[Taxacom] Two primitive mammals in one week

[Geoff Read]

Ken Kinman wrote:
>     The other is particularly interesting biogeographically (as well as 
> ecologically), being a non-volant mammal from the Miocene of New 
> Zealand.  It also is a primitive mammal, splitting off not far from 
> multituberculates, so it too has its origins in the Mesozoic.  Was it 
> climate change that forced such mammals into extinction in New Zealand, 
> or what it something else?  

Like drowning when that part of NZ submerged?  It is described from 
fragments so one immediate thought I had was that it was really a bat, 
but the authors deal to that idea.

Also out today on the topic of NZ biogeography is an essay which looks 
interesting:

Trewick SA, Paterson AM, Campbell HJ 2007. Hello New Zealand. Journal of 
Biogeography 34(1): 1-6.

Abstract: " Islands of the Pacific Ocean have long fascinated 
evolutionists. Oceanic islands, generally the products of volcanic 
activity, provide natural experiments as biological populations are well 
delimited and the age of islands can be determined using radiometric 
dating. 'Continental islands', including New Caledonia and New Zealand, 
provide equally valuable opportunities for evolutionary study. For 
students of New Zealand biogeography, the peculiar composition of the 
biota coupled with a limited interpretation of geology has resulted in 
the widespread acceptance that the flora and fauna is primarily ancient 
and of vicariant Gondwanan origin. There is increasing evidence from 
molecular data that much of this biodiversity is the product of 
evolution following relatively recent colonization. Such data have 
prompted biologists to consider geological information on New Zealand in 
more detail. At the heart of the issue is the question of whether modern 
New Zealand has a terrestrial link through time with the continent 
Zealandia that split from Gondwanaland some 80 Ma. Zealandia, which 
includes New Caledonia, Lord Howe Island and several of the subantarctic 
islands, is now largely submerged, and New Zealand's present terrestrial 
existence is the product of tectonic activity initiated around 26 Ma. We 
argue that for the purposes of biogeographical interpretation, New 
Zealand can be treated as an oceanic island."


Geoff
-- 
   Geoff Read <g.read at niwa.co.nz>
    http://www.annelida.net/
    http://www.niwascience.co.nz/ncabb/