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Re: (fwd) Mammals as a cause of Dinosaur extinction



> Giant reptiles (turtles) have "ruled" the Galapagos islands for a long
> time. It is my understanding that recently imported dogs and cats have
> caused a decline in the turtle population due to their predation of
> turtle
> hatchlings. The same predation has also reduced the population of the
> other
> Galapagos "rulers", the Iguanas. Why is it not a feasible possibility
> that
> newly evolved (Late Cretaceous that is) placental mammals damaged the
> dinosaur population by eating their young. The adult Dinosaurs (just
> like
> adult Galapagos turtles) would be invulnerable to mammal attack but
> their
> young would not be so lucky. Question--- When did definable placental
> mammals evolve? Was it not in the Late Cretaceous, at about the same
> time
> that the number of Dinosaur species declined?

Of course, marine iguanas, dodos, and giant tortoises are totally 
without defenses and unsuited to an environment with predators.  I 
can see a troodontid eating a little rattish pre-mammal, but I can't 
see a dodo eating a cat.  I don't think that thousands of wholly 
different species could be wiped out by the destruction of their eggs 
and young.  I don't think that island bioecology can be compared to a 
global environment.
Chris Straughn

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