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Re: dino extinction



>Mesozoic mammalian faunas of Australasia are very poorly known; to my
>knowledge, only two species, both monotremes (E. Cret., sthn
>Australia), have been found in the region.  Nevertheless, it is
>possible that only monotremes and marsupials existed in the Antipodes
>during the Cretaceous.  In other words, placentals may never have
>arrived there in the Mesozoic.  So, if Archibald's data holds true
>for New Zealand, then the event that nearly wiped out the marsupials
>of North America could easily have wiped out ALL of NZ's mammals.

A condralath (placental) mammal has been found in the Earliest Eocene
deposits of Murgon, south eastern Queenland, strongly suggesting that
placental mammals were present in Australia prior to separation from
Anctartica at 38mya. Although the evidence is scarce, the plot appears alot
more complicated than the old hypothesis of "Marsupials survived in
Australia because placentals were not there to kick their evolutionary
freckles".

While we are at it, salamanders have also been identified at Murgon, a
group not known from modern Australia.

>> I don't think that they were there in the past 65 million years and
>> went extinct. And I don't buy that they weren't there initially.
>
>Almost certainly there were mammals there.  Just the wrong types of
>mammals.

Bah, humbug! this is supposition based on prejudice (exactly what is the
right king of mammal?).

>
>>  Which makes me think that it's likely that whatever did
>> in the dinosaurs did in New Zealand mammals as well.
>
>Agreed.  And the enantiornithines, and the pterosaurs, ...etc. etc.


And the forams world wide? And the ammonites? And the _ad infinitum_? I
have yet to see any serious correlation between the lack of mammals in New
Zealand and the extinction of dinosaurs.

Cheers, Paul


Dr Paul M.A. Willis
Consulting Vertebrate Palaeontologist
Quinkana Pty Ltd
pwillis@ozemail.com.au