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  1. #1
    Forum Smart-**** DinoBear's Avatar
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    Paleontology Questions

    Here you ask whatever questions you may have about paleontology and extinct animals in general.

    Where "normal" theropod shoulder girdles able to allow quadrupedal movement without any restrictions or getting shoved into the animals neck?

  2. #2
    Probably not, the furcula would make the stress distribution quite bad for that purpose. Gripping or flapping forces are quite unlike those of weightbearing. Prosauropods lacked a furcula and ended up making a transition from a forelimb quite similar to a theropod's, but there's NOTHING that would suggest the same happening in theropods. Splitting a furcula probably wouldn't happen evolutive-wise. And Spinosaurus is not an example of that, the sole forelimb element we have is a quite normal theropodian phallanx.

    Modern birds may exceptionally use their forelimbs for movement, but that involves useless hindlimbs, and causes severe trauma in the wrist.

  3. #3
    Were the first angiosperms woody trees and shrubs, or were they small herbs?

    We have two competing hypothesis although scientific opinion currently favors a woody origin.
    The two hypotheses do not simply differ in their statements about relationships, but paint very different pictures about the implications for angiosperm diversification.

    The Woody Magnoliid Hypothesis -- Cladistic analyses by Doyle and Donoghue favor an early angiosperm with morphology similar to living members of the Magnoliales and Laurales. These groups are small to medium-sized trees with long broad leaves and large flowers with indeterminate numbers perianth parts. The carpels are imperfectly fused, and make a physical intermediate between a folded leaf and fused pistil.
    This hypothesis is also favored by molecular studies, and so currently is favored by systematic botanists. It suggests that the earliest angiosperms were understory trees and shrubs, and that the flower was NOT the key innovation for the rapid diversification of angiosperms. In fact woody magnoliids are not particularly diverse, even today.

    The Paleoherb Hypothesis -- The alternative view is an herbaceous origin for the angiosperms. This view has been championed in recent years by Taylor and Hickey, paleobotanists whose cladistic analysis of angiosperms suggests a very different scenario from that previously described. In their analysis, the basal angiosperms are tropical paleoherbs, a group of flowering plants with uncomplicated flowers and a mix of monocot and dicot features.
    The implication here is that the key innovations of flowers and a rapid life cycle were present in the earliest angiosperms. It has been suggested that changes in climate or geography provided opportunities for these early angiosperms to diversify.

    Which do you think is more plausible, and what geographical/climate changes would allow for early herbaceous angiosperms to evolve with such diversification?
    Last edited by Stitch 626; 09-30-2014 at 12:04 AM. Reason: Indentations for a better reading structure.

  4. #4
    Quote Originally Posted by Eriorguez View Post
    Modern birds may exceptionally use their forelimbs for movement, but that involves useless hindlimbs, and causes severe trauma in the wrist.
    I believe they use them for movement quite often on average, just not that close to the ground.

    On the question right above this post: as a rule of thumb most innovations that stick around happen in small species. Small species tend to survive longer than large ones, and are thus less likely to be dead ends. There are also a lot more of them than of large species, increasing the chances that the important change occurs in one of them. So without knowing much about the specific subject, my bet is on the little guys.
    Never give up, never forget, moar colors.

  5. #5
    Would diseases carried by say, sauropods, be transmittable to, ceratopsians or something along those lines?

  6. #6
    Some of them, yeah. Humans can catch bird flu, after all...
    Never give up, never forget, moar colors.

  7. #7
    The Black Huntsman Sanguis's Avatar
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    Quote Originally Posted by Pan Calvus View Post
    Some of them, yeah. Humans can catch bird flu, after all...
    Well no one can say for sure. After all we know nothing about the immune system of any dinosaur, leaving us no other choice than make theories.

    Many thanks to Cykotyk for this awesome signature!

  8. #8
    Given that we know diseases that are shared between enormously different animals, given that bacteria and viruses have a pretty simple body plan and were highly likely amongst the first life forms to evolve and given that there were a buttload of different dinosaur species with an existence spanning about 150 million years between them it's pretty safe to assume there was at least one disease at some point that could infect two or more highly different species. Sure, it's a theory, but the odds are pretty massively in favor of it.

    The immune system of dinosaurs doesn't even really enter into it, unless they developed one that made them immune to all infectious diseases bar none, which would be pretty impressive for species with a generation time measured in years.
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  9. #9
    The Black Huntsman Sanguis's Avatar
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    Of course, I just didn't like the way it sounded like it's a given fact, but yeah it is pretty safe to assume.

    Many thanks to Cykotyk for this awesome signature!

  10. #10
    Do we know ANYTHING about diseases and dinosaurs?

  11. #11
    We know stuff about diseases, and we know stuff about dinosaurs. We know quite a lot about both of them, but especially about diseases. That may not seem like much to go on when discussing how they interacted with each other, but this is a very general question. With what we know of diseases, and assuming dinosaurs were anything like present day animals (as opposed to say supernatural spirit beings that spontaneously generated animal-like skeletons when they died) it's practically unthinkable that there was never one disease that could infect two entirely different species of dinosaur.

    I don't think that should be considered a controversial standpoint. I think that should be considered a safe assumption until there is some extraordinary evidence that it's completely wrong, because that's how diseases work.

    But, more to the point of that last question: no, I don't think the fossilized bacteria we have (going as far back as 3.5 billion years) tell us a lot about what kind of diseases there would have been for what kind of animals, and we probably don't have much or even any evidence to how the immune system of dinosaurs worked either.
    Never give up, never forget, moar colors.

  12. #12
    Occasionally we do find direct evidence of diseases that infected extinct dinosaurs.

  13. #13
    That's awesome. Where would the dino discussion section be without Albertonykus?

    For complete clarity I'd like to note that the article does not state these parasites would be exactly the same species that also infected birds of the time, so it's no prove of my standpoint. I just think it's awesome in itself.
    Never give up, never forget, moar colors.

  14. #14
    Try-ceratops
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    Which do you think is more likely, that Gigantopithecus was more like a Gorrilla or an Orangutan, bipedal or quadrupedal because there is a lot of conflict on the subject and i wanted your thoughts

  15. #15
    Could certain dinosaurs have the possibility of complex living communities? For instance, what if a small dinosaur like the compy lived in large communities that lived in large, underground communities? They could bring back food that was small enough for the young ones and it would be a safe place from larger carnivores. Any dinosaurs that could act like this?

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