The angiosperm pollen Volkheimerites labyrinthus gen. et sp. nov. from the earliest Paleogene (Danian) of Patagonia, Argentina

Palynology ◽  
2021 ◽  
Author(s):  
Paula Liliana Narváez ◽  
Natalia Mego ◽  
Diego Gonzalo Silva Nieto ◽  
Mercedes Beatriz Prámparo ◽  
Nora Graciela Cabaleri
Keyword(s):  
Palynology ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 608-620 ◽  
Author(s):  
Sophie Warny ◽  
David M. Jarzen ◽  
Shannon J. Haynes ◽  
Kenneth G. MacLeod ◽  
Brian T. Huber

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 171-183 ◽  
Author(s):  
E. Schrank

The Tendaguru Beds, southeastern Tanzania, have yielded two palynological assemblages of Kimmeridgian to Tithonian age: (1) the <i>Anapiculatisporites-Densoisporites-Trisaccites</i> assemblage from the Middle Saurian Beds and (2) the <i>Barbatacysta-Pareodinia</i> assemblage from the overlying <i>Smeei</i> Beds. A third assemblage with <i>Rhizophagites</i> and rare angiosperm pollen from the Upper Saurian Beds is contaminated by recent and subrecent material. <br><br> The <i>Anapiculatisporites-Densoisporites-Trisaccites</i> assemblage is characterized by the presence of freshwater algae (<i>Ovoidites</i>), pteridopyhtic-bryophytic spores and gymnosperm (conifer) pollen, with <i>Classopollis</i> as the most abundant element. Among the rare elements of this assemblage is the questionable dinoflagellate <i>Mendicodinium</i>? <i>quadratum</i>, possibly a Kimmeridgian-Tithonian marker. The miospores show palaeobiogeographic links to Southern Gondwana, especially Madagascar, Australia, Argentina and India. Deposition of this assemblage took place in an aquatic environment with strong palynological influx from a terrestrial source and questionable marine influence. <br><br> The <i>Barbatacysta-Pareodinia</i> assemblage contains a considerable number of dinoflagellates suggesting deposition in a marine environment. The terrestrially-derived miospores are impoverished and dominated by conifer pollen, while pteridophytic-bryophytic spores form a very subordinate element or are absent. <br><br> Die Tendaguru-Schichten, Südost-Tansania, haben zwei palynologische Assoziationen, deren Alter als Kimmeridge bis Tithon interpretiert wird, geliefert. Die <i>Anapiculatisporites-Densoisporites-Trisaccites</i>-Assoziation stammt aus den Mittleren Saurierschichten, und die <i>Barbatacysta-Pareodinia</i>-Assoziation charakterisiert die darüberlagernden <i>Smeei</i>-Schichten. Eine dritte Vergesellschaftung mit <i>Rhizophagites</i> und seltenen Angiospermen-Pollen aus den Oberen Saurierschichten ist durch rezentes bis subrezentes Material kontaminiert. <br><br> Die <i>Anapiculatisporites-Densoisporites-Trisaccites</i>-Assoziation ist durch die Anwesenheit von Süßwasser-Algen (<i>Ovoidites</i>), Pteridophyten-Bryophyten-Sporen und Gymnospermen-Pollen (Koniferen) gekennzeichnet mit <i>Classopollis</i> als dem häufigsten Element. Zu den seltenen Elementen dieser Assoziation gehört der fragliche Dinoflagellat <i>Mendicodinium</i>? <i>quadratum</i>, der möglicherweise als leitend für das Kimmeridge-Tithon angesehen werden kann. Die Miosporen zeigen paläobiogeographische Verbindungen nach Südgondwana, besonders nach Madagaskar, Australien, Argentinien und Indien. Das Ablagerungsmilieu dieser Assoziation war aquatisch mit starker Zufuhr von terrigenem Material, während mariner Einfluß fraglich ist. <br><br> Die Dinoflagellaten-führende <i>Barbatacysta-Pareodinia</i>-Assoziation wurde in einem marinen Milieu gebildet, in dem die Zufuhr terrigener Palynomorphe reduziert und im wesentlichen auf Koniferen-Pollen beschränkt war, während Pteridophyten-Bryophyten-Sporen nur sehr untergeordnet vorkommen oder ganz fehlen. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.1999.4860020113" target="_blank">10.1002/mmng.1999.4860020113</a>


2018 ◽  
Vol 58 (2) ◽  
pp. 159-174 ◽  
Author(s):  
Mário Miguel Mendes ◽  
Else Marie Friis

AbstractA new fossil flora is described from the Early Cretaceous of the western Portuguese Basin, based on a combined palynological-mesofossil study. The fossil specimens were extracted from samples collected in the Nossa Senhora da Luz opencast clay pit complex near the village of Juncal in the Estremadura region. The plant-bearing sediments belong to the Famalicão Member of the Figueira da Foz Formation, considered late Aptianearly Albian in age. The palynological assemblage is diverse, including 588 spores and pollen grains assigned to 30 genera and 48 species. The palynoflora is dominated by fern spores and conifer pollen. Angiosperm pollen is also present, but subordinate. The mesofossil flora is less diverse, including 175 specimens ascribed to 17 species, and is dominated by angiosperm fruits and seeds. The mesofossil flora also contains conifer seeds and twigs as well as fossils with selaginellaceous affinity. The fossil assemblage indicates a warm and seasonally dry climate for the Nossa Senhora da Luz flora.


1990 ◽  
Vol 3 (3) ◽  
Author(s):  
J. Heslop-Harrison ◽  
Y. Heslop-Harrison

2018 ◽  
Vol 103 (1) ◽  
pp. 106-161 ◽  
Author(s):  
Ying Yu ◽  
Alexandra H. Wortley ◽  
Lu Lu ◽  
De-Zhu Li ◽  
Hong Wang ◽  
...  
Keyword(s):  

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Miyuki Nakamura ◽  
Claudia Köhler ◽  
Lars Hennig

Abstract Background Small RNAs (sRNAs) are regulatory molecules impacting on gene expression and transposon activity. MicroRNAs (miRNAs) are responsible for tissue-specific and environmentally-induced gene repression. Short interfering RNAs (siRNA) are constitutively involved in transposon silencing across different type of tissues. The male gametophyte in angiosperms has a unique set of sRNAs compared to vegetative tissues, including phased siRNAs from intergenic or genic regions, or epigenetically activated siRNAs. This is contrasted by a lack of knowledge about the sRNA profile of the male gametophyte of gymnosperms. Results Here, we isolated mature pollen from male cones of Norway spruce and investigated its sRNA profiles. While 21-nt sRNAs is the major size class of sRNAs in needles, in pollen 21-nt and 24-nt sRNAs are the most abundant size classes. Although the 24-nt sRNAs were exclusively derived from TEs in pollen, both 21-nt and 24-nt sRNAs were associated with TEs. We also investigated sRNAs from somatic embryonic callus, which has been reported to contain 24-nt sRNAs. Our data show that the 24-nt sRNA profiles are tissue-specific and differ between pollen and cell culture. Conclusion Our data reveal that gymnosperm pollen, like angiosperm pollen, has a unique sRNA profile, differing from vegetative leaf tissue. Thus, our results reveal that angiosperm and gymnosperm pollen produce new size classes not present in vegetative tissues; while in angiosperm pollen 21-nt sRNAs are generated, in the gymnosperm Norway spruce 24-nt sRNAs are generated. The tissue-specific production of distinct TE-derived sRNAs in angiosperms and gymnosperms provides insights into the diversification process of sRNAs in TE silencing pathways between the two groups of seed plants.


1990 ◽  
Vol 45 (11-12) ◽  
pp. 1090-1092 ◽  
Author(s):  
Susanne Hagenberg ◽  
Klaus Wehling ◽  
Rolf Wiermann

Abstract The surface waxes of several gymnosperm and angiosperm pollen were separated into different lipid classes. n-Alkanes were found to be common constituents of these waxes. They appeared as a homologous series ranging from C20 to C33. The distribution patterns of n-alkanes from gymnosperm pollen displayed little variation whereas those of angiosperm pollen exhib­ited pronounced differences from one another. It is noteworthy that especially for the gymno­sperm species, homologues with even and odd numbers of carbons occurred in similar amounts.


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