Re: Blood pressure in Sauropoda

[Graydon <graydon@dsl.ca>]

On Mon, Dec 31, 2001 at 05:04:52PM -0800, Tracy L. Ford scripsit:
Middle bit is graydon@dsl.ca:
> On Mon, Dec 31, 2001 at 12:14:07PM -0800, Tracy L. Ford scripsit:
> [sauropod necks]
>> > I wanted to check and see if they were right. I used Gilmore?s Apatosaurus
>> > monograph and drew each individual cervical and lined it up with the next,
>> > and guess what, the front of the neck turns DOWN!!! So they are right. Just
>> > because WE perceive something as being wrong, doesn?t mean it was. We see a
>> > long neck and automatically think the animal HAD to be eating from a high
>> > tree, not so.
>> 
>> If you're a sauropod who rears up and braces your forefeet on the
>> metasequoia to get at the high leaves, what do you want your neck to
>> curve like?
> 
> Simple, you DON"T rear up! Rearing sauropods IMHO is a myth.

Those are _really big_ neural spines; rather larger than needed for
suspension-bridge style supports.

> Too much strain. I was talking to someone earlier this year and he was
> telling me about an engineer/ amateur paleontologist (who doesn't get
> much respect in the paleo world because he doesn't have a Phd, kind of
> like me :) ), any who, he was working on this problem and said that
> sauropods would break their femur if they did. A local zoo had an
> elephant break its femur when it reared up, and he told them exactly
> where it happened on the femur! 

Tail bracing and possibly forelimb bracing taken into account?

I don't think they all did; it seems plausible for some species, though.

> Another problem is the neck; it's in the way if it leaned on the
> trunk. Take a toy sauropod and place the nose to the tree, rear it up
> then look at the distance between the two. The sauropod would have to
> WALK bipedally (which they just may have, like a theropod, not reared
> up) to lean up against the tree.

It would just have to walk _past_ the tree a little, and then bend a bit
before rearing; not insurmountable.

> Why have a long neck and short legs, why not have a shorter neck and
> longer legs?

The long neck is way cheaper than long legs?

> It's the conception that it has a long neck so it has to eat from treetops!
> No other explanation! Right...

The combine-harvester explanation is probably *also* correct.

We know for sure that sauropods had different feeding strategies, fairly
sharply different ones, because otherwise explaining why so many species
of multi-ton herbivore were in the same environment is a real
headscratcher.  My own view is that sauropods very likely had feeding
strategies that no one has begun to imagine yet, and probably won't be
able to without really careful reconstruction of the paleoenvironment.

-- 
graydon@dsl.ca   |  Hige sceal þe heardra, heorte þe cenre,
                 |  mod sceal þe mare þe ure maegen lytlað.
                 |   -- Beorhtwold, "The Battle of Maldon"