In the process of writing a post on bird evolution, it occurred to me that it might be helpful to re-post something I wrote a couple of years ago covering research reported by Paul Sereno about new fossil material from a theropod known as em>Aerosteon riocoloradensis</em>. When I went to look at my original post, I was reminded that there was quite a bit of other writing on the blogosphere (and elsewhere on the Intertubes) about this find. Here, I'd like to give you the bottom line (insofar as what I wanted people to know when referring back to my repost) and then, in the interest of both full scientific disclosure and prurient fanning of the flames of professional flamosity (though I quickly add that this second outcome is incidental, not my intent) I'll provide a summary of the blogospheric discussion along with my repost, and links for you to follow.
First, the bottom line: em>Aerosteon riocoloradensis</em> is a dinosaur that had a respiratory system like that found today in birds, in the sense that it seems to have been adapted to maximize the flow of air across gas-exchange surfaces (like what we have in the lungs) in order to be super-good at aerobics. It seems that the various experts (to whom I refer below) have various ... ahem ... bones to pick with each other but all agree on the basic fact that this dinosaur breathed somewhat like a bird. Remarkably, this dinosaur is NOT a bird ancestor. It is on another branch of the dinosaurs that were related to birds, but not ancestral to birds. And that is the point I planned to make in my post on bird evolution. Which is not written yet but to which I'll put a link right here instead of this very sentence you are reading right now.
And now, on with the show:
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First, the bottom line: em>Aerosteon riocoloradensis</em> is a dinosaur that had a respiratory system like that found today in birds, in the sense that it seems to have been adapted to maximize the flow of air across gas-exchange surfaces (like what we have in the lungs) in order to be super-good at aerobics. It seems that the various experts (to whom I refer below) have various ... ahem ... bones to pick with each other but all agree on the basic fact that this dinosaur breathed somewhat like a bird. Remarkably, this dinosaur is NOT a bird ancestor. It is on another branch of the dinosaurs that were related to birds, but not ancestral to birds. And that is the point I planned to make in my post on bird evolution. Which is not written yet but to which I'll put a link right here instead of this very sentence you are reading right now.
And now, on with the show:
Read the rest of this post... | Read the comments on this post...