Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 5
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

In this study, two species belonging to the genus Allium and distributed in Turkey are investigated. A thick cuticle is observed on the epidermis of the scapes of the species. The epicuticular layer is not evident in Allium scorodoprasum ssp. rotundum (L.) Stearn. Secretory cavities have been formed in the pith region of the species. Vascular bundles are in the form of two rings, one above and one below the sclerenchymatic ring. The cross- section of the leaf of Allium brevicaule Boiss. & Balansa is circular, unlike A. scorodoprasum ssp. rotundum. In both species, the stomata are located lower than the epidermis cells. The seeds of A. brevicaule are smaller than in A. scorodoprasum ssp. rotundum and they are polygonal shaped. The testa cells of A. brevicaule seeds have scalariform and tuberculate ornamentation. A. scorodoprasum seeds have reticulate sculpture testa. The species have sulcate pollen types. The pollen form of A. brevicaule is perprolate, and that of A. scorodoprasum ssp. rotundum is subprolate. The apertures in both species are monosulcus. In A. brevicaule, the sulcus does not extend to the poles at the proximal end. Therefore, the differences in the scape and leaf anatomy, as well as in palynology and micromorphology, can be used to distinguish Allium species.
Go to article

Authors and Affiliations

Sibel Ulcay
1
ORCID: ORCID

  1. Kırşehir Ahi Evran University, Faculty of Agriculture, Department of Field Crops, Turkey
Download PDF Download RIS Download Bibtex

Abstract

Palynological investigation of the Vrabchov dol locality (Western Bulgaria) which recently yielded fragmentary dinosaur bones attributed to the clade Titanosauria, reveals well-preserved sporomorph assemblages dominated by angiosperm pollen from the Normapolles group, spores and rare gymnosperms. The age assessment of the studied sequence is based on the diagnostic Normapolles species, such as Oculopollis orbicularis Góczán, 1964, Oculopollis zaklinskaiae Góczán, 1964, Krutzschipollis spatiosus Góczán in Góczán et al., 1967 and Krutzschipollis crassus (Góczán, 1964) Góczán in Góczán et al., 1967. The concurrent presence of these pollen species suggests a late Santonian–early Campanian age for the succession. The sporomorph association is encountered in a palynofacies dominated by continental elements, including translucent phytoclasts (tissues, wood remains and plant cuticles). The sedimentary succession shows no evidence of marine elements and a very low proportion of AOM that attests to deposition within a lagoonal to foreshore marine environment, with high continental input and short transportation. The vegetation in the studied area was primarily composed of a range of Normapolles-producing angiosperms and secondarily of pteridophyte spore-producing plants. Gymnosperms were rare. Such a vegetation pattern reflects a warm, seasonally dry climate during the late Santonian–earliest Campanian in the studied area. The dinosaurs inhabited a wet lowland area, probably rich in herbaceous plants.

Go to article

Authors and Affiliations

Polina Pavlishina
Doche Dochev
Vladimir Nikolov
Marlena Yaneva
Ralitsa Konyovska
Download PDF Download RIS Download Bibtex

Abstract

Nothofagaceae fossil leaves and an associated palynoflora from Late Cretaceous sediments of Vega Island, eastern Antarctic Peninsula, are presented. The leaves are described as Nothofagus sp. 1 and Morphotype LDB 1, and come from the Snow Hill Island (late Campanian-early Maastrichtian) and the López de Bertodano (late Maastrichtian) formations, respectively. The palynoflora obtained from levels immediately above and below the Nothofagus sp. 1 and in the same horizon as the Morphotype LDB 1, included terrestrial and marine elements. In the palynoflora associated with Nothofagus sp. 1, conifers are dominant and pollen grains with Nothofagus affinity are represented by four species: Nothofagidites kaitangataensis (Te Punga) Romero 1973 and Nothofagidites senectus Dettmann and Playford 1968, which belong to the ancestral pollen type, as well as Nothofagidites dorotensis Romero 1973 and Nothofagidites sp. of the brassii-type. Cryptogamic spores, marine dinoflagellate cysts and algae, among others, are part of the assemblage. The palynoflora associated with the Morphotype LDB 1 also contains abundant conifer and angiosperm pollen grains with N. dorotensis as the only Nothofagus species recorded. Marine dinoflagellate cysts are scarce while fungi and phytodebris are common elements. The joint presence of marine and non-marine palynomorphs supports a probable nearshore environment at time of deposition for both units. Pollen and spore evidence suggests a mixed conifer and angiosperm forest, with Podocarpaceae and Nothofagus as the main components, and ferns, lycopods, and mosses in the understory. This forest developed under temperate and moist conditions during the middle Campanian-Maastrichtian.

Go to article

Authors and Affiliations

Edgardo Romero
Cecilia R. Amenábar
María C. Zamaloa
Andrea Concheyro
Download PDF Download RIS Download Bibtex

Abstract

The Lidfjellet thrust is the most prominent tectonic structure in the Lidfjellet-Řyrlandsodden fold zone, which stretches NNW-SSE along the western coast of Sřrkapp Land in Spitsbergen. This paper provides a reinterpretation of the Lidfjellet structure, with particular reference to lithostratigraphy of the autochthonous and overthrust sequences involved, and to the position of the thrust surface. Geological and palynologicalal data indicate that the sequence attributed previously to the Lower Cretaceous Helvetiafjellet Formation of the autochthonous cover represents in fact the Carboniferous (Viséan) Sergeijevfjellet Formation forming the lower part of the overthrust unit. The youngest deposits involved in tectonic structures of the Lidfjellet-Řyrlandsodden fold zone are of Upper Jurassic age.

Go to article

Authors and Affiliations

Krzysztof P. Krajewski
Marzena Stempień-Sałek
Download PDF Download RIS Download Bibtex

Abstract

Shallow−marine deposits of the Krabbedalen Formation (Kap Dalton Group) from Kap Brewster, central East Greenland, yielded rich dinoflagellate cyst and pollen− −spore assemblages. Previously, this formation yielded also rich mollusc and foraminifer age−diagnostic assemblages. A Lower Oligocene age of the Krabbedalen Formation seems to be supported by the dinoflagellate cyst assemblage analysis, while the pollen−spore as− semblages point to a wider stratigraphic age range within Oligocene–Middle Miocene.

Go to article

Authors and Affiliations

Krzysztof Birkenmajer
Przemysław Gedl
Elżbieta Worobiec

This page uses 'cookies'. Learn more