Zegh's Dinosaur Thread

Discussion in 'General Discussion Forum' started by zegh8578, Jan 23, 2017.

  1. MutantScalper

    MutantScalper Dark side in da houssah

    Nov 22, 2009
  2. zegh8578

    zegh8578 Keeper of the trout Orderite

    Mar 11, 2012
    Quick check on wiki dates extinction of Moa to around 1300-1400s and Elephant birds to only a couple of centuries earlier, 1000-1200 AD.

    (Moa are New Zealandic, Elephant Birds restricted to Africa. They all are ratites or paleognathids, a group encompassing emus, rheas, cassowaries, ostriches, kiwis and tinamous. The extinct lithornithids are the sparrow-looking tweety-birdy ancestral forms of all these, in case it was ever tempting to imagine ratite birds as "more dinosaur" than other living birds :D)
     
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  3. MutantScalper

    MutantScalper Dark side in da houssah

    Nov 22, 2009
    New study about the Meg is being made. Pretty amazing just to think those things were swimming around in pretty large numbers. There had to have been a lot of them since they keep finding so many of those teeth.

    https://graduatedivision.ucmerced.e...n-massive-ancient-shark-be-explored-nsf-grant

     
  4. zegh8578

    zegh8578 Keeper of the trout Orderite

    Mar 11, 2012
    There wouldn't be any more than say orcas or such. Most likely, at any given time, there were probably less Megalodons swimming around than Great Whites today, simply because the larger any given animal, the fewer the individuals tend to be

    The number of teeth is due to the overall collected number of individuals that existed in total, across time - and the fact that they all would lose teeth regularily, and grow new teeth, for then to drop them as well.

    Teeth are typically abundant in the fossil record. Many important hominids, human ancestors, are known from teeth. Dinosaur teeth are SO common, it is considered "bad form" to attach a names to them, rendering them "pointless" tooth-taxa (didn't stop Danish researchers from naming Dromaeosauroides bornholmensis -.-, based on two teeth... )
    In the past, dinosaur teeth were often given names, and they are today considered "nomina nuda", as in - names that no longer have any scientific significance. For example, there's no way you can say that Trachodon (hadrosaurid teeth) are in reality just another Edmontosaurus, Anatotitan, Hadrosaurus, Parasaurolophus - or any other similar dinosaur with identical teeth.

    A large ammount of Mesozoic mammals are known solely from teeth, and milk-teeth at that, since mammals tend to keep their teeth firmly attached for most of their lives
     
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  5. Crni Vuk

    Crni Vuk M4A3 Oldfag oTO Orderite

    Nov 25, 2008
  6. zegh8578

    zegh8578 Keeper of the trout Orderite

    Mar 11, 2012
    ^I was discussing "borb" with someone recently, the "bird-orb" concept, as in, a bird (or theropod) SO fluffy, it becomes like a rounded little ball of yarn

    I've been been pondering, and came to the conclusion that most of the roundest borb-effect we see in passerines (song birds + crows) or close relatives (such as psittacines, parrots)
    "borb"-ing also occurs outside this group, but it requires the most compact of all bird skeletons, as well as a short (yet very flexible) neck, that can be curled right up into the chest

    While that tyrannosaur-drawing is obviously a joke, many paleo-artists wants to draw at least small dino-birds as "borbs", but I personally think they're trying to force something that wasn't necesarily all that common. Borbing could have been a feature not present in birds untill the development of passerine forms, which happened after the (non-avian) dinosaurs were gone.

    :'(
     
    Last edited: Oct 20, 2018
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  7. zegh8578

    zegh8578 Keeper of the trout Orderite

    Mar 11, 2012
    By the way, Maraapunisaurus is proposed new genus for "Amphicoelias" fragillimus. Quotations simply mean that most researchers agree that "A". fragillimus is not really a true Amphicoelias (which is known from the species A. altus)

    A. altus is a Diplodocid dinosaur known from a fragmented skeleton. Like Apatosaurus or Diplodocus it would have been some 25-30 metres long, and had a long neck and long whip tail. "A." fragillimus, on the other hand, has always been a kind of legend. It was based on a single vertebra, very tall, 2 or 3 metres tall in total. The vertebra was eventually lost, and now exists only as detailed reconstructions. The validity of the animal still holds, except nobody could ever quite figure out WHAT it was. As a diplodocid, it would have reached over 50 metres in length, some estimates reach 60.

    60 metres, or 50, or even 40+, makes it the absolutely very largest of all dinosaurs ever, anywhere.

    WELL
    Turns out "A". fragillimus first of all was not Amphicoelias, and has been given a new name, Maraapunisaurus fragillimus, and turns out further - that it was a Rebbachisaurid. These are close relatives of Diplodocids, but they are known to have shorter tails and necks, and very tall dorsal spines. As in - unusually tall vertebrae.
    With this in mind, M. fragillimus seems to measure around 30 metres in total. This easily makes it a *giant* Rebbachisaurid, but nooot that much of a giant Diplodocid. Legend status has been revoked :(
     
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  8. MutantScalper

    MutantScalper Dark side in da houssah

    Nov 22, 2009
  9. WeissYohji

    WeissYohji First time out of the vault

    Nov 8, 2018
    I've boned up on dinosaurs, pterosaurs, and other paleofauna since I was a little kid. I didn't settle for the kiddie shit. Fuck no, I went for the good stuff (as good as our knowledge was in the '90s). I even schooled my classmates on this stuff in third grade, and even back then I had suspected that non-avian theropods and some ornithischians had feathers. And don't anyone try to feed me any lines that feathered things can't be scary. Cassowaries have feathers and they can kick your ass. Of course, they're Australian birds; what Down Under ISN'T trying to kill everyone in it?

    Fast-forward to today and now I have a little pet dinosaur: A blue-fronted amazon parrot named Ricky. I took him in when my great-grandmother moved to a nursing home, a year before she died. She got too infirm to properly care for Ricky and nobody else would take him. So he's been my little green nugget ever since. I'll play games and watch TV with him on my shoulder. I'll even read science and history books to him. And yes, those include books about his non-avian ancestors, uncles, and cousins.
     
    Last edited: Nov 14, 2018
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  10. MutantScalper

    MutantScalper Dark side in da houssah

    Nov 22, 2009
    Yea large birds can be scary. Saw a white-tailed eagle not long ago, flew right over my head at about tree top level. Eerie how large and quiet it was.
     
  11. zegh8578

    zegh8578 Keeper of the trout Orderite

    Mar 11, 2012
    ^
    This is how a real dino nerd talks!

    As a kid, my family would be aware that I was long past the kid-books, but they had no idea where to turn for "higher tier" material. My grandmother managed to buy me, for my 10th birthday I think, David Norman's "Illustrated Dinosaur Encyclopedia", which for a long time was my heavyest duty book. To this day I hold it very dear

    Later I'd amuse the people at the university book store, because I'd come in there about once a month to buy dino books. (I couldn't keep this up. Those books are really expensive)
    I would have longing dreams about owning Predatory Dinosaurs of the World, which had allready fallen out of print by the time I heard of it.

    And indeed, I had a little budgerigar called Dino, and my whole family knew why I named the bird "Dino" and they all knew by then, how perfectly reasonable it obviously was, that birds and chickens and ducks, were the same as dinosaurs: Because of don't argue with the little nerd, he will babble your head off.

    ///

    By the way, Thanos was recently named Abelisaurid, based on a single incomplete neck vertebra, and this little blog-piece has something to say about it:
    https://waxing-paleontological.blogspot.com/2018/11/thanos-deserves-better.html?spref=tw
    While I personally don't really care about comic-book characters, it does bother me when over-eager paleontologists find it fitting to name fragments that are almost certainly going to be dismissed as a *"nomen dubium" immediately after. To me it also shows impatience. Yes, having the privilege to analyze a vertebra must be great, but have the insight and self control to predict that maybejustmaybe in the future, he will have the oportunity to analyze something much more substantial and complete, that will surely warrant a name...

    * a name given to a specimen so incomplete, there is little-to-no chance of positively comparing the material to other similar species in any productive manner. Typical examples are names given to teeth or single bones with most unique traits worn or broken away. A dinosaur declared "nomen dubium" will usually no longer occur in the litterature.
     
    Last edited: Nov 17, 2018