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The pollen grains of 38 species and one variety of 17 genera in the family Solanaceae were studied using light microscopy (LM) and scanning electron microscopy (SEM). Among them, the pollen morphology of 13 species was described for the first time. Our results suggested that the exine ornamentation of pollen grains could be divided into 11 types, made up of three types (cerebroid, granulate-perforate-punctate and rugulate-perforate) which were observed for the first time in Solanaceae, and other normal types (granulate, granulate-perforate, punctate, reticulate, rugulate, rugulate-striate, spinulose-perforate, striate). In addition, the studied species have pollen grains that differ in size, shape, equatorial view, polar view, aperture features and exine ornamentation, confirming that Solanaceae is a eurypalynous family. Furthermore, the intergeneric and intrageneric relationships of Solanaceae were explored. These results could provide a palynological basis for classification and systematic study of Solanaceae.
The objective of the present study was to characterise the pollen morphology of the African genera Paropsia and Barteria (Passifloraceae sensu stricto, tribe Paropsieae), with the aim of identifying characters diagnostic of the genera. The pollen grains of nine species (two of Barteria and seven of Paropsia) were acetolysed, measured, described and illustrated using light and scanning electron microscopy. The pollen grains of Barteria are apolar with five pores, while those of Paropsia are isopolar and six-colporate with six endoapertures, one endoaperture for each ectoaperture. The endoapertures of Paropsia vary among the species and can be lolongate, lalongate or circular. The ornamentation of the sexine of Barteria is echinate-granulate, which proved important for distinguishing this genus from Paropsia, which has a reticulate sexine. Multivariate analysis based on quantitative data revealed two groups: Cluster 1, formed by species of Barteria; and Cluster 2, formed by species of Paropsia. The present work found the studied genera to be closely associated with Passiflora, the most well-known genus of Passifloraceae sensu stricto. Paropsia and Passiflora subg. Astrophea are closely related phylogenetically, as supported by their palynological affinity observed in the present study. However, the two taxa do differ in the arrangement of their apertures, with Paropsia having six ectoapertures and six endoapertures while species of Passiflora subg. Astrophea have six ectoapertures and three endoapertures. Because Passiflora subg. Astrophea is more derived, it is hypothesised that it experienced fusion of endoapertures during its evolutionary history. The results reported here are significant to the initial understanding of the evolution of pollen grains in Passifloraceae sensu stricto.
Micropalaeontological analyses of two sediment cores (T_A and T_D) collected from a tropical bay in Brazil were conducted. Continental palynomorphs and carbonised particle data were associated with stable isotopes (C and N) assessed using 14C dating. The main objective was to integrate these data with the results of isotopic analyses in order to establish the palaeoenvironmental dynamics of the area during the Holocene. The samples were sub-sampled every 10 cm and then submitted for standard methodological processing for each analysis. The T_A sediment core was dated at three depths, and the oldest depth, 150 cm, had an age between 7241-7339 cal yr BP. The T_D sediment core had an age between 6778 and6948 cal yr BP at its deepest depth, 370 cm. Using radiocarbon dating and micropalaeontological analyses, the integrated assessment of the two sediment cores indicated that the core with a coarser granulometry core was a continuation of the core with the finest granulometry. Consequently, both the lithological change and the preservation of the microfossils could be directly related to periods of sea level variations observed in the coastal region of Brazil.
The multiplicity of dinoflagellate cyst biozones in Cretaceous rocks limits their correlation applications, and the variations in the scientific bases of such zonations complicates age determinations and limits the validity of reliable inter-basinal correlations. The present work provides a useful summary of the dinoflagellate cyst occurrence data in Egypt and a proposed working Egyptian biozonation scheme for the area. The most diagnostic dinoflagellate cyst bioevents, in a definite time interval which occurs widely in most of the studied Egyptian, North African and Tethyan sections, are selected to be marker taxa for the erected zones. The eastern Canadian and northern European data consistently show much higher range tops for the dinoflagellate cysts at those high latitudes. The comparison and correlation of the contemporaneous dinoflagellate cyst range tops from Egypt and geographically neighbouring North African areas are vital for selecting widely distributed marker taxa and testing their validity and applicability to intercontinental correlations in the Tethyan Realm. Based on 29 wells located across Northern Egypt, this work provides a potentially useful scheme that unifies the different previously established dinoflagellate cyst palynozonation frameworks for Cretaceous rocks. The index palyno-events represented by the last occurrence datums (LODs) of the marker dinoflagellate cyst taxa are carefully picked from palynostratigraphies established earlier and methodically, consistently used to create a new regional palynostratigraphical scheme for all of the northern Egyptian territory. Ten dinoflagellate cyst interval zones were identified and described; these are, in descending stratigraphic order from youngest to oldest, Dinogymnium acuminatum (Maastrichtian–Campanian), Odontochitina operculata (Santonian–Coniacian), Cyclonephelium vannophorum (Turonian), Dinopterygium cladoides (late–middle Cenomanian), Coronifera oceanica (middle–early Cenomanian), Oligosphaeridium complex (late–middle Albian), Subtilisphaera perlucida (early Albian), Cribroperidinium orthoceras or C. edwardsii (Aptian–late Barremian), Muderongia simplex or Pesudoceratium anaphrissum (Barremian–late Hauterivian) and Systematophora silybum (Hauterivian–Berriasian).
Jurassic sedimentary successions in eastern Australia are widely thought to have been deposited in nonmarine environments. Thus, the discovery of low-diversity dinoflagellate cyst assemblages with associated colonial algae in the Walloon Coal Measures of the western Surat Basin provides new evidence of either a short-lived marine transgression or the very rare occurrence of nonmarine dinoflagellate cysts in pre-Cretaceous strata. Their small size, thin walls and simple proximate shapes are typical of freshwater to brackish dinoflagellate cysts, as are the low species richness and high dominance nature of the assemblages. Two new species of dinoflagellate cysts (Moorodinium crispa sp. nov. and Skuadinium fusum sp. nov.) and a new species of colonial algae (Palambages pariunta sp. nov.) are described from these assemblages. Tidal channel and tidal mudflat facies associated with these assemblages provide evidence of a possible upper estuarine setting. Support for a marine incursion is provided by U–Pb dating. This yielded an age of 150.11 ± 0.04 Ma (∼100 m above the dinoflagellate cyst assemblage in the Indy 3 well) that ties to an episode of high eustatic sea level during the Tithonian. Thus, a marine transgressive event during the Tithonian may have allowed dinoflagellates to migrate into the interior of the Australian continent. If these dinoflagellate cysts are found more widely, rather than being just an isolated occurrence in this well, they may provide a useful correlative tool for tracing distinctive brackish to marginal marine flooding surfaces in continental successions in eastern Australia.
Rich and well-preserved assemblages of organic-walled dinoflagellate cysts have been recovered from the upper Campanian of the Middle Vistula River section, central Poland. Among the ceratiacean dinocysts, the majority of the recovered specimens are attributed to the newly described Odontochitina dilatata sp. nov. Additional material comes from the Roztocze Hills (SE Poland). The most distinctive features of Odontochitina dilatata sp. nov. are: (i) widely divergent antapical and lateral horns, not connected by pericoel; and (ii) thick central body wall with a three-layered structure, consisting of endo-, meso-, and periphragm. The mesophragm, which is distinctly less homogeneous (spongy) than the other two layers, gives the central body wall a reticulate appearance. The three-layered wall structure is rarely recognised in dinoflagellate cysts, and this is its first record from the ceratiacean dinocysts. The genus Odontochitina is emended to emphasise its more complex wall structure and the importance of other features, such as the angle of divergence between the antapical and lateral horns and compression of the central body. Odontochitina dilatata sp. nov. shares its more complex wall structure with O. streelii and possibly also with Xenascus wetzelii, but differs in this aspect from O. costata, O. diducta, O. operculata and O. porifera. The distinction between the genera Odontochitina and Xenascus needs further discussion, since the only feature distinguishing them is a better development of the processes in the latter genus.
Pollen in the surface sediment collected in a transect from sea to land in the Coringa mangrove wetland was analysed to determine the spatial and quantitative composition of the pollen record for palaeoecological interpretation. Autochthonous pollen preservation of the existing mangrove species was predominant in the sediments and serves as a potential indicator of coastal wetlands. The low quantity of allochthonous and parautochthonous pollen in the sediment reflects the regional plant community. Statistical analysis of the palynological data shows a high association between pollen from Avicennia marina and Clerodendrum inerme and their vegetation. Aegiceras corniculatum, Sonneratia, Ceriops decandra, Xylocarpus mekongenesis, Cocos nucifera, Azadirachta indica, Syzygium, Chenopodiaceae, Poaceae and Cyperaceae show overrepresentation. Ordination techniques for individual species using fidelity and dispersibility indices and regression analyses suggest four different floristic groups, of (i) high dispersibility-moderate fidelity taxa; (ii) high dispersibility-low fidelity taxa; (iii) moderate dispersibility-low fidelity taxa; and (iv) low dispersibility-high fidelity taxa. Species with high fidelity and moderate-low dispersibility indices could be used to identify the vegetation types in sedimentary sequences. The presence of discriminatory taxa (Avicennia marina, Sonneratia sp.), even in small quantities, helps in accurate identification of the local vegetation. Results indicate that while mangrove pollen is transported over short distances, non-mangrove pollen and spores are transported from longer distances. Thus, the status of mangrove and non-mangrove pollen in the sediments provides a clue to the (palaeo)coastal ecology and the (palaeo)climatic conditions.
The multiple biozonal nomenclatures given for the same time segment at different locations in northern Egypt are problematic, as such multiplicity is highly confusing and considerably limits the correlative value of these nomenclatures within the Egyptian territory, in the Elaterates phytogeoprovince and in the Tethyan Realm. Thirty-one wells are selected and used in this work to establish a standard and unified, semi-formal, generalised Egyptian sporomorph palynozonation scheme for northern Egypt. Marker taxa are carefully picked and tracked from the different previously established palynostratigraphies, and they are methodically re-used in the present unified framework on a regular basis, where their first down-hole appearance [last appearance datum (LAD)] palynoevents are utilised to erect a regional palynostratigraphical scheme. Ten sporomorph interval zones (IZ) and two subzones are reconstructed, established and palynologically specified from all of the studied wells. The authors surveyed the palynofloral assemblages characterising different areas of the world in order to derive meaningful palaeobiogeographical implications. Connecting these databases furnishes a comprehensive palynostratigraphical framework for inter-continental correlations with the Egyptian assemblages. In addition, such correlations confirm the dating acquired from the recovered palynological markers and assemblages presented in the current review. Comparisons of coeval assemblages confirm that the extensions and boundary limits of the palaeoprovinces of the recorded sporomorphs exhibited a gradual change and that their areal extent evolved with time. Due to the wide geographical occurrences of the recorded marker taxa during the pre-Albian stages of North and West Africa, western Atlantic and east South America, the proposed sporomorph zones can be confidently applied in these areas. During the Albian–Cenomanian such correlations can be applied only between North and West Africa and east South America.
The Brazil-Falklands/Malvinas Confluence (BFMC), a highly energetic convergence of surface currents in the western South Atlantic, has shifted southward in recent years and this shift is projected to progress in the future. Palaeoecological insights documenting past changes of these currents may help in anticipating future impacts on the environment. We used dinoflagellate cyst analyses from a marine sediment core to reconstruct environmental changes in the Argentine continental margin, western South Atlantic, during the last ca. 12,600 years. The dynamics of the BFMC were reconstructed using the relative frequency of warm-water indicators for the Brazil Current (BC) versus cold-water taxa thriving in the Falklands/Malvinas Current (FMC). We found that the latitudinal position of the BFMC was relatively stable with only minor amplitude migrations between 12.6 and 8.7 cal kyr BP, followed by periods with stronger shifts to the south and the north until 0.66 cal kyr BP. After that, the BFMC shifted continuously to the south. The increase in freshwater algae abundance after ca. 5.7 cal kyr BP suggests an increase in precipitation over the adjacent Rio de la Plata drainage basin in south-eastern South America. As previously documented, such an increase in precipitation was probably related to a higher El Niño-Southern Oscillation frequency and longer, stronger El Niño events since the mid-Holocene. The dinoflagellate cyst record indicates a phase of the enhanced presence of nutrient-rich waters over the core site between ca. 6.3 and 5.7 cal kyr BP, as well as from 0.66 cal kyr BP to the recent. The highest eutrophication in the ocean surface occurred during the last ca. 100 years, most probably due to stronger human impact in the area of the Rio de la Plata drainage basin.
Steppes and grasslands of semiarid environments in the Central Andes are poorly understood in fossil records due to the lack of modern pollen–vegetation studies. This paper is focused on a systematic analysis of the modern pollen–vegetation relationship in three protected areas of the Puna in Jujuy, northwestern Argentina. Vegetation assemblages were described on the basis of their floristic composition in 32 plots. Different multivariate methods, indices of association and simple linear regression models were applied in order to investigate the degree to which the different vegetation assemblages can be distinguished by their pollen spectra. Five plant assemblages were described, which were partially represented by their pollen spectra: mixed and shrubby steppes, scrubland, grassland with shrubs and high Andean grassland. The pollen spectra reflected both altitudinal variations and environmental conditions. In the Puna belt, at 3600 m, shrubs were present in great abundance and their highest pollen percentages were recorded. Both the abundance of Poaceae herbs and their pollen type increased with increasing altitude up to 4220 m, indicating the transition towards the Altoandean belt. Pollen assemblages evidenced the following environmental conditions: (1) the temperature decrease is characterized by taxa adapted to either cold air (<7 °C) or cold soil (Aridisols-Cryids/Inceptisols-Ustepts type) including Poaceae, Frankenia triandra, Apiaceae, Hoffmansegia glauca, Ephedra, Caryophyllaceae; (2) moisture availability in the soil can be discernible by assemblages indicating dry soil (Aridisols-Durids type), such as Baccharis, Fabiana densa, Maihuniopsis boliviana, Fabaceae, Tetraglochin cristatum and Nassauvia axilaris, from those indicating humid soil (Entisols-Psaments type), such as Parastrephia, Astragalus garbancillo and Gentianaceae. Four taxa exhibited both a good association and a significant correlation and could be considered indicative of the steppe (Baccharis and M. boliviana), scrublands (Parastrephia) and grassland (Poaceae) in a fossil record. This work has important implications for interpreting the dynamics of vegetation during the Holocene in the Puna.
In this research palynology has been applied to the study of an adhesive beeswax compound found beneath one enamel of the medieval Evangelistary cover ‘Pace di Chiavenna’, ca 1000 years old and preserved for the last five centuries in the Treasury of the Collegiate Church of Chiavenna (Northern Italy). The purpose of this study was to test whether it is possible to determine the geographical area of wax collection and of the origin of the wooden support of the artefact, using the pollen imprint of plants and their related spatial ranges. Palynological analyses allowed the identification of 184 pollen grains belonging to 33 taxa. The reconstructed vegetation represents dry to humid meadows and pastures (e.g. Artemisia, Apiaceae, Campanula type, Poacaeae, Thalictrum, Asteroideae), wet areas (e.g. Alnus glutinosa type, Salix), woods or forests (e.g. Acer, Tilia, Picea, Castanea), shrublands (Ericaceae, Corylus) and arable fields or gardens (e.g. Cerealia type, Urtica, Plantago major). The Evangelistary cover has been attributed to the Ottonian art, developed especially in Germany, Eastern France and Northern Italy. On the basis of the palynological evidence from the beeswax, we can restrict the provenance area. A Northern Italian or Southern Prealpine origin seems likely since Castanea sativa was much more frequent south than north of the Alps. This geographic origin is corroborated by the material used for the support, made of Juglans regia (walnut), frequently planted in the region at that time. Moreover, the technique used to produce the wooden plate was widespread in Italy during the High Medieval period. The palynological evidence points to a very open, deeply human-affected environment, possibly around a city or a larger village in which the apiary was located. Inferences of this nature cannot be provided by other approaches such as wood or leather analyses; we thus conclude that palynology can provide unique insights into the origin of cultural treasures.
Anderson Pond in eastern Tennessee is one of only a handful of sites in the interior southeastern US where researchers have developed pollen records that extend to the last full glacial period. Pollen data from the site have been widely used in regional syntheses and models of past vegetation and climate. Previous researchers either constructed age models that assumed continuous sedimentation from the Late Pleistocene to the present, and plotted pollen data by radiocarbon or calibrated ages (1976 core), or recognized the likelihood of hiatuses in the postglacial sediments, and plotted pollen data by depth (2007 cores). We present an improved chronology for the 1976 core based on prior delineation and dating of two hiatuses, and on new age modeling using AMS dates on macrofossils from cores collected in 2007. This new age model allows us to plot pollen and microscopic charcoal by age for the entirety of the record, and more accurately represents site history. Plotting pollen and charcoal assemblages by age using our new chronology highlights the long intervals of time that are missing from the postglacial record at Anderson Pond, while improving our ability to make use of proxy data from the fragmented sediments of this classic pollen site.
The botanical heterogeneity found in the Atlantic Forest is essential for the survival of fauna in this biome, especially bees because they depend on resources (pollen and nectar) provided by plants. Pollen analysis is one the main tools employed to understand the resources used by bees and provides information that improves the identification accuracy of pollen grains. The objective of this work was to identify the main pollen types used by Apis mellifera L. bees, in a fragment of Atlantic Forest in the southern region of Bahia State. Bee pollen samples were collected from March 2012 to April 2013. The samples were acetolyzed, mounted, and analyzed based on a minimum count of 500 pollen grains. Identifications were made using the literature and the pollen reference library at the Laboratório de Micromorfologia Vegetal. Thirty-five pollen types were morphologically distinguished in the samples, which belong to 20 plant families. The family Fabaceae had the highest pollen richness (9 types), followed by Asteraceae (4), and Anacardiaceae, Myrtaceae and Poaceae (2 each). Arecaceae was present in all of the samples, although it was represented by only one pollen type, followed by Asteraceae and Myrtaceae (>50%). The statistical analysis detected some groups (cluster) in relation to month/pollen richness, but a correlation between environmental variables/pollen richness was not confirmed (p<0.05). The results show the high apicultural potential of the family Arecaceae and that other factors (such as temperature and rainfall) might influence pollen richness.
Hirtella (Chrysobalanaceae) comprises about 107 species and less than 10% of its diversity has been sampled in palynological studies, which have only used light microscopy. To better understand the pollen morphology of the genus, pollen grains of fourteen species were examined: H. angustifolia Schott ex Spreng., H. bahienis Prance, H. bicornis Mart. & Zucc., H. ciliata Mart. & Zucc., H. corymbosa Cham. & Schltdl., H. glandulosa Spreng., H. gracilipes (Hook.f.) Prance, H. insignis Briq. ex Prance, H. martiana Hook.f., H. prancei Asprino & Amorim, H. racemosa Lam., H. santosii Prance, H. sprucei Benth. ex Hook.f., and H. triandra Sw. All of the species occur in the state of Bahia, Brazil, and belong to Hirtella sect. Hirtella. The pollen of Hirtella duckei Huber, an Amazonian species that belongs to Hirtella sect. Myrmecophila, was also analyzed for comparison. The pollen grains were acetolyzed, measured, described, and photomicrographed using light microscopy, and subsamples of acetolyzed material were also analyzed using scanning electron microscopy. The pollen of the studied species presented features similar to those previously reported for Hirtella, such as size, shape, number of apertures, and general features of the exine. Based on the SEM analysis, three ornamentation patterns of the exine (microreticulate-rugulate, rugulate-perforate, and psilate-perforate) are reported for the first time for the genus. Little could be inferred about the taxonomy of Hirtella based on the pollen morphology, and there were no pollen characters for H. duckei that corroborate or refute its separation in a different section from the other species studied. Nevertheless, the present study provides new data about Hirtella that contribute to what is known about the pollen morphology of the genus.
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