Re: Looking for patterns in extinctions.

["Nicholas R. Longrich" <longrich@phoenix.Princeton.EDU>]

        What is really pretty interesting is New Zealand. I believe 
there's been discussion on this list that it bore fauna similar to those 
of late Cretaceous Australia/Antarctica, which it broke away from during 
the late Cretaceous. Note, however, that not only did nonavian dinos die 
out there, but mammals did as well. Perhaps, of course, they made it 
through and perished sometime in the Cenozoic, but that seems unlikely, 
seeing how well they've done recently- the introduction of rats, etc. 
What NZ does have are tuataras and primitive frogs (geckos, too- did 
those raft in or were geckos around in the Late Cretaceous?) which did 
survive the K/T boundary in New Zealand. As for ratites, does anybody 
have any ideas about whether they became flightless before or after 
breaking away? Were they even around 70 million yrs. ago?
        At any rate, NZ appears to have had an extinction pattern in many 
ways similar to what we seem to see elsewhere- dinosaurs die, lepidosaurs 
and amphibians survive, or at least scrape through (again, does anybody 
have any ideas about whether ratites are part of NZ's original animal cargo 
that broke off of Australia/Antarctica?) - BUT it would seem 
that the mammals would NOT have made it through in this case (or again, 
they could have bought it in the Cenozoic, but that seems less likely).
        This might tend to support the idea that mammals did take quite a 
beating coming across the K/T, and that at least in one place on the 
globe, were completely wiped out. Blatant speculation: Other areas may have 
been depleted by an extinction event as well, but unlike New Zealand, were 
open for recolonization.