Re: Titanoceratops, giant ceratopsian from New Mexico

[Denver Fowler <df9465@yahoo.co.uk>]

what's the point of your post? You don't answer anything that I posted. I know 
you don;t seem to like the Toro=Trike hypothesis, but like many other people, 
you seem to think that diversity should be the default view. Why? You think 
parietal fenestrae are such a big deal? They are well demonstrated to open up 
in 
centrosaurines through ontogeny. Squamosal elongation is seen in all 
chasmosaurines through ontogeny, and has been in print for over 20 years. These 
are just the most obvious easy-answer ontogenetic changes: there are many more.

----- Original Message ----

From: Jaime Headden <qi_leong@hotmail.com>

>TL;DR: Two people arguing that "my taxon is unique, yours isn't" doesn't 
>promote 
>science.

Rubbish. A robust taxonomy is the fundamental underpinning to paleobiological 
interpretation: I don't agree that there are 3 ghost lineages of chasmosaurines 
present during Kirtland time: there is probably only one. this obviously has 
great importance in our interpretation of biodiversity and evolution. I don't 
care whether you have everything as a separate genus or not, it is the number 
of 
contemporaneous lineages that matters.

D





----------------------------------------
> Date: Thu, 30 Dec 2010 12:19:02 +0000
> From: df9465@yahoo.co.uk
> To: dinosaur@usc.edu
> Subject: Re: Titanoceratops, giant ceratopsian from New Mexico
>
> It's astonishing how many of "Titanoceratops"'s characters are known to vary
> (strongly) ontogenetically; I see no reason to split off the OMNH 
Pentaceratops
> into a new genus and species: it is entirely consistent with being a mature
> Pentaceratops. Should we be splitting up all the ceratopsid growth series into
> different taxa? They certainly have different morphologies, but then that's
> because animals change as they grow.
>
> I am coming ever closer to the view that we're going to see a schism in 
>dinosaur
> science; at least in ceratopsid workers, with one side splitting all 
>ontogenetic
> and stratigraphic morphs into different taxa, and the other studying 
>onto
time. Taxa are testable hypotheses using ontogenetic and
> stratigraphic data. if you are just using morphology, then it's a judgement
> call, and not much different from the way taxonomy was conducted 100 years 
ago.
>
> I can't see it is possible to continue with one side trying to convince the
> other: look at Longrich's discussion of Triceratops-Torosaurus. I hesitate to
> call Triceratops-Torosaurus a complex problem (I think it actually simplifies
> things), but Longrich goes into such little detail it feels very dismissive.
> Saying that there are no intermediates is absurd: we see nothing but
> intermediates with the squamosals and other parts of the skull. Why don't we
> find some parietals with tiny fenestrae (ie. intermediates)? because that's 
not
> how the fenestrae form, and if you read the papers and look at specimens, 
>you'll
> see it. New specimens are revealing more data on this; but be patient, we
> collected so many new Triceratops (with the essential strat data) it takes 
time
> to prep them all. It is much more parsimonious if Torosaurus is Triceratops: 
so
> many of the weird biogeographic and stratigraphic trends that we see fall into
> place.
>
> To be fair this paper was submitted before Scannella presented at SVP, and 
>other
> talks at SVP (including mine) show some of the conclusions here to be invalid.
> Triceratopsins in the Campani
> e my full critique of this paper for elsewhere.
>
> D.
>
> ----------------------------------
> Denver Fowler
> df9465@yahoo.co.uk
> http://www.denverfowler.com
> -----------------------------------
>
>
>
> ----- Original Message ----
> From: Tim Williams 
> To: dinosaur@usc.edu
> Sent: Thu, 30 December, 2010 4:09:52
> Subject: Re: Titanoceratops, giant ceratopsian from New Mexico
>
> > In case this new advance publication paper has not been mentioned yet:
> >
> > Nicholas R. Longrich (2010) Titanoceratops ouranous, a giant horned dinosaur
> >from the
> > Late Campanian of New Mexico. Cretaceous Research (advance online 
>publication)
> > doi:10.1016/
7
>
>
> There seems to be a discrepancy in the spelling of the species name
> between the title of the paper (ouranous) and the body of the paper
> (ouranos), with the former having an extra (and unnecessary) 'u'.
> Something to correct before final publication. BTW, the inspiration
> for the species name is Ouranos, the father of the Titans in Greek
> mythology. This is the same dude that gives his name to the planet
> Uranus. Apparently, the etymology is not the same as that of
> _Ouranosaurus_, which comes from the Tuareg name for monitor lizard
> ('ourane'), and is cognate with 'varanus'.
>
>
> Anyway, back to _Titanoceratops_ (cool name, IMHO). Aside from
> erecting a new genus for an erstwhile _Pentaceratops_ specimen, the
> paper puts forward a few more taxonomic changes vis-a-vis
> _Triceratops_. The referral of _Torosaurus_ to _Triceratops_ is
> explicitly rejected; a separate diagnosis is provided for each, and
> the "absence of intermediate forms argues that the two are not part of
> an ontogenetic series." On the other hand, _Nedoceratops_
> (=_Diceratops_) and _Ojoceratops_ are referred to _Triceratops_ as
> junior synonyms. For the latter: "the broad, squared-off end of the
> squamosal, putatively a diagnostic feature of â_Ojoceratops_â is
> approached by at least one specimen of _Triceratops_ (_Triceratops
> âserratusâ_, AMNH 970)." So I guess _Ojoceratops_ is the problem.
> more so t
> an _T. serratus_, which I assume is safe inside
> _Triceratops_. The status of another new genus, _Tatankaceratops_, is
> given as "problematic". It "preserves a bizarre mixture of characters
> seen in juvenile and adult _Triceratops_", so the specimen is either
> an aberrant _Triceratops_ that stopped growing before reaching full
> size, or a dwarf triceratopsin species. I wouldn't be surprised if
> more taxonomic convulsions are in stall for the Triceratopsini.
>
>
>
> Cheers
>
> Tim
>
>
>
>