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1.
Species belonging to the Carboniferous genera Lepidodendron and Lepidophloios are well known from the coalfields of Pennsylvania (Lower Asturian (Westphalian D) substage of the Pennsylvanian) through the publications of Lesquereux and White. They believed that the lycophyte flora was rather distinct from other contemporaneous coal floras elsewhere due to its isolation. A full revision of the lepidodendroid lycophyte species is given here and this reassessment permitted comparisons with those floras known from the European and Canadian Maritimes coalfields. Differences in species distribution suggest there was a barrier (Arcadian Highlands) to species distribution to and from the coalfields of Pennsylvania. Several species are recognized only from the coalfields of Pennsylvania, although the number has been significantly reduced from the original publications.  相似文献   

2.
《Comptes Rendus Palevol》2018,17(7):435-442
Three new localities yielding fossiliferous flints are reported from the Châtellerault area (Vienne, western France). They include one archaeological site (La Grande Vallée) and two zones with alterite deposits (L’Aunas and Les Bariollières). Broken surfaces of flint nodules show co-occurrence of marine invertebrates such as bryozoans, echinoids (Micraster Agassiz, Orthopsis Cotteau), gastropods (Acteonella d’Orbigny), rudists, and sponges. The association of Acteonella, Micraster and Orthopsis confirms the Turonian age (Upper Cretaceous) of the fossil assemblage. The marine invertebrates co-occur with plant macroremains including fragments of conifer leafy axes such as Brachyphyllum? Brongn., Frenelopsis (Schenk) emend. J. Watson and Geinitzia Endl., as well as fragments of angiosperm leaves. Plant remains are preserved as siliceous permineralizations, showing the gross morphology and all tissues in three dimensions. The fossil assemblage suggests that sediments were deposited proximally along the shoreline in shallow environment influenced by both continental and marine inputs. This coastal area was close to a conifer-dominated forest ecosystem, Geinitzia being probably one of the main components of the flora.  相似文献   

3.
The vegetation of many Euramerican coal swamps is known from coal-ball peats in the tropical rainy zone across the paleocontinent of Laurussia in the Upper Carboniferous. The stratigraphic occurrences of coal balls in Europe (lower Westphalian) and in North America (upper Westphalian and lower Stephanian) are largely complementary and a revised correlation chart is given. Quantitative analyses of the vegetation from these autochthonous peats are combined with coal palynology to determine on overview of swamp vegetation patterns during the Westphalian and early Stephanian. In comparison to the dominance and great diversity of pteridosperms in the Upper Carboniferous compression floras, seed ferns were minor to subdominant elements in the coal-ball peats. The quantitative composition of organ assemblages of the principal pteridosperms is given with stratigraphic occurrences of Medullosa and Sutcliffia (Medullosaceae), Heterangium, Lyginopteris, Microspermopteris, and Schopfiastrum (Lyginopteridaceaea) and Callistophyton (Callistophytaceae). The major peat contributors among pteridosperms are Lyginopteris (?90%) in the Westphalian A and Medullosa (?95%) in the Westphalian D and Stephanian. Lyginopteris became extinct in the early Westphalian B and Medullosa became abundant during the Westphalian C–D transition and a subdominant in the Stephanian contributing 13–21% of the permineralized peats. Paleoecological interpretations indicate that medullosan trees were most abundant but patchy in distribution in drier swamp stages with enriched nutrients and near major channels in swamps during the Westphalian D. It is suggested that the swamp pteridosperms are probably quite similar to or identical with some of the representatives in the more diverse compression floras. The evolution and diversity noted in swamp pteridosperms are considered principally the product of adjacent lowland communities which repeatedly introduced seeds into the wetlands. The swamp pteridosperms exhibit the greatest fluctuation in abundance (biomass) from site to site in the same coal, probably the highest level of diversity and the only steady pattern of increase in importance during the Late Carboniferous with the possible exception of the Westphalian B–C interval. The close relationships inferred between swamp pteridosperms and their lowland seed sources are also compatible with the frequent association of tree ferns and seed ferns during the Westphalian D and in the Stephanian when these two kinds of frond-bearing trees formed most of the vegetation in both lowland and swamp environments.  相似文献   

4.
A low-diversity Early Jurassic flora preserved in floodbasin siltstones of the Marburg Subgroup at Inverleigh Quarry in the Clarence-Moreton Basin, eastern Australia, is dominated by Allocladus helgei Jansson sp. nov., a conifer with denticulate leaves tentatively attributed to Araucariaceae. The assemblage also includes Rintoulia variabilis and Caytoniales, (Caytonia cucullata McLoughlin sp. nov. and cf. Sagenopteris nilssoniana), reinforcing the wide distribution of this order in Early to Middle Jurassic floras of Gondwana. Ferns (Cladophlebis and Sphenopteris species) and isoetalean lycophytes (Isoetites sp.) constitute the herbaceous elements of the flora. The palynoflora is dominated by cheirolepidiacean (Classopollis) pollen and is attributable to the upper part of the Corollina (= Classopollis) torosa Zone of late Pliensbachian–early Toarcian age (180–185 Ma). The Inverleigh flora represents one of the few Australian assemblages dated between the major phases of floristic turnover at the end of the Triassic and the Toarcian. Sedimentological characteristics, cuticular features of the conifer leaves and the abundance of free-sporing plants indicate a relatively humid palaeoclimate for the Clarence-Moreton Basin Early Jurassic.  相似文献   

5.
The canga of the Serra dos Carajás, in Eastern Amazon, is home to a unique open plant community, harboring several endemic and rare species. Although a complete flora survey has been recently published, scarce to no genetic information is available for most plant species of the ironstone outcrops of the Serra dos Carajás. In this scenario, DNA barcoding appears as a fast and effective approach to assess the genetic diversity of the Serra dos Carajás flora, considering the growing need for robust biodiversity conservation planning in such an area with industrial mining activities. Thus, after testing eight different DNA barcode markers (matK, rbcL, rpoB, rpoC1, atpF‐atpH, psbK‐psbI, trnH‐psbA, and ITS2), we chose rbcL and ITS2 as the most suitable markers for a broad application in the regional flora. Here we describe DNA barcodes for 1,130 specimens of 538 species, 323 genera, and 115 families of vascular plants from a highly diverse flora in the Amazon basin, with a total of 344 species being barcoded for the first time. In addition, we assessed the potential of using DNA metabarcoding of bulk samples for surveying plant diversity in the canga. Upon achieving the first comprehensive DNA barcoding effort directed to a complete flora in the Brazilian Amazon, we discuss the relevance of our results to guide future conservation measures in the Serra dos Carajás.  相似文献   

6.
Thirty-eight dicotyledonous leaf morphotypes and some monocot leaf fragments are described from the Kapcharar, Kabogongoi, Koibo Chepkweny and Inoswa Kamelon localities in the upper third of the Lukeino Formation, Tugen Hills, Baringo Basin (Kenya). The leaves are preserved in fine-grained paper shales and range in length from 9 to 160 mm. Some of the leaves show affinities with extant species in the Burseraceae, Ebenaceae, Euphorbiaceae, Fabaceae, Loganiaceae, Malvaceae and Sapotaceae families that are common in the local flora today. There are compound and simple leaves, mostly entire-margined and with only 10% non-entire margins. A CLAMP analysis of the Kapcharar leaves indicates that the local climate was seasonal, summer wet with 1723 mm mean annual rainfall and with a mean annual temperature of 19.8 °C. The vegetation was a deciduous forest or woodland with open areas nearby. A monocot leaf and two fragments of fern pinnae are also described; they imply locally wetter environments. The flora described here is directly associated with the early hominid Orrorin tugenensis.  相似文献   

7.
《Comptes Rendus Palevol》2014,13(6):473-481
Well-preserved specimens of Stauropteris oldhamia are described. The material was collected in the early 1920s from the Lower Westphalian (Early Pennsylvanian) Saurue seam from Belgium. The fossil plants occur as permineralized axes fragments within a coal ball. This study confirms most of the interpretations made by previous researchers. The observation of immature axis however suggests a less regular organization than previously interpreted beyond the three first branching orders. We also highlight the presence of profusely and dichotomously branched aphlebiae, the lack of laminate organs as well as the presence of hypodermal aerenchyma in all plant parts. We interpret these features as part of a very specialized assimilatory apparatus indicating an adaptation to a humid swamp environment.  相似文献   

8.
A complete human fecal flora and cultures of defined species obtained from fecal flora were investigated in vitro to determine their ability to ferment the dietary fiber pectin. Bacteroides thetaiotaomicron was tested as a pectin-degrading microorganism alone and in coculture with Escherichia coli. Macromolecular pectins with different degrees of esterification were used as substrates in microbial degradation studies. The levels of oligogalacturonic acids formed in batch cultures were estimated during a 24- or 48-h incubation period by using high-performance thin-layer chromatography and high-performance anion-exchange chromatography. The spectrum and the amount of unsaturated oligogalacturonic acids formed as intermediate products of pectin fermentation changed permanently in the culture media during incubation with the complete fecal flora. After 24 h, no oligogalacturonic acids were detected. The pectin-degrading activities of pure cultures of B. thetaiotaomicron were lower than the pectin-degrading activity of a complete fecal flora. Cocultures of B. thetaiotaomicron and E. coli exhibited intermediate levels of degradation activity. In pure cultures of E. coli no pectin-degrading activity was found. Additionally, the rate of pectin degradation was affected by the degree of esterification of the substrate. Saturated oligogalacturonic acids were not found during pectin fermentation. The disappearance of oligogalacturonic acids in the later stages of fermentation with both the complete fecal flora and B. thetaiotaomicron was accompanied by increased formation of short-chain fatty acids.  相似文献   

9.
10.
Permineralized Lepidostrobus specimens were examined from the Westphalian A of England, Westphalian B (Breathitt) of the Appalachian Basin, and the Westphalian D (Desmoinesian) of the Illinois Basin and Western Interior Coal Region to correlate species of the dispersed spore genus Lycospora with source cones and cone types (“species”) with parent plants. Based on 51 specimens of Lepidostrobus oldhamius sensu Balbach, three cone types, producing three species of Lycospora, are recognized. Lycospora pellucida occurs in smaller diameter cones with a prominently coronate stele; cones are associated with Lepidophloios harcourtii from the Westphalian A-B. Lycospora pusilla occurs in larger diameter cones with a small “pith” containing elongate, sclerified, tanniferous cells from Westphalian D coal balls. Secretory cells also are present in sporophyll trace sheaths and in subarchesporial parenchyma pads in sporangia. The suggested plant source is Lepidodendron hickii. Lycospora granulata occurs in large cones with a large “pith” composed of thin-walled parenchyma; no secretory cells were observed in the “pith,” sporophyll traces, or subarchesporial pads. These cones are associated with Lepidophloios hallii from the Westphalian D. Association of Lycospora species with source lycopods increases the possibilities of paleoecological interpretation using microspores from Carboniferous coals.  相似文献   

11.
Several new remains of fossil insects from the Late Carboniferous (Pennsylvanian: Namurian?B or C) of the Fr?ndenberg/Ruhr Region (Unna District, Western Germany) are described. They comprise seven wing fragments of Homaloneura berenice Brauckmann and Gr?ning, 1998 (Palaeodictyoptera: Spilapteridae), a species which is better and more completely known from the Konservat-Lagerst?tte Hagen-Vorhalle (Namurian?B: Marsdenian) with at least three specimens. Two additional wing fragments belong to Bechala sommeri gen. et sp. nov. (Megasecoptera: Bechalidae fam. nov.). Together with Brodioptera stricklani Nelson and Tidwell, 1987 (Brodiopteridae; earliest Namurian, Kinderscoutian; Utah, USA), Sylvohymen peckae Brauckmann, 1988 and S.?pintoi Brauckmann et?al., 2003 (both: Bardohymenidae; Namurian?B, Marsdenian, Hagen-Vorhalle, Germany), and Xenoptera riojaensis Pinto, 1986 (Xenopteridae; probably late Namurian or early Westphalian; Malanzán, La Rioja, Argentina) they belong to the most ancient members of the Megasecoptera. Both of these species from Küchenberg have a striking specific color pattern. The holotype of B.?sommeri gen. et sp. nov. exhibits both a very fine woven archedictyon and well-developed, cell-forming cross-veins. This combination is appraised to be very plesiomorphic. Additionally, one isolated wing fragment of Kochopteron hoffmannorum Brauckmann, 1984 (??basal Neoptera??) is preserved. The Fr?ndenberg wings were deposited in a mainly limnic/terrestrial environment and have been most probably transported by eolian and/or fluviatile processes.  相似文献   

12.
The data on the plant fossils of the Trout Valley Formation of north-central Maine, U.S.A., are summarized. Evidence from lithological correlation, from plant megafossils and paleopalynology suggest a late Early Devonian (Emsian) age for the Formation. Plant megafossils present are several species of Psilophyton, Pertica quadrifaria, Kaulangiophyton akantha, Prototaxites sp., Drepanophycus sp., Taeniocrada sp. and Thursophyton sp. The microfossil assemblage, through poorly preserved, contains Deltoidospora sp., Apiculiretusispora sp., Emphanisporites rotatus, E. annulatus, Clivosisporites cf. C. verrucata, Grandispora sp. and a chitinozoan, Sphaerochitina sp. The ancient landscape is suggested as having been an area a few square miles in extent with modest relief and comparable to a modern brackish or fresh-water marsh. Three other floras, one in Maine, a second in New Brunswick, Canada, and a third along the coast of Gaspé Bay, Quebec, are thought to have been at least partially contemporaneous with the Trout Valley flora.  相似文献   

13.
Abstract: Generally, lycophytes are not well represented in Anisian floras. Nonetheless, four different genera, each with one species, have been distinguished in the Anisian flora from Kühwiesenkopf (Monte Prà della Vacca), Italy. They were well preserved and yielded leaf cuticles in all four taxa and in situ spores in two of them. Lycopia dezanchei gen. et sp. nov. is the most common form; it is characterized by a dichotomising creeping prostrate rhizome (representing the primary shoot axis) from which arise aerial axes, apically bifurcated and covered with bundles of long leaves. This taxon cannot be attributed to any of the lycophyte orders, but most resembles Lycopodiales. Two representatives of the Isoetales have been found, of which Isoetites brandneri sp. nov. is abundant. This species is characterized by a short stem, which is unusual for this genus. In situ immature microspores and megaspores were found in some specimens. Lepacyclotes bechstaedtii sp. nov. has a quadrilobe corm with fertile scales inserted in whorls or slightly helicoidally. Short sterile leaves arise distally from the corm in some specimens. Selaginellales are very rare in the flora; Selaginellites leonardii sp. nov. is represented by a strobilus that yielded both micro‐ and megaspores. Some sterile fragments have been found associated, but never in organic connection.  相似文献   

14.
Thin continental Carboniferous sequences crop out sparsely in the western Southern Alps (Alpe Logone, Mesenzana, Grantola, Bosco Valtravaglia-Fabiasco, Val Tresa, etc.) and are currently the subject of a detailed litho- and biostratigraphic revision, to reconsider their chronological position with respect to previously published age constraints. The age of these Upper Palaeozoic sedimentary successions, scattered over a wide area and strongly tectonized along major structural lineaments, has long been debated between Westphalian and Stephanian. The present work focuses mainly on the palynology of the Brezzo di Bèdero section (Luino, Lake Maggiore). The recovered palynoflora is assigned to 42 spore genera and 76 species of which one genus and 10 species are newly proposed. Fifty-seven spore species and 19 pollen species are described and illustrated. Qualitatively, the Bèdero palynoflora shows strong affinities to those of Western Europe. The most abundant palynomorphs are trilete spores known to be characteristics of the late Westphalian and early Stephanian assemblages. These are characterized by the remarkable presence of Florinites and subordinately Wilsonites species, low numbers of Potonieisporites, rare Limitisporites and Vesicaspora, and very rare Latensina-Cordaitina pollen. The occurrence of diverse monolete spores Laevigatosporites, Punctatosporites, Spinosporites, Thymospora and Torispora, with common Lundbladispora gigantea, L. simonii, Stenozonotriletes rubius n. sp. together with the absence of plicate and taeniate pollen grains suggests a strong resemblance to the late Westphalian–early Stephanian interval assigned to the OT Zone of Western Europe. Variations in the quantitative composition can be likely attributed to variations in the environmental setting with regards to non-forming peat deposits. The palynological suite is indicative of the existence of a well-established lowland Cordaiteans vegetation and well settled pterophytic, pteridosperm and subordinately sphenophytic and lycophytic, hygrophytic plant communities.  相似文献   

15.
《Geobios》1986,19(6):773-800
The mineralogy and preservation history of the anatomically preserved plants (permineralizations) of Lower Carboniferous age (Upper Visean) from Esnost, near Autun, France is described. The plants are all preserved in silica and are associated with acid volcanism. The permineralized plants occur within a range of different sediments each of which is characterized by a specific floral association and has a distinct mineralization. The structure of the mineralization is dependent on whether fossilization occurred within a site of growth of a plant or at a site of deposition of plant fragments. The timing of mineralization, whether early or late, also influenced the form of the crystals. The most common plant-bearing lithology at Esnost is the Archaeocalamites «peat. This lithology contains fine roots which are interpreted as the terminal roots of Archaeocalamites. These were important in providing channels through the semi-compacted peat for the permineralizing siliceous fluids. The Botryopteris cherts, dominated by one species of coenopterid fern, were fossilized at a much earlier stage giving exceptionally good preservation of the anatomical detail. The third most important plant-bearing sediment is the Diplolabis chert. This represents mineralization at the site of deposition of fragments of this fern. Within this site, mineralization was slow and episodic involving the considerable loss of organic material from the plant organs, resulting in some cases in a mineralization approaching petrifaction. Fusain was rare in the deposits but occurred within the Diplolabis cherts and the fusain-bearing chert where it is associated with a series of microorganisms of unknown affinities. The relationship of the sediments, plants and mineralization offers a basis for reconstructing the original ecology of the plants within the volcanic terrain. These plant deposits are compared to those of the same age, associated with basaltic volcanism, at Pettycur, Fife, Scotland.  相似文献   

16.
Within bituminous coals of Westphalian B age pyritized amoebae of the order Testacea (thecamoebians) were detected. They may belong to the genusArcella. The appearance of this genus, known until now only since the Pleistocene, is extended far into the Palaeozoic by this observation.  相似文献   

17.
Podocytes are unique cells that are decisively involved in glomerular filtration. They are equipped with a complex process system consisting of major processes and foot processes whose function is insufficiently understood (Mundel, P., and W. Kriz. 1995. Anat. Embryol. 192:385–397). The major processes of podocytes contain a microtubular cytoskeleton. Taking advantage of a recently established cell culture system for podocytes with preserved ability to form processes (Mundel, P., J. Reiser, A. Zúñiga Mejía Borja, H. Pavenstädt, G.R. Davidson, W. Kriz, and R. Zeller. 1997b. Exp. Cell Res. 36:248–258), we studied the functional significance of the microtubular system in major processes. The following data were obtained: (a) Microtubules (MTs) in podocytes show a nonuniform polarity as revealed by hook-decoration. (b) CHO1/ MKLP1, a kinesin-like motor protein, is associated with MTs in podocytes. (c) Treatment of differentiating podocytes with CHO1/MKLP1 antisense oligonucleotides abolished the formation of processes and the nonuniform polarity of MTs. (d) During the recovery from taxol treatment, taxol-stabilized (nocodazole- resistant) MT fragments were distributed in the cell periphery along newly assembled nocodazole-sensitive MTs. A similar distribution pattern of CHO1/MKLP1 was found under these circumstances, indicating its association with MTs. (e) In the recovery phase after complete depolymerization, MTs reassembled exclusively at centrosomes. Taken together, these findings lead to the conclusion that the nonuniform MT polarity in podocytes established by CHO1/MKLP1 is necessary for process formation.  相似文献   

18.
Honeybees rely exclusively on pollen and nectar-producing plants for strengthening their colonies and manufacturing honey. Little is known about the indigenous melliferous flora of arid zones of Khyber Pakhtunkhwa (KPK) which is crucial for honey production and how different pollen assessment techniques effect the identification of indigenous melliferous pollen flora. Visual survey and loads ensnaring through pollen traps were used to identify the botanical profile of melliferous pollen flora of Dera Ismail Khan (DIKhan), Khyber Pakhtunkhwa. The test time extended for two consecutive years 2018 and 2019. The study revealed 56 plant species as pollen flora with 18 significant pollen producing species in visual survey technique while 8 species as predominant flora in pollen trapping technique. The major pollen species found common in both the techniques were Brassica napus L., Brassica campestris L., Trifolium alaxandrinum L., Zea mays L., Acacia modesta L., Citrus aurantium L., Euclyptus spp., and Morus alba L. Pollen interception and palynological analysis of pollen were found to be more reliable techniques as compared to focal observations. More than fifty % differences were found by comparing the results of the visual survey and pollen trapping technique in major flora of DIKhan. Based on the availability, utility status and flowering duration of apiphilic flora, mid-February to mid-May was found to be a significant pollen flow period in the study area. Maximum benefit can be taken in this period through trapping ample amount of pollen and stored for using in artificial diets, selling and feeding bees during dearth period.  相似文献   

19.
At the end of Namurian A, in Eurameria, we see agreat change in the composition of the flora, probably instigated by a great modification in the climatic conditions. This flora adapted to very humid places persist during whole the Westphalian and up to the end of Stephanian where it is relayed by a mesoxerophytic flora of which the most typical elements are the Coniferales of the family Lebachiaceae. This «autunian flora is usualy considered as subsequent to the stephanian hygrophytic flora and as the transition to the permian flora which is determined by a new modification of the general climatic conditions.Some observations about the macroflora and about the microflora lead to prove the coexistence of hygrophytic, mesophytic and mesoxerophytic floras, not only during the upper Stephanian but also during Westphalian and Namurian B and C. So, from Devonian to Permian, in Eurameria, there was probably continuity of a mesoxerophytic and mesophytic type floras on which was superimposed during the upper Carboniferous an hygrophytic flora adapted to the swamps surrounding the coal-lakes and coal-lagoon. The time of the appearance of Coniferales is older as we think usually.  相似文献   

20.
The 26 SmaI digest fragments of pTi-B6-806 plasmid have a total molecular weight (121 × 106) which accounts for the size of the plasmid as determined by contour length measurements. We have determined the physical arrangement of all SmaI digest fragments with reference to HpaI digest fragments. Hybridization of individual labeled SmaI digest fragments to HpaI digest fragments (cellulose nitrate transfers) allowed the latter to be ordered and located the SmaI boundary fragments. Recleavage of isolated HpaI fragments with SmaI revealed the SmaI fragments located within each HpaI fragment. The order of these internal SmaI fragments within a given HpaI fragment was determined by partial digestion of the latter with SmaI and hybridization of the resulting fragments with SmaI boundary fragments. From the sizes of partial digest fragments containing each boundary, the order of occurrence of SmaI fragments from each end was deduced. The complete map of the SmaI digest fragments is presented. The map of the HpaI digest fragments is presented with the following ambiguity: The order of fragments 12, 15, and 16, which map within SmaI fragment 1, was not determined. The SmaI digest fragments that contain DNA sequences transferred to plant cells during tumor induction, fragments 3b and 10c, were found to be contiguous on the physical map.  相似文献   

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