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We Asked a Paleontologist What Dinosaurs' Dicks Were Like

Don't act like you've never wondered.
Jurassic Park Screencap via Universal Pictures

The Jurassic Park movies have answered a lot of questions about dinosaurs: They move in herds, but they sneeze on each other. They'll eat you while you're pooping, but bust out some gymnastics while they're attacking and they'll run for the hills. Yet despite this wealth of knowledge, Spielberg and his paleontology consultants left out one glaring question at the front of everyone's minds: What's up with their dicks?


Will Jurassic World, with its new director, Colin Trevorrow, answer the question? Probably not. Hollywood counts on a PG-13 rating to guarantee boffo ticket sales, so some parts of dinosaurs' private lives will never make it to the big screen. That means for vital information on things like dicks, we have to turn to the second best place to learn about dinosaurs: science.

I contacted Dr. Sarah Werning, postdoctoral research fellow at Stony Brook University, who works in the fields of paleontology and evolutionary biology. She's something of an expert on dinosaur fuckin', so I gave her a call to find out what kind of heat dinosaurs were packing, as well as if they had anything weird going on down there like ducks.

VICE: Hi, Sarah. First and foremost, which dinosaur had the biggest dick?
Sarah Werning: That's a big mystery. The problem is that there aren't any fossilized dinosaur wangs. Or, we haven't found any yet. That's partly because most penises in the animal kingdom don't have a bony component. It's usually more of a liquid inflation system, so it starts out limp, and blood gets pumped into it. We have no reason to think dinosaurs would be an animal that had any bones down there.

Right, but different species had different characteristics. So we can make some educated guesses, right?
Well, in most species you'll have the male mounting the female. But there are lots of dinosaurs that had big spikes and stuff all over their backs. It's hard to think about how the hell you're going to mount something that's covered in spikes. From a practical standpoint it seems difficult. So what turtles did is they moved their cloacas [single holes for urine, feces, and reproduction] way back, not just to the base of their tails, but kind of onto their tails. So we know that the male cloaca is even further back, closer to the tip of the tail, so it can kind of curl around.


So does that mean the penis would have to be bigger to compensate for the cloaca's location?
No that's so the male can curl its tail under the shell to get closer to the female turtle's cloaca. I don't know if dinosaurs would have something like that. But there has to be some way of accommodating the fact that stegosaurus is covered in plates. Most dinosaurs don't have something sticking out of their backs.

Related: Watch our documentary about some impressive human penises.

So it's stegosaurus? Stegosaurus wins?
No. We would have to be much more speculative than that.

What would that speculation be based on?
What we do with things we can't observe in dinosaurs, or any extinct animals, is we look for their closest living relatives. The last remnants of the living dinosaur lineage are the birds. Outside of birds, the closest cousins are crocodiles and alligators, and they have really different genitals.

OK. What can we learn from birds and reptiles then, just in general?
Dinosaurs are a specialized type of reptile. So when I say "reptile," I mean that in the sense that it includes birds and dinosaurs. If you look at lizards and snakes, they have penises, but they look different from mammals' penises. If you look at turtles, they have penises. All the distant cousins have them. Some of the oldest lineages of birds, things like ostriches, emus… the big, flightless birds. But most birds don't even have penises. They don't have anything at all in terms of an organ that protrudes out of their body and shoots sperm into the female.


Are you suggesting that dinosaurs didn't have penises at all?
If all the distant cousins had them, and some of the bird groups that we think are some of the first to split off have them, then the ones that are in between—dinosaurs—they probably had them too.

What are some known penises we can use for reference?
Reptiles do penises a number of different ways. Snakes and lizards have kind of a two-headed penis that inverts. When they're feeling amorous they pump blood into it, and it sort of ejects out of their body. Crocodiles have a permanently erect penis hanging out inside of their body, waiting to be ejected at a moment's notice. They've got ejector muscles with a super-fast trigger that can push that thing out.

That's incredible! Please tell me dinosaurs had those.
It could be, but crocodiles and alligators are the only animals that have anything like that setup. Although I admit it'd be pretty amazing if they did. If you think about the sizes involved, and how fast they'd have to eject those things. Most animals with penises don't have permanent erections tucked inside a little pocket, though.

So that wouldn't be a standard dinosaur penis, then?
There's no such thing as a generic, standard-looking penis. Most of them get erect by pumping fluid into their penis like a giant water balloon. All the birds with penises do it that way, so it'd be pretty weird if dinosaurs evolved this very odd way of doing boners, and then for their descendants to go back the other way. Birds that have penises kinda have a flap of skin on the inside that they'll put lymph into, and that'll kind of eject it out. Some ducks have super-long corkscrew penises that shoot out so fast you need a high-speed camera to capture them unfurling. That's not my work, but some scientists at some point filmed that.


So you're saying even if there's a dick, it's not dangling down all the time?
Penises aren't hanging around on the outside in animals that have cloacas. Most animals, including platypuses and kangaroos, which are mammals, have a cloaca, and their penises are either deflated or tucked away inside a cloaca, and when it's time, it'll pop out of the cloaca, and they'll try and get it into the female's cloaca. Birds that don't have penises try and make their cloacas line up, male and female, and squirt the sperm in. That's called a cloacal kiss.

But how likely is a "cloacal kiss" for dinosaurs?
The cloaca's in a pretty inconvenient spot if you have to line them up, back underneath the base of the tail. Probably the fact that birds are able to fly makes the cloacal kiss a lot easier, because they can use their wings to help get into position.

A close relationship to birds doesn't seem like it bodes well for their penises. Is there anything else that separates dinosaurs from birds in terms of sex?
One thing that's interesting about dinosaurs: We were able to figure out how old they were when they hit puberty. Most birds grow to full size, wait a while, and then start reproducing, but all the dinosaurs we found medullary bone in, they seem to hit puberty pretty early on in life, while they were going through their big growth spurt. You know how we hit puberty right at the start of our big growth spurt? It's the same deal in dinosaurs.


Oh, cool, so they had awkward teenage years like us.
They have to deal with puberty on top of changing shape rapidly. So yes.

So crazy duck corkscrew penises and weird gator ejector-penises aside, what kinds of penises do animals with cloacas have?
Birds are the living dinosaurs, and most birds with penises have a pretty small, cone-shaped penis—a boring penis, as penises go. It inflates the normal way, with fluid. I don't know if you can find a picture of an ostrich penis online…

Looks a little like a tongue. OK. So that's pretty likely, huh?
Size and shape? Who knows. But you're asking if it's penis-in-cloaca sex? That's probably how it would work in dinosaurs.

But then again, lots of them have little spikes and bumps, and all sorts of weird things coming off the ends of their penises that might help them anchor onto the female better, or help get sperm in more efficiently. So whatever you want to imagine dinosaur penises looked like, let your imagination go.

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