Re: E & P of Pterosaurs - Notes 3

[David Peters <davidrpeters@earthlink.net>]

D.Peters earlier wrote:
Very few muscle imprints are preserved in fossils, but in some
pterodactylids the trapezius and deltoids appear to make their presence
known. The trapezius impressions appear to extend to the lateralmost
scapula, or about twice the distance shown by Bennett, who followed
muscle
scars exclusively.
>

C. Bennett wrote
It seems that David is making a distinction between "muscle imprints"
and
"muscle scars", a distinction that I do not understand unless imprints
refers to details on fossils that are revealed by his
photointerpretation
methodology and which no one else can see.


>>>>
Not at all. Go to the Nat. Geo article on Pterosaurs. p. 88. If the soft
tissue line at the shoulders is the work of an artist, not nature, then
I've been duped!  Same, I suppose for the cervical and throat soft
tissue zones in the same pic.

CB:
His statement that I "followed
muscle scars exclusively" is incorrect.  As clearly stated in the paper,
I
used the Extant Phylogenetic Bracket method of Witmer as applied to
Maiasaura by Dilkes and combined information from bone morphology
(processes, etc.), muscle scars, and the distribution and attachments of

muscles in the extant relatives of pterosaurs.  I spend about 8 hours a
week
in the cadaver lab and am well aware that muscle attachments may not
leave
marks on bones.  I mapped all the muscle scars I could find, but I
reconstructed many muscle attachments based only on the information
provided
by extant relatives.

>>>
Thank you Chris. The muscles you drew created a rather emaciated look,
much less extensive than I "saw" on p. 88 above.

CB wrote:
By the way, regarding Buffetaut's interpretation of the quadrate region
of
Hatzegopteryx, Eric clearly got it right.

>>>>
We can discuss this online, but I don't think that will help. I think
trading a few jpegs offlist will, if you're interested. You'll have to
go first, of course, due to certain precedents which I don't wish
repeated. I'll be most interested in your comparables. And again, this
may be where a faulty cladogram is to blame, because the azhdarchids, it
turns out, are a far cry from the tapejarids, and so are their palates
and occiputs.

David Peters

Chris