Re: FW: Dracorex's phylogenetic position examined with science

[Tim Williams <twilliams_alpha@hotmail.com>]

Phil Bigelow wrote:

> But what is the harm in leaving a cladistic analysis *out* of this paper?

No harm at all.  However, both papers do draw some very firm conclusions 
regarding the polarity of certain pachycephalosaur characters ("primitive" 
vs "advanced"), and the relationships among pachycephalosaur taxa.  
Furthermore, in doing so, these papers dispute and overturn previous 
phylogenetic studies that were based on cladistic analyses.  For example, 
the work by Maryanska et al. (2004) is described as "seriously flawed" by 
Sullivan (2006).  Then there's this, from the Abstract of Bakker et al. 
(2006) ...

"_D. hogwartsia_ shows an unexpected mix of truly very primitive and very 
advanced features: no dome; wide open supratemporal fenestrae; large, spiked 
nodes on the squamosals; nodes of various
shapes and sizes covering the skull including the cheek and snout; and a 
very long snout and tooth row. ... Consequently, all previous phylogenetic 
analyses are considered inadequate."

> Only those papers that address evolutionary relationships as their *main* 
> thesis should be  required to do cladistic analyses.

The line "all previous phylogenetic analyses are considered inadequate" is a 
challenging statement, and it tells me that the authors very much had 
phylogeny on their minds.

> Taxonomists/ontologists/histologists/biostratigraphers should be allowed to 
> opt out of doing a cladistic analysis if they want to.

Reviewing the taxonomy of a group is one thing; but re-writing the entire 
evolutionary history of a group (and abolishing certain clades along the 
way) is a whole other thing.  Mickey's point (and I can't disagree) is that 
the latter might require more than just a few "key" characters.

Now, I want to make it clear this isn't about who is RIGHT and who is WRONG. 
 I sure don't know.  I found all the NMMNH pachycephalosaur papers 
extremely interesting and informative, and the figures were especially 
impressive.  I know from personal experience how much work goes into a 
paper, and how hard it can be to come up with good illustrations.  Also, it 
was nice to see little _Yaverlandia_ get mentioned; Darren Naish believes it 
to be a theropod (hmm.... maybe it's an abelisaur?)

> Let those who "do" cladistics as their specialty write their papers.  But 
> those who want to opt out of such a pursuit should be allowed to get into 
> print too.

Hey, no argument there.

Cheers

Tim