Re: MORE ON SAUROPOD FEEDING HIGH & LOW

["Nicholas R. Longrich" <longrich@phoenix.Princeton.EDU>]

On Wed, 27 Mar 1996, Stan Friesen wrote:

>  >  The only logical explanation for the extraordinary length of
>  > sauropod necks is to give them the ability to reach beyond where
>  > short necks could, which is only upwards. ...
> 
> At least for graviportal terrestrial animals.
> [The cost of movement in water is higher, and the balance point
> may shift in that case].

        I would be interested in hearing exactly how Elasmosaurus used 
it's neck- snaking through the water, or plunging in from above?

> Overall, I suspect that the modern elephants are the ecological
> equivalent of the camarasaurids - mostly mid to mid-low browsers.
> The main difference is that instead of an expensive long neck they
> have a relatively cheap long nose.

        Bakker makes the comparison between elephant trunks and 
diplodocid necks and heads. Like an elephant trunk, the main function of 
the neck is to strip off leaves so they can be processed further down (by 
the jaws in elephants, and the gizzard in brontosaurs). The skulls and necks
have been reduced down to the bare minimum necessary, so that the amount of 
bone, muscle and brain supported by the skeletal and circulatory systems 
is minimized. Sauropods actually evolved smaller brains to reduce the 
amount of blood needed in the head.

        It would be interesting to know, however, how much low-feeding 
the sauropods did, or if there were any grazers. Mammoths, after all, 
were grazers, not browsers, and one wonders if there weren't sauropods 
specialized for the grazing niche as well. One would probably expect to 
see a sauropod with a downward flexion of the spine in the neck region, 
and a neck just long enough to reach the ground. Stegosaurs look like 
they'd be particularly good at this, even though they show so many 
adaptations for tripod-feeding. Odd that they never did evolve long necks 
like diplodocids, perhaps a greater proportion of their diet came from 
grazing than in diplodocids.