[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

NEW ZEALAND'S WONDERFUL LITTLE WORLD



Darren Naish wrote:

>What would these mammals be, if they were there? Relying on the fossil
record,
>the only candidates (so far as I know) are monotremes. By the Lower Cret,
>Australia had _Steropodon galmani_, and though S. America and presumably
>Antarctica had moderately diverse marsupial, dryolestid, triconodont etc.
>assemblages (Molnar 1989), as far as is presently known none of these got
as far
>as Australia (and, therefore, never as far as NZ). _Tingamarra_, a basal
>ungulate from the Eocene, is Australian. Just what it shows is very open to
>interpretation and I shan't bother to speculate.

My thanks to Darren for all the NZ information, but I am not certain he is
correct here.  My understanding is that NZ is considered to have broken
away, not from Australia, but from West Antarctica, with Australia having
come off East Antarctica, so that there was never a direct connection
between them (I may have this backwards).  Anyway, I gather that there has
been a suggestion that the bit NZ was attached to was in itself more
depauperate than the other half of Antarctica.  If this is true then the
presence of a taxon in Australia is not necessarily a prerequisite for its
presence in NZ (other than for trans-oceanic dispersal or autochthons), but
its presence in Antarctica would be.

[at least on bit of NZ was formally part of Australia - Chris]

--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2          Internet: ornstn@inforamp.net