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re: Pterosaur origins again, Hone and Benton 2007



Which relevant taxa are missing, Dr. Unwin? 

Or are these the relevant pterosaur-y taxa you hope will be discovered soon? 

I know I'm preaching to the choir when I say: You do realize that sauropods 
nest closer to the birds than synapsids, crocodiles and Triceratops, so you 
don't really need a pterosaur-looking critter to nest pterosaurs precisely. 
Langobardisaurus will do. Cosesaurus will do. Heck, Iguana will do.

And now for a bipolar moment:

1. And your mention of a -supermatrix- that brings pterosaurs in line with 
Ornithodires sounds great! As long as squamates of some genus or another are 
included and we can dismiss that possibility once and for all. We're all 
looking forward to a head-to-toe account of character parsimony that exceeds 
all prior efforts. Does that also mean pterosaurs are also digitigrade 
occasional bipeds? -- joining digitigrade bipedal basal crocs and dinos? If so, 
isn't that a configuration problem? Also nice to know those tiny lateral 
fingers and toes will somehow become hypertrophied.

2. And your mention of a -supermatrix- that brings pterosaurs in line with 
Ornithodires brings shudders. Because typically a supermatrix is not the very 
large and inclusive original matrix one would hope for, but rather a 
combination of past published matrices -- NONE of which have included lizards 
-- specific lizards -- not the suprageneric "Lepidosaurs" that always score all 
zeros! For that matter, let's hope no suprageneric taxa are included in this 
-supermatrix- because therein lies many a fudge factor.

Dark days ahead, especially if the publication wheels are already rolling, as 
you infer. 

Let's hope Dr. Hone and Dr. Benton have included original figures this time, 
not silhouette tracings lifted from children's books. 

Let's hope they include a long list of character synapomorphies this time.

Let's hope they tie pterosaurs to a series of sequentially more distant genera 
this time. No more vague assertions, please.

Let's hope there will be fewer "serious questions" about other hypotheses, and 
more "positive statements" regarding their own novel findings and hypotheses. 
Having seen Hone's abstracts and this paper, all I've seen so far are the 
former, never the latter.

David Peters
St. Louis


-----Original Message-----
>From: "Unwin, Dr D.M." <dmu1@leicester.ac.uk>
>Sent: May 18, 2007 12:25 PM
>To: dinosaur@usc.edu
>Subject: Pterosaur origins again
>
>Dear All,
> 
>In reply to the various responses to yesterdays (May 17) post regarding 
>pterosaur origins.
> 
>I would agree that, at present, published accounts of attempts to discover the 
>relationships of pterosaurs to other diapsids are not entirely satisfactory 
>primarily because, for various reasons, they do not include all relevant taxa. 
>Dave Hone made a very creditable attempt to address this issue in his PhD 
>thesis (completed 2005), the first fruits of which are on display in the Hone 
>and Benton paper on pterosaur origins. Having waded through Dave's thesis I 
>can state that this is (very) far from all that Dave has to say on the subject 
>(hence the accidental reference to the 'supermatrix' in the Hone and Benton 
>paper) and as I understand it more will be published err long. I don't think 
>I'm letting any cats out of the bag by mentioning that in future papers Dave 
>will continue to conclude in favour of a home for pterosaurs among the 
>ornithodirans. Doubtless this will not be the last word on the subject, but I 
>predict that until one or more pterosaur-like beasties are found (and
>  whichever perspective, cladistic or otherwise, one cares to take, 
> Scleromochlus and Sharovipteryx don't really fit the bill, or should that be 
> 'have a bill to fit'?) a general concensus on pterosaur origins will remain 
> elusive. So, while we wait for something to turn up, lets get back to the 
> cricket. England are on 457 for 5, as I write (no Colin, I'm not making it 
> up), and Blowers is chuntering on about trains at Paddington station. Bliss.
> 
>The Omnipotent One