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Science

Dinosaurs May Have Been Warm-Blooded 112

Posted by emmett from the yabba-dabba-doo dept.
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."
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Dinosaurs May Have Been Warm-Blooded More

Dinosaurs May Have Been Warm-Blooded

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  • It is great that we are getting more insight into the physiology of dinosaurs. The discovery of a prehistoric animal's organs is amazing!

    This could lend major credence to the theory that birds evolved from dinosaurs, since modern day birds have four chambered hearts.

  • 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..
  • I just saw the show with that insane guy from Australia on the Discovery Channel. He was taunting and trapping big-ass crocs and what-not. I remember him talking about how crocs can only make one quick snap before having to rest. Either that, or they can thrash around for like 5 seconds or so. After that, they just go calm because they have to regain their energy. Moral of the story: if you are attacked by a croc, and he misses you on the first lunge, you'll be able to get away. Relevance to this thread: crocs can tear some stuff up (they showed a huge croc snapping a pig's spine in its mouth), but only for a few seconds.

  • Ha! (Score:3)

    by Lagos ( 67371 ) on Thursday April 20, 2000 @05:54PM (#1120099) Homepage

    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 [amazon.com] 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.

  • But only for a few seconds. Then all that stored up energy is gone. Meanwhile your warm-blooded ass has been generating more waste heat than a Pentium III. If you can survive the croc's initial charge then you have plenty of energy to run screaming for thirty miles while the crocodile has to eat and lay in the sun for awhile to recharge.
  • any time, pal. Thanks for your concise and informative post.
  • 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...)
  • 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.
  • I was stuck thinking that the crater left by the meteorite was part of the Gulf, only far less so than the facts involved in the crater in the Progresso area. However, that actually augments the argument. A theatrical engagement is defined for the purpose of the DoD study as a 'localized skirmish involving three or less parties, with a combined yield of less than 60 MT of standardized trinitrotoluene.'. If they think 1% of humanity would survive at such a low level, I have but pity the species that formerly populated the earth.. While the 60,000 megaton number cited for current total nuclear yield sounds about right, 100 million megatons sounds vastly huge. Are you sure?
  • Yes, and they (and other reptiles) have to basically sun themselves all day to prepare for such bursts of activity.
  • 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..

  • Re:66 million years? uhhuh (Score:1)

    by Anonymous Coward
    The earth is more likely only several thousand years old.

    It's not just the earth. It's the entire universe. The universe was created by God in the year 4,004 B.C. Warning to Slashdot atheists: Either you believe this or not, but if you don't, Jesus will butcher you. He will fucking butcher you. Wipe that smug-ass fucking look off your face. You may have gotten away with teaching evolution in schools for all of these years, but your Lord and Savior will have the last laugh. He will be swift. He will be brutal. And He will be merciless. And in one brief moment, you'll regret your sad devotion to "science" ..
  • Uhm, that's evil! Some of those are worth tons of money on eBay! I sold mine for a mere 50 dollars to someone, I regret doing so now :-(


    He who knows not, and knows he knows not is a wise man
  • 1) Yes one key feature (read required) of modern reptiles is that it is endothermic (read cold blooded) (see http://www.gla.ac.uk/departments/ibls/DEEB/biomedi a/units/rept9.htm), thus both smaller and larger reptiles both thermoregulate.

    2)Your argument in the original post was that larger herbivorous dinosaurs would generally have no need for long sustained periods of activity ...impling from your 1st paragraph that they were the cold blooded group. I was just giving a modern large herbivore which is not cold blooded (maybe elephants, or better hippos would be better, hippos only move quickly on rare occasions and then only for short periods).

    3)I was mearly pointing out that the argument in your 2nd paragraph, impling that larger herbivores did not need to be warm blooded, was rejected by your argument in the last paragraph that there is advantage in being warm blooded to escape predation.

    So is your argument that both herbivores and carnivores are cold and warm blooded without reasons, since the reasoning you gave strongly favored one group being warm and the other being cold. Or is your argument that there are exceptions in each group (BTW the dino heart they found was in a herbivore) which are not representative, and generally follow the logic you layed out.

  • here's a good site with even more evidence of an old earth.

    http://www.cs.colorado.edu/~lindsay/creation/index .html [colorado.edu]

    He also has a cool list of fallacious arguments. http://www.cs.colorado.edu/~lindsay/skeptic/argume nts.html [colorado.edu]

  • Common misconception. It was considered a great affront about 5 or 6 years ago when someone suggested dinos "do it" the way we do. But after a few years of fossil studying it seems pretty clear (and I've stopped seeing "RIVAL SCIENTISTS" dispute) that most scientists now have agreed that for the most part, dinos, do it like most mammals do.

    A good example of how far that thoery has come is that at least one person has put forth the theory that the small arms on dinos such as TRex were there solely for holding the other dino in place during sex... a lot like mammals.

    ---
    Openstep/NeXTSTEP/Solaris/FreeBSD/Linux/ultrix/OSF /...
  • >My local news station presented the story as if the very concept of warm-blooded dinosaurs was a previously
    >unconsidered option.

    *My* local news station teased the story as evidence about "whether dinosaurs were reptiles or mammals". :(
  • Dinosaurs and crocodiles have the same ancestor. But crocodiles branched from the dinosaurs' evolutionary line way before this line ever produced dinosaurs.

    It's very probable that dinosaurs developed warm blood (if they did) after these lines had branched.

    It's also possible that this trait only occurred in some dinosaurs, because one branch developed it, and the rest didn't.

    It's hard to say where in the evolution warmbloodedness first occurred. As it seems, somewhere between this dinosaur and the common ancestor of dinosaurs and crocodiles.

    ----------------------------------------------
  • Could you explain what stars more than 6004 light years distant have to do with the age of the Earth?
  • That the dinosaurs were killed by the extinction and mammals and birds weren't doesnt have anything to do with warm/cold bloodedness, as I understand it. Many species of cold blooded reptiles survived (lizards, turtles, etc). The dinosaurs were vulnerable because they were on top of the food chain. Large herbivores need lots of plant life to feed on, and large carnivores need lots of large herbivores. If there's a big plant die-off, the big animals are all gonna die too, but smaller animals, such as rodent like mammals and birds, can scavenge and survive on fewer resources.

    As for the marine extinctions i believe the groups most afftected were those that lived exclusively in shallow equatorial seas that depended on a warm current that circled the globe. continental movements and lowering sea levels were already messing wiht these conditions, and the big impact pushed it over the catastrophic edge. Or something like that. It's widely regarded that the impact was the key factor in the extinction, but there were other things involved.

  • Yep.. but consider the relative speed of a liazard to its size.. If you were in a full run you could easily keep up a lizard. so quick there is relative :)

  • Yep. There have even been certain situations where museums have re-organized bones in their displays to account for this (to show that dinosaurs were much more `active').

    Too bad the site's videos are in Sorenson.. I think a lot of people interested in this discovery are on Unix systems..
    --
    Ski-U-Mah!
    Stop the MPAA [opendvd.org]
  • How do you know he didn't take the temperatures at night?

    ;-)
  • 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.
  • > "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.

    --
  • This story is redundant. It had already been posted to the science section way earlier in the day. See here [slashdot.org].

    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.

  • You forgot to mention that the discussions quickly shift to whether there were a Beowulf cluster of the devices in question, and what Natalie Portman thought of them while pouring hot grits down my pants

  • Re:hrm (Score:1)

    by AndyL ( 89715 )
    Forget the article did you even finish reading the summary? The news here is the discovery and analysis of the Dino-heart. Not the warm blooded theory.
  • > 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.

    --

  • the reason this is important (Score:3)

    by lubricated ( 49106 ) <michalp@@@gmail...com> on Thursday April 20, 2000 @05:18PM (#1120128)
    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

  • Something to keep in mind. (Score:3)

    by Bowie J. Poag ( 16898 ) on Thursday April 20, 2000 @05:56PM (#1120129) Homepage
    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 [unc.edu])
  • I believe the problem with the asteroid collision was more related to massive overall environmental change causing everything existing at the time to ante up for their survivability. I had heard the cold blooded vs warm blooded thing mentioned but only as a one-of-many factor argument.

    All the food (plants, other animals that ate plants, insects that breed in other animals...) for most critters at the time was dealt a rather hefty shock, so all the critters (love that word lately) had to deal with a drastic change followed by a long period of calamitous weather conditions.
  • 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.
  • Dr. Bakker? Hey, I remember him now. He stayed at my house once when my dad was still teaching Biology at Penn State, but that was 7 years ago. I belive his theories also included that dinosaurs may have been more closely related to birds than reptiles, or at least that they were a link between the two. So, not only is this not breaking news, it's not even the whole story.

    thePsychotron
  • Check your info. Crocodiles actually do have completely divided ventricles! But unlike mammels and birds, they still have the reptilian ability to shunt blood from the lung circuit. This allows crocodilians to regulate their metabolism to some extent between active and languid configurations.
  • 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)
  • [No, this is not off-topic.]

    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

    __________

  • There's been plenty of substantive evidence that dinosaurs were warm blooded and had high metabolism. This find is just more fuel for the fire. The structure of dinosaur bones is like that of warm blooded creatures, with plenty of channels for blood to feed oxygen hungry muscles. The fossil evidence points to very fast growth rates, with large dinosaurs gaining tons of weight within a year or two. Many dinosaurs could fly (a very high metabolism activity). Population densities of the top level preditor dinos is similar to the same population densities of today's mammalian top level predators. The fact that dinosaurs out-competed and suppressed the development of warm blooded mammals for 100 million years, not allowing mammals to develop beyond rat sized critters is also pretty damning (gigantic sluggish cold blooded dinos would have been overrun by fast warm blooded mammals).

    As has been pointed out in other posts, much of this evidence, and plenty more, was presented to the general public over 15 years ago in Robert Bakker's book _The Dinosaur Heresies_. He presents a very solid case, even without a fossilized heart. I highly reccommend his book, it's a great read.

    Burris
  • JOIN THE CAMPAIGN TO STOP SELECTIVE ABUSE OF POSTERS BY USE OF OVERRATED MODERATION TAGS!!!!!!!!!!!
  • 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.

    ------
  • The post to which this is a reply should be moderated (Score: 5, Funny). Unfortunately I don't have any mod points left at the moment.

  • 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 [slashdot.org]. I'd like to see anyone else do that.

    ------

  • No, the orinithiscian and saurithiscian groups diverged in the Triassic, pretty much at the very beginning of dinosaur evolution. Unless dinosaurs had four chambered hearts from the very beginning (somewhat doubtful, but possible), the internal anatomy of an orinithiscian means nothing to that of a saurithscian (including therapods). However, since these animals were living together at the same time, and competing, and had similar anatomical possibilities, its reasonable to assume that they would have somewhat similar metabolic rates. This is the idea of co-evolution. The usual example is a predator and a prey. If the predator evolves something that makes it a better predator, the prey will be driven to develop better defenses, driving th predator to develop somthing else better, and so on, in a sort of "evolutionary arms race".

    I remember a year or two ago a therapod was found with some well preserved internal organs. No heart, but enough to speculate on its respiratory system. They found that this was unique, different from any modern animal- som sort of piston-like setup, i dont quite remember. Anyway, the animal appeared to be cold blooded, but could get short bursts of extremely high energy. This would seem ideal for a predator- low energy consumption until the chase starts.

    Anyway i think this fossil was from 100 mil. yeas ago, or something, so perhaps it represented a stage in the evolution of dinosaur metabolism, or perhaps this all shows that dinosaurs had a wide variety of metabolic solutions, some similar to those in modern animals, some not. Regardless, some dinosaurs were warm blooded and had four chambered hearts by the end of the Cretacious. If not all of them did, then those who didn;t must have had some adaptation that allowed them to keep up.
  • 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...) Mathematica. I do more observation than theory, though, so the correct debate is IRAF or XVista? (XVIsta whenever possible, IRAF usually because it's shoved down my throat...) And anything I write myself is in C++ or Java. Sometimes BASIC.

  • Media Is Stupid (Score:5)

    by waldoj ( 8229 ) <waldo&jaquith,org> on Thursday April 20, 2000 @04:59PM (#1120143) Homepage Journal
    I've been amazed that the reaction that most of the media has taken to this story. My local news station [nbc29.com] 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
  • The original one, yes. There's many more, and a new large one (300 ft) is being constructed. A picture I took when I was there observing this summer is all that's on a website [dreamwindow.org] of mine, currently.
  • 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.

  • Perhaps.. (Score:1)

    by Anonymous Coward
    The hot liquid in their veins was GRITS, not BLOOD
  • 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!!!
  • 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.
  • this isnt new information. i remember these theories being taught in my third grade history class. the relationship between birds and dinosaurs has always been a debate, but is now a generally accepted theory. you might as well post something about the evolution of man being related to apes because i learned nothing new here :-P

    read jurrasic park, its more informative than the article

  • 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.

  • It's not an advantage of warm-blooded vs. cold-blooded that would have enabled the mammals to survive such an extinction event. It's size. The dinosaurs would have required massive amounts of resources to survive. An asteroid collision would have decimated the food chain, and the bulky, wieldy dinosaurs would have had trouble competing for the small scraps with the smaller mammals. Yes, there were small dinos but not the size of a mouse. And a squirrel is about as big as mammals would have been. No monkeys or deer. :)

    -Merlyn42

  • New evidence, old theory (Score:3)

    by Joe Rumsey ( 2194 ) on Thursday April 20, 2000 @05:01PM (#1120152)
    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.
  • In respect to the Kansas Board of Education, I feel it appropriate to present a credible alternative to this "controversial theory that dinsaurs once existed."

    It should be noted the reality of the situation is that they were placed here by God to test our faith as Christians. After all, every real Christian knows in their heart that the entire Universe was created in seven days, culminating in the creation of Man (Eve came later).
    So it is obviously impossible for anything to have been in existence 65 million years ago, with the exception of God, of course, since He is eternal.

    -Vel

    Personal Disclaimer---------------
    Ok, ok. Sorry about the sarcasm. I just felt it had to be said. As crazy as it sounds, I do know people that actually do believe what I have just spouted. :)
  • NOW SLASHDOT OOOGERS ASK FOR OOOG(R)(TM) BRAND MERCHANDIS!!! DON'T GET EATEN IN PROCESS, BUY OOOG(R)(TM) BRAND RECTAL THERMOMETER FOR YOUR DINSOSAUR!!! OOOG NOT SURPRISED YOU NOT RUN OUT AND BUY RIGHT NOW!!!

    *** Visit the OOOG(r)(tm) brand store Right Now and receive FREE OOOG(r)(tm) brand Open Source CDs, fresh from LinuxOne! OOOG is a registered trademark of OOOG Brand Enterprises. ***
  • I didn't even know there was a science section. I recall reading once that there was a seperate BSD page, and there seems to be a seperate Ask Slashdot area. Guess I just never bothered to look.

    Related to missing interesting things here, did the hyped jwz interview ever actually show up? There are so many interviews these days that I always seem to miss the ones I actually want to read, then can never find them in all of the old stuff.

  • The meteor created the Gulf of Mexico!! It was equivalent to the fallout of a small scale nuclear war, for which the DoD estimates less than 1% of the human population of Earth to survive (look at Domestic effect of limited theatre nuclear engagement, 1972 for other rather frightening statistics). In the case of the event that killed the dinos, it was lucky that anything survived!!

  • I don't think it was being warm blooded which allowed the ancestors of mammals to survive, it was size. If I remember my palentology right--not likely since I have degree in physics--about the only critters to survive the extinction were tiny ones. This makes a bit of sense if you think about it in terms of the asteroid collison. The ejecta probably created a huge cloud of dust in hte atmosphere, blocking sunlight, causing a huge plant die off. The only critters that could survive that environment were ones with minimal food requirments.

  • Re:New evidence, old theory (Score:2)

    by Anonymous Coward
    Actually this is not entirely correct. The cold blooded / warm bloooded debate is by no means been decided and is not "commonly" held to be warm blooded. In fact what this suggests is that some dinosaurs may have been warm blooded, but not necessarily all were.

    It is helpful in possibily explaining the evolution of feathers in birds ( though one still has to explain the complexity of feathers as opposed to the fairly dominant method of body heat regulation -- fur -- to help support that thesis ). It should be noted that birds did not evolve from ALL dinosaurs but a branch of the dinosaurs called the Therapods, amoung which Archeaopteryx and Sinusauris were apart of. This however is not new, as there are studies on embryology which suggest that the therapods as they evolved into birds became ( or were ) warm blooded. Like I mentioned before, this is part is an arguement for the development of feathers ( heat regulation ) but cannot be the sole selective factor.

    That being said there are studies with other dinosaur fossils, looking at nostil cavities and other anatomical and morphological data which suggest the opposite ( ie cold blooded ).

    The bigger question in my mind... Top down or bottom up.... and does it help with that arguement?

  • Re:New evidence, old theory (Score:4)

    by HomeySmurf ( 124537 ) on Thursday April 20, 2000 @05:28PM (#1120159)

    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?

  • This brings up something I'd never really thought of before. If a single species of carnivore were to evolve into a warm-blooded creature, would that creature then vastly outperform it's rival carnivores, causing some of the rival species to die off? Would it also be effective enough to kill lots of prey, perhaps even to the point of causing serious instability and even extinction within a species line?

    Could be an interesting proposition as to why certain species of dinos flourished while at the same time others were dying off in large numbers. IANAP (I Am Not A Paleontologist) but this seems like it could be valid.
  • This website is a project of the Center for the Exploration of the Dinosaurian World,

    Isn't the proper word, "Saurian"? I dunno...

    The amazing thing is that the saurian's heart and soft tissue is imageable... not that warm blooded is a new idea. Besides, this is a really cool use of 3D imaging software and hardware. WTF, the media think we is stoopid? Warm-Blooded, oh my! What the Flintstones didn't really meet in Rock-Vegas?

    --// Hartsock //

  • interesting site (Score:1)

    by Anonymous Coward
    There's a neat site pertaining to this topic over here [drdino.com] that has a lot of stuff online, with transcripts [216.248.142.66], mp3 audio [216.248.142.66], slideshows [216.248.142.66], etc.
  • What about crocodiles? They can move very quickly when they want to.
  • you're right. crocs can move quickly at times. so can lizards (ever try to chase one?). for that matter... so can spiders. so can scorpions. heck, even protozoans can dart around (relatively) quickly. -sid
  • First, it's really an old story, I remember I read speculations about this maybe ten years ago.

    Second, if dinosaurs really had warm blood doesn't change so much, because if a body grows ten times in length, its surface grows by hundred, but its volume and mass by thousand. So it is much easier for a large animal to prevent loosing energy to a colder envorinment then it is for a small one.
  • - Robin PS - no, the editors never read Slashdot. :)

    I guess after rereading my comment, I should be lucky that it didn't get marked Flamebait. I was kinda pissy when I wrote that originally. It's just that I have such high hopes for /. and high expectations and standards that really shouldn't be there. I think you guys do a great job, but often fall short on details that sometimes make /. look....amateurish... I shouldn't complain, I guess. Glad you have a sense of humor, though! :)

  • who reads Oog's posts in the voice of Grimlock from the Transformers? Remember the Dinobots? :~( some bitch cleaning lady threw away my hundreds of transformers, including Grimlock.

    "Me Grimlock think this much more gooder!"

    __________________________________________________ ___

  • what the hell? (Score:3)

    by jetpack ( 22743 ) on Thursday April 20, 2000 @06:28PM (#1120168) Homepage
    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?)

    --
  • Nerds must be (force) fed information not directly related to their subject. Ya know one of them might get tickled enough to start "scratching his itch" and give the world a great new "solution for all" software. So dont worry about the immediate response to a posting. I am sure it will produce great things. So keep posting. Incidentally, do you guys watch the tv programme "Connections" on BBC.

  • Re:Musings on warm-blooded vs. cold-blooded (Score:3)

    by zCyl ( 14362 ) on Thursday April 20, 2000 @06:30PM (#1120171)
    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.
  • get the facts to your theories?
  • Even if you think carbon dating is bunk this is not how these samples are dated (Carbon dating is only good to several tens of thousands of years, before that IIRC this is because the measurement of the ratio of the carbon isotopes becomes difficult/unreliable when there is very little C13, i.e. after many half lives) IIRC similar methods but different isotopes are used to determine ealier dates.
  • So, as an astronomer, do you prefer Matlab, or Mathematica for your calculations....

    Not that I'm a scientist, but from what I've seen, TKSolver triumphs over both Matlab and Mathematica.
  • I know this wasn't meant to be taken seriously, but in reality dinosaurs and people were never on the earth at the same time. The Cretaceous peroid ended approximately 65 million years ago, and humans first appeared during the Pleistocene epoch, which started 1.8 million years ago. It's a common misconception that "cavemen" fought with dinosaurs.

    -W.W.
  • Impressive graphics and generally very good I thought. Clearly they depicted dinosaurs as being warm blooded (much more interesting than cold) but one thing annoyed me. They had this silly bit where these two dinosaurs were having this mating ritual of making sounds rubbing bodies and then they had the male dino mount the female from behind and hump her just like mammals do. I thought dino's laid shelled eggs? I thought all (any exceptions?) shelled egg layers fertilize the eggs outside the body. Could it actually be possible that dinos had sex the way we do?

  • Oh my god (Score:3)

    by grappler ( 14976 ) on Thursday April 20, 2000 @11:30PM (#1120177) Homepage
    Did I just read that post I'm replying to?

    Dude,

    oh man, I'm at a loss for words. Just...

    Dude,

    chill OUT. I doubt anyone on /. has any misconceptions about THAT...

    geez

    I wish you could see my fits of laughter I'm in right now.

    --
    grappler
  • I belive his theories also included that dinosaurs may have been more closely related to birds than reptiles, or at least that they were a link between the two. So, not only is this not breaking news, it's not even the whole story.

    I just got done re-reading _Jurassic Park_ (for about the sixth time). It was written in 1990, and it pointed out that many archaeologists/paleontologists (sp?) think that dinosaurs were warm-blooded and more closely related to birds than reptiles. Also, many think that dinosaurs were actually intelligent and quick-moving, unlike the dumb, lumbering animals people imagine them to be.
  • 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
  • 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
  • Okay, let's cover some basics: Birds evolved from small carnivorous dinosaurs in the mid-Jurassic period. However, Archaeopteryx was an example of parallel evolution, where species progress along the same course, despite the fact that others have progressed similarly. Species of what could be considered "modern birds" were already well established by the time Archeopteryx arrived on the scene. It's almost certainly the case that all current species of birds share a common avian ancestor, but it was probably not Archeopteryx. Now, it IS possible, albeit unlikely, that some of today's birds are the decendants of Archeopteryx, while others are the decendants of the other, more advanced bird species at the time. Moving on to this news story, however, this is not old news. Although the warm blooded/cold blooded debate has raged on for decades, this discovery of a more advanced, four-chambered heart, similar to that of mammals, certainly gives the warm blooded argument more credibility.
    -- Chris Dunham
    http://www.chamdex.com

  • Of course I know little or nothing about paleology, but if the meteor did indeed block out a large degree of sunlight, it seems likely that a lot of marine life would also die off. For example, sea algae, I believe, needs sunlight just like any other plant. If the sea algae die off, then a major source of food for some plant-eating marine animals would disappear. Then those animals die off, and so a food source for some other animals disappears. And so on.

    The ecological balance is a delicate thing...

    Really, it is hard to imagine a catastrophic event like a major meteor impact not having significant and deadly repercussions on every ecological niche.

    Well, just my two cents.

  • Read "The Dinosaur Heresies" (Score:3)

    by ericfitz ( 59316 ) on Thursday April 20, 2000 @05:01PM (#1120183)
    Dr. Robert Bakker proposed this theory years ago. Here [barnesandnoble.com] is his book.
  • Well, there was an astroid hit 65 million years ago on the coast of what is now Mexico's Yucatan penninsula, that we can be sure of. There's a huge crater there. A 65 million year old crater.

    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

  • Canadians are very interested in this. It seems that half of this country, judging by its right-wing politics and politically correct opposition, is indeed populated by warm-blooded dinos.
  • Start with this one [talkorigins.org].

    You might start in this section [talkorigins.org] 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 [talkorigins.org] 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

  • broken hearted (Score:3)

    by toh ( 64283 ) on Thursday April 20, 2000 @05:05PM (#1120188)
    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?

  • 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.

  • Musings on warm-blooded vs. cold-blooded (Score:4)

    by Devolver42 ( 177242 ) on Thursday April 20, 2000 @05:10PM (#1120191) Homepage
    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.

  • I think it is definately safe to say that not all of what we group together as dinosaurs were warm blooded. Somewhere along the way some of them became so, because clearly some dinosaurs evolved into birds. I am not sure if we will ever be able to determine exactly where on the spectrum this occurred.

    It was almost assuredly a very gradual process as well. An improved circulatory system as the one discovered, would only be part of the necessary physiological changes necessary. Other important changes include the ability to regulate blood flow to cold areas (why your cheeks turn red in the cold), and being able to control the rate of metabolism to burn up calories to generate heat. I may be going out on a limb also by saying that warm bloodedness was probably something that evolved in predators, for various reasons.

    Anyway, this whole discussion merely indicates how crappy the whole idea of taxonomy really is. It may have been cool and innovative in ancient times, but it is still a hold over to more ancient times. The defintions of different groupings gets more shadowy every year as more evidence is gathered in biochemistry and genetics. Different types of organisms run along a spectrum; they do not fall into discrete groups except as individual organisms. Indeed, Lord Kelvin was most referring to the taxonomy in the biology of his day when he said "Physics is the only science, everything else is just stamp collecting." All these namings and classifications are only loose abstractions of how things really work, and we shouldn't get hung up on what is and what isn't a member of a certain group. Unfortunately the natural world doesn't create nice simple objects with clear rules of inheritance. It's a jungle out there!

  • Comment removed (Score:3)

    by account_deleted ( 4530225 ) on Thursday April 20, 2000 @08:28PM (#1120195)
    Comment removed based on user account deletion

  • Dinosaurs, birds and warm blood (Score:3)

    by jw3 ( 99683 ) on Friday April 21, 2000 @01:04AM (#1120199) Homepage
    Two comments. First, as other have already pointed out, thie idea that dinosaurs are warm blooded is quite old, now widely accepted and supported by lot of evidence. Second, biologically speaking, there ain't no such thing as "dinosaurs":this is a popular term designating two or three groups of distinct animals. A more apriporate term is "archeosauria", which also includes... birds. Actually, there are much less differences between birds and dinosaurs than between bdinosaurs and modern reptiles. Once you start to think about dinosaurs as bird-like animals, or, even much better, about birds a sdinosaurs which haven't died out, the idea that they were warm blooded is quite sound

    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

  • I agree with this comment, if you can't come up with a reason to mod someone down you shouldn't do it.

    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...

  • Then why did they dissappear? (Score:3)

    by ContinuousPark ( 92960 ) on Thursday April 20, 2000 @05:11PM (#1120202)
    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?

  • Re:This is new? (Score:5)

    by Witchblade ( 9771 ) on Thursday April 20, 2000 @05:14PM (#1120207) Homepage
    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. :)

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