[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Belly Ribs and air sacs

Ten years ago (the last time I bought a dinosaur book and went to Dinofest) Bakker was talking about finding belly ribs on a theropod (Trex?). Was this ever confirmed?

I'm an engineer, not a paleontologist, but as I understand it....

Mammals and reptiles have elastic lungs. Air sucked in, air spewed out via the same plumbing. Two way street, less efficient.

Birds have rigid lungs. Air is pulled into air sacks in the belly, then blow n out through different plumbing. I'm not sure if the air goes through the lungs on the inbound or outbound stroke, but the point is that air only goes one way through the lungs, which is more efficient and needed to fly.

Belly ribs are needed to make air sacs work. If T-rex (or raptors or other theropods) had belly ribs, they had air sacs, and if they have air sacs, they are warm blooded. Belly ribs are mostly cartillage (except on Sauropods due to size) and dont fossilize well, so the idea that theopods used bird-type lungs is controversial and not accepted by eveyone until proven.

In the ten years i was one, did anybody ever prove if theropods had air sacs?