Re: DINOSAUR digest 3384

[don ohmes <d_ohmes@yahoo.com>]

--- K and T Dykes <ktdykes@arcor.de> wrote:

> <<In the proposed scenario of heat radiation coming
> from the cloudless sky,
> dinosaur needs not swim to survive.  It is enough to
> submerge in shallow
> water, which will conduct heat absorbed by the body.
> The same scenario
> explains why crocodilians survived.>>
> 
> Nobody proposed a scenario with a cloudless sky,
> Jerzy, seeing as the
> authors explicitely mentioned the possible screening
> effects of cloud cover.
> We know many crocs are very good at staying
> submerged, but I don't know of
> good evidence showing the same for non-birdy dinos.
> 
> <<Number of tracks of swimming dinosaurs were
> discussed on this list few
> weeks ago.>>
> 
> I know, but that's hardly evidence for semi-aquatic
> adaptations or abilities
> at staying submerged (or indeed burrowing).

I am _not_ trying to say this is germane to k/t
extinction patterns (don't think it is); nevertheless,
I would like to point out that the ability to hold
breath correlates positively w/ body size. Large dinos
may not have needed (detectable) adaptations to stay
submerged for significant periods of time. Never seen
this mentioned in discussions of sauropod
lifestyles...

Don

"Never give up." -- anonymous dead guy.