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a closer look at Lu and Ji 2006

And yes, please forgive the typo of Li vs. Li (Ji). Thank you Dr. Unwin.

Let's start with the basal taxon: Anurognathidae. It would be better to start with some Triassic taxon, I would think. So there's the first red flag.

Strangely the anurognathidae are not a sister taxon (to the exclusion of all other pteros) to Dimorphodon + Preondactylus (which form a clade of their own when properly reconstructed (and a tip of the hat to Dr. Unwin again who predicted this many years ago)). Here both are successively basal to Sordes, a mistake I also put into print many years ago. It's easy enough to do given too few taxa and characters. Strangely that forces Eudimorphodon three steps higher in the cladogram, higher than Scaphognathus and Dorygnathus. That's another red flag.

The inclusion of Peteinosaurus(?) Ex3359 and MCSNB 8950 would help this portion of the cladogram.

When MPUM 6009 and Austriadactylus are included, they attract Eudimorpodon ranzii and the other Eudimorphodons abit lower on the cladogram, keeping the Triassic forms at the base, morphologically and chronologically where they belong. In this way, the various Mid Jurassic Campylognathoides, which are strongly attracted to Eudimorphodon, forms a separate branch which, in time, begets the various late Jurassic Rhamphorhynchus species, but not without a size squeeze during the transition. All forms blending and in chronological order.

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). The Dorygnathus more precisely known as SMNS 50164 has a tiny pterosaur as its sister taxon, TM 10341. When this pterosaur is included (which it is not in Lu and Ji 2006) not-so-tiny Beipiaopterus is strongly attracted to it as are a number of other tiny pterosaurs, including SOS 2428, AMNH 1715 and Wellnhofer's No. 42. The last two tiny pteros are sister taxa to SOS 2179 and Huanhepterus on one branch. On another sister branch are a series of increasingly larger forms beginning with Jidapterus and Chaoyangopterus and leading to Zhejiangopterus and Quetzalcoatlus (but not Azhdarcho and Co. more about them later). So, some pterodactyloid-grade pterosaurs show up on this branch, but the rest do not.

The Dorygnathus known more specifically by their numbers as SMNS 55886 and R 156 are basal to a branch that includes in order: D. purdoni (another tip of the hat to Dr. Unwin for that) and Angustinaripterus, long touted as a good transitional form between 'rhamphorhynchoids' and 'pterodactyloids' but strangely missing from this analysis, and as I look back -- all other recent analyses. What happened to our star quarterback? Put him back into the game and see what happens!

Anyway, the wonderful Angustinaripterus with the garage door teeth does lead, not surprisingly, to others with similar teeth and everything else, Gnathosaurus and Ctenochasma + Pterodaustro, but not without yet another phylogenetic size squeeze. And with that we have our second branch of 'pterodactyloid' - grade pteros without including all of them. Strangely, Lu and Ji place the horizontal- toothed pteros with sharp-snouted Germanodactylus, which seems as unlikely as pairing a spoonbill with a woodpecker. There are better matches out there. They just need to be included.

Back to Sordes.

Pterorhynchus is strongly attracted to Sordes, but so far has left no sister taxa. Where is Pterorhynchus in these latest studies? Nowhere.

Scaphognathus is also strongly attracted to Sordes and is basal to all remaining pterosaurs. If one includes all three (?) well-known Scaphognathus specimens (which Lu and Ji do not), one finds that S. crassirostris and SMNS 59395 are basal among them. The third named specimen, the Maxberg specimen, continues a size squeeze that continues even further with an even tinier pterosaur, TM 13104 and further up the line, G-mu 10157, both with slightly elongated metacarpals. Afterwhich one gets a big size jump with cycnorhamphids and ornithochierids (they have the same strange feet among other characters) emerging from the genetic pool. And so a third branch of 'pterodactyloid'- grade pterosaurs emerges with a morphological spectral blend from a 'rhamphorhynchoid' base. Again, remember, this doesn't happen in a cladogram with tiny pterosaur exclusion. In other cladograms you get confusion and 34,000+ MPTs.

There is another pterosaur that is so strongly attracted to Scaphognathus that, if not for its diminutive size and neotenous tail (already on the wane in other Scaphognathus anyway) and its slightly elongated metacarpus, it might have been named Scaphognathus sp. That's the tiny pterosaur Wellnhofer named No. 9. Despite having a short scaphognathine rostrum, it also has a slightly sharper rostrum. And here begins the fourth and final branch of 'pterodactyloid' - grade pterosaurs derived from rhamph-type ancestors.

Strongly attracted to No. 9 is AMNH 1942, which has the same size torso, wings and legs, but a longer neck and rostrum. AMNH 1942 is also known as Pterodactylus and it is basal to the other Pterodactylus forms we all know and love, including the big one, Diopecephalus. Lu and Ji place two Pterodactylus between Beipiaopterus and Eosipterus. In this case, the addition of No. 9, AMNH 1942 and other pteros would provide the realignment.

Another sister to No. 9 is No. 12 which has a longer and noticeably sharper rostrum. It begets all of the sharp-nosed pteros, starting with various versions of Germanodactylus (including Eosipterus). Lu and Ji show Eosipterus to be a sister taxon to Germanodactylus (which is good) and also to the ctenochasmatids + cycnorhamphids (which is bad = doesn't make sense). See above for better matchups.

It is difficult for me to understand how Germanodactylus can be so far removed from (azhdarchids (not including Q. and Co.)) + (nyctosaurs + pterandons)) + (tapejarids + dsungaripterids), but that's how Lu and Ji show it.

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.

Lu and Ji's family tree of tapejarids and dsungaripterids has problems (but that's because Quetzalcoatlus and Zhejiangopterus are incorrectly basal here). The dsungaripterids should branch off first (if germanodactylids are basal, as they should be), followed by the monophyletic tapejarids.

It just takes more taxa and more characters and all the confusion melts away.

David Peters
St. Louis