By Mia Becker-Hansen | Head of Science and Technology
Research from the University of Portsmouth has found that Pterosaurs may have been able to fly as soon as they hatched.
Pterosaurs were a group of flying reptiles that existed on Earth 228 to 66 million years ago, from the late Triassic to the end of the Cretaceous periods. They are known as the earliest vertebrates to have evolved powered flight.
Pterosaurs are often referred to by popular media as “flying dinosaurs”, but dinosaurs are defined as the descendants of the last common ancestor of the Saurischia and Ornithischia, which excludes the pterosaurs. They are nonetheless more closely related to birds and other dinosaurs than to crocodiles or any other living reptile, though they are not bird ancestors. Some were as large as a modern-day fighter jet, while others were as small as a model aeroplane.
A team of scientists studied four previously unearthed hatchling and embryo fossils from two Pterosaur species, Pterodaustro guinazui and Sinopterus dongi. They compared wing measurements, as well as the size and strength of the humerus bone, with those of adult pterosaurs of the same species. The humerus bone is found on the limbs that pterosaurs used to launch themselves into flight, details of that bone help reveal whether a pterosaur could get off the ground. The bone was found to be stronger in hatchlings than in many adults, indicating they were well primed for flight from birth.
The study’s co-author Dr Mark Witton said “These tiny animals – with 25cm wingspans and bodies that could neatly fit in your hand – were very strong, capable fliers… Their bones were strong enough to sustain flapping and take-off, and their wings were ideally shaped for powered, as opposed to gliding, flight. However, they would not have flown exactly like their parents simply because they were so much smaller: flight capabilities are strongly influenced by size and mass, and so pterosaur hatchlings, being hundreds of times smaller than their parents, were likely slower, more agile fliers than the wide-ranging, but less manoeuvrable adults.”.
The young hatchlings may not have been as equipped for long-distance flight like their parents, but were much more agile and capable of nimble, abrupt changes in direction and speed. This may have benefitted them to be able to chase nimbler prey and be able to fly amongst dense vegetation unlike their adult counterparts. This also could have helped the hatchlings escape predators.
“There’s still a lot to learn about the life histories of these animals,” continues Dr Mark Witton, “but we’re confident that, whatever they were doing as they grew up, they were capable of flying from the moment they hatched.”.