Dinosaurs, Birds, and the Avian Lung

[JohnPWest11 (John West)]

I was enjoying reading “Are Dinosaurs Extinct? Modern Birds Connect us to Our Ancient Past”, but was disappointed that one question that bothers me was not addressed… When and in what creature did the avian lung first appear?

JW

[rsewell (RON SEWELL)]

@JohnPWest11

When and in what creature did the avian lung first appear?

There is considerable evidence that similar air sac arrangement may have featured in some dinosaurs. As soft tissue fossilization is rare, especially of internal organs, the extent of physiological systematic similarity is a matter of ongoing investigation.