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S.B.Misra, Department of Geology, Memorial University of Newfoundland, St. Johnís, Newfoundland, Canada
Home > Earliest Papers > Anderson & Misra 1969
Nature, Vol. 223, No. 5210, p. 1076, 1969.
Criteria for Recognizing Pre-Cambrian Fossils
Anderson M.M. and MISRA S.B., (1969)
The use of these criteria is well illustrated by the work of Glaessner and Wad, who have carefully described the relationship of the South Australian Ediacara fossils to the overlying and underlying sediment. Wade3 has given an account of their preservation and by sectioning some of the material, she has been able to show just how individuals came to rest on the substrate, how they were entombed, and what happened to them as they decomposed and were fossilized. Obviously it is necessary to collect the sediment overlying the fossil as well that underlying it.
Anderson and Misra1 mention the doubtful Aspidella trerranovica Billings. This though common, is definitely inorganic. Sectioning shows that many specimens are water or gas-escape structures. Others are partly attributable to the manner in which the highly lithified clay and silt grade rock has parted along a changing stratigraphic level, particularly around load and scour structures.
Unfortunately, Anderson and Misra1 give no evidence for the organic origin of their structures and do not relate them to the underlying and overlying sediment. Although an organic origin cannot be disproved, their illustration does show striking resemblances to impressions of cone-in-cone structure.
Department of Geology
University of Reading
Received December 9, 1968, revised May 12, 1969
Anderson, M.M. and Misra, S.B., Nature, 220, 680 (1968)
Barghoorn, E.S., and Tyler, S.A., Science, 147, 563 (1965)
Wade, M., Lithaia, 1, 238(1968)
Schindewolf, O.H., in Geotecktonisches Symposium zu Ebren con Hans Stille (Ferdinand Enke
Verlag, Stuttgart, 1956)
Our communication1 did not describe new fossils from the Pre-Cambrian of Newfoundland but rather gave brief details of the presence of a metazoan fauna of this age, because our aim was to announce what we regard as an important discovery, and we indicated quite clearly that details of the fauna would be published elsewhere. We concentrated on the stratigraphical aspects of the fossil locality because it is essential to establish from the outset that the rocks containing them are in fact Pre-Cambrian and not Lower Palaeozoic or younger. It is true that we did not provide evidence of the organic origin of the structures interpreted as fossils, but we assumed, perhaps wrongly, that readers would await this information in the actual account of the fauna.
In view of the fact that the organic nature of these structures is discussed in a paper now in the press2, only a brief summary of the reasons for regarding them as organic will be given here:
M. M. Anderson
S. B. Misra
Department of Geology
Memorial University of Newfoundland,
St. John's, Newfoundland, Canada.
Received July 9, 1969