[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Details on Capitalsaurus: Multiple musings....



Tom Lipka wrote-
 
> AFAIK a nomen vanum, an "empty name", is a name without a type specimen.
> Ornithodesmus has one, doesn't it?
 
Yes, BMNH R187.  Howse and Milner wrote
"The relative lengths of sacrals 5 and 6 serve to distinguish this sacrum from that of Saurornithoides, in which sacral 6 is the same length as sacral 5.  It is impossible to diagnose Ornithodesmus cluniculus with respect to any other troodontids, as no other genera are represented by sacral material.  Ornithodesmus cluniculus must be considered to be a nomen vanum (sensu Simpson 1945, p.27; Simpson 1948, p. 31; Mones 1989) within the family Troodontidae, as the holotype and only specimen is insufficient for comprehensive diagnosis."
Guess someone needs to find those Simpson and Mones references.
 
> No. This happens all the time. Who then, should be the final arbiter of a nomenclatural
> dispute? Authors working within the constructs of the ICZN and of course phylogenetic
> systematics are of course. The "proper" action was the exactly what we did.
> In fact, the subject of naming the tooth came up while we were working on the paper.
> AND despite all evidnce to the contrary we could have named it. But what purpose
> would it have served?
 
Oh, "authors working within the constructs of the ICZN and of course phylogenetic systematics" have every right to declare a taxon nomen dubium or contest such a verdict, but I don't think anyone should be able to say "the name you created shouldn't be used in the literature because it's presently recognized as indeterminate."  While naming a new taxon based on the supposedly indeterminate neoceratopsian teeth would have been a bad idea, I think having a sentence or two discussing Kranz's original identification of the tooth as a tenontosaur/dryosaurid that he termed "Magulodon muirkirkensis" would have been useful to readers.  But I'm not a reviewer, so it doesn't matter anymore.
 
> " The first arundel toooth to be found , USNM 33977, was tentatively named by Kranz (1996). > However, no more material besides the one other tooth has been identified, and the high
> amount of variability among neoceratopsian teeth casts doubt on the validity of the name. 
> According to Maryanska and Osmolska (1975, p. 162): "The shape of the protoceratopsid
> tooth and the number and character of the smaller , lateral ribs are variable even in the adult
> individuals and vary accordingly to the place which the tooth occupies in the jaw. For these
> reasons, we recommend that isolated protoceratopsid teeth should not be used as a basis for > the erection of new taxa."  Therefore we regard the name given to the original specimen as a > nomen dubium".
>
> Thus our analysis is based in empirical research and well grounded convention. And I might
> add, a 3rd tooth is in my posession as is a possible fourth!

Have you considered actually doing a thorough comparison to other neoceratopsian teeth?  Back in 1975, they were all just protoceratopsids and many genera weren't known yet.  Makovicky (2001) has over ten dental characters in his phylogenetic analysis of ceratopsians.  I have a feeling you would be able to pin down its relationships (_maybe_ even diagnose it) with such a comparison, even accounting for positional and ontogenetic variation.

> To paraphrase Tom, at least wait until more material comes out. ;-)
 
Oooh.... Sounds interesting.... :-)

> You seem to keep missing the point that by your invoking the new name that you have done > on this list, that (admittedly is a long shot) a possibility exists that that name is regarded as a > published diagnosis by "someone." Or it gets picked up and published in a hardcopy article
> somewhere. So even if you never intended to do so, and I believe you when you say that, the > possibility exists that it does in fact take root and hold.
> That is essentially all that I and others have been trying to say.
 
Okay.  Check. :-)  On the positive side, I couldn't find any apomorphies of "Beelemodon" when I wrote about it, and "Anabisetia" hasn't been illustrated yet.  I'll avoid diagnosing illustrated nomina nuda in the future.  And if it does happen to get published without my permission, at least there are worse people who could have diagnosed it. ;-)
 
>> how is that different from say... George Olshevsky naming Iguanodon exogirarum
>> Ponerosteus. 
> having not been on list for three + months and not keeping up with the (surprising) volume of
> email generated on this list since I have been back, I cannot venture a comment about what
> George allegedly has done. One thing though, G.O. is well versed in the ICZN and Cladistics > so he may have a strong reason for doing so. However, in keeping with my admonition about > naming names on this (or any) list, perhaps he should have not. Again, I don't know the facts.
 
Oh, he published it on paper.  See

>> Same situation, except at least "Capitalsaurus" is definitely not Creosaurus (or >Allosaurus >> or Dryptosaurus), while Ponerosteus seems to be a complete mystery.  >Does the ICZN
>> say anything about having to name a new genus for a species that >obviously doesn't
>> belong in the genus which it was described, and appears to >belong in no currently named >> genus?
>
> Huh?
 
Basically, "Iguanodon" exogirarum isn't Iguanodon, so was renamed Procerosaurus (which was preoccupied).  So George named it Ponerosteus to give it a valid genus name as opposed to leaving it "Iguanodon" exogirarum or "Procerosaurus" exogirarum.  Sounds similar to the "Capitalsaurus" situation to me.

> "Creosaurus potens," in my view, has priority (although still nomen dubium) and should be
> retained for historical reference only unless and until certifiably diagnostic material come to
> light by which time an entirely new name will likely be erected.
 
"Entirely new name"?  If we find more complete and easily diagnosable remains with identical proximal caudal centra (which are weakly diagnostic themselves), wouldn't it be better to call it >insert genus< potens?  I'd hate to see this turn into a Rapetosaurus situation, where Titanosaurus madagascariensis was based on caudals from two different species, so one is renamed Rapetosaurus krausei and other (taxon B) probably won't be called >insert genus< madagascariensis.  If it isn't, I'll be pissed.  We're supposed to preserve names, not kill them.
 
> I agree it's not Dryptosaurus nor Allosaurus because of the temporal paradox the names
> imply. But we really cannot determine what affinities this tailbone has with known taxa.
> What is a "Creosaurus"? And for that matter, what is a "Capitalsaurus"? What shared
> derived characters does this single bone posses to unite it with or separate it from other
> known taxa. What of the possibility of _pathology_ or preservation modification? None of > that has been considered.
 
I don't see how giving anything a valid genus name is supposed to reflect or be dependent on the taxon having a secure phylogenetic placement.  What is a "Capitalsaurus"?  If it were to be published, a large Arundel neotheropod with at least one opisthocoelous caudal centrum with a ventral keel and almost flat ventral profile.  Those separate it from known taxa, but caudal central characters are too homoplasious to use to unite it with other taxa.  While I suppose it's _possible_ that the centrum is distorted or pathologic, the only character I can picture this affecting is the width/height ratio.

> Here's what you are advocating....
> "Allosaurus medius"> "Creosaurus potens"> "Dryptosaurus potens"> and the Kranz name > which I won't use. (No offense) BTW, it is not Acrocanthosaurus either (much as I would > have liked)!
 
I never said anything about Allosaurus? medius.  That tooth hasn't been properly compared to Allosaurus, Acrocanthosaurus, etc. as far as I'm aware (though I'm sure you're working on it).  So yes- "Creosaurus" potens > "Dryptosaurus" potens > "Capitalsaurus" potens.
 
> It's a nomen nudum ("Creosaurus potens") and should properly be referred to as such
> although it will more likely be a n. dubium.
> See (Weishampel et al., 1990: The Dinosauria) p. 98
 
Isn't "Creosaurus" potens _definitely_ not a nomen nudum, as it has been described with a figure and diagnosis?  As an aside, I certainly don't trust the Dinosauria to be an accurate accessment of which taxa are nomina dubia (not that it isn't a fine compendium in other aspects).
 
> One last remark that needs to be made here. The whole Capitalsaurus thing arose in large > part for local _political_ reasons.
 
Oh yes.  That's quite obvious (the IMHO horrible name "Capitalsaurus" is proof enough), but aren't motives for naming taxa irrelevant?
 
Mickey Mortimer