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Re: dino extinction

> >(_Tingamurra_) from the early Tertiary of Australia hints that the
> >dominance of marsupials on this continent came about not through
> >default (i.e. the absence of placentals), but because the marsupials
> >were competitively superior to placentals.

You're right.  I should have wrote "were competitively superior to
placentals IN AUSTRALIA".

>         Actually, I think it would be best to assume that other factor were
> in effect, considering other instances when placentals beat out the
> marsupials.  Perhaps marsupials just had a stronger foothold in Australia?
> As with the invasion of South America by placentals, simple "just-so
> stories" do not seem to always adequately explain evolutionary phenomena
> (although they can be useful, there is a paper in _The Beginnings of Birds_
> which covers this topic in some depth, from a more amicable perspective).

> +--------------------------------------------------------------------------+
> | Jonathan R. Wagner            "You can clade if you want to,     |
> | Department of Geosciences      You can leave your friends behind |
> | Texas Tech University          Because your friends don't clade  |
> | Lubbock, TX 79409               and if they don't clade, |
> |   *** wagner@ttu.edu ***       Then they're no friends of mine." |
> |       Web Page:  http://faraday.clas.virginia.edu/~jrw6f         |
> +--------------------------------------------------------------------------+