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DUMB METATHERIANS vs EVIL, SMART PLACENTALS
On metatherians vs placentals and so on....
I haven't been following this thread, so apologies if I'm adding
comments that don't add up to much BUT - - the concept that
metatherians are somehow intellectually (??) or 'adaptively' (??)
inferior to placentals is surely very very flawed. I don't know if John
Bois is actually stating this in his communications but the inference is
Marsupials successfully invaded Europe, eastern Asia and northern
Africa during the Palaeocene-Eocene and stuck it out in Europe until
the Miocene. In historical times, _Didelphis_ has moved north
through N. America and now occurs as far north as Canada. This all in
the proverbial face of established placental competition. Also worth
noting is that Australasia is far from a 'marsupial haven': murids have
(probably) been in Australia since the Eocene yet there has never been a
mass die-off of small Aussie marsupials at the hands of ruthless clever-
witted rats and mice.
> Then how exactly did marsupials get snuffed when placentals
> didn't? Marsupial bolide homing device?
The [Cretaceous] animals being discussed are not marsupials: they are
metatherians. John's theories seem to rely on simple notions of
competitive replacement, an idea that is too simple when we're talking
about ecologically diverse groups consisting of hundreds of species.
Other researchers recognised this several decades ago.
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