Palynodinium
Extinct genus of dinoflagellate cysts
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Palynodinium is an extinct genus of organic-walled dinoflagellate cyst (or dinocyst). It is a fossil species of dinoflagellate cyst used to demarcate the K/Pg boundary, which marks the terminal Cretaceous and the extinction of the dinosaurs.[1] Palynodinium grallator was among the microfossils which lead to the recent discovery of the K/Pg event record in marine sediments of the northeast Pacific.
| Palynodinium | |
|---|---|
| |
| Bright-field photomicrograph of Palynodinium grallator produced by Sandy McLachlan, University of Victoria from the Oyster Bay Formation of eastern Vancouver Island. | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Sar |
| Clade: | Alveolata |
| Division: | Dinoflagellata |
| Class: | Dinophyceae |
| Order: | Gonyaulacales |
| Family: | †Areoligeraceae |
| Genus: | †Palynodinium H.Gocht, 1970 |
Dinoflagellate cysts are estimated to be produced by 10–16% of living dinoflagellates[2][3] as a dormant, zygotic stage of their life cycle, which can accumulate in marine sediments as microfossils. Organic-walled dinoflagellate cysts are noted for their resistance to degradation owing to their composition of dinosporin, a biopolymer similar to sporopolinin characteristic of many terrestrial palynomorphs.[4][5] Their abundance, cosmopolitan distribution, and quality of preservation in the fossil record since the Middle Triassic[6][7] make dinoflagellate cysts excellent indicators of primary productivity[8][9] as well as tools for biostratigraphy and paleoenvironmental reconstructions.[10][11] The scope of dinoflagellate cyst applications has resulted in ongoing collaborative efforts between industry and academia to refine their taxonomic classification[12] and enhance their utility through database organization.[13]