[Taxacom] Two primitive mammals in one week
g.read at niwa.co.nz
Sat Dec 16 00:06:34 CST 2006
John Grehan wrote:
> They [Trewick SA, Paterson AM, Campbell HJ 2007. Hello New Zealand]
> ignore that fact that that there are biogeographic and geological models
> whereby so-called "oceanic islands" such as the Galapagos and Fiji may
> have inherited older biota through mobile island arcs etc.
They don't. Mobile island arcs as such aren't relevant, but they allow
that ephemeral islands might have existed during 'total immersion' of
Zealandia, and that some Gondwanan lineages might have survived,
although the geological evidence permits the idea of total drowning.
Their point is that the submergence or near submergence greatly, greatly
reduced the biota.
But back to the hard fossil evidence. If it holds up to scrutiny the
apparent survival of a tiny primitive mammal on NZ to post-Oligocene is
a major development in NZ biogeography is it not? It casts doubt on
Trewick et al's more favoured total immersion option. There's a lot
riding on a couple of tiny bits of jaw bone, and a femur head.
Geoff Read <g.read at niwa.co.nz>
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