A Tentative Identification
In the Journal of Vertebrate Paleontology, Vol. 7, No. 1, 19 March 1987, there is a note by Jiri Zidek concerning "...Syntax in Taxonomic Statements." There follows a response from Richard Estes.
Zidek argues (among other things) that "cf." and "aff." are synomymous. Estes disagrees.
Estes, the Editor of the JVP at the time, says the following:
Lucas (1987) also discussed the usage of the qualifiers aff. and cf., stating that "most vertebrate paleontologists understand the meanings of aff. and cf." My discussion with vertebrate paleontologists, and also my reading of their manuscripts, suggests that this may not be the case.
Zidek (1987) believed the two qualifiers to be interchangeable. If he is correct, one of them should probably be abandoned. I think that they often have, and should have, different meanings.
If I have a fossil element that does not differ structurally from that of a particular species, and also does not display diagnostic character states of that species or genus, I may wish to indicate this similarity in a structural sense (there may be stratagraphic and geographic reasons for this as well). The use of cf. in this case indicates a conservative identification, i.e. simply "to be compared with."
To me, the use of aff. indicates a greater degree of confidence. Perhaps I have a specimen that has most of the diagnostic character states of a taxon, or has one or two that differ very slightly, such that I have some minor doubts about referring it directly to that taxon. In this case I use aff. as an indication that I believe this specimen to be very close to the taxon concerned.
Obviously, there is intergradation in these two concepts. and it is certain that different workers will not apply it in exactly the same way. But if there is an attempt to follow such usage consistently, I believe that the author's degree of confidence in the identification is more accurately represented.
Because both [aff. and cf.] are an "alias for tentative identifications" (Zidek, 1987) information content may not be increased; again it is a matter of taste.
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© ©Harry Pristis
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