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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."
I asked Richard Dawkins a similar question while he was on a university tour shortly after 'The Blind Watchmaker' was published. My question was 'Do you think that dinosaurs evolved both warm and cold blooded varieties?'
His answer was 'I don't think so. No.'
Yes, I know I should have had something better to ask, but I was a ten year old kid giddy with the chance to ask Dawkins a question..
Since then, I have thought about it a bit, and his answer makes perfect sense. We don't have any living ancestors from the lines of true dinosaurs, and fossils only preserve bone structures for the most part. Granted, haversian canals and the joint structure are mammillian traits, (and now the heart) but we know independant eveolution of advantageous traits to have occurred time and time again. We have only the 'primitive' reptiles, cartalagenous fishes and mammillian ancestors to go by, so we really can't say. It's like saying what colour they were; No certainty, and the favoured answer waffles..
.sig: Now legally binding!
As a closest paleontologist, I feel a little vindicated. As someone else pointed out correctly, this debate has been going on since the 70s, when John Ostrom unearthed Deinonychus, the speedy dromaeosaur that was the inspiration for Michael Cricton's Jurassic Park (Calling them Velociraptors is Gregory Paul's fault.) One could argue that the debate goes further back, all the way to Darwin's (the man, not the OS) friend Thomas Henry Huxley (the geologist, not the author [though he was the author's ancestor]), who first argued that Compsognathus Longipes could be an ancestor of modern birds. These are the little "Compy" dinosaurs that bite the girl at the beginning of Lost World.
But of course events in recent years have added to the debate. John Horner found evidence of dinosaur nesting and care, for example. Bob Bakker continued the crusade, and discoveries in China such as Sinosauropteryx or Caudipteryx zoui have more or less closed the debate, although purist Paleontologists like Larry Martin have yet to concede with grace.
The point is that this is old news, and nothing that everyone wouldn't know without moderate education. The media is obviously not properly educated in this, or anything.
What is interesting about this discovery is that it deals with a plant eater rather than a Theropod. Most of the evidence for warm-blooded in dinosaurs that I have read largely deals with the nature of the predators, whose active lifestyles lend themselves to a endothermic biology.
If an orinithiscian like Thescelosaurus is warm-blooded, it lends a lot of credit to the argument that Theropods were warm-blooded, as the groups share a common ancestor.
Have a heart... An old one...
The jwz interview was a live chat thing on slashnet,org, not a Slashdot interview. We'll have him here eventually, I'm sure.
:)
- Robin
PS - no, the editors never read Slashdot.
Well yes, and no :) I'll have to ask my GF to clarrify (shes a complete dino freak, shrugs) But anyway suppositivly many experts now say that reptiles existed first, I think this was the early triasic period. Most of these reptiles died out, and one type (which sorta looked like a large compy, don't remember the name), survived, because of its dinosaurian traits -grin- And evolved into pretty much all the dinosaurs we know today. And something that looked very simular to the crocodile also survived, but didn't exactly evolve. And no I don't know where all the other reptiles we have today came from :)
So, as an astronomer, do you prefer Matlab, or Mathematica for your calculations.... or do you write them yourself? (Begging the question: Perl or Python...)
Beware: I believe all are created equal, and have the right to life, liberty, and the pursuit of happiness.
The asteroid theorey looks realy cool on the surface but falls short. No theory I have seen to this point has adequately explained not only the dinosour die off but also the large die off in the sea. The cold, lack of sunlight ,the acid rain, and fires leaves little chance for the anphibians, coral, both fragile groups of animals and all other species that survived. Also, if you look at the number of species of dinosours as you approach the K/T boundary you see a noticable decline in diversity. This hints at the fact that they were allready on the decline.
The only reason the asteroid theory stands out is because it is simple: big boom they all die. The truth will turn out to be far more complex. The largest mass extinction event, at the permo-triasic boundary which was much bigger seems to be the chance combination of multiple factors. None of which by itself could have caused the extinction.
I suspect it will turn out to be the same for the K/T extinction. The asteroid did hit but it probably was not nearly as bad as the popular press would have us believe. Just one of a muultitude of factors which affected not only the land but oceanic environents.
Yes, and they (and other reptiles) have to basically sun themselves all day to prepare for such bursts of activity.
~ radiographite: art by john shepard
Well your both right. (Not really) suppositivly the gulf of mexico was helped out by a meteor, for some other reason, it got alot bigger, probably a plate technonic thing:) But probably not the same meteor that killed out the dinosaurs, but who knows when exactly..
Could you explain what stars more than 6004 light years distant have to do with the age of the Earth?
I'm surprised that they're presenting this as "the dinosaur with a heart". I'm sure some people somewhere will make the assumption that all previous finds had no hearts and this was the first dinosaur with an actual heart.
It's 10 PM. Do you know if you're un-American?
> "I would have mercy, and not sacrifice"..."Go and learn what this means"
Clearly, it means that Bog is willing to forgive axe murderers, baby rapers, and war criminals, but not science teachers, stoners, and homosexuals.
Getting to heaven is easy; you just have to learn which sins count and which don't.
--
Sheesh, evil *and* a jerk. -- Jade
Maybe this means that the science section isn't well trafficked, if the /. people aren't even bothering to check there. I was actually surprised that it had not been posted to the main page origianlly.
I guess I find it odd that there is a science section (which could be such a cool section for the nerds that come to this site), that is so poorly used. There hadn't been any updates to the science page that were not also posted to the main page for a long time. I just wish there was more "news for nerds" in the form of cool science that did not require the use of Linux to make it to slashdot.
> God could have created the light between the stars and us
Yeah, but that's a mighty lot of trouble to go through just to lead scientists astray.
Besides, I thought we had had an explicit disclaimer to the effect that this thread was not about religion.
If you are willing to allow omnipotent dieties into the picture, then the conundrum goes away: you merely posit a Grand Unifying Theory of Science and Religion that says that some omnipotent diety did in fact create the universe 6004 years ago, but exercised his/her omnipotence by creating the universe already 15,000,000,000 years old. That way the scientists are right, because the world really is 15,000,000,000 years old, and the inscientists are also right, because the world really is 6004 years old too.
Occam would be proud of me.
--
Sheesh, evil *and* a jerk. -- Jade
I see alot of people saying " no shit". But this is important. For the first time scientists have found a dinosaur heart. This heart is a four chambered heart. Which means it would allow for a high metabolism that warm blooded animals require. This is the first substinative evidance that dinosaurs were warm blooded before now scientists were only speculating that the dinosaurs were warm blooded
It has been statistically shown that helmets increase the risk of head injury.
This article isn't trying to assert that all dinosaurs were either cold-blooded or they were all warm-blooded. They were almost certainly members of both groups.
:)
:)
If you look at modern reptiles, the larger species tend lead more or less sedentary lives, whereas the smaller ones tend to be far more active. They are specialized to handle whatever environment they exist within..Larger herbivorous dinosaurs (hey look, I used my big word for the day..herbivorous!) would generally have no need for long, sustained periods of activity. They dont hunt. Meanwhile, other species depend on hunting and scavanging for a living, and perhaps could benefit from the advantage of being warm-blooded.
Also, when talking about a period of time as large as this, there were no doubt adaptations from cold to warm-blooded. After the mass extinction that signaled the beginning of the Cretaceous era, generally the only forms of life which thrived were those which were small, warm-blooded, and smart.
Anyway, all that science mumbo-jumbo is beside yje point. If I were a dinosaur, I would prefer being warm-blooded to escape predation. Its kinda hard to hide behind a palm tree when you're 5 stories tall, and as wide as a house.
Bowie J. Poag
Project Founder, PROPAGANDA For Linux (http://metalab.unc.edu/propaganda)
Bowie J. Poag
uhhhhm, no it didn't. It created the Chicxulub crater in the Yucatan peninsula, not the gulf of mexico. something big enough to create the gulf of mexico slamming into the earth would've probably created another moon. oh, and the energy released in the resulting explosion that formed the Chicxulub crater was over (the eqivelent of)100 million megatons of TNT. by comparison the entire world supply of nuclear weapons detonated at once would produce about a 60,000 megaton explosion. next time get the facts, nice try tho.
- "Hear that?! The percolations are imminent! Cease your ingress!"
He said absolutly nothing about religion, did he? Anyways there is reason to believe that our whole idea of carbon half-life is comply bunk. There has been a few examples of things that were known to be only a few hundred years old, that were carbon dated to be several hundred thousand years old. But anyhow I really don't keep up with this stuff, I only ask the previous posted to come back, I am accually interested in his evidence, as its rarly reported. (As for evolution, I honestly don't care, but its a big all hairbrained, I mean geez, if you believed everything evolution taught us, you would know that my golden retriver couldn't mate with your taco bell burrito)
As irritated as I am when generally mainstream scientific theories like dinosaur warm-bloodedness are touted as breaking news decades too late (and as annoyed as I am when stuff shows up in my slashboxes days before it makes the main topic) I'll leave those issues to others.
Instead I'd like to suggest that as you read the many intelligent postings (I hope you're filtering at +2, I'd be afraid to go any lower on *this* topic), you think about man.
The ancient reptile line seems to have had one (or a relatively small number) line that exploded into the panoply of mainstream dinosaurian lines we all know and love so well.
Mankind has similarly exploded into a marked predominance of the earth's biosphere in it's own peculiar sense [But never forget that the ants under your yard may exceeed your family's total biomass -- let's not get too carried away with ourselves). I find it fascinating, whenever I read any new evolutionary tale, to ask what this might mean for man (or his technologies) evolution in 1-100 million years. Pure speculation for a species that has only been around a fraction of a single million, but we monkey men are so fascinated by colorful ideas and sparkly concepts.
For example, it's very odd to think of ourselves diversifying as the proto-dinosaurids must have done, to fill countless niches. But that *IS* the hallmark of biological success throughout the known fossil record.
The hallmark of biological failure, on the other hand, is well known and easily envisioned. Fortunately that doesn't make it any more likely.
[1] since evolution does not 'select' or 'optimize' with a purpose, all evolutionary narratives are simply intelligible "Just so" stories, a la Kipling
__________
If you can go to bed, knowing you did a valuable thing today, you're very lucky. If you can't... it's not bedtime
Actually, it is non-shelled eggs that are fertilized outside the body. Fish and amphibians (sp?) lay such eggs. Shelled eggs, on the other hand, must be fertilized inside the body because they need to be fertilized before the shell is applied.
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Why do people moderate OOG down? I don't get it. What did he do wrong? He is not pissing anyone off, and I actually think his posts are damn funny. He isn't repeating some dumb old line about hot grits or petrification or natalie portman or all three combined. He actually says original, FUNNY stuff. Why do you think he is bad!? Just because he types in all caps? *sigh* It's part of his freeking character!
Actually, keep moderating him down. I find it even funnier when OOG racks up 34 mod points in a single post. I'd like to see anyone else do that.
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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
Think about modern large predators like the big cats. They eat animals that are about the same size as them, therefore they ingest enough food to regular their body temperature. Since T-rex lived during an era where all of its prey would be about the same size it could do the same thing as today's large predators. The logic is that if a large warm-blooded animal eats too small of prey, it will exhaust its food supply just to keep itself at a sustained level. The evidense is that the T-rex formed small pair bonds (mom, pop, baby) and would follow the herbivors about (IIRC). Their small number means they can feed at a higher than sustinence level and be healthy wealthy and mean lookin.
I'm a loner Dottie, a Rebel.
WHY YOU SLASHDOT GEEKS NOT ASK OOG??? OOG LIVE WITH MANY DINOSAUR!!! ACTUALLY, OOG WELL AWARE THAT DINOSAURS WARM BLOODED BECAUSE OF EXPERIMENT!!! OOG BUILD GIANT RECTAL THERMOMETER AND TOOK TEMPERATURE OF MANY DINOSAUR, ALMOST GET EATEN SEVERAL TIMES IN PROCESS!!! ACCORDING TO RECTAL THERMOMETER RESULTS, OOG CONCLUDE DINOSAURS WARM BLOODED!!! THIS NO SURPRISE TO OOG, JUST SURPRISED YOU NO CONSULT OOG ABOUT STORY!!! OOG BREAK HEAD WITH 30 FOOT RECTAL THERMOMETER!!!
OOG THE OPEN SOURCE CAVEMAN!!! OOG BREAK HEAD WITH OPEN SOURCE CD!!!
You're right about the marine extinction. It's easy to deduct, just take a look at the difference between the land masses at the beginning of the Triasic and end of the Cretaceous. There were tons of inland seas that disappeared during the age of the dinosaurs not only due to tectonic plates drifting apart but the formation of large mountain chains.
I'm a loner Dottie, a Rebel.
Would you be so kind as to perhaps point to an online reference where this DoD paper might be found? I did a quick search on google and Fastweb and have yet to turn up anything.
The idea that dinosaurs were warm blooded has been around for many years (I remember a book about it being on my dad's bookshelf in the 70's). It's widely (but not universally) thought to be correct by now. Finding something of the structure of one dinosaur's heart is just one more bit of evidence supporting the theory.
What about crocodiles? They can move very quickly when they want to.
Mea navis aericumbens anguillis abundat
I submitted this story in the goddam Creataceous period! And slashdot is just posting it now? I'm *sooooo* pissed off.
> Anyways there is reason to believe that our whole idea of carbon half-life is comply bunk.
Yeah, and tree rings and ice cores too. And plate tectonics above the Hawaiian hot spot. And burned out suns. And stars more than 6004 light years distant.
All bunk, I say.
(Poll: Should I give a hint for the readers with sarcasm impairment?)
--
Sheesh, evil *and* a jerk. -- Jade
Evolution doesn't work quite like that. An entire category of animals isn't going to evolve a feature in unison. Evolution can be thought of as series of profitable mistakes, and while it is perfectly likely that some species evolved to be warmblooded, and then different dinosaurs evolved from that species, it is rather unlikely that all (or even that most) of the dinosaur types evolved warmblooded traits in parallel.
What would happen instead is one species eventually becomes warmblooded, and because of being warmblooded dominates the other species, eating their food supply. This then causes the warmblooded species to procreate more than the other species in the area, severely limiting the opportunities for the other species to make similar evolutionary advances.
Did I just read that post I'm replying to?
/. has any misconceptions about THAT...
Dude,
oh man, I'm at a loss for words. Just...
Dude,
chill OUT. I doubt anyone on
geez
I wish you could see my fits of laughter I'm in right now.
--
grappler
Vidi, Vici, Veni
I don't know that voice, but I was reading it in the voice of those grunts in Warcraft II.
"Zug Zug!"
Actually, there are lots of good voices in that game.
The death knights sound (and look) just how I imagined Tolkien's ringwraiths would, but I ramble...
--
grappler
Vidi, Vici, Veni
If he keeps this up for just a few more days, I bet he'll earn a permanent place in Slashdot history. All those posts you see that make fun of first posts, emacs/vi flamewars, grits, and all that, will start adding references to OOG.
:-)
OOG HIT SLASHDOT ATTENTION PAYDIRT!!! OOG NO NEED HOURS OF EFFORT AND MENTAL IMBALANCE THAT SIGNAL 11 NEEDED TO GET NOTICED!!! OOG BASH SIGNAL 11 ON HEAD WITH BIG ROCK!!!
Oog groks the concept of "cluestick"
--
grappler
Vidi, Vici, Veni
Dr. Robert Bakker proposed this theory years ago. Here is his book.
As for the mass extinction 230 million years ago, that, too, has been proven to have been caused primarily by an asteroid impact. There are 5 huge craters in the Northern hemisphere that, when you account for continental drift, line up perfectly, indicating that a large asteroid broke up either by an older collision in space, or upon colliding with our atmosphere.
However, yes, you're correct when you state that the dinosaurs appear to have been on the decline towards the end of the Cretaceous period. It's possible that they were headed for a new evolutionary jump prior to the asteroid impact.
Again, as with the Permian/Turassic extinction, the conditions were already set for a global mass extinction. The fact that an asteroid impacted the earth was purely coincidental. The fact that the two largest mass extinctions have coincided with asteroid impacts doesn't necessarily indicate that they were the sole causes. Both periods were undergoing climactic changes, partially because of continental drift, partially because of the age of the planet. Similar events have happened in the last 10,000 years, with humanity's knack for killing things, as well as during the recent (geologically speaking) ice ages and during the Devonian period. Had a catalyst such as an asteroid impact occurred during any one of those periods, it's likely that much of the plant life would have died out, resulting in the collapse of the food chain, again, leaving only the smaller animals to survive. It wouldn't have happened immediately, but over a period of possibly hundreds of years.
-- Chris Dunham
http://www.chamdex.com
Start with this one.
You might start in this section first.
Actually start off with this question. You know about tree rings? Well many things lay down layers year after year in the same fashion. For instance glaciers. If you go to Greenland, drill, and count, you get a record that goes backwards in time a few hundred thousand years, not only saying the Earth is older than that, but also saying that there have been no global floods, etc in that time. The 160,000 year record from Vostok is good enough to make my point though.
Please folks. The fact the Earth is no spring chicken has been an accepted fact of science since before Darwin, and it something we have lots of independent confirmation on.
Regards,
Ben
My usual seat in the cluetrain is at A HREF="http://pub4.ezboard.com/biwethey.ht
It seems likely that the AP headline write just missed the point (headlines frequently have little to do with the real discovery in a science piece). I seem to recall that it's been generally recognised for years (decades, actually) that dinos were probably warm-blooded (like birds), but finding a four-chambered heart with one large aorta sounds fairly new to me. A three chambered heart (like modern reptiles have) makes it difficult to exert large amounts of energy in a short time - a sprint, for instance - because returning venous blood gets mixed with the fresh oxygenated arterial blood from the lungs. A heart like the one they've found (more resembling that in birds or mammals) would be better for jumping around predator style, as my cat is having fun doing at the moment. Since dinos are supposed to be more the ancestors of birds than modern reptiles, this would seem to make sense.
Of course I could be off; it's been a while since evolutionary biology. Anyone remember the author and title of a Scifi mystery story where a creature's three-chambered heart was the deciding whodunit factor?
-- Life is short. Forgive quickly. Kiss slowly. ~ Robert Doisneau
What's with this 66 million years crap? Everywhere I turn, this evolution trash is being shoved down my throat when so little (closer to no) evidence supports it and so much evidence does just the opposite. The earth is more likely only several thousand years old. I know this is all off-topic but it just makes me sick sometimes. Moderate accordingly. I won't offer anything to support my claims right now because frankly I don't feel like it. It's 12:45AM and I have to be at work at 8:00.
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.
Devolver's Homepage... more fun than a box of crackerjacks.
Comment removed based on user account deletion
Once again, I advice the pleno titulo Slashdot editors to ask some biologist before posting any media sensation they find. Look, for me, as a biologist, reading such "sensations" is more or less like for a Linux user reading a media coverage about a new Mindcraft test on Linux and Windows NT, clearly showing that Windows is superior.
I'm always sorry to see Slashdot to fall for any publicity made by Venter et. al. or any other scientist claimingthat he has discovered America.
Regards,
January
On the other hand, it looks to me like OOG was hit with the troll tag by someone who doesn't understand his art, so eliminating the overated tag wouldn't help in this instance.
The overrated tag seems mainly used as a way to "get even" with people on Slashdot who you don't like. (Especially people who have the affront not to check their "no score" box.)
I'm actually more interested in the relative intelligence of dinosaurs compared to other animals. I don't believe they were as non-intelligent as they were portrayed in many of the science fiction stories I've read. Of course, we won't really know this until we start breeding them in captivity...
All the creatures will die, And all the things will be broken. That's the law of samurai. (Jubai, 1605)
I'm no paleonthologist but I remember reading somewhere that if an asteroid caused their extinction, it was because the cloud of dust has so thick that the sun couldn't pass through and so the dinosaurs, cold-blooded as they were, died, and the tiny warm-blooded mammals managed to survive.
So is this theory to be discarded? Was it even likely true sometime?
"All the things one has forgotten scream for help in dreams". Elias Canetti
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. :)