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Dinosaurs May Have Been Neither Warm-blooded Nor Cold-Blooded 54

Posted by Soulskill
from the bbq-sauce-for-blood-like-americans dept.
An anonymous reader writes An article published in Science (abstract) points to the possibility that dinosaurs were mesotherms more akin to modern Tuna. Their internal temperature would have been warmer than their surrounding environment, conferring on them the ability to move more quickly than any ectotherm ("cold blooded" animal), but wouldn't have been constant or as warm as any endoderm ("warm blooded" animal). Their energy use and thus their necessary food intake would have been greater than an ectotherm, but much less than an endotherm. In order to arrive at this possibility, bone growth rings in fossilized bone were used to establish growth rates and then compared to modern ectotherms and endotherms.
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Dinosaurs May Have Been Neither Warm-blooded Nor Cold-Blooded

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  • by Anonymous Coward

    Scientists have deemed it "just right".

    • Blood temperature level: Aladino.
      • Neither warm nor cold, bird nor reptile.

        I think that Dinosaurs were magical trees, fueled by the energy of the stars and filled with aetheric pitch or sap, that responded to the vibratory symphonies described by the planetary epicycles.

        It is said that the largest dinosaurs had two brains - one in the head and another near the tail, like a fireman driving a ladder truck. This is nonsense. Dinosaurs know nothing of firemen, even if one factors their trans-dimensional aspect into consideration. This is because

  • by jphamlore (1996436) <jphamlore@yahoo.com> on Friday June 13, 2014 @03:44PM (#47232815)
    So did the dinosaurs become birds or were they parallel evolved species after some earlier branching point?
    • by wisnoskij (1206448) on Friday June 13, 2014 @03:53PM (#47232873) Homepage

      Obviously Dinosaurs became Tuna.

      • Impossible. There's nothing in between! They couldn't have just made that jump! I'm not a monkey's uncle!!

        (sarcasm, for the humor impaired)

      • by Anonymous Coward

        You can tune a piano but you can't tuna... dinosaur?!

    • Re: (Score:3, Insightful)

      by Anonymous Coward

      "Dinosaurs" werent just a single species. There were quite a lot of them. Some of them developed feathers and went on to become birds, some stayed in the water and went on to become Nessies, but most of them just plain died and their descendants didnt evolve into anything.

      • by mpe (36238)
        "Dinosaurs" werent just a single species.

        They are not even a single class. In the 19th century they were divided into "reptile hip" and "bird hip". So even that long ago it was clear that at least two distinct types of animals were involved.

        Some of them developed feathers and went on to become birds

        Whilst theropods are related to modern birds (Aves) it's unclear how, and when, feathers evolved.

        some stayed in the water and went on to become Nessies

        Plesiosauria, and other aquatic animals are not tec
  • by art6217 (757847)
    Sounds likely, if birds are their warm-blooded descendants.
  • New theory? (Score:5, Interesting)

    by Anonymous Coward on Friday June 13, 2014 @03:51PM (#47232861)

    TFA makes this sound like a new theory, but the first time I read an article proposing this (with supporting evidence) was at least 20 years ago, and may well have been longer ago than that.

    It's nice that they've come up with more evidence for it, but it would also be nice if every time someone tested an idea out they didn't feel compelled to pretend they were the first to have it.

    • Re:New theory? (Score:5, Interesting)

      by Oligonicella (659917) on Friday June 13, 2014 @04:25PM (#47233085)

      Yep. Paleontology is a field rife with one-upmanship. Cold blooded, warm blooded, hot blooded and meso. All had their day multiple times. My personal belief is that the theropods were most likely hot-blooded like the birds and the sauropods were meso-blooded. Their respective activity levels make this likely to me.

      • by Anonymous Coward

        And that modern day theropods are warm blooded doesn't hurt your theory either.

      • by Anonymous Coward

        Sauropods are closely related to theropods and were so huge that they probably had a harder time losing heat than gaining it. They required a temperature stabilizing system so that puts them well into "hot-blooded", rather than tuna liquid-cooled overheating muscle, territory.
        The last common ancestor of all dinosaurs was a theropod-like insectivorous animal, closely related to the ancestors of pterosaurs which are most likely hot-blooded again.
        I could see some dinosaurs having a low-temperature endothermic

    • Re:New theory? (Score:5, Informative)

      by Anonymous Coward on Friday June 13, 2014 @04:31PM (#47233119)

      It's nice that they've come up with more evidence for it, but it would also be nice if every time someone tested an idea out they didn't feel compelled to pretend they were the first to have it.

      I think this is a very unfair attack. The authors of this paper did not make the claim you've attributed to them. They start the actual article with this.

      Over the past few decades, the original characterization of dinosaurs by early paleontologists as lumbering, slow-metabolizing ectotherms has been challenged.

      There are 397 references given in this paper. I think they're clear about what previous science existed. Even the lay article doesn't pretend this is new research it talks about compiling existing research.

    • After several false starts during which she repeatedly and noisily attempts to clear her throat, Ms. Elk spends most of the interview circuitously leading up to the "theory of dinosaurs by Anne Elk bracket Miss brackets", making assertions like "My theory, which belongs to me, is mine." It turns out that in the end Miss Elk's new theory on brontosauruses is rather shallow: "All brontosauruses are thin at one end, much, much thicker in the middle, and then thin again at the far end." Her true concern is that

  • by Anonymous Coward

    Now that the false dichotomy between cold-blooded and hot-blooded has been debunked, let's work on that pesky false dichotomy between animals and plants.

  • Are these classifications entirely distinct? Or do we see animals existing along a range from one end to another?

    • Read the article:

      Today, that middle ground is occupied by animals including tuna, lamnid sharks and leatherback turtles.

  • I first posed the question to my elementary school science teacher circa 1973 whether the dinosaurs weren't in some way usefully self-warming. I didn't have the vocabulary about homeostasis or mesotherms at that age.

    ***

    So, young man, you're suggesting that the dinosaurs might have been mesotherms?

    "Meso", everyone, means "in between" or "intermediate". So the idea here is that dinosaurs would be warmer than modern reptiles but not as warm as modern mammals—whales and cats and dogs and humans and ho

  • Seems that "endoderm" is wrongly spelled.

I am not now, nor have I ever been, a member of the demigodic party. -- Dennis Ritchie

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