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Re: Titanoceratops, giant ceratopsian from New Mexico
----- Original Message ----
From: Jaime Headden <email@example.com>
> I haven't read Longrich's paper, and won't comment on it.
Well there you go. So are we destined to see an endless repeat of your
misreading of the Triceratops work then? I guess so.
>Your responses to said paper were in part due to the discussion on synonymy
>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.
No. my comments were to point out that in the paper you haven't read, the
subject is not discussed adequately, and that understanding ontogeny can
actually inform on why we see some of the character states exhibited by
> The paper has been criticised,[ ...]. I and other have commented on Horner's
>long-held "belief" [...]-- 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
>to the Campanian, one may get a sense that taxic reduction was _not_ so
>if present at all.
Garbage. There are less lineages present in the Hell Creek than in Campanian
units. That's a fact. Whether or not this is indication of slow deterioration
dinosauria towards the KT is up for debate, but you'd be hard-pressed to find
anyone who can demonstrate that immediately prior to the KT there are as many
hadrosaurs (multiple clades), nodosaurs, centrosaurines, etc than there were
the Campanian. Again, my strat work is trying to have some bearing on this in
the Hell Creek, but you know, it takes longer to write a paper than it does to
write a critical email.
> 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 sub
and this includes the proposed but as yet unpublished
stratigraphic argument which somehow (again, argued, pushed, but unpublished)
supports taxic reductionism in ceratopsians.
What is a "taste" issue? The strat work doesn't necessarily support taxic
reductionism (another made up term, which I presume means reduction in the
number of taxa). if you went to meetings you'd see where this line of research
is taking us: once you pull out the stratigraphic and ontogenetic signals, what
you;re left with is the taxonomic signal. You can only make it work the other
way round when you have a sample of 1 (when relative strat and ontogeny do not
matter, or at least not as much). I understand that this is a new way of
at taxonomy (or at least, mostly new to dinosaurs), but it yields advances in
understanding that cannot be achieved through morphology alone.
> 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)
Recognition of variation is the first step, understanding the origin and
significance of that variation is the next step. It could be that the variation
is pathologic, taphonomic, biogeographic, ontogenetic, stratigraphic, or
individual variation within a species. Once you have ruled out all of these
possibilities, you're left with either an unknown factor, or a genuinely
different taxon. Or you can ignore these other possibilities and just call it a
new taxon to begin with ("diversity first": 19th century science, and the
why we had 16 species of triceratops, which didn;t help us understand anything
much). Oversplitting only really helps to identify characters that vary. The
ss these in support of their -- again -- preconceived theory.
"preconceived theory": so if you come up with a hypothesis first which you then
propose to test, is this preconceived? do you actually understand how to
a scientific enquiry, or do you think every analysis starts out as a random
gathering that you hope to find some pattern in?
>Adding in the theory that stratigraphy can inform on taxonomy simply muddles
>mixture, as biostratigraphy continues to to run rampant in some circles while
>remains a statistical non-science.
Egads! Such ignorance!
> The difficulty here is that this completely ignores how taxonomic
>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.
You know... you should read Longrich's paper. you really should.
Current taxonomic practice has great difficulty dealing with morphology change
through time. We're at a point where this is critical, because we have a sample
of Triceratops (coupled with ontogenetic and strat data) that is about as large
as exists for any dinosaur. Adherence to an archaic way of treating taxa is
hindering our ability to understand them. The endless discussion of priority
on this list does nothing to advance understanding. Indeed, it retards
understanding of paleobiology by reducing down lineages (which are continuous
through time) into discrete little packages that only work when time is a
constant: in the fossil record it isn't. Even Hennig recognised this: he never
intended systematics to be used on fossils because the inherent problems with
the method create the very issues that get endlessly debated. And lets not get
started on how systematics deals with stasis and non-stasis. taxonomy and
systematics have great utility to a point, but we are now getting to the point
where datasets are good enough that these previously reliable methods
only reason I have been dogged about this topic and this particular issue
>is because ... I have yet to get a concrete response on this[...]. 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."
I disgaree with many people's research, but I wouldn't label them idiots. Read
Longrich's paper, then I expect to see another endless stream of criticisms
regarding his (proposed) sinkings without making species distinctions. Or you
might just ignore it because you really only want to pick at the same boring
criticisms of a few things that Jack wrote
> 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*
>*Triceratops latus* or *Triceratops horridus* or whatever.
You just don't get it. It's amazing. Maybe we couldn't tell to which species
different Toro specimens belong to without further data. Maybe this happened
because there are too many species already: oversplitting has a negative effect
this way. If you saw Scannella's talk at SVP, you'll see why we have these
taxonomic issues. For at least a little while, we're not going to see taxonomic
stability for all historically described morphologies of Triceratops. We've got
new specimens that are allowing us to decipher some of the described species
(ie, why do they seem to have a mixture of traits), but all the ICZN monster
manuals and latin/greek dictionaries in the world won't help you do this. You
need ontogenetic and stratigraphic data. This comes FIRST, not last, and that's
why the papers come in this order.