Recent fossil discoveries have unveiled surprising insights into the flight capabilities of ancient pterosaurs.
Well-preserved fossils reveal that even the most colossal of these reptiles were not only capable of flight but also had diverse flight styles.
Intact Fossils Offer Window to the Past
The fossils date back 66 to 72 million years to the late Cretaceous Period. Initially unearthed in 2007 in Jordan, they were part of an ancient landmass called Afro-Arabia. The fossils remained in exceptional condition, allowing researchers to analyse the 3D structures within the delicate wing bones using high-resolution CT scans.
Some fossils belonged to Arambourgiania philadelphiae, a giant pterosaur with a confirmed wingspan of 32.8 feet (10 meters). These fossils revealed spiral ridges within the humerus bone. Another set of fossils belonged to Inabtanin alarabia, a new species to science, with a wingspan of 16.4 feet (5 meters). This species was named after the large grape-coloured hill, Tal Inab, where it was discovered.
Diverse Flight Adaptations
CT scans of the flight bones showed distinct differences between the species. Inabtanin alarabia’s bones featured interior struts resembling those in modern birds, suggesting capabilities for flapping flight. In contrast, Arambourgiania philadelphiae had spiral ridges similar to those in vulture wing bones, indicating a soaring flight style.
“The struts in Inabtanin were fascinating to see, though not unusual,” noted Dr. Kierstin Rosenbach. “The ridges in Arambourgiania were completely unexpected.”
Significance of Flight Styles
The largest flying modern bird, the Andean condor, has a wingspan of about 9 feet (2.8 meters). Pterosaurs, however, had wingspans between 16.4 and 39.3 feet (5 to 12 meters), making them the largest animals capable of flight. Different flight styles suggest varied behaviours and lifestyles among these ancient reptiles.
“I think they would look noticeably different if we could watch them fly side by side,” stated Rosenbach.
The fossils did not show how pterosaurs took off from the ground. Researchers are examining these findings to understand the evolution of their flight styles.
Mechanical Forces and Bone Structure
The internal structure of pterosaur bones likely reflects mechanical forces experienced during flight. Flapping flight is considered the default condition, with soaring possibly evolving later for environmental advantages, such as the open ocean.
The team discovered both fossils in areas that were once shallow seas, suggesting that each species adapted different behaviors for foraging.
“This leads me to believe that flapping flight is the default condition, and that soaring would evolve later if beneficial for the environment,” Rosenbach explained.
Evolving Look at Ancient Flight
Pterosaur wing bones had to be lightweight yet strong enough to withstand the pressures of flight. Hollow bones with various internal strengthening structures helped balance these requirements.
“This study provides valuable insight into the structure of two large pterosaurs,” commented Michael Benton, professor of vertebrate paleontology at the University of Bristol.
The study’s findings add new evidence to the debate on whether massive pterosaurs could fly.
“The internal bone structure of these fossils suggests they experienced mechanical forces associated with flight,” stated Rosenbach.
Future Research Directions
Researchers are keen to examine more pterosaur bones to understand their flight capabilities better.
“There is growing evidence that pterosaurs were more diverse approaching the Cretaceous-Paleogene extinction event,” Rosenbach noted.
These findings indicate a catastrophic extinction event rather than a slow decline.
Implications for Paleontology
Future studies on pterosaur fossils may reveal additional information about their flight mechanics and evolutionary history.
Scientific Community’s Perspective
“This research contributes significantly to our understanding of pterosaur biology and evolution,” Benton emphasized.
The discoveries of pterosaur fossils enrich our understanding of these ancient creatures.
These findings highlight the complexity and diversity of flight adaptations in pterosaurs. Their ability to adapt to different environments underscores their evolutionary success.
