Subject: Good question.
Author:
Posted on: 2013-02-06 14:18:00 UTC
I'm sure National Goegraphic did cover that. I think that they are on top of the other, bellies facing each other? I think I already passed the NSFW line.
Is NSFB allowed in the threads? I hope anyone young enough to be shocked by this discussion won't understand it anyway, and I've tried to be as elliptical as possible.
I've been reading through Agent Trojie's very scary missions, and I started wondering what biologically plausible dino reproductive anatomy might have been like. The closest evolutionary relatives are birds, especially if we're considering 'raptors from JP, rather than the legendary sauropod incident. The normal cloacal method in birds is going to get logistically difficult with the larger dinosaurs, isn't it? Most birds don't have "intromittent organs", but they have evolved at least twice (in ratites and in galloanserae, both of which include very large-bodied species), so it's not that unlikely that they could show in dinosaurs, is it? What I can't find out on the internet is whether they'd leave any distinctive skeletal anatomic features that might be visible in fossil forms. I don't think Lagerstaetten fossils are going to help, because the chances of actually having the relevant soft tissues exposed are pretty slim. Does anyone have any ideas, either from anatomy of extant species or from fossils? Eggshell formation (obviously in the female now!) will be happening too low down in the cloaca to tell us anything interesting about the structures deeper in, won't it?
Inevitably, my brain went to the infamous duck videos; I truly and sincerly hope no badficcers ever make that connection.
I'm going to stay away from anything other than pure scientific terms and the offer of some web links if you really want detail! If you do, let me know and I'll find a way of posting a link or two to you.
To be honest the general answer is, everything we know is an educated guess, but our best guess is that it was akin to birds.
In some ways it may well depend on the species as well, but what is highly suggestive is that T-Rex and Allosaurus (and therefore likely most of the related species) had a medullary bone, similar to that found in modern birds. Further the bone has also been found in Tenontosaurus, which diverged from the Allosaurus/T-Rex genetic line very early in dinosaur evolution. This is suggestive that the majority of dinosaurs (at least of these lines in evolution) would have worked in the same way.
Birds produce this type of bone tissue around the time of laying viable eggs.
I hope that nothing in the above is NSFW, if it is I apologise, but I've tried to keep it away from the area.
That tallies with the fossil eggs that definitely show calcium carbonate shells with a similar structure to modern birds' eggs. IIRC, that Tenontosaurus was sub-adult, wasn't she? Another thing we don't want the badficcers to notice!
Is there an internet source you can recommend that explains the process of shell formation in a bit more detail than membrane>shell>cuticle?
From memory yes it was sub-adult, though it is a relative thing as the current thinking is that dinosaurs matured reproductively at a young age (please let there not be any badficers reading this!).
As for links, well there's this entirely reliable starting point:
http://en.wikipedia.org/wiki/Dinosaurreproduction
You could also try this one, but I can't tell what's in it as my wedblocker comes up labeling it as pornography despite it being a paper on electron backscatter diffraction!
<a href="http://www.aragosaurus.com/secciones/publicaciones/artic/Moreno-Azanzaetal2012EBDS.pdf">http://www.aragosaurus.com/secciones/publicaciones/artic/Moreno-Azanzaetal_2012EBDS.pdf
Finally this appears to be one of the best (though I don't know when it was published):
http://catdir.loc.gov/catdir/samples/cam031/93025263.pdf
Therefore, this is only my personal opinion.
You opened this discussion with scientific intent, and didn't use any vulgar words, so I think you are safe. The admins may have different ideas, I'm afraid.
As for dinosaur reproduction, I suggest we use birds only to compare anatomy, or mating behaviour with smaller dinosaurs. Larger dinosaurs, such as Triceratops may have the same problems as elephants, so their reproductive tactics and behaviour may be similar. After all, supporting extra few tonnes of love is hard on the bones, lousy pun intended to keep it SFW.
... the most awesome TV series ever.
No, not that one.
No, not that one either.
No, not-- all right, I'm talking about Walking With Dinosaurs.
Yes, it does cover this specific issue - and for the largest dinosaurs of all, sauropods (specifically Diplodocus). The general gist is that they pretty much had the bone structure for it.
The most useful reference would probably be the book, which I do own but don't have handy. Of course, this is all nearly 15 years old (and specifically predates the whole 'feathers' malarky), but it's probably still pretty accurate.
Or there's the Jurassic Park solution, which as I recall goes: Frog DNA!
hS
That was precisely the sort of logistical problem I was thinking of. How do crocs manage?
I'm sure National Goegraphic did cover that. I think that they are on top of the other, bellies facing each other? I think I already passed the NSFW line.
First of all, even if this discussion is unsafe for work for some folks, you warned for it, so anyone clicking on it is doing so at their own risk.
Second, I don't think it is inherently NSFW, and you're certainly not violating any Board rules. The rules on post content basically boil down to "keep it appropriate for younger readers" and "don't be an offensive meanie jerk," so discussing a scientific topic in a rational manner is perfectly fine. In fact, there's even a rule that says serious discussion is welcome and encouraged. {= )
And third, what admins are you worried about? You mean the whole community, whose responsibility it is to step up if they see someone breaking the rules? 'Cause the Nameless Admin is really just there to deal with spam and such, and the PGs aren't topic police. So, yeah. Just a reminder.
So, relax and enjoy your science!
~Neshomeh, who doesn't know enough about dinosaurs or birds to join in, alas.
Thanks, I was worrying because I'd got into this line of thought from reading distinctly NSFW dino-porn with (badly done) human reproductive anatomy, and started wondering what the real deal would have been like. Throw in the fascinating/disturbing apparatus some ducks have evolved, and you're definitely into NSFB territory.
Could I grab the link to the badfic?
I'm just intrigued and have a long train trip Friday!
The PPC-wikia page is http://ppc.wikia.com/wiki/LandBeforeTime:Littlefootx_Cera I've only read the missions.
The same agents also deal with some Jurassic Park paedophiliac smut.
I really would not recomend reading them on public transport unless you're very good at keeping a straight face and are damn certain no-one is reading over your shoulder. If you do brave the full fics, please let me know if there's any more biological hilarity that doesn't make it into the missions.