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Re: Theropod "migrations"



-----Original Message-----
From: Thomas R. Holtz, Jr. <th81@umail.umd.edu>
To: larryf@capital.net <larryf@capital.net>
Cc: dinosaur@usc.edu <dinosaur@usc.edu>
Date: 23. april 1999 20:34
Subject: Re: Theropod "migrations"


>
>This pattern is also discussed by Farlow in the Ostrom Festschrift, and I
>discussed it in Evol. Bio. seminar as a grad student... (not really
>documented, though).  The big difference between herbivores and carnivores:
>many herbivores are relatively speaking specialists on certain plants.
>Different plant species, in turn, have fairly specific habitat
requirements.
>
>On the other claw, meat is meat.  If you can kill it, you can eat it (if
you
>are a carnivore).
>


This could lead to yet another possible solution: while carnivores didn't
"have to" evolve so rapidly ("meat is meat") the herbivores might have to be
fast in adjusting to the new plant menu and habitat. So while the herbivore
immigrants had to adopt (evolve) rather fast, changing their features, the
carnivores (who followed their prey to the new land) didn't have to change
their feeding habits. So the different rate of evolution change of
carnivorous dinosaurs and herbivorous ones in a new environment during a
certain (not very long) period led to the impression that mainly the
carnivorous dinosaurs were migrating. Fact is, they couldn't have migrated
very far without their food supply: they had to follow their prey - the
herbivores must have crossed the bridge first.

Berislav Krzic (Kr?ic)
illustrissimus@usa.net
ILLUSTRISSIMUS PRODUCTIONS
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BERI'S DINOSAUR WORLD
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