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RE: Titanoceratops, giant ceratopsian from New Mexico
I haven't read Longrich's paper, and won't comment on it. Your responses to
said paper were in part due to the discussion on synonymy with ceratopsians,
which lead to discussion of the argument about the ontogeny you and others
(i.e., Horner et al.) remark on (in various venues) avidly. My arguments had
much to do with the perceived ontogeny (which you had mentioned in the post to
which I replied) being somehow consistent with a single lineage. This is an
extension, if not detailedly intertwined, with the Scannella and Horner paper,
which was only _partly_ based on histologic analysis.
The paper has been criticised, if not in print yet, largely due to the
assumption that if you create a histological lineage and compare it to a
created morphologic lineage, you will somehow have only one lineage (ignoring
the potential "monkey-wrench" in this theory that two distinct taxa may have
identical histological and morphological ontogenies). I and other have
commented on Horner's long-held "belief" --held at least as far back as "The
Complete T. rex" -- that end-Cretaceous dinosaur diversity was diminishing.
When you assess this "belief" in connection with nomenclatural practices
increasing the recognition of named taxa in the Maastrichtian relative to the
Campanian, one may get a sense that taxic reduction was _not_ so marked, if
present at all. Horner has argued against the catastrophic theory of the demise
of nonavian dinosaurs, and instead for a gradualistic termination. In seeming
keeping with this, reducing recognized nomenclatural entities would create a
perceived reduction in taxic diversity, and prompt Horner's theory to the fore.
Thus I would argue that this is a "preconcieved theory" predating the papers
that Horner has been a part of releasing attempting to support reasons for
Horner, Goodwin, Scannella and even Fowler may all be correct in the
ontogenetic schemes presented, and the histological analysis showing late-onset
"adult" morph in some of these taxa, but the question of the taxonomy which
these authors have debated hangs on a taste issue that is not subject for
scientific debate, and this includes the proposed but as yet unpublished
stratigraphic argument which somehow (again, argued, pushed, but unpublished)
supports taxic reductionism in ceratopsians.
These are besides the point. The authors themselves admit large margins for
disagreement when it comes to their theories of synonymies (Horner and Goodwin
indicated that the morphological differences between *Pachycephalosaurus* and
*Stygimoiloch* presented the largest room for debate in their proposal for
synonymy, while Scannella and Horner dismissed the small-bodied "adult" morphs
in their *Triceratops*/*Torosaurus* sample as "variation) but dismiss these in
support of their -- again -- preconceived theory. Adding in the theory that
stratigraphy can inform on taxonomy simply muddles the mixture, as
biostratigraphy continues to to run rampant in some circles while it remains a
This all leads in to a particular criticism of the Scannella and Horner paper:
"jeez. it was necessary to sink toro in triceratops before addressing the
species issue, which is separate, no matter how often you keep saying it isn't."
The difficulty here is that this completely ignores how taxonomic
condensation works. Simply having "Torosaurus is Triceratops" is meaningless
without an understanding that synonymy occurs in TWO different levels, and when
only one level is used, it leaves open the other option. For example,
A. _Generic synonymy_ simply means placing *Torosaurus latus* within a
container including also *Triceratops prorsus* and *Triceratops horridus*, and
using that containing name as *Triceratops* for all three species. However,
this leaves *Triceratops latus* as the correct name for the genus-species
couplet, and when only generic synonymy is considered (as it was in the
Scannella and Horner paper, as they disregarded the species issue entirely)
only generic synonymy should be argued.
B. _Specific synonymy_ means that you must merge two species into one
another, and make an explicit statement that this is so. In this case, the
authors could have placed *Torosaurus latus* into synonymy with either
*Triceratops prorsus* or *Triceratops horridus,* thus rendering *triceratops
latus* a junior synonym of either. Scannella and Horner did not do this, and
seem to have explicitly restricted themselves from doing this.
Because the issue is vague, the least problematic solution is to assume the
authors subsumed only the genus name, and yet it has been argued that they
subsumed the entire entity of *Torosaurus latus*, and conversation with Fowler
on this forum and elsewhere implies that _which_ species-level taxon this
subsumation was supposed to have included will be revealed later. As such,
*Triceratops latus* would still be the correct name. Now unless I miss my
guess, the authors do not contest the existence of either *prorsus* or
*horridus* as separate from one another, and as such they are distinct taxa.
When Scannella and Horner argue there was only _one_ late Maastrichtian
ceratopsian in the northern Great Plains, then they are "misspeaking" as what
they _really_ mean is that there is only one GENUS of late Maastrichtian
ceratopsian in the northern Great Plains.
But that's besides the point. Horner argues for taxic implosion, but keeps
distinct species of some of his "imploded" taxa. I can just as easily argue
that each of his species as recognized are, in fact, deserving of different
_generic_ labels. I can call one *Triceratops horridus*, another
*Triceratopoides prorsus* and a third *Torosaurus latus*. See how that works?
In short, unless you explicitly synonymize *Torosaurus latus* with a specific
taxon, *latus* is a distinct entity and will continue to tromp around; and
unless you manage to create a genericometer by which I can determine that only
one GENUS is really present, along with a method to determine --
scientifically, mind -- that only two species are present, I may still have
leisure to call *latus* by a name other than *Triceratops*, and the synonymy
argued by Scannella and Horner is meaningless.
The only reason I have been dogged about this topic and this particular issue
is because despite being as clear here, as on my blog, as over at Zach's site,
etc., I have yet to get a concrete response on this, and have stated this
precise conclusion to the quandary presented by Scannella and Horner. Instead,
it would be handled in a "future paper," which is idiotic: You do not argue a
synonymy, then state this synonymy will be explained later, and have that
original proposal "stick." So, until the paper that formalized synonymy _at the
species level_ is out, *Torosaurus latus* will remain as likely and viable a
name to use for *latus* as *Triceratops latus* or *Triceratops horridus* or
I hope this is either clear, or the repetition has made it more so.
Jaime A. Headden
The Bite Stuff (site v2)
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion
> Date: Thu, 30 Dec 2010 22:08:36 +0000
> From: firstname.lastname@example.org
> To: email@example.com
> Subject: Re: Titanoceratops, giant ceratopsian from New Mexico
> ----- Original Message ----
> From: Jaime Headden
> > My statements are consistent with a generalistic response to yours,
> > including
> >the theroies on the taxonomy of the "*Triceratops* complex" os "species" and
> >genus usage being employed by various authors. You are entirely incorrect
> >you assume that I "don't like the Tor=Trike hypothesis," as I've never said
> >anything of the sort. What I've argued, here and elsewhere, has dealt with
> >particulars of the argument, not the end result -- reiterating this gets
> >tiresome. It is not that difficult to "get" that an hypothesis can be wrong
> >if its result can be rightly conceived, as long as it is poorly arrived at in
> >the present. Similarly, the use of said hypothesis to judge the utility of
> >splitting or lumping taxonomy (one of the cruxes of a complex matter here) is
> >illogical, as one literally has nothing to do with the other.
> I have no idea what you're trying to say here.
> > My reply regarded specifically the issue of Scannella and Horner
> Right. When the thread is on titanoceratops, which you don;t seem to comment
> just a pet stab at the Trike-Toro paper.
> >...(and your support in their work, and your involvement in as-yet
> >work) follows previous condemnation of preconcieved lumping advocated by the
> >authors including the [hypothetical] *Pachycephalosaurus* implosion.
> "preconceived lumping"? it was based on histologic analysis. It may not be
> correct, but I feel that it is closer to the correct result than the previous
> state of affairs (see later)
> >That it is possible -- nay, likely -- for convergence to occur in close
> >is an issue for reconstruction of phylogeny, rather than presumptions of
> >phylogeny before the fact.
> Is it more "likely"? based on what statistics? based on what concept of
> speciation? Vrba's work? has that been shown conclusively to be the model for
> dinosaurs? Are there examples of closely related contemporaneous dino species
> that are convergent? How sure a
> > Making statements about how some features (such as the criticism leveled at
> > the
> >*Torosaurus*/*Triceratops* issue -- ignoring the *latus*/*prorsus*/*horridus*
> >problem horrifically ignored by various authors) are less meaningful (again,
> >both sides) shows that the debate is based on a pre-concieved, _a priori_
> >assumption of the end result, a lumping versus splitting mentality.
> jeez. it was necessary to sink toro in triceratops before addressing the
> issue, which is separate, no matter how often you keep saying it isn't. You
> we have a paper coming that sheds light on this issue. Simply put: this is the
> scientific process! Torosaurus = triceratops is a necessary logical step in
> order to solve other problems! As we learn more about the ontogeny and
> stratigraphy, so the various different morphs of triceratops make more sense.
> You seem to think it should all be in one paper, but the science didn't evolve
> that way. if you did any research yourself, you'd understand that key concepts
> lead to further understanding: it doesn't all come at once.
> > This has NOTHING to do with my personal thoughts on the existence of a
> separate "generic" entity called *Torosaurus* (which I've never stated in any
> forum, nor spoken to anyone on a personal level). This has to do with
> lumping/splitting -- and the presumption that stratigraphy has a splitter
> on species.
> What? stratigraphy has a splitter effect how?