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RE: Horner's Pachy Lumpin' - Your Thoughts?



--- On Mon, 1/11/10, Michael Erickson <tehdinomahn@live.com> wrote:

> Don Ohmes wrote:

> > There may not be an extant analogue, but so what? Is
> > there a dinosaur that grew annual antler-analogs? Should we assume one
> > existed, just because we now have elk?

> That's a weak argument right there. [...] But anyway, I think that the 
> fact that no extant organism more derived than a fish seems to grow in 
> such a manner is a bit too weighty an argument to be cast off 
> automatically. [...] Why isn't it most parsimonious to conclude that 
> pachycephalosaurids did not grow in this manner, considering that no 
> extant reptile or bird does? 

Parsimony does not apply as you present it, because the _lack_ of an extant 
analogue is not relevant UNLESS you argue that the claims made for an extinct 
animal actually violate physical law(s), i.e., are physically impossible. 
Making the argument that a given process is impossible simply because no living 
animal is engaged in a similar process is fallacious on it's face. Hence the 
'reduction to absurdity' by using the lack of dinosaur-ian elk-analogue to 
reverse the time line...

Again -- I have no opinion on splitting/lumping, the existence and/or 
interpretation of the data, etc. I only point out that lifestyles that could 
lead to the evolution of a herbivorous and social critter that reduces it's 
headgear as it ages don't seem impossible or even relatively  unlikely, and 
that the lack of an extant functional analogue is not relevant data.

As to the validity of the specific 'patchy-rhinoid' data cited by Holtz and 
(iirc) Fowler I await further developments w/ some interest. 

> We actually have to get as basal as FISH before finding it, which is 
> still weird no matter how you slice it.

Heh. Nothing unusual about weirdness. It happens all the time.