this makes me sound like a pervert but I would LOVE a post on dinosaur genitalia, I've always been confused on the subject
First of all, let me warn you: Do not click on any of the links in this post, unless you want a big old eyeful of archosaur dick.
The burning question here is, what kinds of genitals did dinosaurs have?
The only living group of dinosaurs is Aves - birds. The vast majority of birds possess cloacas - singular orifices that vent digestive waste and serve as reproductive organs, transferring sperm from the male to the female via a “cloacal kiss”. Male birds, therefore, generally do not possess penises. However, a few of the oldest and most primitive bird groups - such as ratites and waterfowl - do possess penises. The presence of penises in more primitive types of birds implies that dinosaurs may have had them as well.
The second-closest relatives of dinosaurs - crocodilians - have penises that are contained within the cloaca and ejected during mating. This means that penises are generally present only in archosaurs more primitive than modern birds - a group that includes dinosaurs.
What did dinosaur penises look like? We can guess by observing the penises of modern archosaurs. Ducks have terrifying spiral-shaped penises, which can grow longer than the animal’s body length in some species; maybe theropod dinosaurs were similar. Ostrich and crocodile penises are a little bit more “traditional” and mammalian (although still pretty gross).
However, it’s also important to consider the physical mating needs of dinosaurs. As some of the largest animals to ever walk the Earth, dinosaurs probably had amazingly exotic genitalia. Sauropod penises were likely flexible enough that the animals could mate without having to bear one another’s massive weight; and stegosaur penises, to paraphrase Darren Naish, were probably the most terrifyingly dexterous penises in Earth’s history, in order to circumnavigate the plates and spikes of mating partners.
(Above: C.M. Kosemen’s illustraton of a Stegosaurus in the throes of a hormonal frenzy, attempting to mate with a hapless sauropod. Note the gargantuan, tentacle-like penis - a plausible adaptation for a species covered in pointy bits.)