Dinosaurs May Have Been Warm-Blooded

PxT writes: "According to this AP story, the remains of a 66 million-year-old dinosaur suggest that the extinct creatures were warmblooded - not coldblooded as once believed - and capable of the swift and sustained motion typical of modern birds and mammals. A whole site dedicated to the discovery of this specimen is here."

Comments

Media Is Stupid

[waldoj]

I've been amazed that the reaction that most of the media has taken to this story. My local news station presented the story as if the very concept of warm-blooded dinosaurs was a previously unconsidered option.

(Yes, I'm fully aware that this doesn't settle the question and, yes, I know that there was the warm-blooded backlash a few years ago, and a new push for the cold-blooded theory.)

Still, you'd think that they'd mention that this isn't any huge surprise, as exiciting as this discovery is.

-Waldo

Re:New evidence, old theory

[HomeySmurf]

I believe you are refering to The Dinosaur Heresies by Robert T. Bakker. He was one of the first people to put forth the idea that dinosaurs were warm blooded, I actually believe he was the first. He was/is something of a maverik and published his results in newspaper articles and "popular" books such as this one instead of peer reviewed journals, and his thus his ideas took a while to catch on in the mainstream paleontology world. However, it is now a commonly accepted idea the field. (I think the male paleontologist character in Jurassic Park was loosely based on Bakker, but Bakker looks like a hacker).

It is now believed that birds are the direct descendent of the dinosaurs, eg the Archaopteryx which was the first bird-like creature to have feathers. However, it had teeth, a reptile like tail, and feathers on each wing. It is only known to be essentially a bird because of the preserved feathers. Indeed, feathers are really modified scales, wrapped around on themselves. They are hollow, and have fluffy parts to provide insulation, something especially helpful at higher altitudes. Without the feathers, it would have been mistaken for a small dinosaur.

This sort of points in the direction of feathers being a development after warm bloodedness. Cold blooded creatures would be at a disadvantage when they were trying to warm themselves in the sun if they were all insulated. This points to birds being, essentially, just another type of dinosaur with just a warmer covering.

There are numerous other indicators including the appearance of what appear to be channels for blood vessels in the skulls of dinosaurs. Warm blooded creatures need to control the blood flow to the head and to both keep it warm at times and also to cool it; reptiles don't need this feature. The long strides of the predator dinosaurs point toward fast metabolisms, unlike cold blooded reptiles today, etc.

This new evidence though points clearly toward the advanced circulatory system of dinosaurs. A reptile heart only has three chambers (indeed the medical condition of a septumless heart is refered to as a having a reptile heart, I believe). A four chambered heart is required for efficient circulation, and is a feature of birds and mammals. It really shows compelling evidence for dinosaurs being able to maintain homeostasis in body temperature.

(Not bad for a physicist, eh?

Musings on warm-blooded vs. cold-blooded

[Devolver42]

I find the entire debate to be amusing.First of all, much of the evidence for warm-blooded dinosaurs dates from the late Creataceous (meaning just before the Big Dino Die-Off); likewise, most of the cold-blooded evidence dates from the Triassic and early Jurassic periods (the early Age of the Dinos). Is it possible in the 150 million year gap that dinosaurs evolved to become warm blooded, because warm-bloodedness has distinct evolutionary advantages (speed, high metabolism in a food rich environment)?Just something I've mused over a lot.

Re:This is new?

[Witchblade]

Um, yes. the news here is not that dinosaurs were warmblodded (the accepted view of paleontologists for at least a decade now) but the detail of the specimen itself.

As an aside rant this is what I hate about the "science" submissions on Slashdot. The Community knows far more about obscure networking cable adapters than junior high level scientific knowledge. As an astronomer I long ago got tired of even trying to contribute to the almost weekly astronomy story posted here. Think of all the stories you tell each other about AOLer's and newbie support calls. To a scientist y'all sound that bad sometimes. I'm sorry, but it's true. On the other hand most science discussions tend to quickly shift focus to the research hardware, or whether the analysts use PERL or Python, so the quality of the post go up, but it's no longer about scientific discoveries. Oh well. Guess this is just a single-interest audience. :)