Recent freshwater oscillatoriacean analogue of the Lower Palaeozoic calcareous alga Angulocellularia
Version of Record online: 9 OCT 2007
Volume 15, Issue 2, pages 105–114, July 1982
How to Cite
RIDING, R. and VORONOVA, L. (1982), Recent freshwater oscillatoriacean analogue of the Lower Palaeozoic calcareous alga Angulocellularia. Lethaia, 15: 105–114. doi: 10.1111/j.1502-3931.1982.tb01983.x
- Issue online: 9 OCT 2007
- Version of Record online: 9 OCT 2007
- 15th June, 1981.
- biostromes Early Cambrian;
- East Asia;
- North America
Recent freshwater cyanophyte oncoids from Canandaigua Lake, New York, consist almost entirely of minute irregular, bush-like, micritic masses comparable with the calcareous alga Angulocellularia Vologdin from Lower Cambrian algal-arehaeocyathan bioherms and biostromes of the Siberian Platform and western Mongolia. The Recent specimens arc radially orientated within the oncoids and occasionally contain moulds of axial filaments 15 μm in diameter. Acid-residues of the oncoids yield abundant Schizothrix calcicola. The micritic bush-like masses are interpreted to have formed by the calcification of the sheaths of these cyanophytes. This analogue allows Angulocellularia to be reinterpreted as a calcified oscillatoriacean cyanophyte, rather than a rhodophyte as previously suggested. It indicates that filamentous cyanophytes can produce apparently solid calcareous fossils, not only porostromatc tubes. The occurrence of Angulocellularia has been overlooked in some previous studies of Cambrian and Ordovician bioherms. The generic diagnosis is emended.