Re: Floating Dinosaurs

[Michael Habib <mbh3q@virginia.edu>]

On 10/27/03 2:32 AM, "zone65@bigpond.com" <zone65@bigpond.com> wrote:

> It's rather about time people came 'round to the idea of sauropods
> being semi-aquatic, if not fully so. The counter-intuitive concept of
> sauropods being solely dry-land dwellers has gone on way too long.  If
> only we can also begin to dispel the absurd spindly-legs imagery of
> them...
> It's almost as if some people sit around dreaming up the least logical
> behaviours (and other aspects) for dinosaurs, then take them on board
> and promulgate them. The scavenger T. rex being another case in point.
> 
> Peter Markmann

Careful; you're reading too much into this study.  Those two papers
demonstrate that sauropods crossing shallow water for short distances could
create the rare forefeet-only prints.  It does not imply that they were
semi-aquatic.  In fact, the same authors also found that they were prone to
tipping in water, so sauropods would have had trouble in deep water.

There is a host of evidence to show that sauropods were terrestrial.  It has
been discussed here before, I believe, so I would refer to the archives for
an extended explanation and list of references.  However, in short, it is
known beyond most reasonable doubts that they were terrestrial because of
limb morphology (columner limbs are a terrestrial adaptation and very poor
for swimming), trackways (most were made on land), axial elements (they were
built like suspension bridges, very cool), and perhaps most
importantly...they lived in dry habitats.  Wet/dry seasonal conifer forests
do not make for good aquatic living.

It's actually not that counter-intuitive.  Large animals with straight limbs
tend to live on land.  Giant tortoises (columner foot), elephants,
Indricotheres, etc. are all examples.

--Mike Habib