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Re: Abydosaurus mcintoshi, a new sauropod from the Albian of Utah

I'm not sure I understand what point Jaime is trying to make here, but
I will say this.  My paper noted 26 distinct osteological differences
between Brachiosaurus and Giraffatitan, and showed that of the
thirteen similarities proposed by Janensch, only four are valid
synapomorphies of Brachiosauridae.  Now I am not saying that means my
conclusion is cast-iron or can't be challenged.  But I do think it's
enough evidence to have shifted the null hypothesis -- so that anyone
who wants to challenge it really ought to make the effort to dig out
some actual evidence themselves.  What Chure et al. wrote -- "the
identified differences have not been defended as separating genera,
rather than species, populations, or individuals" -- really doesn't
advance the discussion at all.  It's an argument from laziness, and
all it does is muddy the waters (and perpetuate the discredited notion
that the Morrison and Tendaguru formations shared a fauna).

On a more positive note: I am delighted that a sauropod has, at last,
been named after John McIntosh.  (Yes, there was
Ultrasaurus/Ultrasauros macintoshi, but that is long dead.)  The guy
is an absolute legend: the comprehensiveness and insight of his
publications would be way impressive if they were the work of a
professional, but when you think that he did all that in his spare
time while being a high-energy physics professor at Yale, it's just
astonishing.  No-one has ever more richly deserved to have a sauropod
named after them.

On 24 February 2010 11:03, Jaime Headden <qi_leong@hotmail.com> wrote:
> Mike Taylor wrote:
> <The paper is open-access -- help yourselves! 
> http://www.springerlink.com/content/lpn30h8tx2231223/
> Truly awesome material (even if their brachiosaur taxonomy is misguided :-)>
> Another can of worms:
> Chure et al., page 1 of the digital, preprint paper:
> "Based on numerous differences between overlapping parts of both holotypes, 
> Taylor (2009) proposed that the African species should be known as 
> *Giraffatitan brancai.* While we are open to this possibility, we do not 
> believe that it is sufficiently justified at present because the identified 
> differences have not been defended as separating genera, rather than species, 
> populations, or individuals. The sister-taxon relationship between the two 
> species recovered in the phylogenetic analysis performed by Taylor (2009) 
> neither supports nor refutes their generic-level separation. At this point, 
> we consider the decision to recognize the African species as a
> genus apart to be arbitrary. We choose to retain the original nomenclature in 
> this contribution, distinguishing between the two species where appropriate."
>   It is nice to see a bunch of well-wrought paleontologists repeat what I 
> said when Taylor (2009) was published.
>   As the issue is taxonomic and not phylogenetic, the debate largely 
> influencing Taylor's change, being the lack of adequate use of *Brachiosaurus 
> altus* in the works of sauropod phylogenetics is the only point here worth 
> contending over. I would suggest supplementing analyses produced in the past 
> with separated codings to resolve the issue in an historical look, but so far 
> the most recent analysis to include both taxa separately even found them to 
> be sister taxa and that was Taylor (2009), and it did not separate the taxa 
> in a fashion that the nomenclature proposal of Paul would be useful.
> Cheers,
> Jaime A. Headden
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