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Re: How Did Hadrosaurs Survive?
On Tuesday, October 29, 2002, at 10:26 PM, Tim Donovan wrote:
Newly introducd predators have devastated some ecosystems. The brown
tree snake wiped out nearly all of the native birds on Guam. New
species, including predators, are said to evolve in isolation, then
spread. Essentially there may be little difference between the effects
of a newly evolved predator and a newly introduced one. The advent of
Tyrannosaurus apparently resulted in the extinction of various
Edmontonian taxa least able to fight it or evade it e.g.
Euoplocephalus, which was replaced by a larger Lancian defender.
There is a BIG difference between the effects of a "newly evolved"
predator and a newly introduced one. Evolution of a predator gives time
for an evolutionary response from prey. Predators do not evolve in a
vacuum. For this reason I take exception to the line "advent of
Tyrannosaurus", as if Tyrannosaurus just "arrived". Tyrannosaurus
evolved alongside hadrosaurids, and hadrosaurids with it - show me the
fauna with tyrannosaurids but no hadrosaurids.
Euoplocephalus was one of the LEAST able to defend itself?! What
possible reason could there be for thinking so? Such a statement seems
John Conway, Palaeoartist
"Do I contradict myself? Very well, then I contradict myself, I am
large, I contain multitudes." - Walt Whitman
Systematic ramblings: http://homepage.mac.com/john_conway/