Groovy kind of love: Researchers discover dinosaur mating dents in ground

© Steve Chen
While it may not be a box of chocolates or a dozen roses, new evidence has been uncovered in Colorado which shows that dinosaurs had their own form of mating dance.

In an attempt to attract the ladies, the study details how male theropod dinosaurs, large two-legged carnivorous animals, would scrape out grooves in the rock, showing off their ability to make a nest.

Paleontologists from the University of Colorado in Denver say the markings, some of which were as big as bathtubs, were found in 100 million-year-old sandstone rock at four different sites in Colorado.

Such romantic behavior is similar to what their modern relatives, birds such as puffins and ostriches, do during the mating season, but until now scientists could only speculate on the dinosaurs’ “sexual selection” behavior.

"These are the first sites with evidence of dinosaur mating display rituals ever discovered, and the first physical evidence of courtship behavior," Martin Lockley, a professor of geology behind the study, said in a statement. "These huge scrape displays fill in a missing gap in our understanding of dinosaur behavior."

The dinosaurs fancy footwork was found in areas known as “display arenas” or “leks” in what the Lockley say is “physical evidence of prehistoric foreplay” that is very similar to birds today.

The study claims the evidence offers a “tantalizing clue” that dinosaurs in “heat” would gather in certain areas to breed and then nest nearby.

Unable to remove the scrapes from the rocks without damaging them, 3D images of the scrapes were created and have been stored in the Denver Museum of Nature & Science.