“Courting” Dinosaurs Found in Mongolia?

iStock (hearts) / Wikimedia Commons (dinosaur) // CC BY 3.0

Stop the presses! A prehistoric power couple might have just been exposed. Fourteen years ago, paleontologists dug up the remains of two Mongolian dinosaurs who apparently died together some 75 million years BCE. This pair wasn’t given much thought until last week, when it began attracting global media attention.

Why the sudden interest? New research claims that maybe—just maybe—they were more than friends. In fact, they’ve even been nicknamed “Romeo” and “Juliet.”

Okay, time to break out your field guide. The species we’re dealing with is called Khaan mckennai—which, sadly, has no connection to everyone’s favorite Star Trek baddie. Khaan hails from a group of beaked, odd-looking dinosaurs known as “oviraptorids.” Paleo-enthusiasts adore these critters for their short snouts, toothless jaws, and the garish head crests that many of them sport.

Yet, if you really want to understand an animal (extinct or otherwise), outward appearances are just a small piece of a much larger equation. Blessedly, fossil clues also hint at oviraptorid behavior. For example, one skeleton from a genus called Citipati earned the nickname “Big Mama” because the valiant beast seemingly breathed its last breath while draped over a nest of eggs. Ergo, oviraptorids are now widely viewed as good parents, guarding their clutches until the bitter end.

But—at least in most cases—before she can lay fertilized eggs, a gal’s gotta get pregnant. Recently, much ado has been made about how oviraptorid studs wooed eligible babes. University of Alberta grad student Scott Persons thinks that, come mating season, these Casanovas put a unique spin on the phrase “chasing tail.”

“Their tails were not only very, very flexible, but quite muscular,” he noted in a 2013 presentation. Furthermore, fanning feather impressions are often found around oviraptorid tail tips. Persons added that, “in some oviraptors, the last few vertebrae were actually fused together to become one solid, rigid, bladelike structure.” Dubbed a “pygostyle,” you can see this feature in present-day birds. Function-wise, it’s designed to support the tail feathers.

So, theoretically, a male Khaan would attract bachelorettes by raising his tail and vigorously shaking its feathers in an unforgettable display. Enter, stage left, those two Shakespearean specimens.

After taking a good, hard look at the Khaan pair, a University of Alberta group led by Persons noticed some slight skeletal differences. “We discovered that, although both...were roughly the same size, the same age, and otherwise identical in all anatomical regards, Romeo had larger and specially shaped tail bones.” Juliet, on the other hand, “had shorter, simpler tail bones less suitable for ‘peacocking’ and was probably female.”

Did this pair—like the Bard’s lovers—die during courtship? The evidence suggests they were covered up pretty quickly when a waterlogged sand dune collapsed above them. Hence, if they didn’t perish together, at least they seem to have been buried together. However, figuring out a given dinosaur’s sex is flat-out impossible under most circumstances. Person’s argument may be persuasive, but both Khaan still could’ve been males or females.

Nevertheless, this study might be on to something. It's worth at least imagining our dino-Romeo and dino-Juliet as star-crossed lovers. “Oh, Khaan, Khaan! Wherefore art thou, Khaan?”