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Re: DinoMorph Strikes Back!... or does it?
What Scott says about the adventures of the WDC Camarasaurus is very
interesting. Of course I am happy to read that the osteology of actual cervical
articulations favors an erect neck. Even so, it is basically impossible that
Camasaurus and all sauropods would have had trouble holding the neck
fact, they all could lower the head to, or at least close to, ground level.
Why? Simply because they had to drink. (A similar point applies to deinotheres,
which are often restored with trunks too short to allow them to snarf up
water.) I said that they had to be able to reach at least close to the ground
because it they could bend the arms to bring the head the rest of the way down
they needed to (rather like giraffes, albeit probably not with the same spread
arm posture used by giraffes and okapis). Now, if some sauropods had to
partly disarticulate the cervicals to get the head down far enough to drink
looks like they did so. As long as a joint is not bearing a major load of the
body, i. e. a leg joint when on the ground while walking or running, it is
possible for some joints to regularly partly disarticulate in order to achieve
normal function (the premeire example being the wrist of the horse).
Kent said that the dorso-cervicals of AMNH 5761 are fused in a straight line.
Actually they are fused in a modest upwards kink, almost as much as in that
preserved in the classic juvenile CM 11338 in which the neck is at full
vertical retraction! I've long used those two fused vertebrae to pose the neck
Since Kent's computer necks are not correctly replicating the fossils it
appears there is something fundamentally wrong with the methodology. And so
for the camarasaur neck being held normally horizontal, since in the somewhat
shoulder high camarasaurs the anterior dorsals were tilted up a little already.
Presumably the rest of the neck remained sufficiently flexible to lower the
head to water level.
At the opposite end of things, a number of Camarasaurus and some other
sauropods of course have the necks in a vertical position, with all cervicals
in full articulation even though they are at their maximum dorsal retraction.
People forget that because sauopods had so many cervicals that just modest
rotation between any two of them adds up to a lot of total flexion. There is no
good reason to conclude that such sauropods (and not all sauropods are like
this) when alive could not raise the neck vertically to high browse or get the
maximum view of the landscape.
What I am getting at is that an odd view has developed, one that seems to
think that the only way to legitimitely illustrate or mount dinosaur skeletons
with the cervicals in perfect neutral osteological articulation. There is no
such law. In fact it's silly because animals flex their necks into all sort of
positions outside of ostelogical neutral (which may not be the same as
postural nuetral in long necked animals anyway). That's what necks are for. Do
place the legs in only the exact nuetral posture indicated by the articulations
when putting skeletons together? No. I'm still stratching my head why Kent
criticized my Brachiosaurus neck posture in the literature because I did not
the centra ends lined up because there is nothing wrong with showing the neck
outside its osteological nuetral posture in the first place. As long as the
neck is in a pose that is plausible because it does not grossly disarticulate
the cervicals in key regards then it's OK. You want to illustrate a giraffe
with the neck horizontal go ahead. Want it vertical, why not? Same for