From: Michael Lorrey (retroman@together.net)
Date: Wed May 27 1998 - 17:31:17 MDT
EvMick@aol.com wrote:
> And I was wondering if any other similar interesting info was known?
>
> And sure enough Micheal Lowery ( sorry, its Lorrey) comes thru.
>
> >>>The reason why dinosaurs that we know
> popularly (most were actually quite small) are so big is that they developed
> at
> a time when all or most of the continents were part of the Pangea super
> continent. Studies have shown that there is a direct correlation between the
> evolved sizes of animals and the size of the land mass which they inhabit.
> <<<<<
>
> So that explains it..."Range Size"...
>
> Small countinents don't have enough grub for really BIG critters...
Yes, and it also includes other factors, like the geographic features that limit
an animals range beyond just oceans. Also a really effective big predator will
evolve when there is an oversupply of really big herbivores, yet if it is too
effective, it may kill itself off when it kills off its main food supply, or it
may evolve to be smaller if its constant effective predation restricts its main
food supply. As for the swimming or non-swimming status of brontos, which while
they may not have lived totally submerged, could easily have been merely waders.
Then again, there are plenty of ocean faring dinosaurs which were quite large and
had long necks, and were very nearly the size of brontosaurs.
Another factor lending to large body size is climate. In a cold climate, large
animals will tend to develop, since you have the ratio of body mass to surface
area in an animal changing drastically the larger you grow. A large animal retains
body heat in a cold climate much easier than a small animal. It is likely,
especially considering the cold-blooded and semi-cold blooded physiques of the
dinosaurs, that they grew in size to better retain body heat in a climate that was
slowly shifting toward the chilly side.
We can see this during the last ice age, when the woolly mammoth had grown to
almost twice the size of the present elephant, and we had the Cave Bear, a
creature several times the size of the largest grizzlies today, as well as the
Sabre Toothed Lion, which was twice the size of present day mountain lions.
-- TANSTAAFL!!! Michael Lorrey ------------------------------------------------------------ mailto:retroman@together.net Inventor of the Lorrey Drive MikeySoft: Graphic Design/Animation/Publishing/Engineering ------------------------------------------------------------ How many fnords did you see before breakfast today?
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