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re: pterosaur palate paper, Osi et al. 2010
New Interpretation of the Palate of
ATTILA OSI* EDINA PRONDVAI, EBERHARD FREY,
AND BURKHARDT POHL
THE ANATOMICAL RECORD 293:243–258 (2010)
The new paper on pterosaur palates presents some interesting and much needed
data. It also, for some strange reason, says one thing and does another when it
comes to conclusions.
1. A wonderful 3D specimen of Dorygnathus is revealed. It's a big one, about
50% longer than the others.
2. Supplementary Data provides a good history of the understandings and
misunderstandings of the pterosaur palate. Seems we can blame Williston 1902
and later Huene 1914 for misidentifying the palatal plate of the the maxilla as
the palatine when earlier authors Newton (1888), Seeley (1901), Woodward
(1902), had it right.
3. Nice to get confirmation. They gave credit to Peters 2000 for recognizing
the correct labels in this fashion: "More recently, Peters (2000) identified
the broad palatal bone as the ‘‘medial maxilla process’’ and briefly noticed
that this structure has been mislabeled as the palatine by earlier authors.
However, he did not give a detailed explanation why he considered this palatal
region as part of the maxilla."
The reason was the very clear homologies with Macrocnemus and Sharovipteryx.
4. They found a specimen in which the ectopterygoid and palatine were unfused
(which is a revelation). If this is indeed a juvenile character, then this
specimen was larger yet as an adult.
5. A foramen incisivum was found, also a novelty.
6. They found "Apertura maxillo-premaxillaris, " also a novelty.
7. Their Figure 8 was a good reconstruction of the available material, with the
palatine in close association (forming an L shape) with the ectopterygoid.
These elements are fused in virtually all other pterosaurs, as shown in the
pterosaurs in their Figure 9.
1. Comparisons were only made to archosaurs when in fact no line up of
archosaurs documents a gradual increase in pterosaurian characters and all
archosaurs have reduced lateral digits (#4 manus, #5 pes). They report: "Hone
and Benton (2007, 2008) provided new evidence to support the origin of the
Pterosauria within Archosauria and we follow their definition here."
Unfortunately, Hone and Benton made their test by omitting the data from
Peters, 2000, including omitting the two fenestrasaurs closest to pterosaurs
and scoring the other two for only a quarter of their available characters, so
their so-called 'test' was no test at all, but a foregone conclusion with only
one possible outcome.
2. Figure 3 is a multiview photo of the premaxilla of the new specimen.
Unfortunately the authors failed to recognize the pmx/mx suture essentially
extending from the antorbital fenestra not quite to tooth #4. So a healthy
portion of the maxilla is present here laminated to the pmx. The break occurred
at the narrowest portion below the naris.
3,The sagittal rdge (SI) in the pmx is the paired, fused, anterior vomers.
4. Considering the proportions of the very elongate premaxilla, longer than in
any other Dorygnathus of which I am aware, and as long as the maxilla, this is
probably a derivation of Dorygnathus, but sufficiently distinct to merit its
own genus. I would encourage the authors to erect a new genus and perform a
phylogenetic analysis of all known Dorygnathus specimens to confirm the new
specimen's closest relations. There is an unrecognized variety in Dorygnathus
that needs to be explored. I don't think this specimen is basal to any known
taxa, which all have a shorter pmx.
5. Fig. 9 Misidentified the entire broken rostrum of Gnathosaurus as the
premaxilla, when it should have included only the first four teeth.
6. Paradoxically, and contra the evidence of their specimen, the hypothetical
reconstructions in Figure 11 separate the palatine from the ectopterygoid,
giving each a separate articulation on the pterygoid for no apparent reason,
other than possibly this is the pattern seen in crocodilians. No pterosaur
specimens document this configuration, and certainly not their very special
"Dorygnathus" or their also included Rhamphorhynchus and Gnathosaurus.
Reconstructions need to be consistent with the data.
7. Figure 11 also purports to extend the premaxilla in "(B) pterodactyloid
pterosaurs" to include over a dozen teeth. This is also wrong. The premaxilla
in all pterosaurs includes up to 4 teeth, no more.
8. The authors need to reconstruct the posterior vomers lateral to the anterior
pterygoids, not medial.
9. The authors ascribe a lateral pterygoid process contacting the jugal to all
basal pterosaurs, but this process is restricted to Rhamphorhynchus.
cc: OA, EP, MW, DF, DML