RE: Armalligator was: Email

G'day,

> Here, I am not so much concerned with tool use as with locomotion. 
> Unless the athmosphere/fluid where it habitually lives is 
> dense enough to provide significant buoyancy, 
> moving with splayed legs implies significant energy costs.  

Depends on the linkages - look at millipedes etc, not the same energy
costs
as other linkages (like lobsters).

> Would that be sufficient to maintain continent-spanning 
> ecosystems for very long time spans ? 

Yep. Current ecosystems based on this stuff are turning out to be
richer,
more diverse and wide spread than expected. The seep fauna are turning
out
to be a huge deal. Also current theory has it that it may well be what
the
first ecosystems were like before they set up more photosynthetic
friendly
conditions.

> Something similar to hot-vent animals operating at 100+ 
> degrees celsius and high air pressure requires fewer leaps of faith 
> and would be equally plausible for an environment that is 
> uncomfortable for humans. 

That's how I'm viewing them though, there are actually less changes
(apart
from sizeable increases in mass) between deep vent/seep fauna and these
alien critters than you'd expect.

Cheers