Re: Sloping terrain Re: Woman against Abelisaur

[Don Ohmes <d_ohmes@yahoo.com>]

On 7/24/2011 3:10 PM, Thomas R. Holtz, Jr. wrote:
> Well, to be fair, we are obligate bipeds with about the stupidest stance
> that evolution could come up with and still be successful! Far better
> balance when you have front quarters and a balancing tail...

Agreed -- but one tail still does not = 2 legs.

The biped necessarily spends time balanced on one foot. The quad can 
traverse the same ground and have three feet solidly planted at all 
times, if necessary.

In conditions of highly variable substrate yield stress (in both the 
temporal and spatial senses), and/or where the weight-bearing substrate 
varies vertically from one standpoint to the next, the ability to be a 
'constant tripod' is an overwhelming advantage in terms of stability.

Given that the dinosaur world essentially boiled down to bipedal 
predators and quad herbivores over it's entire span, and the obvious 
negative aspects of falling down while being a mega-biped with 
teeny-tiny arms, I am surprised that the ecological implications of the 
respective dinosaur locomotion modes have not received more attention.

I pretty much come up w/ zip when I search the lit...

But I nevertheless stand by several contentions, the most notably 
controversial perhaps being that giant sauropods were extremely 
well-suited to walking through swamps, rather than around them -- and 
lolling around in them at will, much as elephants use swamps today.

Giant theropods either walked around the swamps or came to grief...

Testing is possible if one accepts mechanical models, theoretical 
analyses, or the behavior of extant animals.