Results 141 to 150 of about 1,358 (181)

British Cambrian acritarchs — A preliminary account

Review of Palaeobotany and Palynology, 1974
Abstract A brief characterization of acritarch assemblages from sequences of known Cambrian age is presented. Cambrian acritarch assemblages have great potential for zonation and long-range correlations.
openaire   +1 more source

The Ordovician acritarch Frankea:Some critical remarks

Geobios, 1997
Abstract The taxonomy of the acritarch genus Frankea Burmann , 1970 is clarified. Five species belong to thegenus: breviuscula, hamata, hamulata, longiuscula and sartbernardensis . Intraspecific variability is great, and it is difficult to distinguish the species sartbernardensis, breviuscula and longiuscula , which show a gradual increase
Oldrich Fatka, Stewart G. Molyneux, Thomas Servais   +2 more
openaire   +1 more source

Biogeography of upper Llandovery and Wenlock acritarchs

Review of Palaeobotany and Palynology, 1995
Abstract The world-wide spatial distribution of upper Llandovery and Wenlock acritarch microfloras is assessed using qualitative data, similarity indexes and cluster analysis. The database consists of comprehensive lists of taxa available essentially from eastern North America, South America, western Europe, Baltoscandia, Siberia, North Africa and ...
Alain Le Hérissé, Rémy Gourvennec
openaire   +1 more source

Clypeolus, A new acritarch genus from the Ordovician and Silurian

Review of Palaeobotany and Palynology, 1997
Clypeolus Miller, Playford et Le Hérissé, gen. nov. is established as a new acritarch genus based on C. tortugaides (Cramer) Miller, Playford et Le Hérissé, comb. nov. et emend. as the type species. The genus incorporates distinctly muronate vesicles that are shield-like or hemispherical and open equatorially, possibly resulting from an undetermined ...
Miller, Merrell A., Playford, Geoffrey, Le Hérissé, Alain   +2 more
openaire   +4 more sources

The Ordovician Arkonia-Striatotheca acritarch plexus

Review of Palaeobotany and Palynology, 1997
Abstract The original diagnoses, stratigraphical ranges and geographical distribution of all infrageneric taxa attributed to the genera Arkonia Burmann 1970 and Striatotheca Burmann 1970, are critically evaluated in a review of published literature supplemented by studies of new material from Belgium and Germany, including sections from type ...
openaire   +1 more source

Chapter 9.1 Neoproterozoic Acritarch Evolution

2009
Acritarchs are key for unravelling Neoproterozoic biodiversity changes because they represent the only fossil group occurring throughout the era. Their Neoproterozoic evolution is characterised by drastic diversity changes, which, coupled to the occurrence of taxa with restricted stratigraphic range, represents a powerful biostratigraphic tool for the ...
Claudio Gaucher, Peter Sprechmann
openaire   +1 more source

Tremadocian acritarchs from northwestern Argentina

Review of Palaeobotany and Palynology, 1997
Abstract A Tremadocian acritarch assemblage is described from the Santa Rosita Formation, Cordillera Oriental, Salta Province, northwestern Argentina. The microplankton corresponds to trilobite-bearing strata assigned to the lower to upper Tremadocian from the middle part of the Santa Rosita Formation.
openaire   +1 more source

Acritarchs

2011
Joachim Reitner, Volker Thiel
openaire   +2 more sources

Early Ordovician provincialism in acritarch distribution

Review of Palaeobotany and Palynology, 1997
Abstract Palynological evidence on the distribution of fossil marine microplankton corroborates presumed provincialism during the late Early Ordovician. Closely similar acritarch assemblages and other palynomorphs, namely cryptospores, were recovered from coeval sedimentary sequences within a sedimentary belt rimming the northern margin of Gondwana ...
openaire   +1 more source

acritarch, n.

2023
openaire   +1 more source