a closer look at Hanson 2006

[David Peters <davidrpeters@earthlink.net>]

Mike Hanson wrote:

<<For a reference, my analyses tend to indicate the following for the  
classification of non-pterodactyloid pterosaurs:
Pterosauria
`--+--Preondactylus
`--+--Anurognathidae
`--+--Nesodactylus
`--+--Peteinosaurus
`--+--Dimorphodon
`--+--+--"Eudimorhpodon" rosenfeldi
| `--+--Austriadactylus
| `--+--Eudimorphodon ranzii
| `--Campylognathoides
`--+--+--Sordes
| `--Scaphognathus
`--+--Parapsicephalus
`--+--Cacibupteryx
`--+--+--Dorygnathus
| `--+--Rhamphorhynchus
| `--"Odontorhynchus"
`--+--Angustinaripterus
`--+--Pterorhynchus
`--Pterodactyloidea>>

So, Mike, good to see your work, but Triassic forms are sprinkled  
around in your analysis, but they are all basal in mine. Also Mid  
Jurassic forms are higher than some Late Jurassic forms here, but  
they are in chronological order in mine. While Dorygnathus and  
Rhamphorhynchus appear similar, there are major differences with  
better matches among other pterosaurs. For instance the sternal  
complex on all  Campylognathoides and all Rhamphorhynchus are large  
and similar in morphology. Not so in Dorygnathus, which has a tiny  
sternal complex. The antorbital fenestra gradual shrinks in Campy >  
Rhampho. Not so in Dory. When standing bipedally with the hands on  
the ground, the wing is much taller than the head in Campy > Rhampho.  
Not so in Dory. In palatal view Campy > Rhampho have a sharply  
pointed rostrum. Not so in Dory, which is more like  
Angustinaripterus, broad and toothy. Then, of course, I'll have to  
ask, 'which Dorygnathus are your using? Which Rhamphorhynchus? Which  
Scaphognathus?

Also, I would note that Nesodactylus has a big perforated prepubis  
and a split pubis/ischium, both not present in your sister taxa,  
Peteinosaurus and Dimorphodon, but are present in Campylognathoides.  
I can see  why you might nest Neso. next to Anurognathidae because of  
manual 4.1 reaching the elbow, but then you are forced to start with  
Preon. which doesn't have this; move to Anuro, which does; Neso,  
which does; then back to Peteino > E. ranzii, which don't; then back  
to Campy, which does; then Sordes > Dory., which doesn't; then back  
to Rhampho, which does; then back to some head only forms followed by  
Pterorhynchus and Pterodactyloidea, which don't. The back- and-forth  
morphology that appears here should be a red flag that something is  
wrong. In my study Anurognathids gradually increase m4.1 to the elbow  
and Campy, Neso and Rhampho form a bushy clade with an elongate m4.1  
remaining rather constant.

<<    A growth series. JVP 2 or 3 years ago, bone histology: there is  
such a thing as immature *Rhamphorhynchus* in the fossil record.
True, but Bennett is also a fanatic lumper. >>

Thank you for noting that too.

<<    When six Dorygnathus are used in a cladogram, instead of one as  
in prior works, you find that the short-toothed Donau specimen is  
basal to the more derived wicked-toothed forms, and that Sordes is  
its sister (more about Sordes and Co. later).

As HP Marjanovic stated earlier, this specimen is likely a juvenile.  
Also, in my experience, it is a very bad idea to base anything off of  
x-ray photos. >>

The x-ray specimen is the same size as the other Dorys. And who says  
the teeth grow longer through ontogeny? If you apply WSIWYG, then  
your a priori assumptions will be turned on their ear to become  
discoveries.

Why is an X-ray very bad in your experience. Thousands of hospitals  
use them every day!


<<My analysis indicates that Parapsicephalus (along with the very  
similar Cacibupteryx) is a transitional form between Scaphognathids  
and Rhamphorhynchids (which include Dorygnathus). Angustinaripterus  
is a sister taxon to the clade containing Pterorhynchus and the  
Pterodactyloidea. >>

See comments above.

<<I've recently been shown photos of the skull of Pterorhynchus and  
the characters it shows are strongly pterodactyloid. >>

How so? And which 'pterodactyloid'? There are dozens to choose from.  
But then, there's that gigantic tail and short metacarpal. So,  
nothing else is strongly or even weakly pterodactyloid. There are  
better matches out there.

<<The x-ray photos published in the [bad] description are inadequate  
at the least in illustrating this similarity.>>

Difficult, but not inadequate.

<<This is because Lü and Ji based their character list largely off of  
Kellner, 2003 with only a few modifications. I suspect Kellner may be  
excluding characters from his list in order to support his  
"Archaeopterodactyloidea" which basically includes ctenochasmatids,  
cycnorhamphids, and "germanodactylids," essentially all basal  
pterodactyloids, and places them in a clade seperate from the  
ornithocheiroids and tapejaroids. >>

Interesting observation. I wonder if it is true?

<<My analysis is closer to Unwin's in this respect.

Pterodactyloidea
`--+--+--Pterodactylus
   |  `--+--Lonchodectes
   |     `--+--Cycnorhamphidae
   |        `--Ctenochasmatidae
   `--+--+--Haopterus
      |  `--+--Istiodactylidae
      |     `--+--Boreopterus
      |        `--+--+--Pteranodontidae
      |           |  `--Nyctosaurus
      |           `--Ornithocheiridae
      `--+--+--"Daitingopterus" rhamphastinus
         |  `--+--Germanodactylus cristatus
         |     `--+--Dsungaripteridae
         |        `--+--Tapejaridae
         |           `--+--Tupuxuaridae
         |              `--Azhdarchidae
         `--Normannognathus >>

Okay, Mike, you know what's coming. No tiny pterosaurs are included  
here. Which Pterodactylus are you using? Are any characters, other  
than dental similarities attracting Cycnos to Ctenos? Why do sharp-- 
snouted Pteranos and Nyctos nest within toothy broad rostrum forms--  
especially when other sharp-snouted forms are out there? Evolution  
works gradually. Warped deltopectoral crests can appear twice, as  
they do in my analysis which puts all the needle-noses together.  
Which Azhdarchids are you using? Suprageneric taxa you assume to be  
monophyletic, but it may be too soon to determine that.



<<Nothing wrong about Sordes and Scaphognathus being realted.>>

Thank you.


<< As for different branches of "pterodactyloid grade" pterosaurs  
descending from a "rhamphorhynchoid base," that seems unlikely. Here  
I reiterate HP Marjanovic's question, "What is your criterion for  
declaring a pterosaur adult?" >>

Because pterosaurs inside of eggs have proportions and tooth counts  
very close to those of adults, one can employ embryos, juveniles and  
adults in the same cladogram. If you want to determine juvenile vs.  
adult you can look to bone fusion, texture, etc. for clues. Shape is  
no longer on the list.

<< If one were to construct a cladogram of homonids including babies,  
young chimpanzees and humans would form a clade separate of the  
adults with adult humans perhaps being closer to this "juvenile  
clade" than chimpanzees and with adult humans closer to juvenile  
chimpanzees than to juvenile humans. >>

This you will have to demonstrate. Currently it is fiction. And even  
if so, in the case of primates, it is demonstrably not so in pterosaurs.

<<While this case would be different from the above mentioned  
analysis, it demonstrates how including individuals of the same  
species but of a different developmental stage would dramatically  
change the outcome.>>

Again, without actually doing the testing, you have assumed a  
conclusion. The weasel-word 'would' gives you away.

<< think my analysis sufficiently demonstrates pterosaur  
relationships in a "morphological blend" and gives only a hundredth  
of the number of MPTs given above, but it has over 120 characters and  
over 80 taxa, far more than Unwin's or Kellner's analyses.>>

Above I have listed many 'bumps' in your 'blend'. If your results  
produce a hundredth of 34,000+, then your results produced 340 trees.  
Right? That's still too many, and more than one, which is the number  
you are competing against.



<< Well, Pterodactylus kochi and P. antiquus should fall together in  
an analysis, >>

And they do...

<<but P. micronyx may be a juvenile Diopecephalus or Gnathosaurus and  
P. elegans is a juvenile Ctenochasma. >>

Wow. You're all over the place here. Pick one. Also, which P.  
micronyx. We've gotten to the point now that specimen numbers are  
required because one P. micronyx may not be the same as another P.  
micronyx.



<<    As mentioned earlier, the addition of more tiny pteros and more  
pteros in general pulls Quetzalcoatlus, Zhejiangopterus, Jidapterus  
and Chaoyangopterus away from Eopteranodon + Eoazhdarcho + Azhdarcho,  
which form a separate clade with a convergent elongated cervical  
series. The flat versus pointed shapes of the dentaries are  
diagnostic, as are a whole raft of other post-cranial characters.

Again, adding juveniles will only cause confusion.>>

This is your a priori assumption. And with your assumption you are  
left with an incomplete tree and 340 MPTs. Take it to the next level  
and complete your tree. Other comments reiterate earlier points.


<< Sure, the results may make sense, in fact, they are very likely to  
make sense one way or another, but they may not reflect the true  
evolutionary relationships.  >>

Once again, the weasel-word 'may' demonstrates that this is an  
opinion based on a priori assumption. I have argued here that your  
tree has some unwarranted reversals and other unusual morphological  
alignments. What I've produced is an hypothesis that theorizes  
relationships, and one that places derived features at the tips of  
branches without unwarranted reversals. It also demonstrates that we  
already know, essentially, the entire tree of the Pterosauria. Future  
discoveries can simply be plugged in.

re: Lu vs. Lü. I am sometimes lazy and abbreviate. I confess.

DP
StL