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Re: MORE ON SAUROPOD FEEDING HIGH & LOW
Below are excerpts from Stan Friesen's comments (03/27/96; 7:23p) on my
posting of 3/27/96:
>From: "King, Norm" <email@example.com>
>>If sauropod brains were twice the size (or so) they actually are, would
>>that have made the amount of blood needed in the head prohibitively
>It would increase maintenance costs more than you would imagine.
>First, to support that larger brain, you need a larger skull.
I disagree with this premise, which is the basis of everything else in
your discussion. Why not increase brain size without increasing skull
size? Horses have much larger brains in skulls of similar size or
smaller than those of diplodocids.
>So, doubling the weight of the brain has probably at *least* doubled
>the weight of the whole neck. Boy that was an expensive increase.
I don't think you have shown that your premise is correct, so I can't buy
>>Are we sure this is WHY sauropod brains are small?
>But given that they have the smallest EQ, and the longest necks,
>it seems reasonable that the two are related!
But they were also the largest dinosaurs, and maybe it was over-all size
that was linked to smallest EQ. They had the thickest, heaviest legs,
Maybe some of you mammal experts know for sure, but I'd guess that horses
have larger brains than cattle, yet they have longer necks. Are giraffes
especially small brained? When compared to the over-all size of
sauropods, don't giraffe necks make up a greater portion of the animal's
total mass (so it's REALLY expensive for giraffes to have large brains)?
In any case, wouldn't we expect giraffes also to have a small EQ, if long
necks indeed foster small brains? Of course, it may be true that in
dinosaurs, small brains and long necks are linked, whereas in mammals
that is not the case. So, I don't mean to compare apples with oranges,
but just point out that maybe we really don't know why sauropods could
"get away" with having such small brains.
What advantage would it have been for sauropods to have had larger
brains? (Or, in other words, what skills, senses, etc. were
missing/poorly developed with their small brains?) Did it affect
coordination? Sense of smell? Alertness? Maybe "might makes right,"
irrespective of brain size--with their over-all size, they didn't need to
be any "smarter," and long necks had nothing to do with it.
Just things to think about before rushing to a conclusion.
Norman R. King tel: (812) 464-1794
Department of Geosciences fax: (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712 e-mail: firstname.lastname@example.org