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Palynology is one of the most useful tools for constructing biostratigraphic charts in the late Paleozoic basins of South America, but the lack of radiometric ages often makes it difficult to establish the precise age of the biozones. This paper focuses on two points: (i) the description of new Argentinian palynological assemblages referred to the Lueckisporites/Weylandites (LW) Biozone and (ii) the application of a new isotopic age that enables more confident large-scale correlations with the neighboring Paraná Basin of Brazil. The palynofloras were recovered from the upper part of the De La Cuesta Formation that crops out in the retroarc basin of the Paganzo Basin, more specifically obtained from mudstones intercalated with limestones, cherts, and tuffs interpreted as being deposited in a shallow water body. The assemblages are characterized by an abundance of bi-taeniate pollen grains of the Lueckisporites complex and multitaeniate pollen grains such as Lunatisporites, Protohaploxypinus, Striatopodocarpidites, Tornopollenites, and Vittatina. Colpate pollen grains are also represented by Marsupipollenites and Pakhapites. A U-Pb CA-ID-TIMS age of 278.84 ± 0.22 Ma, obtained from a tuff level interstratified with the fossiliferous strata, allows the age of the LW Biozone in the Paganzo Basin to be constrained for the first time and the adjustment of the record Lueckisporites virkkiae in Gondwana. Moreover, this date enables precise correlations with other basins, such as the San Rafael Basin (Yacimiento Los Reyunos Formation) in Argentina and the Brazilian Paraná Basin (Iratí Formation).
The Neogene was a critical interval in the establishment of the modern geography and biotic composition of Amazonia. Because the region is covered with rainforest vegetation and lacks extensive outcrops, most of the understanding of its geological and evolutionary history relies on the study of rock cores. We studied the Miocene paleoenvironments and paleoclimate of borehole 1-AS-15-AM, drilled in western Amazonia, by analyzing the palynological content of 107 samples from the Solimões Formation. Graphic correlation indicates that the borehole spans palynological zones T13 to T16 (middle to late Miocene). We found 342 morphospecies of pollen and spores, including 280 angiosperm taxa and 62 pteridophyte taxa. Sixteen new species are described: 12 angiosperms and four pteridophytes. Pollen counts are dominated by elements associated with aquatic grasses, palms and ferns that can be associated with the Pebas ecosystem. We also found 11 morphospecies of dinoflagellate cysts and microforaminiferal linings between 115.4m and 118.95m that correlate with the middle Miocene marine flooding event of western Amazonia. Average Miocene temperature was estimated to be 24.9°C (min = 14.40, max = 27.30) while precipitation was 1946mm/y (min = 1,080, max = 3000), not significantly different from Holocene estimates.
Forty-seven rock samples from the stratotypes of three upper Paleogene formations – Prussian, Palvé, and Kurshskaya formations – were collected from the biggest amber deposit worldwide (Primorsky quarry, Kaliningrad Oblast SE Baltic coast), and have been palynologically analyzed. The presence of age-diagnostic dinoflagellate cyst species has allowed us to refine and update the previously questionable age of regional lithostratigraphical units. Based on the presence of Rhombodinium perforatum, the ‘Upper Wild Earth’ and ‘Upper Blue Earth’ members of the Prussian Formation correspond to the early Priabonian (Late Eocene) Rhombodinium perforatum Zone. The overlying ‘Upper Quicksand’ and ‘White Wall’ members of the Prussian Formation contain the key-species Thalassiphora reticulata, and are correlated with the latest Priabonian T. reticulata Zone. The overlying Palvé Fm (‘Green Wall’), comprises a dinoflagellate cyst assemblage very close to that recorded from the Prussian Formation, and also corresponds to the T. reticulata Zone, late Priabonian. The lower part of the Kurshskaya Formation – ‘Chocolate clays’ and lower ‘Brown sands’ members, contain an impoverished dinoflagellate cyst assemblages as a result of significant environmental changes. However, the common presence of Areosphaeridium diktyoplokum and Glaphyrocysta semitecta, along with an absence of early Oligocene key-species Wetzeliella gochtii or Chiropteridium galea, and pollen key-species Boehlensipollis hohli or Aglaoreidia cyclops, suggest the lower Kurshskaya Formation can be correlated with the uppermost Eocene, and very close to the Eocene/Oligocene boundary. Based on the revised stratigraphical ages presented here, we suggest an important regional marine transgression occurred during the Priabonian, which allowed the direct marine connection between the NW European Basin and Peri-Tethys via the Polish-Luthuanian Seaway. This was then followed by a regression at the end of Priabonian that culminated in a transition to continental sedimentation in the early Rupelian. A new dinoflagellate cyst species Oligokolpoma balticus sp. nov. is formally described.
A diverse and abundant organic-walled microphytoplankton assemblage is reported from two measured sections of the Lower Devonian (Lochkovian) Ross Formation in Benton and Decatur counties, Tennessee, USA. The palynoflora comprises 24 genera and 34 species of acritarchs, including one new genus and species (Caulissoma gordonii); and five genera and 11 species of prasinophyte phycomata (excluding Leiosphaeridia and Tasmanites). Other components include chitinozoans, miospores, and scolecodonts. This is the first Early Devonian acritarch/prasinophyte assemblage to be described from Tennessee, and it is assigned a Lochkovian age based on marine invertebrate faunas, stratigraphic relationships, and the palynomorph assemblage. A high degree of similarity (67% commonality) exists between this palynoflora and that from the stratigraphic and age-equivalent Haragan and Bois d'Arc formations of Oklahoma. Appreciable numbers of the microphytoplankton taxa identified herein are common to the Haragan and Bois d'Arc formations and are, moreover, restricted to the Lochkovian and endemic to Laurentia. Additionally, a number of species are widely distributed and confined to the Early Devonian, and three species, Demorhethium lappaceum, Riculasphaera fissa, and Thysanoprobolus polykion – all cosmopolitan – are constrained to the Lochkovian. With increasing knowledge of Early Devonian palynofloras, the apparent degree of provincialism is progressively declining as seemingly endemic taxa are reported from more regions in both hemispheres. The Ross Formation sediments were deposited in a low-energy, offshore, normal marine environment, punctuated by intermittent episodes of shallow-water current and storm deposition.
The acritarch Teleostomata rackii gen. et sp. nov. is described and illustrated from the Middle Devonian Skały Beds that outcrop at Miłoszów, Holy Cross Mountains, Poland. At the type locality, its stratigraphical range is within the ‘Geminospora’ extensa (Ex) Miospore Zone (= hemiansatus–varcus Conodont Zones), which correspond to the early and middle Givetian. The same acritarch has been illustrated from the Eifelian strata of the Gondwanan shelf in Tunisia, but it was unnamed at the time. This acritarch from Miłoszów can be distinguished from other phytoplankton genera of tetrahedral shape because of its broad processes with distal pore-like openings.
The family Vitaceae has a wide distribution, occurring in temperate, subtropical, and tropical climates. Vine members of the family thrive in different types of vegetation. Currently, the family includes five recognized tribes: Ampelopsideae, Cisseae, Cayratieae, Parthenocisseae, and Viteae. This study describes the pollen morphology of representatives of Ampelopsideae, Cayratieae, and Parthenocisseae. The other tribes are not described because they have been the subject of previous studies. The aim was to assess the relationships among the five tribes using multivariate analysis and to reconstruct the evolution of pollen characters using existing phylogenetic hypotheses. Specimens representing the three tribes were obtained from herbaria, treated by the acetolysis method, measured, photographed, and described using light and scanning electron microscopy. Results showed that pollen grains are medium (25–50 µm) in size, isopolar, tricolporate, and subprolate to prolate. Ornamentation varies between species. Multivariate analysis was based on quantitative characters, of which pollen diameters, apocolpium side, and polar area index were the most significant. Tracing of pollen characters showed that size, shape, and ornamentation are an evolutionary trend within the family. This investigation expands the palynological knowledge on representatives of Vitaceae tribes, contributing to future palynotaxonomic and evolutionary studies.
Honey farming is a young industry in Colombia, where it is gaining relevance as a source of jobs and food security, especially in post-conflict low-income communities that place bee colonies in native forests. Previous studies on the palynological composition of this honey are insufficient and the role of native plants for the production of honey is therefore unknown. Here we present a palynological analysis of honey produced by two bee species, the introduced Apis mellifera and the native Melipona eburnea, both commonly used by low-income communities in the eastern region of the Department of Antioquia, in the Central Cordillera of Colombia. We analyzed species richness and diversity of pollen, characterized some life history traits of those species preferred by bees, and estimated the interaction web between the bee and selected plant species. The overlap between the two species was very small. We found that the source of nectar for A. mellifera were plants with different growth habits, both native and introduced. Instead, M. eburnea used mostly native tree and shrub species, at a constant height level. Our results suggest that setting bee colonies of A. mellifera close to those of M. eburnea may not result in competition between them. However, it is key to evaluate whether this pattern is the same using other sources of food, such as pollen, or in other geographic regions.
Boraginaceae s.l., the single family of Boraginales, are extremely diverse in terms of morphology, and their species are well distributed in South America especially in Brazilian ecosystems. The pollen morphology of 11 Brazilian native species and four genera (Cordia L., Varronia P. Browne, Heliotropium L. and Myriopus Small) of Boraginaceae s.l. was investigated to expand the morphological knowledge of the species, contributing new data on the palynology, taxonomy, and conservation of the family. The pollen grains were acetolyzed, measured, photographed using light microscopy (LM) and scanning electron microscopy (SEM), and described qualitatively. The analyzed species present differences in size, shape, type and number of apertures (3-porate, 3-colpate, 3-colporate and heterocolpate) and exine ornamentation (psilate, echinate, microechinate-verrucate, reticulate and rugulate) of the pollen grains, allowing the species studied to be distinguished. Multivariate analysis of measurements confirms the qualitative description and pollen diversity in Cordiaceae species. Smaller diameter values and similarities in aperture and exine ornamentation characterize the Heliotropiaceae species. Our data reinforce the taxonomic importance of pollen morphology and of Boraginaceae s.l. as eurypalynous.
The Late Cretaceous and Paleogene strata of the Norwegian continental shelf are rich and diverse in dinoflagellate cysts. The assemblages are generally well-preserved, which allows high-resolution biostratigraphic studies and sometimes the identification of new species with chronostratigraphic significance. This paper proposes the formal description of eight new species from the Møre Basin, offshore Norway: Adnatosphaeridium tubulosum, Canningia crassimura, Canningia exilimura, Palaeohystrichophora elongata, Palaeoperidinium minusculatum, Senoniasphaera porosa, Trithyrodinium ioannidesii and Trithyrodinium verrucatum. The key diagnostic and morphological features of each species are discussed and compared with those of other forms outside and within the same genera. The new species presented here have been recognised in a stratigraphic interval ranging from the early Campanian to the early Danian; their occurrence can be used in conjunction with previously published markers to enhance the stratigraphic breakdown of wells across the region and wider offshore Northwest Europe.
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