Ancient dinosaur tracks reveal that some carnivorous theropods used to perform an odd mating dance to attract potential partners, a new study suggests.
Palaeontologists said that the newfound scrape marks that were made millions of years ago are evidence of a mating display known as “scrapping,” which modern ground-nesting birds usually perform.
On average, each of these marks is about 6.6 feet (two metres) long. They were found on four different sites – from the Cretaceous period – in Colorado.
Martin Lockley, co-author of the study and emeritus professor of geology at the University of Colorado, Denver, said that when he and his colleagues first discovered the scrape marks, they were partially covered with sand. According to him, these marks were unlike anything that they had seen before.
As the investigation continued, the researchers found about sixty of these marks only in one of the sites. Because of the claw marks, they were able to link the footprints to dinosaurs. Some of them resembled the three-toed footprint of the meat-eating theropods – a group of bipedal dinosaurs – Lockley said.
Based on the clues left behind, the researchers tried to recreate an accurate scenario. They had to consider – and then rule out – various possibilities. To find an explanation for the dinosaurs’ behaviour, Lockley and his colleagues also looked at the behaviour of modern birds – descendant of dinosaurs.
After analysing accounts of mating display behaviour in birds, the researchers came to the conclusion that the scrape marks could have been made as part of the activities called “pseudo nest building” or “nest scrape display”. During these mating activities, males start scratching the ground to impress females – which would be like saying: “Look! I can build a nest!” Lockley said.
In the study – published January 7 in the journal Nature Scientific Reports – the researchers found a long list of modern birds that perform such nest scrape displays. These include seven species of shorebirds and the puffins – parrots from New Zealand.
Paul Sweet, manager of the Ornithology Collections at the American Museum of Natural History, said that this behaviour can be observed in many branched of the bird tree family.
Researchers said that the four sites where they found the scrape marks were probably leks – areas where males gather to engage in competitive displays to woo females – where theropods went to find a partner.
Image Source: nature