Evolution of bird lungs from reptile lungs impossible?

Since birds are not usually classified as reptiles it is true that reptiles are not monophylogenic.However, the majority concensus is, I believe, that the synapsids (mammals ancestors) split from the amniote line earlier than the diapsids (turtles) and anapsids (other reptiles) split from each other. It is possible to define reptiles to be the crown group of turtles and lizards. In that case, birds would be reptiles by definition.

I might add that the closest extant relatives to birds are believed to be the crocodiles (classed together as Archosaurs). It appears that modern crocodiles have certain features in the heart and lungs in common with modern birds.

Hello, deerbreh.Unfortunately, I am not an expert in this stuff by any means. I only know what I gleen out of magazines, books, and a few internet pages.I love the Palaeos website. Not only does it have some cool cladograms, but it is full of fun information. I only wish I knew how much of the information reflects the scientific consensus and how much of it is the authors favored theories. But it really is a great site.It has a nice page describing the history and problems of sorting out the phylogenies of the archosaurs. But it seems to claim that the Euparkeriidae were close to being a basal archosaur. It seems that the Euparkeriidae were already beginning down the road to what we think of "dinosaur-looking" -- the crocodile line then took a turn to becoming "lizard-like" again.The top picture on this page has an artist's rendition of a euparkeriidan.Cheers!

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we actually breath rather inefficiently, mixing our oxygen and carbon dioxide.

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Wait a minute! Does that mean we have that "half-a-lung" that creationists say cannot exist?

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"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt