The subject has always been a spiny one…let alone the problem of size and the (sometimes) the spikes! Her are a couple of my solutions. The first one is this couple of T.rexes having fun and putting their puny forelimbs to some use (as hooks to grapple their partner)… here’s the sketch where the previous illustration was based:
But the really thorny issue is tackled in these next two unpublished sketches where I have tried t0o solve the very popular issue of how Stegosaurus had sex… my solution was pretty basic: there’s ONE obligatory point in their anatomy where the two animals had to meet at all costs (that is: the cloacas). I reconstructed the anatomical possibilities of the posture of the rest of the bodies around the united cloacas instead of going other ways around. Of course I had to take in consideration how flexible could have been the tail with all those big plates on top, holding it stiff… the tail could not flex down, but it could go up and down and sideways fairly easily!
I came with this solution (obviously there have been challenges to it and anyone is welcome to propose even more challenges!), There’s also the distinct possibility that they also had some sort of penis (and since penises don’t fossilise we don’t know how long that could have been). In any case, I thought it was a remarkable exercise for expanding and challenging anatomical knowledge. How do Stegosaurus had sex? very carefully!
I’d like to leave you with an old, famous image that only Ken Carpenter dared to publish in his book “Eggs, Nests and Baby Dinosaurs” by Indiana University Press. It is indeed the Joy of (Carnotaurus) Sex…!
Ok, so what about ankylosaurs, with their armor? Or sauropods? I remember the couple of Diplodocus from Walking with Dinosaurs, but actually I heard is a innacuratte reconstruction.
I think I’m providing here a basic recipe for reconstructing dinosaurs having sex. There are several possibilities according to the different shapes, etc but what is mandatory is that one part of the anatomy of both the animals meet: the cloacas. Based on that assumption, anyone reconstructing the animals copulating would have to go around that fact taking in consideration their anatomy, their weight and size and the general engineering of their postures. There is also another basic fact: either they copulate and procreate or they don’t survive as species, so no matter how difficult it looks to us… it happened… and more often than not! Needless to say, this could be a fascinating subject for a future serious book on the subject!
“There’s also the distinct possibility that they also had some sort of penis (and since penises don’t fossilise we don’t know how long that could have been).”
Correct me if I’m wrong, but wouldn’t non-avian dinos having penises be the most likely possibility, given that both modern crocs & primitive modern birds have penises? Also, the Carpenter reference reminded me: In his book, he compared stegosaurids to porcupines; Until recently, I had no idea how the latter did it; Then, a friend sent me the video in the following link. The point is that I can totally see stegosaurids doing it like that. Even they couldn’t bend their tails that high up, they could probably bend them far enough to the side for that to work.
Yes, that I definitively contemplated in my proposal: dinosaur had penises. Just look at an ostrich penis… weird stuff! However penises in avians and reptiles are not the quite the same as mammals. They are more like anchor devices to hold the cloacas together. There is still the question that those two crucial points in their anatomy had to meet and I doubt they had penises that were like long hoses that could be used from a distance!
Maybe stegs had prehensile penises, like whales and turtles/tortoises.
That might have made things easier.