Benton 1985, etc.

[David Peters <davidrpeters@earthlink.net>]

Okay, David, sure more taxa is better than fewer taxa. That goes  
without saying.
Still, if all you want to do is find out if pteros are closer to one  
taxon or another, you can find out with a dozen of each. Or five if  
you want to get down and dirty.

For an outgroup, be safe. Try Ichthyostega.

I've also checked matrices for miscodings: Irmis et al. 2007 and Hill  
2005. It's daunting, but it can be done. You asked about time put in?  
10 years with time out for meals, sleeping, etc. It's fun, so the  
work goes fast.

re: Atanassov's thesis: indeed he has a close sister taxon to the  
Pterosauria. It is a langobardisaur, one of the taxa I employed in my  
2000 paper.

re: Triassic pterosaur with parasagittal hind limbs: more common than  
you might realize.

re: pteros next to the Archosauromorpha. Well, lots of interest  
there. Benton 1985 nests pterosaurs between Lepidosauria and  
Trilophosaurus + Rhynchosaurs + Prolacertiformes + Archosauriformes.  
With Trilophosaurus and Rhynchosaurs actually closer to  
Lepidosauriformes (they are Rhynchocephalians with unfused ankles)  
than Archosauriformes, that's a very good nesting. Prolacerta is  
close to the base of the Archosauriformes, so that also makes sense.  
The attraction of Macrocnemus to tanystropheids also makes sense, but  
far from pterosaurs is a problem. The only other nesting that is not  
reflected in the comprehensive cladogram is Prolacerta with  
Macrocnemus. In the absence of other taxa, evidently convergence won  
out here. In my 2000 paper, I deleted first Longisquama, then  
Sharovipteryx, then Cosesaurus, then Langobardisaurus to see when  
pterosaurs might begin to nest again with archosaurs, using matrices  
by Evans, Jalil and Bennett. By the time I got down to tanystropheids  
pterosaurs shifted back to the archosaurs. Not saying that would  
happen again using a more comprehensive set of characters, but it did  
happen once.

In 23 years since Benton 1985, no one has published a matrix that  
includes any lepidosauriformes with pterosaurs. If you can find one,  
please send it to me. That's a powerful a priori paradigm at work.

You wrote: "No, I can't imagine that finger IV grew secondarily, so  
it cannot have done that"? I'm not saying you're wrong; I'm saying  
that if you're right, you're right for the wrong reasons.

Parsimony is the reason I use.

You wrote:     *_WRONG_*. Benton had Younginiformes (as a whole!!!)  
and "Lepidosauriformes" derived from a common ancestor, and he had  
that common ancestor and Archosauromorpha derived from another common  
ancestor. This common ancestor is *_NOT_* "Youngina and kin". Why do  
you keep making such confusions? An ancestor on a cladogram is a  
node, not a terminal taxon!

It's shorthand, David. Youngina and kin means Younginiforms + more  
primitive diapsids.

You wrote:  Why can't it happen that, at least with our imperfect  
knowledge of the imperfect fossil record, two large groups can be  
sister-groups of each other?

That's a world view that is the current paradigm. That world view  
permits pterosaurs, ichthyosaurs and diadectids, among others, to  
remain mysterious and poorly connected from other amniotes. This  
results from using suprageneric taxa and just a few dozen taxa at  
most (i.e. your suprageneric "two large groups"). A comprehensive  
cladogram, on the other hand, using species and a few hundred taxa  
demonstrates that such enigmas do indeed have close generic sister  
taxa somewhere on the tree. And you'll be able to chart and see the  
spectral blend of morphologies across the tree.

You wrote: but the unpublished pterosaur with the parasagittal  
hindlimbs certainly does smell like a dinosauromorph, so we better  
both shut up till it's published.

Try not to hang your hopes on just one character. I'll just hazard a  
guess, but I'll bet this unpublished pterosaur has a prepubis, an  
elongated pedal digit V, hyper-elongated manual digit IV, multiple  
cusp teeth, chevrons parallel to the centra, an elongated coracoid, a  
sternal complex (interclavicle + clavicle + sternum), a non terminal  
naris, an antorbital fenestra without a fossa and other characters no  
dinosauromorph has. As mentioned earlier, some pterosaurs have a  
femur with an inturned head, just like dinos.

re: Huehuecuetzpalli: you wrote: What is so pterosaurian about it?   
Well, its actually closer to Cosesaurus, which leads to pteros, but  
here goes:

1. non terminal naris
2. ascending process of premaxilla extends beyond naris
3. low distinct coronoid process (a bump)
4. posteriorly sharp quadratojugal making poor contact with quadrate
5. short descending process of squamosal
6. clavicles, interclavicle
7. posterior lean to quadrate
8. eight cervicals (pre-scapula verts)
9. low scapula
10. poorly ossified carpals (phylogenetic, not ontogenetic character  
-- this is how the centralia migrate to become preaxial carpals and  
pteroids)
11. manual digit IV is the longest
12. metacarpals III and IV subequal
13. manual digit V reduced but retaining three phalanges
14. fibula less than half diameter of tibia
15. unfused tarsals
16. metatarsals III and IV subequal and longer than I and II
17. pedal digit IV the longest
18. Metatarsal V short and torsioned
19. Pedal 5.1 elongated.
20. Tail chevrons  are preserved parallel to centra. Was this their  
orientation in life?
21. Posterior tail attenuated.
22. and it's the right size