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Re: Alamosaurus as biggest North American sauropod



Ok, I'll admit I overreacted, but I still think you make over-critical comments 
without having the background to back it up.


The main issues:

1. You think morphology is separate from ontogeny and stratigraphy. Through 
careful ontogenetic and stratigraphic work we are showing that it isn't, and it 
doesn't help others' understanding to keep pushing this claim. You can't just 
say that stratigraphy becomes irrelevant; that it is trumped by morphology. 
Taxonomic methods are based on description of morphology, but this system was 
designed for use in the extant world where time is a constant. In a 
stratigraphic section, you can step up a few hundred thousand years in only a 
few metres. We see morphology changing slowly and subtly as we move up or down 
in section. These changes are so gradual (or maybe our stratigraphic sampling 
is just getting pretty fine) that it makes defining separate morphospecies 
problematic. We are seeing shades of grey and trying to draw a line. Ontogeny 
presents similar problems. 


On Alamosaurus:

 
I asked whether Texas and Utah material can really be referred to Alamosaurus. 
Ultimately, we have a holotype scapula, and a selection of other isolated 
material from the type stratum: the Naashoibito of New Mexico. I suspect that 
the Naashoibito represents a shorter period of time than the Javelina or North 
Horn Fms, although right now I don't have any real evidence to back this up 
other than simple thickness differences... although there is some evidence that 
only one depositional sequence is present in the Naashoibito, whereas there 
appear to be at least two in the Javelina; assuming that sequence boundaries 
are conserved over such a huge distance, which is a big assumption. In 
formations which are well sampled (for dinosaurs) we see changes in morphology 
over this sort of stratigraphic distance (e.g. Hell Creek, Dinopark, JRF, 
2Med). In the postcrania we have for Alamosaurus, maybe this isn't discernible.

I still think it is most parsimonious to assign Naashoibiito sauropod material 
to Ala
more complete material down the line, and it turns out that the new specimens 
are indeed something different, then it's okay, they can have new labels made. 
I would prefer not to have the idea floating around that there is higher 
diversity in the Naashoibito than there is evidence for.






----------------------------------
Denver Fowler
df9465@yahoo.co.uk
http://www.denverfowler.com
-----------------------------------


----- Original Message -----
From: Jaime Headden <qi_leong@hotmail.com>
To: Denver Fowler <df9465@yahoo.co.uk>; Dinosaur Mailing List <dinosaur@usc.edu>
Cc: 
Sent: Thursday, 8 December 2011, 19:18
Subject: RE: Alamosaurus as biggest North American sauropod


  Wait, do I have to spend another whole post pointing out the _ad hominem_ 
characterizations, or will you just "get it" one of these days? Have I done 
something to you, injured you, or impaired or threatened your reputation? I am 
tired of this passive-aggressive crap. What level of professionalism and 
concern for communication do you have? My understanding at this point is that 
you refuse to be engaging on the topic and prefer to deconstruct the principle 
based on the author. Not one thing I wrote deal sin any manner with arguing YOU 
or anything YOU wrote is BAD, or WRONG. The point of the argumentation is to 
make a proposition for a thing, not to simply heckle or harangue because you 
find it amusing or you had a really bad day at work. That was the whole point 
of my last response to this ridiculous vitriol, up to and including the 
accusation I am apparently making "gobbledegook" or making up words (in this 
case, the use of "morphologic" is only
 unusual because it is not conventional, but it is grammatically correct, as if 
I were to be writing "characteristic feature" rather than "characteristical 
feature").

Cheers,

  Jaime A. Headden
  The Bite Stuff (site v2)
  http://qilong.wordpress.com/

"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 
Backs)


----------------------------------------
> Date: Fri, 9 Dec 2011 01:57:55 +0000
> From: df9465@yahoo.co.uk
> To: dinosaur@usc.edu
> Subject: Re: Alamosaurus as biggest North American sauropod
>
> ----- Original Message -----
>
> From: Jaime Headden <qi_leong@hotmail.com>
>
>
>  > The best strategy, in my opinion, is to simply do away with crap taxa.
>
> Well then, I look forward to your paper on the subject.
>
>  > I prefer the use of type specimen comparison over any other process so far 
>used to "assess" the _reasonableness_ of a "genus"'s validity, including but 
>not limited to ontogeny, stratigraphic and geographic distribution.
>
> Right. Pick one. Only idiots would try to assess all the available data.
>
> >Morphologic comparison, placed first and foremost, assures us that degree of 
> >unique features can affirm characters distinguishing organisms.
>
> It's common in your posts to see your writing descend into incomprehensible 
> gobbledegook when you are just making stuff up (sometimes, whole words). This 
> sentence makes no sense. how do you be assured of something in science? do 
> you now what hypothesis testing is?
>
>
> >At this point, ontogeny can only inform,
>
> inform what?
>
> > and stratigraphy and geography can only expand or reduce the range of the 
> > taxon, rather than provide real evidence to distinguish taxa in the absence 
> > of other data.
>
> I give up trying to figure out what you're saying here.
>
> > The weight of the latter points can increase with age and distance, such as 
> > a ceratopsian from the Oldman Formation (Alberta, Canada) and one from the 
> > Judith River Formation (Montana, USA) [ignoring the Two Medicine Formation 
> > for the moment as it is effectively an extension of the JRF]
>
> I am guessing that you don't actually understand what a clastic wedge is, or 
> how basin flexure affects deposition.. or in fact, very much at all outside 
> of taxonomy, but do go on...
>
> >; when the two are morphologically similar, enough so that features may be 
> >ontogenetically or individually variable when compared to the same range in 
> >other taxa, provenance and horizon are irrelevant.
>
> Nope. I am guessing you haven't actually studied ontogenetic and 
> stratigraphic effects on morphology. Or maybe you will surprise us all with 
> some insightful (self-pr
> h that you write.
>
>
> (I gave up on the rest of that paragraph as it was just garbage; hypothetical 
> made-up rubbish).
>
>
> >  As it is somewhat common to note, the holotype of *Alamosaurus 
> >sanjuanensis* is apparently based on a juvenile, and it lacks distinctive 
> >characteristics permitting it's segregation from other particular 
> >titanosaurs.
>
> Non-mature. I am generally uncomfortable with anything other than mature and 
> non-mature since people's interpretations of these terms vary, but we can say 
> juvenile (I probably do elsewhere). Further, body size variation is generally 
> undocumented in dinosaurs, such that relative size may not be a very reliable 
> indicator of relative age.
>
> Anyway, Wilson spoke about the holotype scapula at SVP2011. I think, if you 
> want to get to the bottom of this problem, answer this: are sauropod 
> specimens found in the North Horn and Javelina Formations (ie. outside of the 
> type stratum: the Naashoibito) referable to Alamosaurus using any kind of 
> parsimony?
>
>
> >As the lack of reasonably complete material for the taxon exists,
>
> Not really. if you think that the Texas and Utah material is referable then 
> there is quite a bit of material.
>
> >
 Cretaceous of southern Laramidia
>
> The super-giant biggest material yes, but smaller material is pretty common. 
> Which, if you read the press release, you would know.
>
> (Gave up again on the remaining convoluted text).
>
> I'll agree that maybe we should have written c.f. Alamosaurus in the paper, 
> but the text explains in detail the rationale behind the referral. Even 
> Wilson now agrees that there is no evidence for more than one taxon of 
> sauropod in the US SW.
>
> D.
>
> ----------------------------------
> Denver Fowler
> df9465@yahoo.co.uk
> http://www.denverfowler.com
> -----------------------------------
>
>
>
> Cheers,
>
>   Jaime A. Headden
>   The Bite Stuff (site v2)
>  http://qilong.wordpress.com/
>
> "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
>
>
> "Ever since man first left his cave and met
> fferent 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 
> Backs)
>
>
> ----------------------------------------
> > Date: Fri, 9 Dec 2011 11:25:23 +1100
> > From: tijawi@gmail.com
> > To: dinosaur@usc.edu
> > Subject: Re: Alamosaurus as biggest North American sauropod
> >
> > Matthew Martyniuk <martyniuk@gmail.com> wrote:
> >
> > > I don't see the issue with using parsimony. In fact I have kind of an
> > > issue when people don't use it. If the remains can't be differentiated
> > > from _A. sanjuanenis_, and there is no evidence to suggest multiple
> > > taxa were present in this environment, it should be considered _A.
> > > sanjuanenis_ until evidence to the contrary can be produced.
> >
> >
> > As a rule of thumb, this "rule" is unevenly applied. For example,
> > Carpenter and Tidwell (2004) referred all sauropod material from the
> > Arundel Formation to a single taxon. All the Arundel sauropod
> > material was consistent with the presence of a single species, which
> > took the name _Astrodon johnsoni_. In the process,
coelus
> > nanus_ and _P. altus_ were considered to be subjective junior synonyms
> > of _Astrodon johnsoni_, a taxon that was originally established on
> > material that is not diagnostic at the genus level (tooth + tooth
> > fragment).
> >
> >
> > On the other hand, Wilson and Upchurch (2003) did *not* combine
> > _Titanosaurus indicus_ and _Antarctosaurus septentrionalis_ into a
> > single taxon in their revision of the titanosaur material from the
> > 'Sauropod bed' of the Lameta Formation at Bara Simla. This was
> > despite the fact that this study found no reason to recognize more
> > than one species at Bara Simla. The Conclusion makes this clear:
> >
> >
> > "The discussion above, however, demonstrates that
> > Huene & Matley’s (1933) decision to separate the
> > ‘Sauropod bed’ specimens into several individuals
> > from two taxa is not supported by the available
> > evidence. It is possible that
> was
> > present, as originally suggested by Matley (1921).
> > Even if more than one individual is represented,
> > two or more taxa cannot yet be reliably distinguished.
> > However, although morphological and geological data
> > do not argue against the presence of a single species
> > at Bara Simla, there is simply no positive evidence
> > supporting this hypothesis."
> >
> >
> > Because _T. indicus_ was based on material (two caudal vertebrae) that
> > Wilson and Upchurch (2003) found to be non-diagnostic at the genus
> > level, these authors declared _T. indicus_ to be a nomen dubium. _A.
> > septentrionalis_ had been previously assigned its own genus
> > (_Jainosaurus_; Hunt et al., 1994), which was the name adopted by
> > later studies for the "valid" titanosaur from Bara Simla (e.g., Wilson
> > et al., 2009, 2011 - the latter study assigned additional titanosaur
> > material from a separate site [Chhota Simla] to _J. septentrionalis_
> > ). However, I'm confused as to why all the titanosaur material from
> > Bara Sima wasn't simply assigned to a single taxon that carried the
> > name _T. indicus_,
onalis_
> > (=_Antarctosaurus septentrionalis_) as a junior synonym.
> >
> >
> >
> >
> >
> >
> >
> > Cheers
> >
> > Tim