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Re: ... vs energy deficient gigantothermy (boo hiss)

Yesterday I wrote:

> > [...]
> > let's also remember that 140 million years of evolution has
> > yet to produce a bird that even comes in at a tonne, much less a
multitonne one;
> > and birds are twice as metabolically active as mammals.
> And birds are K-strategists,

Big ratites are, as HP GSP informed me, quite classic r-strategists. (I
should have known that... :-] )

The rest, however, has held up so far:

> and they have IMHO not yet had a chance to grow
> to gigantic sizes. The carnivorous ones had no gigantic prey available,
> the herbivorous ones are seemingly too young (the biggest aepyornithids
> moas were among the last).
> Of course, this changes if we interpret "birds" as Aves, accept the usual
> definition of Aves as *Archaeopteryx* + Neornithes, and "accept" my
> phylogeny... then the biggest bird weighed something between 4 and 7
> was 12 -- 14 m long, and is known as *T. rex*. B-P