformity between the Ordovician and the underlying rocks in most areas of the Qinghai-Tibetan Plateau.In southern Xizang,a warm-water biota of Middle Ordovician age was recovered from oolitic limestones,suggesting a likely palaeogeographical location in low-latitudes near the equator.In the Himalaya and Sibumasu regions,the Upper Ordovician was typified by the occurrence of red carbonates with distinctive reticulate structures,which are correlative to their equivalents in the Yangtze region of South China,and might be deposited under similar geological conditions.The global end-Ordovician glaciation and sea-level drop likely caused the wide absence of late Katian strata in western Yunnan of China and the Shan State of Myanma,and may have also affected deposition in the Xainza and Nyalam areas of the QinghaiTibetan Plateau during this time interval.

Palaeobiogeographical constraints on the distribution of foraminifers and rugose corals in the Carboniferous Tindouf Basin,South Morocco

The northern flank of the Tindouf Syncline in southern Morocco exhibits a continuous, well exposed Carboniferous succession with limestones of Late Asbian to Early Bashkirian age containing rich and diverse foraminiferal and rugose coral assemblages. Analysis of these assemblages provides new data on the relatively poorly known Saharan basins. The palaeobiogeographical relationship of the Tindouf Basin with other Palaeotethyan basins is complex. Although there is a predominance of cosmopolitan taxa for the Palaeotethys, it is recognized that there was an influence of basins from NW Europe, such as the UK and Ireland. Some taxa are recorded in both NW Europe and Tindouf without any characteristic contributions from intermediate basins in northern Morocco. The neighbouring Béchar Basin in Algeria presents distinct assemblages. The bulk of the data analyzed suggest that this sector of the western Palaeotethys can be subdivided into four palaeobiogeographical subprovinces: the Atlantic Subprovince (UK, Ireland, N France and Belgium), the Mediterranean Subprovince (Pyrenees, Montagne Noire, Betic Cordillera, Rif (N Morocco) and Balearic Islands), and the Saharan Subprovince (Béchar, Reggan, Ahnet-Mouydir and Tindouf). In between, mobile belts of mixed faunal assemblage characteristics are observed (e.g., SW Spain and Central Meseta) forming the West peri-Gondwanan Subprovince.Analysis of the Tindouf Basin faunas shows that, as in other Saharan basins, there is a high diversity and abundance of foraminiferal taxa, with a higher proportion of survivors and longer stratigraphic ranges; these features also are mirrored by rugose corals. This emphasizes the longevity of the carbonate platform in a tropical setting, where periodic transgressions introduced new assemblages, and oceanic currents are interpreted as one of the main controlling factors for the distribution of the taxa in these subprovinces. Moreover, not only were water temperatures on the platform higher, but also tectonic stability greater. It is considered that the effects of the first phases of the Gond-wanan glaciation were minimal on the Tindouf faunas.

Fruits of Scirpus(Cyperaceae) from the early Miocene of Weichang,Hebei Province,North China and their palaeoecological and palaeobiogeographical implications

This paper describes the fossil fruits of Scirpus weichangensis X.Q.Liang,sp.nov.from the early Miocene of Guangyongfa Village,Weichang County,Hebei Province,North China.The fossil fruits are obovate in shape and their lateral sections are plumply trigonous.The cell walls of the surface are straight.The persistent stout bristles have downward-directed barbellae in distal 1/2.The occurrence of the fossil Scirpus indicates that Guangfayong was a wetland in the early Miocene.Based on the fossil data,the genus likely originated in Western Siberia in the Oligocene,spread during the Miocene,and was finally distributed worldwide in the Holocene.

Callovian-Oxfordian hecticoceratins from western India:Their biostratigraphic and palaeobiogeographic implications

The Kutch Basin of western India is famous for its rich assemblages of the Callovian-Oxfordian ammonites.The family Oppelidae Douvillé is the second most diverse ammonite group after perisphinctids during the Middle-Upper Jurassic.Hecticoceratinae is the most diverse subfamily within Oppelidae and has wide palaeobiogeographic(near cosmopolitan) and temporal distributions(Bathonian-Oxfordian).Some species were well timediagnostic and thus help in interprovincial correlation.The taxonomy of the subfamily Hecticoceratinae of Kutch was in a state of flux until recently.It was not revised since Spath’s(1927-1933) great contribution.Many genera and species were morphogenera or morphospecies and they again suffer from excessive subjective splitting.It was therefore badly needed for a comprehensive taxonomic revision of the subfamily with modern aspects of systematics i.e.,sexual dimorphism and population dynamics.A lithostratigraphic framework has already been well documented in the Kutch Basin of western India.A high resolution biostratigraphy incorporating stage-intrastage fossil assemblages have been used in interbasinal correlation based on the Callovian-Oxfordian hecticoceratins.Near cosmopolitan distribution of many hecticoceratin genera were widely used for biostratigraphic zonation as well as an understanding of the palaeobiogeographic pattern.The phylogeny of the subfamily Hecticoceratinae has been used to construct the cladograms depicting area relationships among different provinces during the Callovian-Oxfordian.

Diversity patterns and palaeobiogeographical relationships of latest Devonian-Lower Carboniferous foraminifers from South China:What is global,what is local?

During latest Devonian and early Carboniferous times,calcareous foraminifers were abundant,widely distributed,and showed the most rapid rate of evolution in the shallow?sea deposits.These factors,especially their fast phylogenetic changes,make them an essen?tial element in biostratigraphic schemes of this time interval.However,the distribution patterns of calcareous foraminifers depend on a series of biological and non?biological factors,such as population sizes,dispersion,oceanic currents and temperatures,and substrate types,which are not always well?controlled when interpreting spatial and temporal distribution patterns.For this study,a dataset of calcareous foraminifers was compiled containing the tempo?ral distribution(biozone level)of 420 species belonging to 155 genera currently described from Strunian(latest Devonian)to basal Serpukhovian(Lower Carboniferous)key sections in southern China,and the presence of those species in eleven palaeobiogeographical units.The comparison of the regional Chinese diversity curve,which has a bell?shaped form with a dou?ble peak in the Ivorian,to a global curve shows the influence of local and regional factors.Mini?mum values in the Chinese Strunian,basal Tournaisian and early late Visean can be explained by the small number of studied outcrops,unfavourable facies and depositional gaps in these stratigraphic intervals in South China.This is especially obvious in the late Visean and Serpuk?hovian,which is a peak time of global diversity.The fall observed at that time interval in southern China is easily explained by the fact that this time peried is far less intensively studied and thus fewer data are present in the database.The opposite situation is seen around the TournaisianVisean boundary.Here,a peak is found in both regional and global curves,but that up to 87%of all known species are found in southern China seems to be unlikely,especially when the normal average value are 35%-40%.This anomalously high percentage is a consequence of the work undertaken on the Global Stratotype Section and Point(GSSP),and it shows that a species deficit may exist in the global curve.*Cluster,hierarchical cluster and Nonmetric multidimensienal Scalingel(NMDS)analyses have been calculated to study the palaeobiogeographical affinities of the southern Chinese calcareous foraminifers.The palaeobiogeographical patterns for the complete studied interval or parts of it(substages)are comparable on the genus and species level and stable throughtime.The assemblages found in southern China are well connected to other palaeo(bio)geo?graphical entities supporting the idea of relatively abundant widespread and cosmopolitan taxa in the studied interval.A cluster of South China,Europe and the Russian Platform is found in all analyses.This cluster often attached to the units Far-East Russia and Turkey rep?resents the northern Palaeotethyan Realm.The relatively close affinities between South China and North America cannot be well discussed yet.Chinese data for endemicity,geographical spread and biodiversity in the Tournaisian-Visean boundary interval can be roughly correlated to 3rd-order sea-level fluctuations.Migration patterns into and out of South China can only be suspected,but not yet quantified.

A new early Visean coral assemblage from Azrou-Khenifra Basin,central Morocco and palaeobiogeographic implications

A new early Visean coral assemblage has been recorded from turbidite facies in the southern part of the AzrouKhenifra Basin,northwest of Khenifra,central Morocco.The newly discovered Ba Moussa West(BMW)coral fauna includes Siphonophyllia khenifrense sp.nov.,Sychnoelasma urbanowitschi,Cravenia lamellata,Cravenia tela,Cravenia rhytoides,Turnacipora megastoma and Pleurosiphonella crustosa.The early Visean age of the coral assemblage is supported by foraminiferal and conodont data,with the recognition of the basal Visean MFZ9 Zone.This confirms that the first transgression in the Azrou-Khenifra Basin was during the earliest Visean.The allochthonous coral assemblage was recovered from coarse-grained proximal limestone debris flow and turbidite beds within a faultbounded unit,lying to the west of a thrust syncline containing upper Visean limestones.No evidence exists of the former early Visean shallow-water platform from which the corals were derived.All other in situ platform carbonate rocks around the southern margin of the Azrou-Khenifra Basin are probably of late Visean(Asbian–Brigantian)age.The early Visean Ba Moussa West coral fauna can be compared with that at Tafilalt in eastern Morocco,as well as in other Saharian basins of Algeria.Many of the genera and species in the Ba Moussa West assemblage are identical to those in NW Europe,with which it must have had marine connections.The new rugose species described,Siphonophyllia khenifrense,is probably endemic to North Africa.Its ecological niche in NW Europe was occupied by S.cylindrica or S.aff.garwoodi.