Dinocysts
Selected dinocysts and their occurrence in the geological past
Source: BGR
“Organic-walled dinoflagellate cysts”, or dinocysts, are formed by unicellular protists that have existed mainly in marine but also in fresh water environments from about 210 million years ago (Upper Triassic) up to the present day. Due to their short life span and the broad regional distribution patterns of specific species, this fossil group is highly relevant in view of the age dating of sediments.
As dinocysts are quite small (average size 0,05–0,1 mm), one smatchbox-sized sediment sample may contain many thousand specimen.
Due to the very resistant material of their organic wall, dinocysts are not destroyed by calcite dissolution. This characteristic is of special importance in carbonate-free sediments.
Dinocysts as well as pollen grains and spores are generally referred to as palynomorphs; the scientific generic term is palynology.
At BGR dinocysts are used for age dating (biostratigraphy) from Campanian to Pleistocene.
Dinocysts in the Cenozoic of Germany
Dinocysts are the most important microfossil group for age dating, because
The microfossil groups most important for international correlation (planktonic foraminifera, calcareous nannofossils and bolboforma) are only sporadically present in Germany. Besides relatively unfavourable ecological conditions (shallow water, fluctuating salinities, occasionally high terrigenous input), calcareous dissolution is mainly responsible for the absence of these organisms.
- Other microfossil groups, such as benthic foraminifera, only allow a rough biostratigraphic subdivision and correlation in north-western Europe. However, pollen and spores, ostracods and molluscs are of limited use for the international correlation of Cenozoic sediments. Dinocysts though are almost always present in sediments from Germany and north-western Europe.
Dinocysts allow a very detailed and precise age designation which can be easily fitted into the international geological time scale. Correlation of dinocyst zones with the international time scale and with calcareous nannoplankton zones (PDF, 33 KB)
The Stratigraphic distribution of more than 350 species of dinocysts in Paleogene and Miocene Germany (PDF) was published by Köthe&Piesker (2007).
References
Köthe, A. (2003): Dinozysten-Zonierung im Tertiär Norddeutschlands. – Revue Paléobiologie, 22(2): 895-923, 27 figures, 3 tables, 7 plates; Geneve.
Köthe, A. (2005): Korrelation der Dinozysten-Zonen mit anderen biostratigraphisch wichtigen Mikrofossilgruppen im Tertiär Norddeutschlands. – Revue Paléobiologie, 24(2): 697-718, 18 figures; Geneve.
Köthe, A. & Piesker, B. (2007): Stratigraphic distribution of Paleogene and Miocene dinocysts in Germany. – Revue Paléobiologie, 26(1): 1-39; Geneve.
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