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Favorite Dinosaur Reconstructions
Topic Started: Sep 28 2013, 09:05 PM (305,650 Views)
Acinonyx Jubatus
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I AM THE UNSHRINKWRAPPER!

Austroraptor
Feb 15 2015, 01:55 PM
HENDRIX
Feb 15 2015, 01:35 PM
I simply don't see why archosaurs couldn't be viviparous - we just do not know of any viviparous archosaur. It happened several times in other taxa, so why not there too?
Because archosauriforms take calcium from their eggs during their embriologycal development, birds and turtles have been going at the sea for a far longer stretch of time than any dinosaur and yet they've still failed to produce viviparous forms, im no bird specialist or embriologist for that matter, but iirc the hard eggshells are intrinsically linked to their embriological development in a way they just can't get rid of them.
Pterosaurs are archosaurs, yet they had soft eggshells. And if it's still impossible, would Ovoviviparity be plausible? Retaining the hard eggshell, but keeping it within the body until it hatches?

That being said, I'm no supporter of Spinosaurus being viviparous. I rather like the idea that it slid on its belly, like a loon or grebe, with its arms tucked up under its torso.

On topic...
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Yi Qi
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Acinonyx Jubatus
Feb 15 2015, 06:00 PM
Pterosaurs are archosaurs, yet they had soft eggshells. And if it's still impossible, would Ovoviviparity be plausible? Retaining the hard eggshell, but keeping it within the body until it hatches?

They'd still need the calcium from the eggshells for embriological development, look it up, again, im no archosaur embriologist so i can't really explain it, however there are many papers concerning the subject. And IIRC ovoviviparity isn't feasible either, AFAIK either heliosphoros or someone else already explained it somewhere in this forum.
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Furka
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Mathius Tyra
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Rat snake is love... Rat snake is life

Wait... There is something lying on the ground behind them as well...
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Posted Image Dacentru
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A second tyrannosaur I suppose. :P
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Even
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@Tyra: that's a felled theropod I think, seemingly another Tarbosaurus

Regarding the Spinosaurus stuff: I can see only two ways to go, with our knowledge of orionidan hand anatomy and archosaurian constraints: either Spinosaurus are fully aquatic except for dredging themselves out to shore to lay their eggs, or Spinosaurus developed whatever musculoskeletal mechanism which allows cranes and other such birds to keep their necks erect...
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babehunter1324
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I honestly had my doubts about large marine "crocodiles" like Plesiosuchus beign able to leave the water in order to lay eggs...

That say I think Spinosaurus was oviparous let's not forget that it's hip bone was further reduced compared to other theropods...
Edited by babehunter1324, Feb 16 2015, 08:30 AM.
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Furka
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Folks, remember that we Have a Spinosaurus speculation topic ;)
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Luca9108
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Master of Dinosaurs

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Jon Sam
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CyborgIguana
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I like it, though it doesn't have NEARLY enough feathers. :P
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Okeanos
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^^Like CI said, not enough feathers, but damn that background is awesome :O
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Luca9108
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Master of Dinosaurs

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Furka
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Finally a quadrupedal Spino that isn't skinny.
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Luca9108
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Master of Dinosaurs

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