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The Earliest Known Dino? 69

Posted by Soulskill
from the movies-rights-for-triassic-park-already-sold dept.
sciencehabit writes "A team of paleontologists thinks it may have identified the earliest known dinosaur — a creature no bigger than a Labrador retriever that lived about 243 million years ago. That's at least 10 million years earlier than the oldest known dinos and could change researchers' views of how they evolved. But some scientists, including the study's authors, caution that the fossils could instead represent a close dino relative."
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The Earliest Known Dino?

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  • The absolute definition of a dinosaur, when we now consider most of them to be birds, seems to be pointless - They used to be reptiles, or others.

    What I'm guessing this find is an early reptile, it's happened before... I may be way off base though.

    • The absolute definition of a dinosaur, when we now consider most of them to be birds, seems to be pointless

      Yes and no. It's no more useless than "fish", for exactly the same reasons.

      Polyphyletic classes FTW.

    • by Sique (173459) on Wednesday December 05, 2012 @05:16AM (#42189777) Homepage
      "Reptiles" is a paraphyletic group, and is no longer used. The classification "reptile" has some serious problems, as for instance turtles branched early from the other reptiles, later the mammal-like reptiles, and then the other branches of reptiles radiated. So reptiles would cover a very incomplete tree where one early branch is missing (mammals) and one very late one (birds). Instead we are talking "amniotes", meaning animals whose early development involves the growing of an amnios, a pouch in which the embryo develops. The amniotes then branch into Anapsides (including turtles), Synapsides (mammals and their predecessors) and Diapsides (all other reptile-like animals including the birds).
      • by Sique (173459) on Wednesday December 05, 2012 @05:34AM (#42189859) Homepage
        Upon reading a little about those groups, I noticed that molecular analysis does suggest that even though turtles have no additional holes in their skulls (which would morphologically put them into the anapsid group), it seems that they are closer related to some diapsid groups, especially lepidosauridae (lizards, snakes etc.pp.). So the point in time when the last common ancestor of turtles and other reptiles lived, is still debated.
        So the question for this reconstructed animal is not so much if it fits a morphological definition of a dinosaur, but rather if the last common ancestor of this animal and a bird was living later than the last common ancestor of birds and crocodiles. If yes, then it would put it definitely into dinosaur territory, being either an early dinosaur or a member of one of the sister groups of early dinosaurs. If no, it might still be an archosaur, closer related to recent birds and crocodiles than to other lizards and snakes.
      • by serviscope_minor (664417) on Wednesday December 05, 2012 @06:38AM (#42190115) Journal

        "Reptiles" is a paraphyletic group, and is no longer used.

        Well, that's a little harsh. It's widely understood what it means, and is easier to say than non mamallian, non avian amniotes. :)

        It's no worse than fish, which would include all vertibrates, and possibly hagfish too, depending on how you feel about it. (Though to my mind, "is a hagfish a fish" is up there with "is pluto a planet".)

        Perhaps they're not used all that much when one is working in the taxonomy/classification literature, bit I've definitely heard cell biologists claim they work with fish instead of mice.

        • by Sique (173459)
          So lets call "reptil" and "fish" more or less a morphological type, not so much a classification, the same as "lizard" is not a classification, more a description of a certain habit, as there are lizards in different groups (archosaurs, lepidosaurs, anapsides), which also contain non lizard forms (birds, snakes, turtles). Thus we still have mammals and birds as animals with reptile ancestors, and all of them together with fish ancestors. Still, this does not help in determining, if Nyasasaurus is a dinosaur
  • Um, this Snorkasaurus [wikipedia.org]?
  • The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania [royalsocie...ishing.org]
    The open access model would like to say "you're welcome".
  • The earliest known dinosaur — a creature no bigger than a Labrador retriever [polyvore.com][...].

  • I saw something recently that made me have to do some Wiki'ing.

    Stegosaurus lived around 150 to 155 million years ago.
    T-Rex lived 67 to 65 years ago.

    This means that we live closer to T-Rex than T-Rex lived to Stegosaurus. Crazy eh?

  • that this would turn into a troll thread rather a rational discussion of one of the greatest paleontological finds? Sad that so many 'open minded' people are as bigoted && mean spirited as they perceive others to be.

    It is exciting to me to have any new scientific discovery of this magnitude. Hopefully, this will lead to the further study of earlier finds to push the veil back even further on the predecessors of these fossils.

    And to explode the minds of the trolls, I confess that I'm an orthodox Chr

  • Misread as article title as "The Earliest Known Dildo"

    Nevermind.

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