Catalogue of Selected Angiosperm Pollen Grains from Palaeogene and Neogene Sediments of India

2020 ◽  
Author(s):  
Surya Kant Mani Tripathi
Keyword(s):  
Pollen Grains ◽  
Neogene Sediments ◽  
Angiosperm Pollen

scholarly journals The Nossa Senhora da Luz flora from the Early Cretaceous (early Aptian-late Albian) of Juncal in the western Portuguese Basin

2018 ◽  
Vol 58 (2) ◽  
pp. 159-174 ◽  
Author(s):  
Mário Miguel Mendes ◽  
Else Marie Friis
Keyword(s):  
Early Cretaceous ◽  
Pollen Grains ◽  
Fossil Flora ◽  
Spores And Pollen ◽  
Fossil Assemblage ◽  
Seasonally Dry ◽  
Palynological Assemblage ◽  
Conifer Seeds ◽  
Angiosperm Pollen ◽  
The Village

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.

Angiosperm pollen grains of San Just site (Escucha Formation) from the Albian of the Iberian Range (north-eastern Spain)

2010 ◽  
Vol 162 (3) ◽  
pp. 362-381 ◽  
Author(s):  
Uxue Villanueva-Amadoz ◽  
Denise Pons ◽  
José B. Diez ◽  
Javier Ferrer ◽  
Luis M. Sender
Keyword(s):  
Pollen Grains ◽  
Iberian Range ◽  
North Eastern ◽  
Angiosperm Pollen

scholarly journals Three-dimensional refractive index distributions of individual angiosperm pollen grains

2018 ◽  
Author(s):  
Chansuk Park ◽  
SangYun Lee ◽  
Geon Kim ◽  
SeungJun Lee ◽  
Jaehoon Lee ◽  
...  
Keyword(s):  
Refractive Index ◽  
Three Dimensional ◽  
Pollen Grains ◽  
Optical Diffraction ◽  
Diffraction Tomography ◽  
Optical Diffraction Tomography ◽  
Internal Structures ◽  
Quantitative Analyses ◽  
Angiosperm Pollen ◽  
Preparation Techniques

Three-dimensional (3D) refractive index (RI) imaging and quantitative analyses of angiosperm pollen grains are presented. Using optical diffraction tomography, the 3D RI structures of individual angiosperm pollen grains were measured without using labeling or other preparation techniques. Various physical quantities, including volume, surface area, exine volume, and sphericity, were determined from the measured RI tomograms of pollen grains. Exine skeletons, the distinct internal structures of angiosperm pollen grains, were identified and systematically analyzed.

On the polarity and tetrad arrangements in some mono- and diaperturate angiosperm pollen grains

Grana ◽  
1979 ◽  
Vol 18 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Sunirmal Chanda ◽  
Kalyani Ghosh ◽  
Siwert Nilsson
Keyword(s):  
Pollen Grains ◽  
Angiosperm Pollen

scholarly journals Why do leafcutter bees cut leaves? New insights into the early evolution of bees

2011 ◽  
Vol 278 (1724) ◽  
pp. 3593-3600 ◽  
Author(s):  
Jessica R. Litman ◽  
Bryan N. Danforth ◽  
Connal D. Eardley ◽  
Christophe J. Praz
Keyword(s):  
Pollen Grains ◽  
Ecological Niches ◽  
Evolutionary Constraints ◽  
Foreign Material ◽  
Larval Food ◽  
Key Innovation ◽  
The Family ◽  
Angiosperm Pollen ◽  
Cut Leaves ◽  
Key Innovations

Stark contrasts in clade species diversity are reported across the tree of life and are especially conspicuous when observed in closely related lineages. The explanation for such disparity has often been attributed to the evolution of key innovations that facilitate colonization of new ecological niches. The factors underlying diversification in bees remain poorly explored. Bees are thought to have originated from apoid wasps during the Mid-Cretaceous, a period that coincides with the appearance of angiosperm eudicot pollen grains in the fossil record. The reliance of bees on angiosperm pollen and their fundamental role as angiosperm pollinators have contributed to the idea that both groups may have undergone simultaneous radiations. We demonstrate that one key innovation—the inclusion of foreign material in nest construction—underlies both a massive range expansion and a significant increase in the rate of diversification within the second largest bee family, Megachilidae. Basal clades within the family are restricted to deserts and exhibit plesiomorphic features rarely observed among modern bees, but prevalent among apoid wasps. Our results suggest that early bees inherited a suite of behavioural traits that acted as powerful evolutionary constraints. While the transition to pollen as a larval food source opened an enormous ecological niche for the early bees, the exploitation of this niche and the subsequent diversification of bees only became possible after bees had evolved adaptations to overcome these constraints.

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