Analysis of a small pterosaur fossil has provided further evidence that the flying reptiles of the Jurassic period used their long arms to rock back and forth in order to ‘pole-jump’ themselves into the air.
The research, recently published in the journal Scientific Reportsevaluated a tiny pterosaur fossil in rock from the Late Jurassic period about 163 million years ago to 146 million years ago unearthed in Germany.
Scientists who have studied pterosaur fossils since their first discovery over two centuries ago have concluded that the flying reptiles’ physical characteristics, including a “forward center of gravity,” prevented them from a bird-like takeoff.
Researchers have theorized a launch of water bodies for pterosaurs, similar to a method seen in modern water-eating birds and bats.
However, direct physical evidence for such a mechanism has so far been elusive.
In the new study, scientists, including Michael Pittman from the Department of Earth Sciences and University College London, analyzed the fossil remains of a species called pterosaurs polar lights Excavated from the Jurassic rocks of Germany with well-preserved soft tissue, including a wing membrane and webs.
Their analysis suggests that the soft tissues were primary propulsion contact surfaces needed for the pterosaur’s water start using a four-legged pole-vaulting mechanism.
With previous studies suggesting that pterosaurs weren’t strong swimmers, scientists say the soft tissues likely helped with takeoff from the water, rather than being swimming adaptations.
When folded, the pterosaur’s wings may have helped the reptile push itself off the water’s surface.
The results “show that a four-legged water start was theoretically feasible and that webbed significantly affected takeoff performance,” the researchers said.
They were also able to identify key factors that limit waterstart performance in all pterosaurs, including “available propulsion contact area, range of forelimb extension, and force of forelimb extension around the shoulder.”
Scientists believe the new results also provide a comparative context for further investigation of water start potential and evolution in pterosaurs.
“While many small pterosaurs probably had enough contact area, range of motion, and power to escape the water surface, it is quite plausible that more terrestrial taxa were unable to start water, particularly when a lack of pedal harness limited propulsion contact area,” they wrote in the study.
The new results follow a collection of studies published last year in which researchers evaluated the fossil of a giant pterosaur Quetzalcoatlus which weighed over 250 kg and had a wingspan of almost 12 meters.
The 2021 research suggested that giant pterosaurs were likely leaping, leaping at least 8 feet (2.5 m) into the air before taking off.
Scientists have called for further analysis of additional specimens in the future to unravel the evolution of flight in pterosaur species.