Where’s the best place to meet a mate? For theropod dinosaurs around 100 million years ago, the answer was probably a lek. A lek, or a lekking site, is a special area where the members of a species, typically the male members, gather to dance and display — and to generally strut their stuff — all in an attempt to attract the attention of a female mate.
According to a new study in Cretaceous Research, scientists have identified a new lekking site at Dinosaur Ridge in Colorado — a spot famous for its iconic fossils, including Stegosaurus, Apatosaurus, Allosaurus, and more. Based on the Ostendichnus, or fossilized theropod tracks, that have been discovered there, the study authors suggest that the site was visited by gaggles of dancing dinosaurs around 100 million years ago, which grouped together to twist, turn, mate, and nest.
“Newly documented theropod scrapes (Ostendichnus) at Dinosaur Ridge suggest the site was a lek,” the study authors stated in their study, providing “insight into the social behavior of the trace-making theropods.”
Read More: Dancing Dinosaurs Twisted and Turned to Attract Mates
The Traces of Dancing Dinosaurs
Over the years, a number of Ostendichnus or “Ostendichnus-like” tracks have been found in North America, including at one site in Alberta, Canada, and at five sites in Colorado. Based on the density and the distribution of these tracks across several strata, scientists have thought that the theropods that made them gathered at these sites in groups, and repeatedly returned there across several seasons.
The new study supports that theory, finding 25 new Ostendichnus and “Ostendichnus-like” tracks at the Dinosaur Ridge site, about 15 miles west of Denver. Discovered through drone images, the tracks appear across two different stratigraphic surfaces (24 on one, and one on the other), and can be characterized into two types: the less common circular indentations and the more abundant scratches, or scrapes, that are thin, troughed, and tightly clustered.
According to the study authors, while the circular indentations may be tied to the theropod’s attempts at nest building, the scratches are more likely the remains of their ritual dance-offs, in which male dinosaurs dug deep into the sand, slashing their claws and sending spews of dust into the air.
“The high density of these trace fossils and the way in which they are grouped,” says Caldwell Buntin, a study author and a paleontologist at Old Dominion University in Virginia, “Seems most consistent with a group of individuals performing nest display courtship behavior.”
Read More: How Did Dinosaurs Have Sex, Anyway?
Learning the Steps to Dance Like a Dino
Indeed, Buntin says that these traces were probably not left behind by dinosaurs searching for food or for water. And they likely weren’t traces from territorial behavior, either.
“If this were territorial behavior,” he says, “we would expect to find one or two traces on a surface this size.”
But if the best explanation is dancing, what were these dinosaurs’ dance moves, exactly? According to Buntin, the theropods’ steps can be deciphered, thanks to the tracks’ shape, orientation, and organization.
“These tracks tell us quite a few things. First, these animals would alternate between each foot when kicking up sand behind them, and when they were finished, they would walk backwards out of the area where they were scraping,” Buntin says. “If they were really excited, they would step a few feet backwards and repeat the motion. […] When this happened three or more times, a few of [the tracks] show a counter-clockwise turn, kind of like the moonwalk with a little spin.”
The study authors suggest that the tracks were made by theropods around the size of our biggest birds today. “Tracks found alongside some of the scrapes point to them being a small dinosaur, very similar in size and appearance to a cassowary or an emu,” Buntin says. “They were probably plant eaters or omnivores.”
Of course, dinosaurs weren’t the only creatures to dance in display arenas. Birds, the modern-day relatives of theropod dinosaurs, still gather at lekking sites to show off their moves — a similar, but smaller, rendition of the displays in Colorado around 100 million years ago.
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Cretaceous Research. A New Theropod Dinosaur Lek in the Cretaceous Dakota Sandstone (Dinosaur Ridge, Colorado, USA)
Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.
