SIOUX FALLS, S.D. (KELO) — A Dakota State University made a recent discovery as part of a research team — courtesy of a little feathered dinosaur more than 100-million-years old.
Alex Dececchi is an assistant professor of biology at DSU, and he was part of an international team that discovered an instance of a dinosaur using a “flap-run” to move at higher than expected speeds.
“Much of my research looks at how birds evolved and how flight evolved, which are slightly different things,” Dececchi said on a Tuesday Zoom call with KELOLAND.
He says that often means looking at fossils and thinking of the way in which bones connect to muscles — building computer models and even physical models.
But Dececchi says catching flight in fossil records is hard. “You can say, ‘oh, the wing is this big, it’s got this type of shape. So it’s probably flying’, but it’s really, really hard,” he said. “So there’s a big debate going over years about — before birds — did their dinosaur ancestors, who also had big feathers, did they use those wings for really anything?”
It appears so.
“A few years ago, when I was working on a different project, I came across these trackways. They were published by a group from South Korea. And I immediately was interested because they were so different than other tracks I’ve ever seen,” said Dececchi.
What set them apart was the stride between the tracks. They were long; much longer than they should have been.
“We wanted to confirm that the pattern that we saw of these really long strides was real,” said Dececchi. “These strides suggested that this really small animal, this little small raptor — about the size of a sparrow, was moving at somewhere on the order of 30 miles per hour.”
That didn’t make any sense, according to Dececchi.
The raptor in question was what is known as a Microraptor; a small feathered dinosaur from the Cretaceous Period.
“When you look at their anatomy with the feathers and that speed, what does make sense is if when they’re moving their wings, they actually get a little bit of lift,” said Dececchi.
He compared the motion he and the team saw born out in the trackway to the movement of geese as they take off, flapping their wings as they run to gain momentum before flying.
“You notice what they do is a sort of flap run,” he said, “and if you actually watch that, they get bigger and bigger strides because their wings are pushing them off the ground.”
Dececchi says these tracks showed that because the strides were too long to be made by a Microraptor simply running, it would have had to have the assistance of a lift.
“It’s just the distance, travel and the speeds, when you look at it — it’s almost impossible for it not to be then taking off,” he said.
Now Dececchi speculates that the dinosaur was likely not flying well — at least not the standard of most birds today.
“But it could have some kind of take off,” said Dececchi, “and that is really special because for the first time, it looks like we have solid evidence of these kind of behaviors in the fossil record and from a source that no one really thought to look at before.”
Dececchi emphasized that this trackway is special and relatively unique.
“If you think about it, something’s walking around every day,” he said. “It leaves lots of footprints even running — but when you’re doing something as extreme as this could be –take off or landing — that’s a very short snapshot of time, you know, a couple of seconds at most. So to actually have a record of that is really extraordinary.”
Some of the significance of the discovery also relates to something Dececchi said earlier: “how birds evolved and how flight evolved, which are slightly different things.”
“These guys, these Raptors aren’t directly on the line to birds,” he said. “They’re kind of like a cousin to them. They split from the line of birds — so we know that there’s been tens of millions of years and tens of millions of generations of this group, these raptors evolving besides birds, but on their own. And so now that we know they could use their wings like this, the question is what else were they using them for?”
While some feathered dinosaurs likely used their wings for flight, others were likely too big to fly, said Dececchi, comparing these to the modern day flightless ostrich.
“But they could maybe use display or to help them run — to get that little extra speed,” he said. “If something is the size of a turkey, that’s nothing the size of something the size of a T-Rex.”
Dececchi speculates that the speed boost and lift from using their wings could have helped dinosaurs escape predators, catch prey, turn faster while running or even extend jumping range.
Looking forward, Dececchi says he and his colleagues are going to look back through their trackways in their collections to look for more helpful data, and he hopes that other paleontologists will be able to build off their work to continue making breakthroughs.
