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Re: Do not misunderestimate the king was Re: Evolution of tyrannosauroid
Michael Habib writes:
The one thing that can be
said for certain is that the forelimbs were placed under substantial
loads. That, in itself, is very intriguing. I remain skeptical that this
clinches a particular feeding dynamic for a number of reasons, but the
information is quite informative, regardless.
I'm skeptical that *adult* tyrannosaur forelimbs were used to capture or
manipulate prey at all. It wouldn't matter how strong the arm muscles
themselves were if the shoulder joints weren't up to withstanding the forces
generated by struggling multi-tonne prey. If I were an adult tyrannosaur,
I'd rather use my massive jaw and neck muscles to subdue prey - or use a
'bite and retreat' method and not attempt to hold onto prey at all.
I've always thought that tyrannosaurs may have outgrown their forelimbs as
far as predatory behaviour went, using them extensively as juveniles (when
the forelimbs were relatively larger), and using them less (or not at all)
as adults, once bite strength was sufficient in itself to kill prey.
Perhaps the main use adult tyrannosaurs had for their forelimbs was to help
them rise from a crouching position? If they used their pubic boot as a
pivot point, they could have rocked forward while straightening their legs
beneath them, and dug their forelimbs into the ground to prevent the animal
scooting forward on its chest. Once the legs had straightened enough, the
feet would have become the new pivot point. By throwing the head and neck
back over their shoulders (perhaps thrusting back with the forelimbs at the
same time) and lowering their tail, they could then have rocked back into a
standing posture. Such use of the forelimbs might result in the stress
fractures and muscle avulsions of the humerus that have been observed - with
no predatory role for the forelimbs required.
GIS / Archaeologist geo cities.com/dannsdinosaurs
Melbourne, Australia heretichides.soffiles.com