Is there a level of classification in fossil labeling below cf.?

[-Andy-]

Is there a level of classification in fossil labeling below cf.? E.g. I have a unidentified tooth similar to a tyrannosaurid, I'm not comfortable labeling it as cf. Tyrannosauridae indet. as it lacks diagnostic characteristics.

 

However, I think that's still a possible family due to its size and morphology. If I don't want to call it cf. Tyrannosauridae indet. or Theropoda indet., what can I label it as?

 

As I understand, the surety of classification goes from: Tyrannosauridae indet. > ? Tyrannosauridae indet. > cf. Tyrannosauridae indet.

 

Can I write something like:

 

Fossil tooth

Probably Tyrannosauridae indet.

66.8 - 66 Ma | late Cretaceous

Hell Creek Formation

Montana, USA

[Tidgy's Dad]

Cf. can indicate a great deal of uncertainty. It just means 'compare with'. It's up to the reader to decide upon the closeness of the relationship. 

[FossilDAWG]

I don't know that I agree that "cf" is the lowest level of "surety".  For example, "Isotelus cf. I. gigas" (Isotelus comparable to I. gigas) would (to me) mean "this is an Isotelus, and of all the described species it is most similar to and should be compared with Isotelus gigas".  I don't read "cf" as meaning "I don't have any diagnostic characters to use so I'm just taking a guess".  That would be either Isotelus ?gigas (definitely an Isotelus, guessing at gigas) or ?Isotelus gigas (no or hardly any diagnostic characters even to genus, so I'm guessing at the genus and species.  For example, suppose you find a broken fragment of a large smooth trilobite, so you don't have any genus or species level diagnostic features to go by.  However the only large smooth trilobite known from the formation you are collecting is Isotelus gigas.  In that case you might label it ?Isotelus gigas.  Also if you have a hunch but haven't had the time to research the taxonomy of trilobites in the area you are collecting, you could label it as ?Isotelus gigas as a "placeholder" until you get around to more detailed research.

 

In your example, I would read "cf Tyrannosauridae indet" as indicating enough diagnostic characters to suggest a comparison to Tyrannosauridae, either lacking some characters so as to make the ID uncertain, or having other characters that are incompatible with Tyrannosauridae.  ?Tyrannosauridae indet is, to my mind, indicative of a specimen that lacks diagnostic features, except maybe the most rudimentary.  For example, a worn tooth that is large but has the serrations, tip, and base completely eroded away could be called ?Tyrannosauridae" based only on the idea that there are not other known teeth of that size.

 

Don

[Troodon]

I think you are over thinking this.  In your example if its similiar to Tyrannosaurid then "Tyrannosaurid indet" works.  If its really unknown than "Theropod indet" is the proper designation.  I use cf when a species is described in a different formation but not the one my specimen comes and they look identical...for example Troodon teeth from the Hell Creek Fm should be described as "cf Troodon formosus".

[Harry Pristis]

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 [Estes], 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.