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Re: dino extinction
From: Nick Longrich <longrich@phoenix.Princeton.EDU>
> Now, I can understand severe environmental shifts, but the
> disappearance of ALL large land herbivores and ALL large land carnivores
> implies to me something more on the order of environmental holocaust.
Or a series of lesser events that each stressed the animal populations
before they had recovered from the previous event. Not a knock-out
punch, but rather a rain of punches that accumulate to make a knock-out.
> New Zealand. New Zealand broke apart from the remains of
> Gondwana ~80 mya ago bearing a full cargo, and the only things that
> survived to modern times were ratites, geckos, the tuatara, frogs, etc.
> Now, what the HELL happened to all the mammals? ... Which makes me
> think that it's likely that whatever did in the dinosaurs did in
> New Zealand mammals as well.
That is certainly a possibility. The fossil record would help here.
However there some things to keep in mind:
- extinction rates are generally higher the smaller the
- there was also a substantial mass extinction at the
end of the Eocene, and there have been many extinctions
during the Pleistocene/Holocene, which may or may not
have been anthropogenic.
- The Maori certainly caused many animals to become extinct
in New Zealand, and other island peoples have caused at
least mmost mammals to become extinct on their islands.
[And I think the Easter Island people drove about everything
So, we have several more possiblities here, which singly or in
combination may have done in the New Zealand mammals. Only a close
look at the mammalian fossil record of New Zealand will allow us to
distinguish these causes. I do not know much about the New Zealand
fossil record, so I cannot tell what it says about this issue. (It
may be too sparse to answer it definitively).
The peace of God be with you.