Re: Resources, energetics and dinosaur maximal size

[Augusto Haro <augustoharo@gmail.com>]

> A 56-tonne *Brachiosaurus altithorax*? OK, a fifteen-tonne one might be too
> light despite all air sacs, given the reported existence of ten-tonne and
> apparently even thirteen-tonne elephants. So let's say twenty. OK, thirty.
> But fifty-six? In an individual that's not grossly obese? Seriously?

That's some question I always have: how much of the visceral cavity in
non-neornithean dinosaurs was filled with air sacs? Has someone
estimated if there is some correlation between pneumatization of
vertebrae/ribs and proportion of the visceral cavity occupied with air
in birds, in order to at least approach an answer? I suppose diving
birds may decrease the correlation, but truly do not know, and do not
know if the correlation would exist even if removing those birds.
Wedel (in one of his many papers) says the presence of air sacs in
non-pneumatic dinosaurs is a likely possibility, in such a case the
problem of determining weight should be greater...