Pentasters
A small number of dinoflagellates contain an internal skeleton. One of the best known species is perhaps Actiniscus pentasterias, in which each cell contains a pair of siliceous five-armed stars surrounding the nucleus. This species was originally described by Ehrenberg.[1] Although the description is incomplete and without illustrations, Ehrenberg described the skeletal elements but mentioned that the living cell was colorless and non-motile. Ehrenberg subsequently diagrammed the silicified skeletal elements (pentasters) from geological deposits in various parts of the world.[2] These can be found as microfossils. Pentasters were studied from the Cenozoic South Pacific by Dumitrică http://deepseadrilling.org/21/volume/dsdp21_25.pdf [3] Tappan [4] gave a survey of dinoflagellates with internal skeletons. This included the first detailed description of the pentasters in Actiniscus pentasterias, based on scanning electron microscopy.
The ultrastructure of Actiniscus pentasterias was investigated.[5]
References
- ^ Ehrenberg, C. G. 1841. Uber noch jetzt zahlreich lebende Tierarten der Kreidebildung und den Organismus der Polythalamien. Abh. K. Akad. Wiss. Berlin 1839:81-174, pls. 1-4.
- ^ Ehrenberg, C. G. 1854. Mikrogeologie das Erden und Feslen schaffende Wirken desunsichtbaren kleinen selbstandigen Lebens auf der Erde. Leopold Voss, Leipzig, 374 pp., pls. 1-40.
- ^ Dumitrică, P., 1973: Cenozoic endoskeletal dinoflagellates in southwestern Pacific sediments cored during Leg 21 of the DSDP. In: Burns, R.E. et al., Deep Sea Drilling Project, Washington, Initial Reports, v.21, p.819-835, pl.1-5.
- ^ Tappan, H. 1980. The Paleobiology of Plant Protists. Freeman and Company, San Francisco, 1028 pp.
- ^ Hansen, G. 1993. Light and Electron Microscopical Observations of the Dinoflagellate Actiniscus pentasterias (Dinophyceae). Journal of Phycology. 29, 486-499 (1 993)