Re: Peters' analysis

[david peters <davidrpeters@earthlink.net>]

from Chris Bennett

Can't...... resist......  force!......;    must.....  reply!


> Chris Bennett wrote:
>
> As I discussed on this list back in 2001, my examination of
> Peters' analysis revealed many problems in interpretation and coding.
>
> >>>> A little vague. Name two.
>

CB wrote: When this came up in 2001 I wrote David Peters a three or four page
single-spaced letter in which I detailed problems in interpretation and
coding.  Peters should refer to that letter for more than two of each.  I do
not have the letter at hand but as for problems in interpretation I pointed
out Peters' interpretation of the fourth finger as hyperelongate on
Sharovipteryx and his interpretation of the sternal complex of [I think it
was] Cosesaurus, in which he rotated the sternum without justification so as
to make it look more like a basal pterosaur.  As for problems of coding, I
pointed out his multiple instances of recoding characters used by others
without any justification and his addition of soft tissue characters that
could not be coded for many taxa.


>>>>>>>  I'll go digging through my files. I would imagine that the sternal 
>>>>>>> complex issue you mentioned, though, would probably be better 
>>>>>>> attributed to Longisquama in which the sternal complex is 
>>>>>>> taphonomically rotated out of the traditional pterosaur position into 
>>>>>>> the traditional tetrapod condition. If, in my reconstruction, I 
>>>>>>> improperly rotated the sternal complex, then we have the issue of the 
>>>>>>> anteriorly projecting interclavicle being way out of place from its 
>>>>>>> traditional ventral mooring and a similar problem with sternae in the 
>>>>>>> throat. In support of the drifting sternal complex theory is the 
>>>>>>> observation that one set of scapula+coracoid is similarly anteriorly 
>>>>>>> displaced, though here a bit ventrally. 

In Cosesaurus nothing is out of place and the morphology shown here is a great 
precedent for what follows in Longisquama.  Laterally oriented clavicles, 
ventral keel. Hey, I was like you and the Jones+Ruben clade in accepting that 
the furcula in Longisquama was just like that in every other tetrapod. Thank 
good ness Rupert Wild came along to show how pterosaurs did their own thing. It 
gave me a model to test with Longisquama and doggone it, it worked better than 
the traditional interpretation. 

The hyperelongate finger of Sharovipteryx, or rather the tip of it, was noted 
by Sharov, but he did not know what it might belong to because of its proximity 
to the pelvis. The intervening portions are missing because the matrix is gone 
there. On the opposite side however, Sharov found the match after digging 
through the matrix in a small trench.

The soft tissue issue I assume refers to uropatagia, something that can only be 
coded for a few taxa because only a few taxa preserve it and/or have it. This 
one issue, though, certainly did not tip the scales. It was a landslide and the 
soft tissue was icing on the cake.


CB wrote: 
I do not see how attacking my interpretations in any way supports Peters'
methodology or interpretations.  It would be better if Peters would put his
effort into convincing people that his methodology is reliable and his
interpretations valid.

>>>>>>  Questioning the rationale behind your interpretations, Chris, is only 
>>>>>> designed to demonstrate that we're all prone to error, that your word is 
>>>>>> not gold, and that every scientist should question every other 
>>>>>> scientist's work. And that's a good thing!  If I made a mistake, I would 
>>>>>> want it aired out so that others don't follow.  If someone thinks I've 
>>>>>> made a mistake, I would want to hear about it to either defend it or fix 
>>>>>> it.

As I mentioned before, we're a bunch of testers here, not a bunch of believers. 
Just because I say something doesn't mean its true. It needs to be tested and 
defended. And the same goes for you and all the other experts. If your work 
holds up to testing, you're right and congratulations. If cracks appear, then 
the work needs to be torn down and rebuilt. I"m sure you would agree. The truth 
comes first. And emotions stay out of it.


>
> And on the same issue... is this a "press leak?" Aren't you two
> scientists bound to some sort of confidentiality agreement not to reveal
> the contents of papers you review or have access to prior to
> publication? If so, this makes incidence number two for you, Chris.
>

CB wrote:  I do not know what Peters is refering to as 'incident number one', 
but in
this case this is not a "press leak."  I have not reviewed the manuscipt in
question for any journal and my comments, which do not reveal any of the
substance of the manuscript, are based on conversations with the author.

At this moment I am holding the confidence of several colleagueswho have 
trusted me with drawings, photos, written work,  conversations, emails, etc. I 
wouldn't dare discuss even their existence in a public forum like this. 
Incident number one was when I sent you, in confidence, working drawings of 
Anurognathus for private contemplation and discussion.  Now it's on the web. 
But that's old news.

David