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Re: The New Paper That Time Forgot

My question in regard to all of this is do we actually know that any dinosaur had a cross-current unidirectional system in place? I can accept that the most bird like dinosaurs (maniraptors, deinonychosaurs etc) probably had the full suite of avian respiration in place, but I'm less inclined to say the same thing for dinos further from the avian side of the family.

We have evidence of air sacs, but what evidence do we have for unidirectional flow of air? Surely one likely came before the other. As there are other animals today (certain snakes and insects) that have air sacs, but no flow through system of gas exchange, I'm inclined to think that air sacs came first; flow through second.

Sure, but what is the possession of both cervical and abdominal air sacs good for? And evidence for both is known from carnosaurs (most prominently *Aerosteon*) and sauropods.

The authours [sic] argued that Lehman and Woodward had based their data strictly off of long bone studies, but they didn't. Lehman and Woodward used the exact same specimens that Erickson et al had used. Sander and Clauss obviously had no problem with those specimens, as Erickson et al was frequently cited, so I see no reason for them to complain about the Lehman and Woodward study either.

OK, I'll read the paper. (I'm woefully behind on dinosaur literature.)

The authours also stated that gastric mills were not present in sauropods. Has that been confirmed now? Are sauropods officially considered not to have gizzards anymore?

There was a paper on this topic a few months ago that got a lot of DML coverage, as I recall.