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Re: Blood flow in Sauropods



>      I don't doubt that having a long neck increases the feeding
>range without moving the body, I just don't see the point of doing so
>if you can cover the same range by moving the body and having a shoter
>neck.
>
>J.Martz

The problem with this approach, and others like it, is the one aspect, one
purpose, one benefit limitations. Sauropods, like all living organisms,
have an enormous number of functions that their limited number of features
must cope with. True, this arguement sopunds great if you consider a
sauropod is purely an eating machine, but I have a funny feeling that
sauropods were more than this.

Consider; as a large organism, a sauropod has to dump heat (regardless of
if they were endo or ectothermic). So structures have to develop that
enhance heat loss such as attenuating the whole body form thus increasing
surface area to volume etc etc. Now if you do this by increasing the neck
length, you can also use the new long neck to increase the feeding range
without moving the body. In smaller animals where long necks for cooling
are not necessary, the development of a long neck to increase horizontal
feeding range is not viable. However, if you are big enough that the
elongate neck works as a heat sink and offers increased horizontal feeding
range, then you might have a viable combination. Add to such speculations
the unknown effects of an unknown physiology and bingo, you have extinct
animals doing things differently to living animals.

I read somewhere that lizards make a poor model for a mammal but that
mammals make equally lousy lizards. The same argument can be extended to
dinosaurs. While modern analogues may produce theoretical models of
activity, these projections must not be applied in a restrictive or
definative manner.

Cheers, Paul

pwillis@ozemail.com.au