The first time I ever heard about the warm-blooded/cold-blooded debate was when I was quite little, courtesy of my older brother. He was going through his dinosaur phase at the time. (I’m convinced that all little kids – particularly of the male variety – go through a dinosaur phase.) At the time, it seemed kind of ridiculous, since everyone knew that dinosaurs were big lizards – hey, that was even what their name means, right? But I’ve felt more and more drawn toward the warm-blooded camp the more I’ve seen about feathered dinosaurs – and also the more videos I’ve seen of large modern day reptiles. My imagination just likes the idea of a fast, scary, warm-blooded T-rex a lot.
The new research fits well with a previous study on dinosaur cardiovascular anatomy, based on a CT scan of a 66-million year old dinosaur fossil with a preserved heart.
…wow. And I thought the preserved soft tissue thing was cool. However, I did some googling around trying to find more about this bit of awesomeness, and was pretty disappointed. There are some articles that mention it, but then there’s this: Dinosaur with a Heart of Stone which basically says, “Well, we thought it was a heart but it’s actually a normal concretion.” The link in the article isn’t that helpful, other than to confirm that the article from Science and the Wired article are talking about the same thing. But from what I’ve been able to sniff out so far on Google, there are a lot of articles from 2000 about how awesome the dinosaur with the heart is, and then a couple in 2001 claiming that it’s actually just a concretion. There’s this site about the dinosaur, Willo but it doesn’t really address the counter claims at all. So I have no idea what to think, here. If there are any more recent papers or refutations, they’re not to be found easily with internet searches. Maybe that means the initial paper stands as far as people are concerned, and that’s why it comes in to play in this newest round of the debate.
Other than the article on Science, I’ll also note that there were a lot of creationist sites trumpeting that “the dino heart isn’t real!” Because, don’t you know, the entire case of evolution hinged on a preserved dinosaur heart. Or something. Whatever.
I also thought this was pretty interesting:
But other anatomical studies have led to different conclusions: A survey of dinosaur noses, for example, found that dinos lacked special bones in their nose, called turbinates, that protect against water loss during rapid breathing and are found in 99 percent of warm-blooded animals.
It just kind of makes me wonder where the turbinates came from, since presumably birds have them. Or what kind of pressures would cause them to evolve in birds… and when that happened. (Since what I’m thinking is… well, what if the dinosaurs were warm blooded, but conditions on Earth were such that they didn’t need these special nose bones at the time, and things changed later.) Lots of interesting questions there. I could probably go looking for papers about it, but I doubt I’d be able to understand much in them.
And the debate rages on.