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Re: Dinosaur weights

In a message dated 97-08-21 19:12:36 EDT, mattf+@pitt.edu writes:

<< You are right, of course, about how to define density, but I think that
 point at issue here is whether the dinosaurs were less dense than water,
 since it is being argued that there volume was, in part, composed of
 non-living gas poskets.>>

The issue is thus whether the density of the bones is sufficient to average
out the density of air pockets and whatnot. Who knows? To a first
approximation, it certainly does. To within a few percent, maybe dinosaurs
were lighter than water.
<< What about birds?  Same density as water? >>

Pretty close. Diving birds lose the hollows in their bones and are thereby
able to travel underwater to capture fish. Ducks and other waterfowl require
air-trapping feathers to float on pond surfaces; if these lose their
air-trapping ability, the birds ride much lower in the water.