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Name derivation:
Classification:
Entophysalis Kützing 1843; 28 of 37 species descriptions have been accepted taxonomically (Guiry and Guiry 2013). Order Chroococcales; Family Entophysalidaceae
Morphology:
Gelatinous irregular colonies attached to substrate with cells in radial or erect rows, each with their own laminated envelope.
Similar genera:
Precambian prokaryotic fossil rcord and experimental silicification of modern analogues
Entophysalis has the capacity to bind sediment particles, forming stromatolitic ‘structures’ (Golubic and Hofmann 1976). Along with Prochloron and other coccoid prokaryotes, Entophysalis helped to debunk presence of eukaryotes in the Precambrian (~2 billion years ago). When living prokaryote cells were experimentally silicified with ethyl silicate, a process developed by Barghoorn for wood (Leo and Barghoorn 1976) they resembled fossil cells with ‘spots’ previously interpreted as nuclei (Francis et al. 1978).
Habitat:
Marine pools and rocky intertidal zones globally, less frequent in freshwater lakes. Have been found on terrestrial damp serpentine rocks in central Europe. (Guiry and Guiry 2013).
References:
Francis, S., E.S. Barghoorn and L. Margulis 1978. On the experimental silicification of microorganisms. III. Implications of the preservation of the green prokaryotic alga Prochloron and other coccoids for interpretation of the microbial fossil record. Precambrian Research 7:377-383. Golubic, S. and H.J. Hofmann 1976. Comparison of Holocene and mid-Precambrian entophysalidaceae (Cyanophyta) in stromatolitic algal mats: Cell division and degradation. Journal of Paleontology 50(6):1074-1082. Guiry, M.D. in Guiry, M.D. and G.M Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 04 February 2013. Kützing, F.T. 1843. Phycologia generalis oder Anatomie, Physiologie und Systemkunde der Tange... Mit 80 farbig gedruckten Tafeln, gezeichnet und gravirt vom Verfasser. pp. [part 1]: [i]-xxxii, [1]-142, [part 2:] 143-458, 1, err.], pls 1-80. Leipzig: F.A. Brockhaus. Leo, R.F. and E.S. Barghoorn 1976. Silicification of wood. Botanical Museum leaflets, Harvard University 25(1). [online]