The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the ...The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area.The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m.The reef-building organisms include Archaeoscyphia, Recepthaculitids,Batostoma,Cyanobacteria and Pulchrilamina.Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area,four sorts of biofacies are recognized,which are(1) shelly biofacies:containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community;(2) reef biofacies:including the Batostoma,Calathium-Archaeoscyphia, Pelmatozoa-Batostoma,Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies:including the Acanthograptus-Dendrogptus and Yichangopora communities;and(4) allochthonous biofacies:containing Nanorthis-Psilocephlina taphocoense community.The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area,and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space.The authors hold that reefs were mostly formed in the high sea level periods.Because of the development of several subordinate cycles during the sea-level rising,the reefs are characterized by great quantity, wide distribution,thin thickness and small scale,which are similar to that of Juassic reefs in northern Tibet.The research on the evolution of communities shows that succession and replacement are the main forms.The former is favorable to the development of reefs and the latter indicates the disappearance of reefs.展开更多
Phylloid algae arc important rcef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County, Guizhou Province. Phylloi...Phylloid algae arc important rcef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County, Guizhou Province. Phylloid algae growing closely packed arc attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup-shaped, cabbage-shaped and clustering cup-shaped. The thalli arc of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine orgam＇sms arc relatively scarce. Obviously, phylloid algae arc stronger competitors for living space than other co-occurring organisms.展开更多
The reef-shoal depositional system of the Ordovician carbonate platform margin is well exposed in the Yijianfang （一间房） outcrop of the Bachn （巴楚） uplift region, which offers an advantageous condition to study ...The reef-shoal depositional system of the Ordovician carbonate platform margin is well exposed in the Yijianfang （一间房） outcrop of the Bachn （巴楚） uplift region, which offers an advantageous condition to study their paleoecology. Using a detailed field geologic survey and illustrated profiles of typical depositional systems, three types of genetic facies associations can be recognized in the reef-shoal depositional system： an organic reef, an organic shoal, and an upper slope. The organic reef is composed of three types of genetic facies （a reef base, a reef core, and fore-reef breccias）; the organic shoal is formed from five types of genetic facies （tide channels, fore-reef inner shoals, fore-reef outer shoals, back-reef inner shoals, and back-reef outer shoals）. The studies of the paleontological assemblage in each genetic facies of the depositional system indicate that the fauna preserved in each genetic facies are varied. The calathium, archaeoscyphia, bryozoan, and calcareous alga are well preserved in the organic reefs. The organisms preserved in the organic shoals are generally fragmented, while weil-preserved girvanella and nuia siberica with a content of about 15% in the back-reef outer shoals are the most characteristic and different from others. The sinoceras, trilobites, and gastropods are well preserved in the upper slope deposits. The studies will demonstrate that the reef-shoal complexes developed above the base of the fair-weather wave base and that the original hydrodynamic conditions for the reef core forming is the stronger and become more and more low-energy from the inner part to outer part of the organic shoals.展开更多
To enable the lithostratigraphic and biostratigraphie study of the Gurpi Formation, within the ＇Dezak＇ or Globigerina Marl, a stratigraphic section at Booraki, located to the NNW of Shiraz, SW Iran, through the late...To enable the lithostratigraphic and biostratigraphie study of the Gurpi Formation, within the ＇Dezak＇ or Globigerina Marl, a stratigraphic section at Booraki, located to the NNW of Shiraz, SW Iran, through the late Cretaceous was examined. The formation consists of shale and greenish-gray marls interbedded with cream limestone, brown sandstones and siltstones with an exposed thickness of 160 m in the studied section. Samples were taken at regular intervals in all yielding 14 genera and 16 different species of benthic and planktic foraminifera that allowed determination of the age of the beds as Maastrichtian. To examine the paleoecology of the formation, some important ecological factors including water level, salinity, and oxygen regime change during the depositional courses of the formation were analyzed. The density of foraminiferans decreases from the base to top of the Gurpi Formation whereas the ratio of planktic to benthic Foraminifera （i.e., P/B） and proportion of shallow-water fauna increase. These foraminiferal changes indicate an increase and decrease in depth, temperature, salinity and oxygen, respectively, at the base and top of the Formation.展开更多
Five grab samples from the southwestern part of the Indian ocean were collected by ORV Sagar Kanya during the third expedition to the southern Indian ocean in June 2009. The sediment samples have been analyzed and rec...Five grab samples from the southwestern part of the Indian ocean were collected by ORV Sagar Kanya during the third expedition to the southern Indian ocean in June 2009. The sediment samples have been analyzed and recorded 36 benthic foraminiferal species belonging to 21 genera and 3 suborders. All the species were taxonomically identified, SEM photographed and illustrated. Deep sea-benthic foraminiferal species at different locations of South of West India Ocean (3150-4125 m water depth) is examined in terms of number of species (n) and diversity (d). The observed depth ranges of benthic foraminifera have been documented to recognize their bathymetric distribution. The valves of these parameters reached their maximum at 3190 m water depth. Productivity continued in the Indo-Pacific Ocean (the biogenic boom) and the Oxygen minimum zone (OMZ) intensified over large parts of Indian Ocean continually. The diversity values show more abrupt trend as depth increases. Species like Epistominella exigua and Pullenia bulloides occur at both 3150 m & 3465 m depths indicating depth persistence. Further, Oridorsalis umbonatus and Melonis sphaeroides occur at both 3150 m & 3465 m depths. Species like Gyroidina sp an indicate of low oxygen environment and Uvigerina hispida-costata indicative of high organic carbon are found to occur at 3150 m & 3740 m respectively. Factor analysis and Pearson correlation matrix was performed on foraminiferal census data of 10 highest ranked species which are present in at least one sample. 3 factors were obtained accounting for 72.81% of the total variance. Thus the study suggests that fluctuations in species diversity at the locations of the present study were related to changes in productivity during the geological past. Further, the faunal data do indicate the early Holocene Indian Ocean was influenced by increased ventilation perhaps by North Atlantic deep water and or circumpolar deep waters.展开更多
Taphonomy and paleoecology(biological behavior)of the Early Cretaceous fish fossils are poorly described.This study reports for the first time a detailed taphonomical and paleoecological study on Lycoptera in the Meso...Taphonomy and paleoecology(biological behavior)of the Early Cretaceous fish fossils are poorly described.This study reports for the first time a detailed taphonomical and paleoecological study on Lycoptera in the Mesozoic strata of western Liaoning Province,NE China.The XRD analysis shows that gismondine is the dominant clay minerals that could have contributed to the preservation of Lycoptera fossils and microbial mat fragments in the fossil-bearing horizon.Gismondine may have formed under volcanism-related hydrothermal regime that was transformed from crystal and lithic fragments.Theμ-XRF imaging analysis shows a dominant chemical composition of Al,Si,P,S,Rh,K,Ca,Ti,C,Cr,Mn,Fe,Ni,among which P,Ca,C and S are enriched in the fish skeleton in comparison to the matrix.This suggests a dominant apatite composition for the fish skeleton.Hydrothermal influence did not smear off these organic signals probably because of protection of gismondine.The coexistance of C and S with Ni is assumed to represent recovered primary productivity following volcanic explosions and toxic gas emissions.The head of juvenile fish stays close to the body of adult fish.Pending further discoveries,such phenomenon is interpreted to suggest that adult fish actively protected juvenile fish in the presence of environmental pressures such as anoxia and deterioration of water quality induced by volcanism.Ocean acidification and hypoxia in association with volcanism created a harmful environment causing mass extinction of fish.The adult Lycoptera protected their juveniles by its body at the moment before death.Such biological behavior will be increasingly reported given the wide occurrence of Lycoptera in Mesozoic strata.展开更多
We here report a paleoecological analysis and depositional history of the marine Jurassic (Toarcian–early Bajocian) strata cropping out in the western part of Thailand, based on bivalve assemblages with additional da...We here report a paleoecological analysis and depositional history of the marine Jurassic (Toarcian–early Bajocian) strata cropping out in the western part of Thailand, based on bivalve assemblages with additional data from ammonites, brachiopods, and microfossils. Generally, the benthic bivalve facies in most outcrops is rich in infaunal, semi-infaunal and epifaunal suspension-feeders. Of these, infaunal forms dominate. The diversity of this benthic assemblage was influenced by energy level, substrate, sedimentation rate, and salinity. Low to intermediate energy levels and rather soft fine-grained siliciclastic substrate are proposed as factors governing faunal distribution and explaining the greater abundance and diversity of infaunal than epifaunal suspension-feeders. There were paleoenvironmental changes both in space and time, i.e., from south to north (Umphang to Mae Sot) and from Early Bajocian to Toarcian. In the Toarcian, most outcrops in Umphang are dominated by benthic bivalve facies (infaunal, semi-infaunal, and epifaunal associations). This implies warm, shallow water (inner neritic, 50―100 m) and oxygenated conditions except for the Mae Sot area where a deeper setting (outer neritic to possibly upper continental slope, 50―200 m) with restricted basinal anoxic conditions is favored as indicated by the presence of Bositra. After higher energy conditions in the Toarcian, lower energy conditions with low sediment supplies prevail in the Alenian, and the Mae Sot area was still a restricted basin. As a result of higher sea levels, the oxygen content in the basin is increased, resulting in the presence of the ammonites. By the end of the Alenian-early Bajocian, an ammonite-bivalve association (mixed facies A) and the presence of corals and microfauna (mixed facies B) are dominant but pass upwards to near-shore higher energy conditions in most areas except for restricted basin in Mae Sot. By the middle Bajocian the environment in all areas had changed from marine to nonmarine.展开更多
Knowledge on the Villafranchian faunas of Greece was limited for a long time,but over the past 3 decades several new fossiliferous sites have been discovered and new material has been unearthed.The carnivores co...Knowledge on the Villafranchian faunas of Greece was limited for a long time,but over the past 3 decades several new fossiliferous sites have been discovered and new material has been unearthed.The carnivores constitute a remarkable part of this material and their study has provided useful information for the taxonomy,chronology and palaeoecology.The Villafranchian carnivoran guild includes numerous taxa belonging to various families.Some of them are interesting as they are differentiated from the other Eurasian families.They cover the entire Villafranchian but the mass is known from the Middle to the Epi-Villafranchian(EVC).Despite the discontinuous data,they provide useful biochronological results.The coexistence of Pliocrocuta perrieri and Pachycrocuta brevirostris in the locality of Gerakarou 1 is strong evidence for the Middle Villafranchian(MVC)/Late Villafranchian(LVC)boundary.The composition of the Villafranchian carnivores suggests that the canids predominate,while the felids,hyenids and mustelids are well represented;the ursids are represented by a single taxon,the well-known Ursus etruscus,which seems to be common during the entire Villafranchian.The carnivoran guild structure and the multivariate analysis of the Greek Villafranchian carnivoran assemblages(MVC,LVC and EVC)in comparison with modern assembalges from open and closed environments indicate a relatively open landscape,which is in agreement with previous results for the Villafranchian of Greece.During the EVC there is a faunal renewal that is related to a more open and dry environment,like savannah bushland/grassland.展开更多
Sedimentological and foraminiferal paleoecological studies were carried out for the Oligocene-Miocene Ogwashi-Asaba Formation of the Anambra Basin at the Issele-Uku area in southern Nigeria,to reconstruct paleoenviron...Sedimentological and foraminiferal paleoecological studies were carried out for the Oligocene-Miocene Ogwashi-Asaba Formation of the Anambra Basin at the Issele-Uku area in southern Nigeria,to reconstruct paleoenvironments.The pattern of rock successions and textural characteristics suggest the prevalence of fluvio-deltaic setting during the formation of lignites and clastic rocks of Ogwashi-Asaba Formation.Agglutinated benthic foraminiferal species such as Ammotium sp.,Textularia sp.,Gavelinella sp.,Milliamina sp.,Reophax sp.,Bolivina sp.,Eponides sp.,Pseudobolivina sp.and Lenticulina sp.dominate the shale units whereas the planktonic forms are absent.All these species have very low population and diversity in the shales,which could be due to the presence of harsh conditions such as low oxygen level and scarcity of food,leading to poor survival.The assessments of benthic foraminifera's habitat suggest middle-to-inner neritic marine environment for the shales.Granulometric results suggest fluvial environment for the sandstone and deltaic for the lignite.The Ogwashi-Asaba Formation in Issele-Uku area of Anambra Basin,southern Nigeria,therefore,have records of shallow marine,and fluvio-deltaic paleoenvironments.展开更多
Decades of species composition changes can lead to the eutrophication-driven loss of submerged macrophytes in shallow lakes.Investigating the mechanisms of these nature-and human driven changes is crucial for the rest...Decades of species composition changes can lead to the eutrophication-driven loss of submerged macrophytes in shallow lakes.Investigating the mechanisms of these nature-and human driven changes is crucial for the restoration and management of such lakes.To investigate the changes in aquatic macrophyte communities over the past two centuries,we analyzed macrofossils in sediments from a^(210)Pb-dated core obtained in Dongping Lake in the lower Huanghe(Yellow)River Basin,eastern China.Multiple factor analysis(MFA)revealed an association between macrophyte shifts and changes in various environmental stressors(invertebrates,grain size,geochemistry,and documented records),indicating that macrophyte community changes before 1960 were predominately driven by flood disturbances.Ever since,anthropogenic pollution and the construction of water conservancy projects have caused variations in hydrology and nutrients,leading to significant changes in the composition of macrophyte communities.Macrofossil data reveal a decline in diversity and pollution-intolerant species during the late 1980 s and the early 2000 s,which is indicative of eutrophication.We also found that the current environment of Dongping Lake exhibits a clear degeneration in emergent plants and a proliferation of macrophyte species associated with eutrophic conditions,which could be attributed to water level fluctuation and nutrient input due to the water supply from the eastern route of the South-to-North Water Diversion Project as well as climate warming.Our results provide valuable insights for assessing ecosystem health and the restoration and management of Dongping Lake and similar lakes in the Huanghe River region and elsewhere.展开更多
The Raohe area of Heilongjiang Province,Northeast China belongs to the Nadanhada Terrane,which was in low latitudes of Panthalassa during the Triassic.The composition of the Late Triassic conodont fauna,derived from l...The Raohe area of Heilongjiang Province,Northeast China belongs to the Nadanhada Terrane,which was in low latitudes of Panthalassa during the Triassic.The composition of the Late Triassic conodont fauna,derived from limestone lenses interpreted to formed on seamounts,provides important new information on the pelagic biota in this ocean.New conodont samples collected from sections at Minzhu,Minnan and Chigangbei sections belong to three Norian conodont zones.In ascending order,they are:Mockina postera Zone,Mockina bidentata Zone and Parvigondolella andrusovi Zone.The Norian conodont fauna in the Raohe area has distinct attributes:there are a lot of cosmopolitan species(e.g.,Mockina postera,Mockina bidentata,Parvigondolella andrusovi)which enable good global correlation;endemic conodont species are also present(e.g.,Mockina sakurae,Mockina shamiseni,Norigondolella nadanhadaensis)indicating that Panthalassa Ocean conodont populations also contained unique taxa;and some conodonts belong to taxa with much shorter ranges in surrounding epeiric seas(e.g.,Carnepigondolella pseudoechinata,Neocavitella cavitata and Epigondolella vialovi).The presence of the latter“relicts”indicates that the seamounts were persistently suitable habitats for many millions of years in the Late Triassic.展开更多
Hopane separation and isotope determination were conducted on 11 source rock samples from various sedimentary environments.A schematic diagram of the carbon isotope distributions of hopane across different depositiona...Hopane separation and isotope determination were conducted on 11 source rock samples from various sedimentary environments.A schematic diagram of the carbon isotope distributions of hopane across different depositional environments was constructed.By integrating biomarker and organic petrology evidence,the geological significance of hopane carbon isotopes in oil source correlation and paleoclimate and paleoecology reconstruction was revealed.The results showed that the carbon isotopic compositions of hopanes vary considerably with depositional environment.展开更多
Abundant microconchid worm tubes were extracted from the microbialites deposit near the Permian-Triassic boundary at the Zuodeng Section, Baise area, Guangxi Zhuang Autonomous Re- gion, South China. These calcareous w...Abundant microconchid worm tubes were extracted from the microbialites deposit near the Permian-Triassic boundary at the Zuodeng Section, Baise area, Guangxi Zhuang Autonomous Re- gion, South China. These calcareous worm tubes were studied in both petrographic thin sections and isolated specimens using optical microscope and sensitive electronic microscope （SEM）, respectively. They are categorized into two morphological types： helically coiled and planispirally coiled tubes, which are assignable to Microconchus aberrans （Hohenstein, 1913） and M. utahesis （Zatofi et al., 2013）, respectively. The tube wall ultrastructnre is characterized by laminated micrites, which distinguish the studied microconchids from comparable microgastropods or spirorbid polychaete that usually has shell nltrastructnre of spar texture. The overwhelm majority of microconchids from the microbialite possess the planispirally coiled tubes. The lifestyle of extant, morphologically convergent spirorbids suggests that these planispirally coiled microconchids may have colonized in some local oxygenic oases probably produced by photosynthetic cyanobacteria in the oxygen-poor microbialite ecosystem in which they may have settled densely with high competition among various individuals and with other associated animals for oxygen consumption and food soucres. The deleterious environment condition of the mi- crobialite ecosystem immediately after the Permian-Triassic biocrisis is also indicated by various geochemical signals derived from the same section. Such a deleterious habitat may be inhospitable for most metazoans, but it has some local oxygenic oases that was favorable for opportunistic taxa to dwell.展开更多
The Huadu flora of Guangdong Province, South China contains the lepidodendrid Lepidodendron shanyangense Wu et He, its putative rhizophore Stigmaria cf. ficoides （Brongniart） Sternberg; sphenophyte s.l. Archaeocalam...The Huadu flora of Guangdong Province, South China contains the lepidodendrid Lepidodendron shanyangense Wu et He, its putative rhizophore Stigmaria cf. ficoides （Brongniart） Sternberg; sphenophyte s.l. Archaeocalamites scrobiculatus （Brongniart） Stur; bowmanitid Sphenophyllum tenerrimum （Ettingshausen） Stur; pteridophyll Sphenopteris sp. of uncertain taxonomic position; undetermined ferns gen. et sp. nov.; lyginopterid pteridosperm Rhodeopteridium hsianghsiangense （Sze） Zhang, Zhao et Wu, a trigonocarpoid pteridosperm represented by fronds and isolated pinnules of Paripteris gigantea （Sternberg） Gothan, male fructifications of Potoniea sp., and seeds of Trigonocarpus sp. Ecologically, the Early Carboniferous （Visean） Huadu vegetation was divided into two neighboring communities： （1） a near-shore hydrophilous ＂community A＂ with predominating Archaeocalamites and Rhodeopteridium; and （2） a wet forest ＂community B＂ with predominating shrubby trigonocarpalean pteridosperm Paripteris gigantea （Sternberg） Gothan and tall tree-like lepidodendrid Lepidodendron shanyangense Wu et He. The Huadu vegetation was physiognomically similar to present-day low-latitude mangrove forest.展开更多
Bryozoan nodules, coralline algae, scleractinian corals and oysters form an important organic buildup, 1.2-4.5 m thick in the Langhian-Serravaliann sediments of Egypt. Based on type, shape and size of the substrate, b...Bryozoan nodules, coralline algae, scleractinian corals and oysters form an important organic buildup, 1.2-4.5 m thick in the Langhian-Serravaliann sediments of Egypt. Based on type, shape and size of the substrate, bryozoan nodules take tree-like and globular morphologies. Tree-like speci- mens reach 10 cm in maximum height and 3 cm in diameter, while Globular ones attain 9 cm in maxi- mum diameter. Most tree-like nodules are perforated with wide or narrow pores, few are non-perforated. Globulars and few tree-like forms are with mamelon-like structures. Perforations on the outer surfaces may indicate a symbiotic relationship between bryozoans and a live plant substrate. Nod- ules from Homiera and Gharra areas of the Cairo-Suez District with wider perforations may indicate growth in slightly lighter or turbid areas of the continental shelf than those of North Western Desert of narrower perforations. Non-perforated nodules may assume an incrustation on ephemeral substrate .展开更多
After the end-Permian mass extinction, genus Claraia （Bivalvia） was the most abundant and most noticeable fossil during the survival and recovery stage. However, the reasons for the proliferation of Claraia are stil...After the end-Permian mass extinction, genus Claraia （Bivalvia） was the most abundant and most noticeable fossil during the survival and recovery stage. However, the reasons for the proliferation of Claraia are still debated. This paper describes a new Griesbachian （Early Triassic） mollusc fauna from deep-water settings in South China in the aftermath of end-Permian mass extinction. This fauna yielded five bivalve species in two genera （Claraia griesbachi, C. wangi, C. stachei, C. radialis, and Promyalina putiatinensis） and two ammonoid species （Ophiceras sp. and Ussuridiscus sp.） and could be assigned to the Claraia wangi-C, griesbachi assemblage zone, indicating a Middle-Late Griesbachian Age. The bivalves were dominated by Claraia griesbachi and were featured by articulated Claraia fossils. As Claraia was epibyssate, it was an excellent autochthonous fauna. While the shallow and deep marine water became dysoxic to anoxic globally, as indicated by recent studies of the early Early Triassic, we suggest the genus Claraia could tolerate dysoxic and/or anoxic conditions and its proliferation could be attributed to its physiological features which were adapted to the stressed environment. The wide distribution of Claraia was probably related to its planktonic larval stage. Where the larva of Claraia could have been transported by ocean flow and increased its potential for long-distance dispersal. In addition, Claraia was a significant disaster and opportunistic taxon during the Early Triassic based on observations in South China.展开更多
Terrestrial plants and insects currently account for the majority of the Earth＇s biodiversity, and approximately haft of insect species are herbivores. Thus, insects and plants share ancient associations that date ba...Terrestrial plants and insects currently account for the majority of the Earth＇s biodiversity, and approximately haft of insect species are herbivores. Thus, insects and plants share ancient associations that date back more than 400 Myr. However, investigations of their past interactions are at the preliminary stages in Western Europe. Herein, we present the first results of our study of various feeding damage based on a dataset of nearly 3500 examined plant specimens from the Lower Miocene of the Lagerstaette Bflina Mine in the Most Basin, Czech Republic. This site provides a unique view of the Neogene freshwater ecosystems. It has long been studied by scientists working in different branches of sedimentology, paleobotany, and paleozoology. The fossils are preserved in three characteristic horizons overlaying the coal seam （Clayey Superseam Horizon, Delta Sandy Horizon, and Lake Clayey Horizon）, reflecting paleoenvironmental changes in a short time period of development. The trace fossils are classified as functional feeding groups or ＂guilds＂, without searching for a direct cause or a recent analog host relation. Approximately 23% of specimens of dicotyledonous plant leaves were found to be damaged and associated with some leaf ＂morphotypes＂. Deciduous plant-host taxa, and those with a chartaceous texture typical of riparian habitats, were frequently damaged, such as Populus, recorded with two species Populus zaddachii and Populus populina （57.9% and 31% herbivory levels, respectively）, followed by Acer, Alnus, and Carya, averaging almost 30% of damaged leaves/leaflets. There has been evidence of 60 damage types （DT） representing all functional feeding groups recorded at the Bflina Mine, including 12 types of leaf mines and 16 gall- type DT. In total, Lower Miocene of the Lagerstaette Bilina Mine exhibits a high level of external foliage feeding types （23.7%）, and a low level of more specialized DT, such as galls （4.3%） and leaf mines （〈1%）. A broader comparison based on DT of the main sedimentary environments shows significance supporting different biomes by frequency of damage levels and DT diversities.展开更多
Grassland cover and composition respond to climate and have undoubtedly changed during the Holocene, but quantitative reconstructions from fossil pollen have been vague about spatial scale and taxon-specific cover. He...Grassland cover and composition respond to climate and have undoubtedly changed during the Holocene, but quantitative reconstructions from fossil pollen have been vague about spatial scale and taxon-specific cover. Here, we estimate the relevant source area of pollen for sedimentary basins approximately 50 m in radius, and we report pollen productivity estimates for 12 plant taxa in the tallgrass prairies of central North America. Both relevant source area of pollen and pollen productivity estimates were calculated via the Extended R-Value Model. To obtain these estimates, we collected and quantified the pollen found in surface sediment samples from 24 ponds across the study area. Vegetation was surveyed in the field in a 100 m radius around each pond, and vegetation maps from the Kansas Gap Analysis Project (GAP) were used to a radius of 2 km. Pollen fall speeds were calculated according to Stoke’s Law. Pollen assemblages from basins approximately 50 m in radius have a relevant source area of 1060 m in this grassland landscape. Pollen productivity estimates range from 0.02 to over 30 among the 12 taxa: Artemisia, Ambrosia, Asteraceae, Chenopodiaceae, Cornus, Fabaceae, Juniperus, Maclura, Poaceae, Populus, Quercus, and Salix. Woody taxa generally have higher pollen productivity than herbaceous taxa (except for Chenopodiaceae and Ambrosia).展开更多
基金supported by the National Natural Science Foundation of China(No.40972019)the S&T plan projects of Hubei Provincial Education Department(No. 03Z0105)+1 种基金the Project of Scientific and Technologic Development Planning of Jingzhou(No.20101P031-5)the Innovative Experimenting Plan of Undergraduate Students of China(No.091048934)
文摘The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area.The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m.The reef-building organisms include Archaeoscyphia, Recepthaculitids,Batostoma,Cyanobacteria and Pulchrilamina.Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area,four sorts of biofacies are recognized,which are(1) shelly biofacies:containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community;(2) reef biofacies:including the Batostoma,Calathium-Archaeoscyphia, Pelmatozoa-Batostoma,Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies:including the Acanthograptus-Dendrogptus and Yichangopora communities;and(4) allochthonous biofacies:containing Nanorthis-Psilocephlina taphocoense community.The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area,and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space.The authors hold that reefs were mostly formed in the high sea level periods.Because of the development of several subordinate cycles during the sea-level rising,the reefs are characterized by great quantity, wide distribution,thin thickness and small scale,which are similar to that of Juassic reefs in northern Tibet.The research on the evolution of communities shows that succession and replacement are the main forms.The former is favorable to the development of reefs and the latter indicates the disappearance of reefs.
基金This study is supported by a grant （No. 40572014） from National Science Foundation of China （NFSC）.
文摘Phylloid algae arc important rcef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County, Guizhou Province. Phylloid algae growing closely packed arc attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup-shaped, cabbage-shaped and clustering cup-shaped. The thalli arc of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine orgam＇sms arc relatively scarce. Obviously, phylloid algae arc stronger competitors for living space than other co-occurring organisms.
基金supported by the SINOPEC Forward Looking Project of China (No. YPH08114)
文摘The reef-shoal depositional system of the Ordovician carbonate platform margin is well exposed in the Yijianfang （一间房） outcrop of the Bachn （巴楚） uplift region, which offers an advantageous condition to study their paleoecology. Using a detailed field geologic survey and illustrated profiles of typical depositional systems, three types of genetic facies associations can be recognized in the reef-shoal depositional system： an organic reef, an organic shoal, and an upper slope. The organic reef is composed of three types of genetic facies （a reef base, a reef core, and fore-reef breccias）; the organic shoal is formed from five types of genetic facies （tide channels, fore-reef inner shoals, fore-reef outer shoals, back-reef inner shoals, and back-reef outer shoals）. The studies of the paleontological assemblage in each genetic facies of the depositional system indicate that the fauna preserved in each genetic facies are varied. The calathium, archaeoscyphia, bryozoan, and calcareous alga are well preserved in the organic reefs. The organisms preserved in the organic shoals are generally fragmented, while weil-preserved girvanella and nuia siberica with a content of about 15% in the back-reef outer shoals are the most characteristic and different from others. The sinoceras, trilobites, and gastropods are well preserved in the upper slope deposits. The studies will demonstrate that the reef-shoal complexes developed above the base of the fair-weather wave base and that the original hydrodynamic conditions for the reef core forming is the stronger and become more and more low-energy from the inner part to outer part of the organic shoals.
文摘To enable the lithostratigraphic and biostratigraphie study of the Gurpi Formation, within the ＇Dezak＇ or Globigerina Marl, a stratigraphic section at Booraki, located to the NNW of Shiraz, SW Iran, through the late Cretaceous was examined. The formation consists of shale and greenish-gray marls interbedded with cream limestone, brown sandstones and siltstones with an exposed thickness of 160 m in the studied section. Samples were taken at regular intervals in all yielding 14 genera and 16 different species of benthic and planktic foraminifera that allowed determination of the age of the beds as Maastrichtian. To examine the paleoecology of the formation, some important ecological factors including water level, salinity, and oxygen regime change during the depositional courses of the formation were analyzed. The density of foraminiferans decreases from the base to top of the Gurpi Formation whereas the ratio of planktic to benthic Foraminifera （i.e., P/B） and proportion of shallow-water fauna increase. These foraminiferal changes indicate an increase and decrease in depth, temperature, salinity and oxygen, respectively, at the base and top of the Formation.
文摘Five grab samples from the southwestern part of the Indian ocean were collected by ORV Sagar Kanya during the third expedition to the southern Indian ocean in June 2009. The sediment samples have been analyzed and recorded 36 benthic foraminiferal species belonging to 21 genera and 3 suborders. All the species were taxonomically identified, SEM photographed and illustrated. Deep sea-benthic foraminiferal species at different locations of South of West India Ocean (3150-4125 m water depth) is examined in terms of number of species (n) and diversity (d). The observed depth ranges of benthic foraminifera have been documented to recognize their bathymetric distribution. The valves of these parameters reached their maximum at 3190 m water depth. Productivity continued in the Indo-Pacific Ocean (the biogenic boom) and the Oxygen minimum zone (OMZ) intensified over large parts of Indian Ocean continually. The diversity values show more abrupt trend as depth increases. Species like Epistominella exigua and Pullenia bulloides occur at both 3150 m & 3465 m depths indicating depth persistence. Further, Oridorsalis umbonatus and Melonis sphaeroides occur at both 3150 m & 3465 m depths. Species like Gyroidina sp an indicate of low oxygen environment and Uvigerina hispida-costata indicative of high organic carbon are found to occur at 3150 m & 3740 m respectively. Factor analysis and Pearson correlation matrix was performed on foraminiferal census data of 10 highest ranked species which are present in at least one sample. 3 factors were obtained accounting for 72.81% of the total variance. Thus the study suggests that fluctuations in species diversity at the locations of the present study were related to changes in productivity during the geological past. Further, the faunal data do indicate the early Holocene Indian Ocean was influenced by increased ventilation perhaps by North Atlantic deep water and or circumpolar deep waters.
基金supported by the State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences(No.223115)to Zhongwu Lan.
文摘Taphonomy and paleoecology(biological behavior)of the Early Cretaceous fish fossils are poorly described.This study reports for the first time a detailed taphonomical and paleoecological study on Lycoptera in the Mesozoic strata of western Liaoning Province,NE China.The XRD analysis shows that gismondine is the dominant clay minerals that could have contributed to the preservation of Lycoptera fossils and microbial mat fragments in the fossil-bearing horizon.Gismondine may have formed under volcanism-related hydrothermal regime that was transformed from crystal and lithic fragments.Theμ-XRF imaging analysis shows a dominant chemical composition of Al,Si,P,S,Rh,K,Ca,Ti,C,Cr,Mn,Fe,Ni,among which P,Ca,C and S are enriched in the fish skeleton in comparison to the matrix.This suggests a dominant apatite composition for the fish skeleton.Hydrothermal influence did not smear off these organic signals probably because of protection of gismondine.The coexistance of C and S with Ni is assumed to represent recovered primary productivity following volcanic explosions and toxic gas emissions.The head of juvenile fish stays close to the body of adult fish.Pending further discoveries,such phenomenon is interpreted to suggest that adult fish actively protected juvenile fish in the presence of environmental pressures such as anoxia and deterioration of water quality induced by volcanism.Ocean acidification and hypoxia in association with volcanism created a harmful environment causing mass extinction of fish.The adult Lycoptera protected their juveniles by its body at the moment before death.Such biological behavior will be increasingly reported given the wide occurrence of Lycoptera in Mesozoic strata.
基金Supported by Special Basic Research Program of Ministry of Science and Techno-logy of China (Grant No. 2006 FY 120300) National Committee of Stratigraphy of China
文摘We here report a paleoecological analysis and depositional history of the marine Jurassic (Toarcian–early Bajocian) strata cropping out in the western part of Thailand, based on bivalve assemblages with additional data from ammonites, brachiopods, and microfossils. Generally, the benthic bivalve facies in most outcrops is rich in infaunal, semi-infaunal and epifaunal suspension-feeders. Of these, infaunal forms dominate. The diversity of this benthic assemblage was influenced by energy level, substrate, sedimentation rate, and salinity. Low to intermediate energy levels and rather soft fine-grained siliciclastic substrate are proposed as factors governing faunal distribution and explaining the greater abundance and diversity of infaunal than epifaunal suspension-feeders. There were paleoenvironmental changes both in space and time, i.e., from south to north (Umphang to Mae Sot) and from Early Bajocian to Toarcian. In the Toarcian, most outcrops in Umphang are dominated by benthic bivalve facies (infaunal, semi-infaunal, and epifaunal associations). This implies warm, shallow water (inner neritic, 50―100 m) and oxygenated conditions except for the Mae Sot area where a deeper setting (outer neritic to possibly upper continental slope, 50―200 m) with restricted basinal anoxic conditions is favored as indicated by the presence of Bositra. After higher energy conditions in the Toarcian, lower energy conditions with low sediment supplies prevail in the Alenian, and the Mae Sot area was still a restricted basin. As a result of higher sea levels, the oxygen content in the basin is increased, resulting in the presence of the ammonites. By the end of the Alenian-early Bajocian, an ammonite-bivalve association (mixed facies A) and the presence of corals and microfauna (mixed facies B) are dominant but pass upwards to near-shore higher energy conditions in most areas except for restricted basin in Mae Sot. By the middle Bajocian the environment in all areas had changed from marine to nonmarine.
基金I wish to thank Professor M-R.Palombo for inviting me to participate in this special volume.I also thank A.Athanassiou,G.Lyras and S.Roussiakis for providing photos of the material housed in the Museum of Palaeontology and Geology,University of Athens.Many thanks are due to other reviewers for their valuable comments and suggestions on the manuscript.
文摘Knowledge on the Villafranchian faunas of Greece was limited for a long time,but over the past 3 decades several new fossiliferous sites have been discovered and new material has been unearthed.The carnivores constitute a remarkable part of this material and their study has provided useful information for the taxonomy,chronology and palaeoecology.The Villafranchian carnivoran guild includes numerous taxa belonging to various families.Some of them are interesting as they are differentiated from the other Eurasian families.They cover the entire Villafranchian but the mass is known from the Middle to the Epi-Villafranchian(EVC).Despite the discontinuous data,they provide useful biochronological results.The coexistence of Pliocrocuta perrieri and Pachycrocuta brevirostris in the locality of Gerakarou 1 is strong evidence for the Middle Villafranchian(MVC)/Late Villafranchian(LVC)boundary.The composition of the Villafranchian carnivores suggests that the canids predominate,while the felids,hyenids and mustelids are well represented;the ursids are represented by a single taxon,the well-known Ursus etruscus,which seems to be common during the entire Villafranchian.The carnivoran guild structure and the multivariate analysis of the Greek Villafranchian carnivoran assemblages(MVC,LVC and EVC)in comparison with modern assembalges from open and closed environments indicate a relatively open landscape,which is in agreement with previous results for the Villafranchian of Greece.During the EVC there is a faunal renewal that is related to a more open and dry environment,like savannah bushland/grassland.
文摘Sedimentological and foraminiferal paleoecological studies were carried out for the Oligocene-Miocene Ogwashi-Asaba Formation of the Anambra Basin at the Issele-Uku area in southern Nigeria,to reconstruct paleoenvironments.The pattern of rock successions and textural characteristics suggest the prevalence of fluvio-deltaic setting during the formation of lignites and clastic rocks of Ogwashi-Asaba Formation.Agglutinated benthic foraminiferal species such as Ammotium sp.,Textularia sp.,Gavelinella sp.,Milliamina sp.,Reophax sp.,Bolivina sp.,Eponides sp.,Pseudobolivina sp.and Lenticulina sp.dominate the shale units whereas the planktonic forms are absent.All these species have very low population and diversity in the shales,which could be due to the presence of harsh conditions such as low oxygen level and scarcity of food,leading to poor survival.The assessments of benthic foraminifera's habitat suggest middle-to-inner neritic marine environment for the shales.Granulometric results suggest fluvial environment for the sandstone and deltaic for the lignite.The Ogwashi-Asaba Formation in Issele-Uku area of Anambra Basin,southern Nigeria,therefore,have records of shallow marine,and fluvio-deltaic paleoenvironments.
基金Supported by the National Natural Science Foundation of China(Nos.42007397,41871073)the Natural Science Foundation of Shandong Province(No.ZR2020QD002)。
文摘Decades of species composition changes can lead to the eutrophication-driven loss of submerged macrophytes in shallow lakes.Investigating the mechanisms of these nature-and human driven changes is crucial for the restoration and management of such lakes.To investigate the changes in aquatic macrophyte communities over the past two centuries,we analyzed macrofossils in sediments from a^(210)Pb-dated core obtained in Dongping Lake in the lower Huanghe(Yellow)River Basin,eastern China.Multiple factor analysis(MFA)revealed an association between macrophyte shifts and changes in various environmental stressors(invertebrates,grain size,geochemistry,and documented records),indicating that macrophyte community changes before 1960 were predominately driven by flood disturbances.Ever since,anthropogenic pollution and the construction of water conservancy projects have caused variations in hydrology and nutrients,leading to significant changes in the composition of macrophyte communities.Macrofossil data reveal a decline in diversity and pollution-intolerant species during the late 1980 s and the early 2000 s,which is indicative of eutrophication.We also found that the current environment of Dongping Lake exhibits a clear degeneration in emergent plants and a proliferation of macrophyte species associated with eutrophic conditions,which could be attributed to water level fluctuation and nutrient input due to the water supply from the eastern route of the South-to-North Water Diversion Project as well as climate warming.Our results provide valuable insights for assessing ecosystem health and the restoration and management of Dongping Lake and similar lakes in the Huanghe River region and elsewhere.
基金supported by the National Natural Sciences Foundation of China(Nos.42372005,41830320,41972033)。
文摘The Raohe area of Heilongjiang Province,Northeast China belongs to the Nadanhada Terrane,which was in low latitudes of Panthalassa during the Triassic.The composition of the Late Triassic conodont fauna,derived from limestone lenses interpreted to formed on seamounts,provides important new information on the pelagic biota in this ocean.New conodont samples collected from sections at Minzhu,Minnan and Chigangbei sections belong to three Norian conodont zones.In ascending order,they are:Mockina postera Zone,Mockina bidentata Zone and Parvigondolella andrusovi Zone.The Norian conodont fauna in the Raohe area has distinct attributes:there are a lot of cosmopolitan species(e.g.,Mockina postera,Mockina bidentata,Parvigondolella andrusovi)which enable good global correlation;endemic conodont species are also present(e.g.,Mockina sakurae,Mockina shamiseni,Norigondolella nadanhadaensis)indicating that Panthalassa Ocean conodont populations also contained unique taxa;and some conodonts belong to taxa with much shorter ranges in surrounding epeiric seas(e.g.,Carnepigondolella pseudoechinata,Neocavitella cavitata and Epigondolella vialovi).The presence of the latter“relicts”indicates that the seamounts were persistently suitable habitats for many millions of years in the Late Triassic.
基金funded by the Open Project of State Key Laboratory of Geological Process and Mineral Resources(GPMR−2022−07).
文摘Hopane separation and isotope determination were conducted on 11 source rock samples from various sedimentary environments.A schematic diagram of the carbon isotope distributions of hopane across different depositional environments was constructed.By integrating biomarker and organic petrology evidence,the geological significance of hopane carbon isotopes in oil source correlation and paleoclimate and paleoecology reconstruction was revealed.The results showed that the carbon isotopic compositions of hopanes vary considerably with depositional environment.
基金supported by the 973 Program (No. 2011CB808800)the China 111 Program (No. B08030)+1 种基金the National Natural Science Fundation of China (Nos. 41002003,41272023, 41172036)a research grant from the State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (No. GBL11206)
文摘Abundant microconchid worm tubes were extracted from the microbialites deposit near the Permian-Triassic boundary at the Zuodeng Section, Baise area, Guangxi Zhuang Autonomous Re- gion, South China. These calcareous worm tubes were studied in both petrographic thin sections and isolated specimens using optical microscope and sensitive electronic microscope （SEM）, respectively. They are categorized into two morphological types： helically coiled and planispirally coiled tubes, which are assignable to Microconchus aberrans （Hohenstein, 1913） and M. utahesis （Zatofi et al., 2013）, respectively. The tube wall ultrastructnre is characterized by laminated micrites, which distinguish the studied microconchids from comparable microgastropods or spirorbid polychaete that usually has shell nltrastructnre of spar texture. The overwhelm majority of microconchids from the microbialite possess the planispirally coiled tubes. The lifestyle of extant, morphologically convergent spirorbids suggests that these planispirally coiled microconchids may have colonized in some local oxygenic oases probably produced by photosynthetic cyanobacteria in the oxygen-poor microbialite ecosystem in which they may have settled densely with high competition among various individuals and with other associated animals for oxygen consumption and food soucres. The deleterious environment condition of the mi- crobialite ecosystem immediately after the Permian-Triassic biocrisis is also indicated by various geochemical signals derived from the same section. Such a deleterious habitat may be inhospitable for most metazoans, but it has some local oxygenic oases that was favorable for opportunistic taxa to dwell.
基金supported by the National Basic Research Program of China(973 Program)(No. 2012CB822003)the National Natural Science Foundation of China(No.41210001)+2 种基金the subsidy of the Russian Government to support the Program of Competitive Growth of Kazan Federal University among World's Leading Academic Centresthe Fundamental Research Funds for the Central Universities(No.121gjc04)the Key project of Sun Yat-sen University for inviting foreign teachers
文摘The Huadu flora of Guangdong Province, South China contains the lepidodendrid Lepidodendron shanyangense Wu et He, its putative rhizophore Stigmaria cf. ficoides （Brongniart） Sternberg; sphenophyte s.l. Archaeocalamites scrobiculatus （Brongniart） Stur; bowmanitid Sphenophyllum tenerrimum （Ettingshausen） Stur; pteridophyll Sphenopteris sp. of uncertain taxonomic position; undetermined ferns gen. et sp. nov.; lyginopterid pteridosperm Rhodeopteridium hsianghsiangense （Sze） Zhang, Zhao et Wu, a trigonocarpoid pteridosperm represented by fronds and isolated pinnules of Paripteris gigantea （Sternberg） Gothan, male fructifications of Potoniea sp., and seeds of Trigonocarpus sp. Ecologically, the Early Carboniferous （Visean） Huadu vegetation was divided into two neighboring communities： （1） a near-shore hydrophilous ＂community A＂ with predominating Archaeocalamites and Rhodeopteridium; and （2） a wet forest ＂community B＂ with predominating shrubby trigonocarpalean pteridosperm Paripteris gigantea （Sternberg） Gothan and tall tree-like lepidodendrid Lepidodendron shanyangense Wu et He. The Huadu vegetation was physiognomically similar to present-day low-latitude mangrove forest.
基金supported by King Saud University, Deanship of Scientific ResearchCollege of Science Research Center
文摘Bryozoan nodules, coralline algae, scleractinian corals and oysters form an important organic buildup, 1.2-4.5 m thick in the Langhian-Serravaliann sediments of Egypt. Based on type, shape and size of the substrate, bryozoan nodules take tree-like and globular morphologies. Tree-like speci- mens reach 10 cm in maximum height and 3 cm in diameter, while Globular ones attain 9 cm in maxi- mum diameter. Most tree-like nodules are perforated with wide or narrow pores, few are non-perforated. Globulars and few tree-like forms are with mamelon-like structures. Perforations on the outer surfaces may indicate a symbiotic relationship between bryozoans and a live plant substrate. Nod- ules from Homiera and Gharra areas of the Cairo-Suez District with wider perforations may indicate growth in slightly lighter or turbid areas of the continental shelf than those of North Western Desert of narrower perforations. Non-perforated nodules may assume an incrustation on ephemeral substrate .
基金supported by the National Natural Science Foundation of China (No. 41502012)the Yangtze Youth Fund of Yangtze University China (No. 2015cqn27)
文摘After the end-Permian mass extinction, genus Claraia （Bivalvia） was the most abundant and most noticeable fossil during the survival and recovery stage. However, the reasons for the proliferation of Claraia are still debated. This paper describes a new Griesbachian （Early Triassic） mollusc fauna from deep-water settings in South China in the aftermath of end-Permian mass extinction. This fauna yielded five bivalve species in two genera （Claraia griesbachi, C. wangi, C. stachei, C. radialis, and Promyalina putiatinensis） and two ammonoid species （Ophiceras sp. and Ussuridiscus sp.） and could be assigned to the Claraia wangi-C, griesbachi assemblage zone, indicating a Middle-Late Griesbachian Age. The bivalves were dominated by Claraia griesbachi and were featured by articulated Claraia fossils. As Claraia was epibyssate, it was an excellent autochthonous fauna. While the shallow and deep marine water became dysoxic to anoxic globally, as indicated by recent studies of the early Early Triassic, we suggest the genus Claraia could tolerate dysoxic and/or anoxic conditions and its proliferation could be attributed to its physiological features which were adapted to the stressed environment. The wide distribution of Claraia was probably related to its planktonic larval stage. Where the larva of Claraia could have been transported by ocean flow and increased its potential for long-distance dispersal. In addition, Claraia was a significant disaster and opportunistic taxon during the Early Triassic based on observations in South China.
基金the Grant Agency of the Czech Republic(No.205/09/J019)the German Science Foundation(No.WA 1492/4-1)(bilateral project)+1 种基金Ministry of Schools MSM 0021620828the support of his Masters study at Charles University Grant Agency(GAUK)(No. 46509/2009/B-Bio/PrF)
文摘Terrestrial plants and insects currently account for the majority of the Earth＇s biodiversity, and approximately haft of insect species are herbivores. Thus, insects and plants share ancient associations that date back more than 400 Myr. However, investigations of their past interactions are at the preliminary stages in Western Europe. Herein, we present the first results of our study of various feeding damage based on a dataset of nearly 3500 examined plant specimens from the Lower Miocene of the Lagerstaette Bflina Mine in the Most Basin, Czech Republic. This site provides a unique view of the Neogene freshwater ecosystems. It has long been studied by scientists working in different branches of sedimentology, paleobotany, and paleozoology. The fossils are preserved in three characteristic horizons overlaying the coal seam （Clayey Superseam Horizon, Delta Sandy Horizon, and Lake Clayey Horizon）, reflecting paleoenvironmental changes in a short time period of development. The trace fossils are classified as functional feeding groups or ＂guilds＂, without searching for a direct cause or a recent analog host relation. Approximately 23% of specimens of dicotyledonous plant leaves were found to be damaged and associated with some leaf ＂morphotypes＂. Deciduous plant-host taxa, and those with a chartaceous texture typical of riparian habitats, were frequently damaged, such as Populus, recorded with two species Populus zaddachii and Populus populina （57.9% and 31% herbivory levels, respectively）, followed by Acer, Alnus, and Carya, averaging almost 30% of damaged leaves/leaflets. There has been evidence of 60 damage types （DT） representing all functional feeding groups recorded at the Bflina Mine, including 12 types of leaf mines and 16 gall- type DT. In total, Lower Miocene of the Lagerstaette Bilina Mine exhibits a high level of external foliage feeding types （23.7%）, and a low level of more specialized DT, such as galls （4.3%） and leaf mines （〈1%）. A broader comparison based on DT of the main sedimentary environments shows significance supporting different biomes by frequency of damage levels and DT diversities.
文摘Grassland cover and composition respond to climate and have undoubtedly changed during the Holocene, but quantitative reconstructions from fossil pollen have been vague about spatial scale and taxon-specific cover. Here, we estimate the relevant source area of pollen for sedimentary basins approximately 50 m in radius, and we report pollen productivity estimates for 12 plant taxa in the tallgrass prairies of central North America. Both relevant source area of pollen and pollen productivity estimates were calculated via the Extended R-Value Model. To obtain these estimates, we collected and quantified the pollen found in surface sediment samples from 24 ponds across the study area. Vegetation was surveyed in the field in a 100 m radius around each pond, and vegetation maps from the Kansas Gap Analysis Project (GAP) were used to a radius of 2 km. Pollen fall speeds were calculated according to Stoke’s Law. Pollen assemblages from basins approximately 50 m in radius have a relevant source area of 1060 m in this grassland landscape. Pollen productivity estimates range from 0.02 to over 30 among the 12 taxa: Artemisia, Ambrosia, Asteraceae, Chenopodiaceae, Cornus, Fabaceae, Juniperus, Maclura, Poaceae, Populus, Quercus, and Salix. Woody taxa generally have higher pollen productivity than herbaceous taxa (except for Chenopodiaceae and Ambrosia).
