The trajectories of theropod dinosaurs could be used as indirect evidence of pre-avian aerial behavior, according to a new study.
The animals in charge are Dromaeosauriformipes larus Trucks are thought to be small microraptid dinosaurs related to the ancestors of birds. Image credit: Julius Csotonyi.
In the study, University of Maryland paleontologist Thomas Holtz Jr. and his colleagues examined two-toed footprints made by fast-moving, small, bird-like microraptid dinosaurs.
with scientific name Dromaeosauriformipes larus these footprints are almost 100 million years old (Cretaceous period) and were discovered preserved in rock slabs in Korea.
“This guy is lanky. He's one of the smallest dinosaurs we have fossils of,” Holtz said.
“These footprints were a puzzle because they were so small and so far apart.”
Paleontologists believe that the producers Dromaeosauriformipes larus It's not just about running on land.
The animal gained lift by flapping its winged arms, allowing it to move faster than relying solely on leg strength.
This form of exercise, known as flap running, falls somewhere between running and flying.
This generates enough aerodynamics to lift the animal off the ground in one go, allowing it to run up a tree, for example, but stops short of flying at full power.
Microraptors are cousins, but Velociraptor And it is unknown whether it is a modern bird Dromaeosauriformipes larus You will be able to fly for longer periods of time.
Trajectory of a Microraptorian theropod excavated from the Jinju Formation in Korea. Image credit: Dececchi others., doi: 10.1073/pnas.2413810121.
“We can overcome the debate over whether pre-avian dinosaurs used arms for locomotion before flight evolved and provide missing details such as which species had these abilities, when they developed them, and to what extent. We can now begin to find out,” he said. Michael Pittman is a paleontologist at the Chinese University of Hong Kong.
“Our findings show that Dromaeosauriformipes larus “It would have needed to run at about 10.5 meters per second (23.5 miles per hour) to make the track using just the power of its hind legs,” said paleontologist Dr. Alex DeCecchi of Dakota State University.
“The relative speed of our footprints is faster than that of modern running animals such as ostriches and cheetahs.”
“This is also unlikely, so we think the dinosaur could have used the aerodynamics created by flapping its feathered arms to lengthen its stride, creating a slower trajectory.”
“The footprints also suggest that the raptor was in the midst of taking off or landing,” Holtz said.
“It's like a plane descending, bouncing a little bit on the runway, and then slowing down.”
“Microraptors, capable of powered flight, were less sophisticated than modern birds in terms of flight equipment. They would have been relatively clumsy.”
of result Published in Proceedings of the National Academy of Sciences.
_____
T. Alexander Dececchi others. 2024. Theropod trajectories as indirect evidence of pre-avian aerial behavior. PNAS 121 (44): e2413810121;doi: 10.1073/pnas.2413810121
Source: www.sci.news
