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Re: GSP's hadrosaurian reconstructions



Allan Edels wrote:

<I still say that SOME of the reconstructions look silly to me -
remember I grew up starting in the 1950's, so I've seen several
variants of reconstructions throughout the years. Also, remember that
I'm from Phila., where I have had close contact with _Hadrosaurus
folkii_ and _Corythosaurus_ at ANSP since 1985 (and actually since
1958 in their original mounts). Naturally, I think that I know what a
hadrosaur ought to look like.  :-)
 
  Looking over the reconstructions in the publication, I LIKE the
thick neck with _Shantungosaurus_, _Saurolophus_, _Anatotitan_,
_Kritosaurus_, and _Edmontosaurus_.  I DON'T LIKE the neck with
_Ouranosaurus_, _Tsintaosaurus_, _Corythosaurus_, and
_Parasaurolophus_.>

  The necks of all these taxa except *Ouranosaurus* are slender,
narrow, and proportionately low compared to length. That's the real
kicker. The processes of iguanodont-grade necks are larger, more
robust than those of hadrosaur, and generally shorter, relative to the
length of the back. The reverse for hadrosaur necks. *Ouranosaurus*
falls in the iguanodont-grade, but that means only a little.

  The nice thing I've noticed in studying Greg's reconstructions
(sorry, I've only seen the ones published in the big 3 of 1997, and
Lessem and Glut (1993)), is that there are skeletal correlations to
the nuchal "sails".

  Generally, in mammals, the dorsal anchors for the nuchal ligaments
are broad, the top of the neural spine as broad or broader than the
length, with the anterior neural spines more blade-like, flattened
laterally. This is so in iguanodontian ornithschians. Funny
correllation. I studied the necks of various mammals, long and
short-necked, to see how far the correllary went (not far) and the
studies were both muscular, skeletal, and integumental.

  I don't have much details on hadrosaur necks, but much of the
material that has recently come out, as well as Glut's earlier
"dictionaries", I have had a chance to look through, and it was an
invigorating project. I was not able to complete it. I need to examine
the literature, if not the specimens themselves, on hadrosaurs and
iguanodonts and *Ouranosaurus* (just for fun) so my work is far from
done.

  Now, in several taxa that I noted, *Lambeosaurus* had the most
anteriorly placed dorsal nuchal anchor. *Anatotitan* had the most
posterior, and *Parasaurolophus* in the middle, closer anteriorly than
posteriorly. My study on *Ouranosaurus* is not in, 'cause I haven't
seen any dorsal aspect of the dorsum itself, or neck, just the shaded
and line drawings, and the rearing photo in Norman, 1983 and Glut, 1983.

  Such positions of the anchor would have altered the shape of the
"flap" from species to species, if not specimen to specimen.

  I haven't much else done, for the reasons in the paragraph two
before the last one.
 
<Essentially, I find that the longer-necked morphs don't look as good
as the shorter-necked morphs - AT LEAST TO MY ADMITTEDLY PREJUDICED
EYES.>

  This is probably because of the balance of a really big head on a
slender neck. Most hadrosaurs probably held the anterior half of the
skull vertical, with cervicals 3 and forward curving anteriorly or
anterodorsally. This aided balance in the head, and the dorsoventral
flattening of hadrosaur cervical centra prevented side-to-side
swaying. But how about fore-aft tilt? Nuchal ligaments, for us; those
big bulging shafts behind your neck (paired, of course; nature loves
symmetry) in hadrosaurs could find anchors from the posterodorsal rim
of the skull (behind the parietals) to the first few broader dorsal
neural spines.

  Skin would have enclosed the whole thing, with muscles along the
sides, but would still have been thin, probably in *Lambeosaurus* only
three inches thick, which is about as wide as the neural spine's width
to which I think the nuchal attached. That's thinner than the neck
itself, so I doubt the "withers" image and "sail" image, just a
muscular nuchal "whatever".

==
Jaime A. Headden

Qilong, the website, at:
http://members.tripod.com/~Qilong/qilong.html
---
All comments and criticisms are welcome!

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