DSU professor and international research team discover dinosaur flap-run

October 25, 2024 | DSU professor and international research team discover dinosaur flap-run

After spending 15 years researching dinosaurs and decades longer fascinated by them, Dr. Alex Dececchi, assistant professor of biology in Dakota State University's College of Arts & Sciences, is part of an exciting recent discovery.

Dececchi led a team of international researchers in discovering evidence for the first time that small-feathered dinosaurs ran at speeds achieved only by using their wings to 'flap-run.'

He worked with Dr. Michael Pittman at the Chinese University of Hong Kong (CUHK)'s School of Life Sciences, Dr. Hans Larsson of McGill University, and a team of researchers from South Korea and the USA.

The researchers have been collaborating for years, studying the origin of flight in birds and their closest theropod dinosaur relatives.

The researchers studied a 106-million-year-old fossil trackway in South Korea that preserved two-toed footprints of a small microraptorine, a feathered, four-winged raptor dinosaur from the Cretaceous Period.

"For a long time, there has been a lot of debate about how flight evolved in birds and their immediate ancestors, pre-avian dinosaurs, or small, feathered meat-eating dinosaurs like a velociraptor, but the size of a crow," Dececchi said. Pre-bird dinosaurs are referred to as non-avian theropods in literature because birds are dinosaurs.

This research proves that at a minimum, these pre-bird dinosaurs achieved a prolonged aerial phase to their stride, meaning the time period when both legs were off the ground was longer based on the fossilized tracks, he explained.

"I feel these strides look to be so elongated that they hint that the maker was very likely doing what we see some modern birds like geese do, that is a running start to taxi and take off," he said.

The implication of this is that other feathered dinosaurs besides birds were experimenting with flight and flight-related behaviors.

While Dececchi and his fellow researchers have long been developing models of different parameters such as flapping speed, angle, and the ability of the wing to generate lift to help determine how these feathered dinosaurs moved, the analysis of the trackways appears to show the dinosaurs were able to use running starts to get the speed and momentum needed to take off for flight.

"Using new sources of data, in this case trackways, can inform and provide new clues to solve problems that have been around for over 150 years," Dececchi explained.

By looking at footprints instead of just what the arms or wings are doing, Dececchi and his colleagues were able to find information that had been overlooked and apply it to how flight began.

"Now we have proof that feathered dinosaurs who are closely related to the first birds were using their wings to do some fight or flight-adjacent behaviors on the ground early in their evolutionary history," Dececchi said.

Additionally, he said this research helps highlight how different sizes, species, and ages can show how diverse and varied evolutionary traits can be. The researchers examined closely related species to microraptorine, which show different sizes, arm lengths, feathering levels, and other features suggesting wings may have been used for more behaviors than just flight.

Dececchi is excited to find this discovery opens more questions, lines of thinking, and complications, but he sees fun hypotheses and research paths to follow in the future, something he hopes to involve his students with.

The team of researchers, including Dececchi, will co-host a meeting this upcoming summer in Hong Kong for the top researchers in the field.