Re: Waimanu

[john bois <jbois@verizon.net>]

I said:
> Yes...but perhaps the lack of diversity among small size classes (due to
avian competition/predation) >placed the whole pterosaur taxon on a ratchet
of no return.  They were doomed to low diversity of size >classes at least.
This is problematic from a taxon-wide standpoint.

My understanding is that large species (w/low reproduction rates, etc.) are
more prone to extinction.  This would seem to require a more or less
constant refuelling from among the smaller species from the same taxon.
This fuel may not have been present.for pterosaurs--if true they may have
been doomed, period.

Also, please excuse my Yogi Bera moment: "ratchet of no return".