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a closer look at Hanson 2006

Mike Hanson wrote:

<<For a reference, my analyses tend to indicate the following for the classification of non-pterodactyloid pterosaurs:
`--+--+--"Eudimorhpodon" rosenfeldi
| `--+--Austriadactylus
| `--+--Eudimorphodon ranzii
| `--Campylognathoides
| `--Scaphognathus
| `--+--Rhamphorhynchus
| `--"Odontorhynchus"

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.

   |  `--+--Lonchodectes
   |     `--+--Cycnorhamphidae
   |        `--Ctenochasmatidae
      |  `--+--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.