This research assesses the impacts of climate change and relative sea level (RSL) fluctuations on coastal vegetation during the past 2000 years along the Mahanadi River delta, northeast coast of India. Sediment samples of a 2.6 m trench from Barhatubi area located in the lower flood plain of Mahanadi River delta were studied for sedimentological and pollen analysis. Mangrove succession can be divided into three zones: (1) Freshwater marsh (∼1980–1420 cal yr BP); (2) Tidal flat (∼1420–770 cal yr BP) and (3) Landward mangrove margin (∼770 cal yr BP-Present). A transgressive shift from floodplain freshwater marsh to a tidal flat is recorded between ∼1980–1420 cal yr BP which is evidenced by upland tree taxa, Poaceae, pteridophyte and fungal spores along with low percentage of mangroves such as Avicennia, Sonneratia and Rhizophora representing the landward edge of the tidal region. Dominance of Sonneratia and a decline in terrestrial taxa reflects a rise in the relative sea level around ∼1420 cal yr BP with less freshwater input from land suggesting a weakened monsoon condition. After ∼770 cal yr BP, an overall regressive phase with small cycles of relative sea level rise/fall has been observed due to the dominance of salt tolerant Avicennia along with Rhizophora, Excoecaria agallocha and Aegialitis rotundifolia alternating with Sonneratia and other marine palynomorphs.

New palynological studies from the Xiaoyangqiao section (Jilin Province, north-east China), which has been selected as an Auxiliary Boundary Stratigraphic Section and Point (ASSP) for the base of the Ordovician, confirms the presence of Goniomorpha Yin 1986 in intervals ranging from the late Cambrian (Furongian) to the Early Ordovician (Tremadocian), and allow us to clarify its morphology and affinities. Despite being compared originally to vesicular microfossils with processes arising from one pole, Goniomorpha lacks an enclosed cavity, so it cannot be classified as an acritarch in the strict sense. Instead, we find that the specimens originally described as Goniomorpha are actually part of a wider spectrum of morphologies that are identifiable as the pharyngeal teeth of priapulid worms. The best-preserved specimens resolve the ‘processes’ as denticles arising from an arch on the margins of a cuticular pad, sometimes with an extending spur and polygonal microstructure. Closely equivalent forms have been reported from Cambrian assemblages of small carbonaceous fossils (SCFs) and in situ on Burgess Shale specimens of the priapulid Ottoia. The findings from the Xiaoyangqiao section extend the taphonomic range of Cambrian-type SCFs into the Ordovician, and provide the first evidence for priapulids from the Ordovician of northern China. More generally, our results demonstrate the reciprocal insights from palynological and SCF-type processing for identifying problematic microfossils.

Bees of the genus Melipona found in the Amazon are investigated given their ecological, sociocultural and economic importance. The objective of this work was to analyze the scientific literature to recognize patterns in the richness of pollen types foraged by Melipona, comparing four methodological approaches. In the literature review, two databases were consulted: Web of Science (WoS) and the Scientific Electronic Library Online (SciELO). A record of 18 Melipona species investigated in 23 studies was found. These foraged 498 pollen types distributed in 88 botanical families. Many factors affect this richness. The main factor is the sampling time, which can influence other decisions. The highest richness estimates were found in the 12 month studies. The differences between the vegetation types reflect the patterns of diversity naturally found between them. Material from the meliponaries and bee corbels will result in a greater diversity of pollen types. Although there has been an increase in Melipona studies in the Amazon more effort is needed to fill the gaps in this vast territory.

In melissopalynological studies, the investigation of pollen composition in honey samples reveals the geographical and botanical origin of the samples and links them to the regional climatic conditions. Honeybees (Apis mellifera), collect pollen and nectar for their nutritional requirements based on the seasonal availability of surrounding flora. In this study, pollen content in honey was temporarily investigated for seasonal differences of the bee foraged plants. A melissopalynological investigation was applied to honey samples harvested from 13 beehives located in the Greater Kruger National Park, South Africa. Multivariate statistics (NMDS and Rarefaction curves) were used to show spatial and temporal clustering of the samples. The melissopalynological data were then compared to the species' flowering season and a botanical survey of the surrounding area. The turnover in pollen composition for different seasons signifies seasonal variation in pollen types. For example, during summer, bees foraged from fewer floral sources. The highest species richness was observed during winter, suggesting a higher dependence on a diversity of floral resources during the driest months. Various seasonal pollen spectra were characterised by a pollen turnover from numerous species, including Combretum type, Sclerocarya birrea, Poaceae, Harpephyllum caffrum and Lannea schweinfurthii but also neophytes such as Medicago sativa. Therefore, honey samples from the Lowveld region in South Africa reflected the seasonal patterns of the surrounding flora although pollen from taxa such as Combretum spp. (average 56%) and Sclerocarya birrea (average 14%) were continuously sought after by bees throughout the year.

This study presents the first palynological characterisation of the five endemic plant genera of the Madeira archipelago: Chamaemeles Lindl, Melanoselinum Hoffm., Monizia Lowe, Musschia Dumort and Sinapidendron Lowe. Pollen grain morphology of ten endemic species was studied using light and scanning electron microscopy techniques. The size and shape of pollen grains, the polar axis, the equatorial diameter, and the exine ornamentation were measured and described. We found that the pollen grains of the five endemic genera are all medium-size monads. The close relative apiaceous Melanoselinum and Monizia differ in polar (P) and equatorial (E) diameter size and exine ornamentation while Sinapidendron species show differences in P, E, and P/E ratios. The pollen grains of the two Musschia species are very similar to each other, but differ in morphology and ornamentation from the Macaronesian endemic bellflowers Azorina vidalii and Canarina canariensis. This study unveiled differences between the endemic taxa and with their close related species, thus providing support to previous taxonomic findings.

Fossil pollen and spores are a vital source of information on the geological history of tropical vegetation including reconstructions of vegetation diversity and composition. However, such work relies on a sound taxonomic framework, and this is challenging to achieve because of the large number of pollen and spore morphotypes that are encountered in palynological preparations from tropical sediments. In tropical West Africa, for example, extensive taxonomic work on Cretaceous–Paleogene pollen and spores was undertaken in the later part of the twentieth century, but more recent palynological work has focussed on stratigraphy and basin evolution, and there is a need for additional taxonomic work on the pollen and spores of this region. We have undertaken a descriptive systematic study of pollen and spores (sporomorphs) from 15 sediment samples spanning the Upper Palaeocene–Lower Eocene of south-eastern Nigeria. A palynoflora consisting of 29 spores, two gymnosperm pollen grains, and 138 angiosperm pollen grains is described. Two new spore species are proposed, and one new genus and 18 new species of angiosperm pollen are proposed. The general vegetation type represented by the palynoflora consists of palm-dominated swamps, perhaps with mangroves. The richness of each sample ranges from 29 to 76 sporomorph taxa, and rarefaction analysis suggests an increase in diversity from the Palaeocene to the Eocene in this region. Samples from the Palaeocene Upper Nsukka Formation are dominated by pollen with botanical affinities to the Arecaceae (palms) and Araceae (arums), and this assemblage is very similar to the Palaeocene in the Neotropics.

Pollen micromorphology and sporoderm ultrastructure of 10 species of the genus Gagea sensu lato (including Lloydia) were examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. The results showed variation in all quantitative characters of pollen micromorphology. In terms of qualitative characters, oblate pollen shape and two pollen types (medium and large) were seen. Exine ornamentation of the equatorial surface differed from that of the sulcus margin region. Intine ornamentation in the sulcus region was similar in all taxa. Furthermore, the situation of the furrow among cristates and granulates in muri differed, as did the lumina connections. The qualitative and quantitative characters of the pollen sporoderm, such as the presence or absence of endexine, number of intine layers in the sulcus region, and sporoderm thickness, also varied. A dendrogram of all qualitative and quantitative palynological characters, created by the unweighted pair group method with arithmetic mean (UPGMA) based on Euclidean distances, identified six pollen types. Palynological types strongly supported the transfer of Lloydia to Gagea. However, the palynological dendrogram did not support reducing the number of sections in these taxa. A dichotomous key is also presented based on pollen micromorphology and ultrastructure.

The present work documents the stratigraphic distribution of dinoflagellate cysts from the upper part (60–585 m) of the YPF.Ch. PV. es-1 borehole, Península Valdés, Argentina. The assemblages exhibit a relatively moderate to low diversity. Most samples are characterized by frequent to abundant taxa of the order Gonyaulacales, such as Spiniferites/Achomosphaera spp., Reticulatosphaera actinocoronata, Operculodinium centrocarpum, and Melitasphaeridium choanophorum. Furthermore, a continuous succession of Early Miocene–Late Miocene diagnostic dinoflagellate cyst events was recorded for the first time from the Península Valdés region. Eight diagnostic events of highest occurrences (HOs) of dinoflagellate cyst taxa are identified. These bioevents allowed a subdivision of the sedimentary succession into two well-defined stratigraphic sections: Early to Middle Miocene (Burdigalian–Langhian/probably Serravalian, 430/425–330/325 m) based on the HOs of Emmetrocysta urnaformis, Cannosphaeropsis quattrocchiae, Cousteaudinium auybriae, and Cleistosphaeridium ancyreum, and Late Miocene (Tortonian–Messinian, between 175–170 and 80/85 m) based on the HOs of Labyrinthodinium truncatum subsp. truncatum, Operculodinium piaseckii, and Reticulatosphaera actinocoronata. The ranges of these taxa are compared with well-documented information on Neogene dinoflagellate cysts recorded from different sites across the North and South Atlantic Ocean and adjacent seas. In general, the dinoflagellate cyst assemblages, as well as the selected diagnostic taxa, exhibit a clear similarity to those of the Northern Hemisphere. The only exception is Hystrichokolpoma rigaudiae, which is asynchronous, possibly indicating local paleoenvironmental conditions.

The Lashkarak Formation (Lower–Middle Ordovician) in the Gerdkuh locality, 10 km west of Damghan city, northern Iran, has been found to contain acritarchs and chitinozoans. This study aimed to understand these chitinozoan and acritarch successions as well as brachiopods in this part of the Alborz Mountains, in a novel manner. Ninety-seven surface samples from this succession were collected and analysed. Thirty samples yielded well-preserved palynomorph taxa such as acritarchs, chitinozoans, and scolecodonts, as well as graptolite remains. In total, 53 taxa were identified among the acritarchs (38 species belonging to 21 genera) and chitinozoans (15 species belonging to 10 genera). Although scolecodonts and graptolite remains were also observed, they were not studied in detail. The palynological analyses revealed the presence of several diagnostic acritarchs in the Lashkarak Formation, including Vulcanisphaera simplex, Arbusculidium filamentosum, Coryphidium bohemicum, Dactylofusa velifera, Striatotheca mutua, Arkonia virgata, and Orthosphaeridium ternatum. These acritarchs allowed the recognition of five acritarch assemblage zones. Similarly, seven chitinozoan biozones were recognised: Eremochitina brevis, Desmochitina ornensis, Belonechitina henryi, Cyathochitina protocalix, Cyathochitina calix, Siphonochitina formosa, and Laufeldochitina clavata. These findings confirm the inclusion of the Alborz Mountains in the peri-Gondwana palaeoprovince during the Early–Middle Ordovician. The co-occurrence of the acritarch and chitinozoan taxa with previously identified brachiopods allowed for the establishment of a more detailed Early–Middle Ordovician biozonation, demonstrating their potential usefulness for global chronostratigraphy. Based on palynological and brachiopod assemblages, a shallow marine inner shelf setting is suggested for the Early–Middle Ordovician at the Gerdkuh locality. Moreover, in this study, four new morphotype species were erected, consisting of one new chitinozoan (Cyathochitina gerdkuhensis sp. nov.) and three new acritarchs (Baltisphaeridium razii sp. nov., Navifusa alborzensis sp. nov., and Orthosphaeridium iranense sp. nov.). However, Othosphaeridium cf. ternatum was left in open nomenclature.

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Forest fragments in the Cerrado are areas of prominent biological importance due to their great species richness and biodiversity. These areas host endemic species of Celastraceae, the knowledge of which contributes to the preservation of this biome. This study aims to characterize the pollen morphology of 10 native species of Celastraceae found in forest fragments in the state of São Paulo, Brazil, contributing to the knowledge of the taxa for future taxonomic studies, and providing data for the conservation of the species in the forest areas. The pollen grains were acetolyzed, measured, described qualitatively and illustrated using light microscopy and scanning electron microscopy. The pollen characters referring to the pollen unit, polarity, type and number of apertures are similar in all the species studied. The shape, amb and exine ornamentation of pollen grains are the diagnostic qualitative morphological data for Celastraceae in this study. Microreticulate pollen grains were observed in Celastrus, Hippocratea and Pristimera; reticulate pollen grains with a very thick exine characterize the analyzed species of Plenckia; and reticulate and microreticulate ornamentation was observed among the species of Monteverdia. The results obtained here allow us to distinguish species of the analyzed genera and confirm the pollen diversity previously reported for Celastraceae.