Re: Rigid dinosaurs?

[Michael Habib <mhabib5@jhmi.edu>]

On Friday, February 17, 2006, at 11:29 AM, Kent A. Stevens wrote:

> Scott Hartman's "stiff as an ostrich neck" analogy is apt.
>
> Furthermore, to equate ligaments with rigidity only disregards their 
> roles as passive tensile structural elements and in energy 
> storage/recovery and/or damping...

> ...It would not do for tyrannosaurids to be flopping all over the 
> place as they ran briskly from one carcass to the next in a frenzy of 
> competitive scavenging.

There is also the problem (already alluded to) of equating rigidity in 
the body and neck to poor mobility.  Avian theropods are very rigid, 
and yet generally quite maneuverable (both on the ground and in the 
air...though the aerial portion is besides the point here).  Being 
inflexible throughout much of the body does not render an animal bad at 
turning unless it uses flexibility to turn.  Thus, a rigid cat would 
turn poorly, but a rigid ostrich turns well.

Cheers,

--Mike Habib