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Palynological assemblages from the Tehuacán Formation (TF), geochronologically dated as Middle Miocene (15.6 ± 0.4 Ma), provide evidence of a highly diverse flora that, at the generic level, is similar to the extant flora in the Tehuacán Valley. We propose that, during Miocene times, plant communities may have been formed of similar botanical elements to those seen today in the region, with some taxa adapted to semiarid conditions. While major temperate floristic elements of Pinus, Quercus, Juniperus, cloud forest and mexical vegetation can be recognized, components of tropical deciduous forests, such as Burseraceae, Leguminosae and Cactaceae, are also present, indicating semiarid conditions. Semiarid local conditions are also inferred from the geological record, consisting of lacustrine and alluvial fan deposits, which contain abundant evaporites beds. This lithology was formed under high evaporation and moderate precipitation conditions, as usually occurs in small basins fed by a seasonal input of water in semiarid environments. Important differences in the vegetation from the TF palynoflora as compared to older associations from south-central Mexico can be inferred, such as an increase in the diversity of semiarid taxa, belonging to Leguminosae and Burseraceae, and the oldest abundant occurrence of the Cactaceae.
Fossil fungal spores, endemic Paratethyan dinoflagellate cysts, organic-walled algal cysts, spores and pollen are very common in the onshore and offshore Neogene sediments of the Black Sea, Turkey. Amongst these assemblages, the fungal spore form-genus MediaverrunitesNandi and Sinha 2007, emend. nov., described from Neogene strata from tropical to temperate paleoclimates, commonly occurs in Upper Miocene sediments. The presence of stratigraphically important dinoflagellate cyst and pollen taxa confirms the stratigraphic importance of this genus in the Upper Miocene of the Black Sea. Two new fungal spore species, Mediaverrunites batii sp. nov. and Mediaverrunites pontidiensis sp. nov., are described from Upper Miocene sediments of the Black Sea.
Biostratigraphical investigations of Miocene deposits from the southern North Sea Basin, the Oligocene and Miocene of the Bahamas, and the lower Pliocene of northern Iceland revealed the presence of new acritarch species. Halodinium eirikssonii n. sp. is recovered from the lower Pliocene Serripes Zone of the Tjörnes beds in northern Iceland, where its range is well constrained through magnetostratigraphy and biostratigraphy using dinoflagellate cysts. Leiosphaeridia spongiosa n. sp. is recovered from lower to upper Miocene deposits of the southern North Sea Basin and from upper Oligocene and Miocene deposits of the Bahamas. Palaeostomocystis orbiculata n. sp. appears to be restricted to the middle Miocene of the North Sea Basin.
A palynological analysis has been conducted on the Cretaceous sediments of the Abu Tunis 1x borehole, in the northern Western Desert, Egypt. The palynomorphs recovered have been analysed both qualitatively and quantitatively, and permit a refinement of the original stratigraphy with the identification of four time-rock units. These have been divided into four informal sporomorph units and one dinoflagellate cyst palynozone. These biozones are, from oldest to youngest: the Afropollis jardinus-Tricolporopollenites-Elaterosporites klaszii Assemblage Zone (early—mid Albian), the Elaterosporites verrucatus-Sofrepites legouxae-Cretacaeiporites Assemblage Zone (late Albian—early Cenomanian), the Sofrepites legouxae Partial Range Zone (early—?mid Cenomanian), the Proteacidites cf. africaensis Total Range Zone (mid—late Cenomanian) and the Canningia senonica Total Range Zone (early? Santonian). A barren interzone has been identified immediately below the youngest palynozone, and this may be related to the unfavourable lithology (i.e., limestone and dolostone). The absolute abundances of spores and pollen represent the first quantitative description of an Egyptian Albian—Cenomanian palynofloral, a flora that is characteristic of the Albian—Cenomanian Elaterate Phytogeographical Province. The early Santonian palynoflora is exclusively marine phytoplankton; terrestrial palynomorphs representative of the Senonian Palmae Province are completely absent. The quantitative and semi-quantitative distributions of Afropollis jardinus are compared with similar semi-quantitative distributions of this species from other wells in the northern Western Desert of Egypt, and this permitted the identification of a mid Albian—early Cenomanian Afropollis jardinus ‘acme’ as an important local biostratigraphical event in the mid Cretaceous.
Pollen rain studies in Amazonia are scarce but of utmost importance to support interpretations of pollen records. We have investigated modern surface pollen spectra and vegetation in an Amazon location, Carajás, Brazil, where open and woody types of vegetation, swamps and lakes develop under rock outcrops. Both plant inventories of different savanna types along with bryophytic surface samples were analysed with ecological ordination. The results point to taxa that can be used in the differentiation of dry and flooded systems within the savannas studied. Dry savannas, either open or wooded, are indicated by the herbs Cuphea, Asteraceae, Borreria, Caryophyllaceae and Polygonaceae, and by woody taxa such as Myrtaceae, Byrsonima, Sapotaceae, Neea and Rubiaceae. Flooded savannas (swamps) and lakes are indicated by herbs like Sagittaria, Montrichardia, Nymphaea, Cyperaceae and Mimosa and palms. Poaceae was found to have a bipolar signature, and using it as an indicator should be done with caution.
In Brazil, the production of bee pollen loads began modestly in the late 1980s, stimulated by consumption of natural products. Demand and consumption have increased, and there has been no increase in scientific studies. This work aims to expand scientific knowledge by identifying the plants used by Apis mellifera L. as sources of pollen loads in the State of Sergipe, Brazil. Twelve samples were collected from January to December 2011, in the municipalities of Barra dos Coqueiros, Brejo Grande, Estância and Pacatuba, all located in the eastern region of Sergipe. For the study of the pollen grains, the bee pollen underwent the usual laboratory processing techniques (acetolysis). For the analysis 500 grains were counted from each sample and, for botanical identification, the specialised literature and the pollen library were used. A total of 46 pollen types, distributed in 19 families, were found. Fabaceae was the family displaying the greatest diversity of pollen types (19), and the genus Mimosa L. was the most diverse (8). The families Asteraceae, Anacardiaceae, Myrtaceae and Rubiaceae were represented by three pollen types each, and Lamiaceae, only two types. The other 13 families presented one pollen type each. Only eight pollen types were classified as very frequent (> 50%); however, only Cocos nucifera occurred in 100% of the samples. It can be concluded that the families Arecaceae and Fabaceae are the major pollen sources for production of bee pollen in the state of Sergipe, followed by Asteraceae, Anacardiaceae, Poaceae and Rubiaceae. Pollen spectra revealed that at least 29 genera of plants contribute to the bee pollen load production in the tropical rainforest zone in northeastern Brazil.
A new organic-walled dinoflagellate cyst species, Spiniferites multisphaerus sp. nov., is described from Late Quaternary sediments of Guaymas Basin, Gulf of California (Mexico). This species is characterized by a pronounced apical protuberance and bubble-like elements that comprise the central body wall, sutural septae and processes. The central body wall is ∼1.0–2.1 µm thick and appears pseudoreticulate in transmitted light microscopy. Processes are generally stubby and have blunt or furcated tips. Tabulation is expressed by low to moderate sutural septae, and is typical of the genus. Spiniferites multisphaerus sp. nov. has been found in low abundances throughout the Late Quaternary in Guaymas Basin with maximum abundances of 6% or 1670 cysts g-1, and is rare in the Holocene, including modern sediments.
The spore-pollen zonation developed for the Gippsland Basin, southeast Australia, is widely used to date Paleogene—Neogene terrestrial sediments elsewhere in Australia. Microfloras preserved in an argon-40 (40Ar)/argon-39 (39Ar) dated 23 Ma claystone on the summit of the Great Dividing Range at Toowoomba in subtropical southeast Queensland indicate the Gippsland zonation, and the parallel schemata developed for the epicontinental Murray Basin in southeastern Australia provide only a general guide to the age of Late Paleogene—Neogene sediments as far north as Queensland. The finding reiterates the need to develop regional spore-pollen palynostratigraphies for Queensland (and northern Australia) centred on Cenozoic microfloras whose geologic age can be independently verified by other dating techniques. The same microfloras, however, are reliable evidence of past vegetation and climates, in this instance that a form of Nothofagus-gymnosperm temperate rainforest was colonising basaltic soils at Toowoomba during the Oligo-Miocene transition when southeast Queensland was located c. 15° south of its present latitudial position.
Pollen grains are complex three-dimensional structures, and are identified using specific distinctive morphological characteristics. An efficient automatic system for the accurate and rapid identification of pollen grains would significantly enhance the consistency, objectivity, speed and perhaps accuracy of pollen analysis. This study describes the development and testing of an expert system for the identification of pollen grains based on their respective morphologies. The extreme learning machine (ELM) is a type of artificial neural network, and has been used for automatic pollen identification. To test the equipment and the method, pollen grains from 10 species of Onopordum (a thistle genus) from Turkey were used. In total, 30 different images were acquired for each of the 10 species studied. The images were then used to measure 11 morphological parameters; these were the colpus length, the colpus width, the equatorial axis (E), the polar axis (P), the P/E ratio, the columellae length, the echinae length, and the thicknesses of the exine, intine, nexine and tectum. Pollen recognition was performed using the ELM for the 50-50%, 70-30% and 80-20% training-test partitions of the overall dataset. The classification accuracies of these three training-test partitions of were 84.67%, 91.11% and 95.00%, respectively. Therefore, the ELM exhibited a very high success rate for identifying the pollen types considered here. The use of computer-based systems for pollen recognition has great potential in all areas of palynology for the accurate and rapid accumulation of data.
Pollen was analysed in 30 unifloral Euphorbia honey samples from the Ifni Massif Region (Anti Atlas, Morocco). The honey samples were directly provided by beekeepers. The quantitative analyis showed that nectar is the main honey source in the samples studied. The qualitative analysis of the samples showed the presence of 35 taxa belonging to 17 families. The Moroccan Euphorbia honeys of the studied region are characterized by their low—medium number of pollen grains (NGP; mean = 5700), 76% of the honeys belong to Class I and II of Maurizio, and by their low honeydew indicator (HDE/NGPn < 0.28), wich indicates their floral origin. For the Euphorbia officinarum subsp. echinus honeys, the most characteristic accompanying species are Eryngium ilicifolium, present in > 90% of the samples, followed by Bellis sp., Capsella f. and Reseda sp. (85%). However, for the E. regis-jubae honeys, the most characteristic accompanying species are Crepis f., present in 100% of the samples.
The present communication reviews the pattern of modern pollen-rain studies carried out in southwestern Madhya Pradesh, India. The study largely revealed that Tectona grandis (teak), despite being an enormous pollen producer (7500 average number of absolute pollen/flower) and the dominant forest constituent (80 to 95% of the total forest constituents), is recorded mostly in low frequencies, attributable to its low pollen dispersal efficiency as well as poor pollen preservation in the sediments. However, Madhuca indica (Mahua) and other dominant members of Sapotaceae (cf. Manilkara hexandra and Mimusops elangi) have always shown their typical behaviour in the pollen spectra and are represented in high frequencies, which are assigned to their local abundance around the provenance of the samples, coupled with high dispersal efficiency as well as good pollen preservation in the sediments. Meanwhile, the other usual and characteristic associates of teak (Tectona grandis) in the tropical deciduous forests, despite being the common elements of the forests, are under-represented, sporadically represented or not represented at all, which could be ascribed to their low pollen productivity owing to entomogamy. Various factors that affect the deposition pattern of the diverse constituents of the tropical deciduous forests dominated by teak (Tectona grandis) have been discussed and suggestions are also given while interpreting the pollen sequences generated from the sedimentary beds in terms of past vegetation and climate in a chronological order in the region during the Late Quaternary Period.
The pollen morphology of Podostemum (Podostemaceae) was analysed with the aim of providing detailed descriptions of pollen for all species of the genus. Pollen grains were obtained from anthers of flower buds, acetolysed, and examined using light and scanning electron microscopy. The pollen grains are dyads or monads, small or medium sized, with shape ranging from 14.7 to 32.3, prolate spheroidal, oblate spheroidal, prolate, subprolate, with a circular, subtriangular or triangular amb. Pollen grains are tricolpate, and the colpus membrane conspicuously ornate. The exine is thin, spiculate with mamilloid elements with acute apices. Hierarchical cluster analysis (HCA) was used to divide the main pollen taxa into three groups based on pollen morphology. Statistically distinctive taxa were identified using principal components analysis (PCA). Pollen analysis revealed a significant overall correspondence between pollen variation amongst species of Podostemum and phylogenetic patterns.
Two species of a distinctive new genus of dinoflagellate cyst are described from the Early Cretaceous of northern Alberta, Canada. The genotype, Lopsidinium subrisum, comes from the Lower Albian Clearwater Formation, in wells drilled to extract the enormous heavy oil and bitumen resources of the Athabasca and Cold Lake Oil Sands areas, northeastern Alberta. The second species, Lopsidinium paxense, occurs in the Middle Albian, upper Loon River Formation exposed in the banks of the Peace River, northwestern Alberta. Lopsidinium subrisum occurs in assemblages of dinoflagellate cysts associated with brackish water and it is likely that L. paxense is derived from similar environments.
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