Romancing the Raptor

Adrian Currie writes...

“She wasn't sure if her sudden arousal was because of her earlier thwarted climax in the cool stream, or if she was just desperate for one last pleasant sensation before being torn limb from limb by the great, scaly beast. Either way, Azog relished the rasp of its tongue, hot and rough, on her sensitive skin.”

-          Christie Simms, In the Raptor’s Nest.

The above is an example from the rather underappreciated genre of dinosaur erotica (see this from jezebel). Immensely fun if that kind of thing floats your boat and—relevant for this post—the bold hypotheses about dinosaur anatomy are striking. They are pretty explicit about size, color and technique. It makes one wonder...

 Photo Credit: Mario Modesto. Jurassic Museum of Asturias. Wikimedia Commons

Photo Credit: Mario Modesto. Jurassic Museum of Asturias. Wikimedia Commons

I’ll cut to the chase: I want to know how dinosaurs bonked, and with what equipment. I want to know positions, mechanics—the length and intensity of climaxes—the ins-and-outs of getting busy in the Mesozoic. I don’t think this is an unreasonable request. Beyond the question’s intrinsic interest, sex is often an essential part of biology and evolution (for instance). Moreover, the attention paid to dinosaurs making war should surely be countered with at least some attention to how they made love (and there’s even direct philosophical interest, but we’ll get to that below…).

There’s certainly a fair bit of speculation about sex in dinosaur art and in some museum displays (for instance), and it comes up occasionally in lectures and blogs (Brian Switek does a nice job), but respectable scientific articles about dinosaur sexual anatomy and mating behaviour are few and far between. It’s not that dinosaur sex doesn’t play any role in palaeontology. The more apparently frivolous aspects of dinosaur anatomy—ceratopsids with uselessly curled horns, flamboyant head adornments on hadrosaurs, and those ridiculous, ridiculous sauropod necks—are often chalked up to sexual selection (Darren Nash has a delightful article on mutual sexual selection in the Mesozoic). And recently, these fascinating theropod trace fossils have been interpreted as the remnants of bird-like dancing rituals. But that is about dinosaur courtship; I want to know about dinosaur mating. By comparison, paleontologists often speculate about specific killing method mechanics (and those are just relevant to T. rex!) in journal articles.

So, why do palaeontologists care so much about dinosaur fighting and so little about dinosaur shagging? Well, we might just have better evidence of the former. After all, pathology is a great boon for both forensic scientists and palaeontologists, and the fossilized remains of long-ago battles are often recorded in fossils. All that squishy sexual anatomy, to say nothing of all that apparently unpreservable sexual behaviour, fades from the prehistoric record (except in super-rare cases, for instance).

There’s probably something right about this, but I don’t think it can be a complete explanation. To see why, let’s consider how we might work out the proclivities and organs involved in dinosaur sex.

to begin, we can employ the ‘comparative method’. All living things, including those sexy, sexy dinosaurs, are connected through ancestry—and ancestry retains information. This means that in some circumstances I can infer from living critters to dead critters (I discuss this here and here). For instance, my ancestry has left me with just a touch of ginger, particularly in my facial hair. Do you reckon my great-grandfather had the same? Well, my having red hair is at least some reason to think he did, because l could have inherited the trait from him.

Paleontologists often use this kind of reasoning to infer an organism’s traits. Perhaps this means we should expect dinosaurs to follow extant birds and reptiles and sport rather unexciting cloacas (not that you can't have fun with a cloaca)! However, Patricia Brennan’s work on the very diverse sexual anatomy of waterfowl might suggest otherwise. There’s at least some reason to think that the water-fowl approach to sexual anatomy was basal—that is, the ancestors of birds (that is, theropod dinosaurs) were water-fowl like. It was only later that birds became relatively boring. Further, (this is speculation on my part), Dinosauria were an extremely diverse clade, expressing wide variation in phenotype, behaviour, niches, and so forth: I don’t see why we shouldn’t expect them to be diverse in terms of sexual behaviour and anatomy too (of course, this diversity could present its own epistemic issues!).

Just as for dinosaur battles, biomechanics can surely shed light on dinosaur sex. Back in 1989, R. Alexander drew on biomechanics to disagree with the hypothesis that sauropod mating must have occurred in water. This might be an especially useful approach for critters like stegosaurus and the ankylosaurs, whose prickly, spiky anatomy surely put strict constraints on possible positions. Further, other simulation-studies (similar perhaps to those used to hypothesize about the gaits of extinct animals) could also be bought to bear.

So, it’s not that we simply have no inroads into dinosaur sex. Even if fighting is easier to access, this doesn’t explain the near-complete dearth of published work on dinosaur mating and sexual anatomy.

Perhaps another explanation is bias. Scientists are often pretty awful at thinking straight about sex (Lisa Lloyd highlights this brilliantly). And concern for such misstepping is certainly a reason for caution. But I take it that the lesson from feminist philosophy of science is not that bias should be expunged, but that it is something that is here to stay. As Helen Longino has argued, objectivity should be understood ‘procedurally’, it is found in the various social practices we adopt to ensure that no one person’s biases have overweening priority. As Elizabeth Anderson might put it, we shouldn’t be worried about bias per se, but whether those biases determine our results. So long as we get push-back from the world, the apparent subjectivity introduced by bias does not undermine scientific progress.

Besides, we’re hardly very good at thinking about violence either (man the hunter, anyone?). So if possible bias is not sufficient to disallow research of fighting, nor should it be to disallow research of loving.

Finally,  dinosaur sex might not be respectable because of squeamishness. However, in my experience, paleontologists are about as unsquemish as they get…

I am not interested in dinosaur bonking for purely natural-historical reasons. It’s also an opportunity to adjudicate a difference of opinion between Derek Turner and myself. I’ve argued that we tend to underestimate how much evidence will ultimately be available about the past. This is because historical investigation is often scaffolded: we have to know a fair bit about some past target before new questions, and new routes for testing, are visible (this is why speculation is so important). And so, prior to an investigation we will often be more pessimistic than we should about how much evidence there will be to draw on. In short, I’m optimistic about us being able to find out about the past, but pessimistic about our capacity to judge which research directions will be fruitful.

In contrast, Derek argues that our understanding of historical processes often leads us to expect the past’s signal to decay over time. So, we should expect much of the past to be lost to us. Moreover, in a lovely recent paper, he points out that predicting the fruitfulness of future research is something required by scientific practice: of all the possible things to study, scientists need to decide which will likely provide epistemic dividends. For instance, recently some of Calgary’s philosophy students (and me!) had the honour of taking a behind-the-scenes tour of the Tyrell Museum with Don Brinkman. He emphasized both how long fossil preparation took – each prepared fossil means years of work - and how many fossils there were to choose from. The Tyrell, and other natural history museums, have enormous rooms full of unprepared specimens, many sporting gloomy tags bearing their long-ago excavation dates. Deciding which fossils to prepare involves guessing which will produce the best research.

As Derek puts it:

One challenge is to identify questions that seem answerable using available methods, and where there is some reasonable expectation of finding or producing relevant evidence. 

Derek, then, is more pessimistic about our capacity to find out about the past, but more optimistic about our capacity to identify fruitful research avenues.

So, when we find an unexamined area of palaeontology, such as that concerning us here, both Derek and I might explain this by scientists having (implicitly or otherwise) decided that the area is a non-starter. Derek, who is optimistic about our capacity to predict future science, but pessimistic about how much we can know about the past, will take these judgements to be justified. I’m pessimistic about our capacity to make the former judgement, but more optimistic about what we can know about the past: so I’ll tend to think that judgment is unjustified.

So I’d like to make a bet.

If, over the next ten years, palaeontologists make a concerted effort to find out about dinosaur sex – and I don’t mean courtship, I mean sex – and they don’t start coming up with plausible, well supported hypotheses, then I’ll owe Derek Christie Simm’s complete back-catalogue of dinosaur erotica.

So, come on palaeontologists. Tell us about sex.