Re: Sauropod Rearing

[DinoBoyGraphics@aol.com]

I just wanted to add a few things to Mark's post:

1) Humans are not even remotely adapted to the behavior known as 'ballet.'  
Forgetting for a moment the large mechanical differences between mammals and 
archosaurs, it is still ridiculous to compare what has been interpretted as a 
major adaptive strategy (rearing in sauropods) to non-adaptive human behavior.  
Whether in sports or dance, we routinely engage in ctivities with much smaller 
margins of mechanical safety than do organisms in their natural habitat.  So 
using human injuries in this manner cannot be constued as a valid baseline to 
make comparisons.

2) As Mark noted, dipldocids have a number of anatomical modifications which 
shift their center of mass much closer to the hips.  Combined with their axial 
musculature, it isn't obvious that the speed of descent for a rearing sauropod 
would have been great at all (contrary to those "Walking with Dinosaurs" 
Diplodocus').  It's even been hypothesized that apatosaurines could have moved 
bipedally if they so chose, in which case there may have been almost no 
deceleration at all when they resumed quadrepedal locomotion.

Obviously neither of these objections proves that sauropods reared habitually, 
only that Rothchild has failed to cast any significant doubt on the subject.

Scott