GEOSCAN, résultats de la recherche

Menu GEOSCAN


TitreIntroducing Pulcheripollenites sweetii in honour of the late Dr. A.R. Sweet, as part of a revised stratophenetic framework for Pulcheripollenites spp.
AuteurBell, K M
SourceThe 51st Annual Meeting of AASP-The Palynological Society and Annual General Meeting of the Canadian Association of Palynologists (CAP), programs and abstracts; 2018 p. 9
Année2018
Séries alt.Ressources naturelles Canada, Contribution externe 20180259
RéunionThe 51st Annual Meeting of AASP-The Palynological Society and Annual General Meeting of the Canadian Association of Palynologists (CAP); Calgary, AB; CA; août 5-10, 2018
Documentlivre
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
Sujetspaléontologie systématique; taxonomie; évolution; fossiles; biostratigraphie; morphologie des fossiles; Crétacé supérieur; Campanien; Maestrichtien; Formation d'Horseshoe Canyon ; paléontologie; stratigraphie; Phanérozoïque; Mésozoïque; Crétacé
ProgrammeBouclier à Selwyn du corridor de Mackenzie, GEM2 : La géocartographie de l'énergie et des minéraux
Diffusé2018 08 01
Résumé(disponible en anglais seulement)
When the genus Pulcheripollenites was first designated, three species attributed to this genus (P. inrasus, P. krempii and P. narcissus) were described from the lower part of the Horseshoe Canyon (formerly Edmonton) Formation of central Alberta (Srivastava, 1969). This genus was not recognized as having significant biostratigraphic value as all holotypes came from a single sample now considered to be of late Campanian age. Subsequent studies of Campanian and Maastrichtian strata from west-central Alberta, east-central Yukon Territory and west-central Northwest Territories reveals that the described species of Pulcheripollenites have distinct biostratigraphic ranges. The re-description of three existing species (P. inrasus, P. krempii and P. narcissus), the generic reassignment of a single species (P. pseudomagnificus), and the description of a new species (P. sweetii), along with the documentation of these five species over an extended stratigraphic interval, allows the recognition of biostratigraphic and stratophenetic trends within the Pulcheripollenites complex of species.
The upper age range of Pulcheripollenites has been established as being late Maastrichtian, with P. sweetii and P. pseudomagnificus both associated with assemblage 9 and P. sweetii also associated with assemblage 10 of Nichols and Sweet (1993). The lower age range of Pulcheripollenites in northern Canada is late Campanian with P. narcissus found in association with assemblage 6 taxa (Nichols and Sweet, 1993). Observed through the late Campanian and Maastrichtian are changes: 1) in the polar outline from sub-triangular, to rounded-triangular, to sub-circular; 2) in the equatorial outline from oblate to sub-circular; 3) in the aperture style from brevicolpate, to elongate and then equidimensional pores; 4) in the compound ectexinal sculpture from dominantly striate with prominent lirae and reduced interlirae muri to a more fine and even reticulation; 5) from a tectate margo bordering the colpi to an entirely intectate ectexine; 6) from a footlayer of approximately uniform thickness to one thickening towards and sometimes protruding at the aperture and; 7) in pollen grain diameter, with reduction in size through time. The recognition of these trends within Pulcheripollenites enhances the biostratigraphic utility of this genus in the upper Campanian and Maastrichtian of North America.
Résumé(Résumé en langage clair et simple, non publié)
La valeur biostratigraphique des espèces de pollen appartenant au genre Pulcheripollenites n'était pas reconnue auparavant. La redescription d'espèces existantes et la description d'une nouvelle espèce, ainsi que l'enregistrement d'informations les concernant sur un intervalle stratigraphique prolongé au Yukon et dans la partie centrale ouest des Territoires du Nord-Ouest, révèlent des tendances qui améliorent l'utilité de ce genre pour ce qui est d'établir la corrélation biostratigraphique relative au Crétacé tardif.
GEOSCAN ID312993