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.

scholarly journals Fossil seeds from the La Cantera Formation, Early Cretaceous, San Luis Province, Argentina

2020 ◽  
pp. 181-198
Author(s):  
María A. Gómez ◽  
Gabriela G. Puebla ◽  
Mercedes B. Prámparo ◽  
Andrea B. Arcucci
Keyword(s):  
New Species ◽  
Early Cretaceous ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Fossil Flora ◽  
San Luis ◽  
Fossil Seeds ◽  
Dispersal Vectors ◽  
A New Species

In a study of fossil seeds recovered from the La Cantera Formation, Early Cretaceous, San Luis Basin, we establish a new species, Carpolithus volantus, and describe other specimens attributed to Carpolithus spp. and Ephedra canterata. The botanical affinity of winged seeds assigned to Carpolithus volantus is discussed in relation to the fossil flora recovered from this formation. Based on the abundance of Gnetales in the San Luis Basin (pollen grains, reproductive and vegetative structures assigned to Ephedra), we propose that Carpolithus volantus is affiliated with Gnetales (Weltwitschia). We suggest that Carpolithus spp. seeds may be angiospermous, because this group, represented by leaves and flowers, dominates the fossil macroflora of the La Cantera Formation. Micro- and macrofloral analyses of the La Cantera Formation and an assessment of available dispersal vectors suggests that wind (anemochory) and water (hydrochory) may have been the most important dispersal strategies for these seeds. The abundance and small size of seeds recovered from the La Cantera Formation, together with their morphological characters, such as the presence of wings in Carpolithus volantus, also favour abiotic mechanisms of dispersal such as anemochory or hydrochory.

scholarly journals Impact of mid Eocene greenhouse warming on America’s southernmost floras

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Damián A. Fernández ◽  
Luis Palazzesi ◽  
M. Sol González Estebenet ◽  
M. Cristina Tellería ◽  
Viviana D. Barreda
Keyword(s):  
Middle Eocene ◽  
Pollen Grains ◽  
Late Eocene ◽  
Significant Rise ◽  
Spores And Pollen ◽  
Deep Time ◽  
Nonparametric Estimators ◽  
Southern Patagonia ◽  
Marine Realm ◽  
High Diversity

AbstractA major climate shift took place about 40 Myr ago—the Middle Eocene Climatic Optimum or MECO—triggered by a significant rise of atmospheric CO2 concentrations. The biotic response to this MECO is well documented in the marine realm, but poorly explored in adjacent landmasses. Here, we quantify the response of the floras from America’s southernmost latitudes based on the analysis of terrestrially derived spores and pollen grains from the mid-late Eocene (~46–34 Myr) of southern Patagonia. Robust nonparametric estimators indicate that floras in southern Patagonia were in average ~40% more diverse during the MECO than pre-MECO and post-MECO intervals. The high atmospheric CO2 and increasing temperatures may have favored the combination of neotropical migrants with Gondwanan species, explaining in part the high diversity that we observed during the MECO. Our reconstructed biota reflects a greenhouse world and offers a climatic and ecological deep time scenario of an ice-free sub-Antarctic realm.

An inverse relationship between moisture and grazing intensity in an arid mountain-basin system

2021 ◽  
pp. 030913332110600
Author(s):  
Jun Zhang ◽  
Xiao-zhong Huang ◽  
Jia-le Wang ◽  
Richard HW Bradshaw ◽  
Tao Wang ◽  
...  
Keyword(s):  
Arid Region ◽  
Influencing Factor ◽  
Regional Climate ◽  
Fungal Spores ◽  
Grazing Intensity ◽  
Pollen Grains ◽  
High Mountains ◽  
Spores And Pollen ◽  
The North ◽  
Basin System

Precipitation has been suggested as a crucial influencing factor in the primary productivity in arid and semi-arid regions, yet how moisture fluctuation in an arid mountain-basin system of the north Qinghai–Tibetan Plateau has affected human activities is poorly understood. Here, we reconstruct the variations of grazing intensity in high elevations and regional humidity based on independent and high-resolution records of Sporormiella-type coprophilous fungal spores and pollen grains in the same well-dated sediment core from Lake Tian’E in the western Qilian Mountains over the past 3500 years. We find that stronger grazing activity was associated with low regional effective moisture, and propose that the drier regional climate pushed people and their livestock into the mountainous areas. A notable exception was a reduction of human and grazing activities in arid region with high mountains during 380–580 CE caused by centennial-length dry and cold conditions. In addition, it is also noteworthy that intensified grazing activity occurred during 580–720 CE and after ∼1920 CE, corresponding to a warmer and wetter climate and diverse subsistence strategies with social developments in the lowlands of the Hexi Corridor. Our findings potentially provide a historical reference for understanding how ancient people adapted to the climate change in arid region with high mountains.

scholarly journals The molecular structure of plant sporopollenin

2018 ◽  
Author(s):  
Fu-Shuang Li ◽  
Pyae Phyo ◽  
Joseph Jacobowitz ◽  
Mei Hong ◽  
Jing-Ke Weng
Keyword(s):  
Molecular Structure ◽  
Minor Component ◽  
Pollen Grains ◽  
Outer Wall ◽  
Land Plant ◽  
Spores And Pollen ◽  
Biomimetic Polymers ◽  
Wide Range ◽  
Nmr Techniques ◽  
A Minor

Sporopollenin is a ubiquitous and extremely chemically inert biopolymer that constitutes the outer wall of all land-plant spores and pollen grains. Sporopollenin protects the vulnerable plant gametes against a wide range of environmental assaults, and is considered as a prerequisite for the migration of early plants onto land. Despite its importance, the chemical structure of plant sporopollenin has remained elusive. Using a newly developed thioacidolysis degradative method together with state-of-the-art solid-state NMR techniques, we determined the detailed molecular structure of pine sporopollenin. We show that pine sporopollenin is primarily composed of aliphatic-polyketide-derived polyvinyl alcohol units and 7-O-p-coumaroylated C16 aliphatic units, crosslinked through a distinctive m-dioxane moiety featuring an acetal. Naringenin was also identified as a minor component of pine sporopollenin. This discovery answers the long-standing question about the chemical makeup of plant sporopollenin, laying the foundation for future investigations of sporopollenin biosynthesis and for design of new biomimetic polymers with desirable inert properties.

A LATE CRETACEOUS PLANT ASSEMBLAGE FROM EAST-CENTRAL BRITISH COLUMBIA: I, FOSSIL LEAVES

1967 ◽  
Vol 4 (6) ◽  
pp. 1185-1197 ◽  
Author(s):  
G. E. Rouse
Keyword(s):  
Pollen Grains ◽  
Rocky Mountain ◽  
The United States ◽  
Spores And Pollen ◽  
East Central ◽  
Mountain Ranges ◽  
Plant Assemblage ◽  
The Pacific ◽  
Fossil Leaves ◽  
The Pacific Ocean

Leaf compressions, spores, and pollen grains referrable to about 45 species were collected from a series of fine silts and coal stringers in the Parsnip River valley of the Rocky Mountain Trench. The leaf assemblage described in this paper indicates a late Maestrichtian to Danian age, somewhat younger than generally comparable assemblages previously reported from the lower part of the Edmonton Formation of Alberta, and from the Hell Creek, Lance, and Fox Hills Formations in the western interior of the United States. It also contains several species reported from the Nanaimo Group on eastern Vancouver Island. Plant microfossils (to be described in a later paper) include species of Glyptostrobus, Sciadopitys, Aquilapollenites, Pistillipollenites, Alnus, Myrica, Tilia, Pterocarya, and Carya, together with tricolpate pollen of uncertain affiliation. The combined leaf and microfossil assemblages indicate a warm mesothermal and humid paleoecological setting of low relief, suggesting absence of major mountain ranges westward to the Pacific Ocean.

scholarly journals SEM Investigation of Pollen Taxa in Honeys from Autochtone Apis cerana in Godavari, Lalitpur District, Nepal

2015 ◽  
Vol 26 ◽  
pp. 29-67 ◽  
Author(s):  
Khum Narayan Paudayal ◽  
Ishan Gautam
Keyword(s):  
Honey Bees ◽  
Apis Cerana ◽  
Pollen Grains ◽  
Species Level ◽  
Palynological Assemblage ◽  
Wide Range ◽  
Multifloral Honey ◽  
Plant Sources ◽  
Sem Investigation ◽  
Scanning Electron

Pollen analysis of 8 multifloral honey samples collected from 4 locations of Godavari, Lalitpur district, Nepal was performed using Scanning Electron Microscope (SEM). In this investigation, a wide range of foraging plant sources for Apis cerana honey bees was identified which demonstrates the adequate potential for expanding and sustaining beekeeping in this area. The palynological assemblage of a total of 44 species of pollen flora representing 28 families was identified to the generic and some up to species level. Some of the pollen grains identified to only families, belong to Acanthaceae, Apiaceae, Araliaceae, Chenopodiaceae, Compositae, Lamiaceae, Loranthaceae, Meliaceae, Poaceae, Rosaceae, Rutaceae and Pteridaceae. The pollen assemblages in honeys were mostly belonging to angiosperms while the gymnosperm pollen was completely absent. One pteridophyte spore belonging to family Pteridaceae recovered. In this paper the morphology of the pollen grains based on SEM observation are described and the importance of the systematic documentation of various bee flora are discussed.J. Nat. Hist. Mus. Vol. 26, 2012: 29-67

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