The way some pterosaurs, these gigantic flying reptiles from the time of the dinosaurs, reached such enormous sizes has long been a subject of intrigue. A new study offers a surprising answer.
Pterosaurs like Balaenognathus filtered their food from shallow waters, much like modern flamingos.
Credit: Rudolf Hima
Pterosaurs not only had to fly but also walk efficiently to evolve into colossal sizes. These creatures had to adapt to a terrestrial lifestyle.
This discovery was made by a team from the University of Leicester, which studied the hands and feet of pterosaurs throughout their evolution. The observed variation suggests that these animals lived as much on land as they did in the air.
Contrary to common beliefs, the early pterosaurs, though excellent climbers, were limited by their small size. Their arboreal way of life restricted their physical evolution. In the Middle Jurassic, an evolutionary turning point enabled their limbs to adapt to walking. This transformation allowed for new feeding strategies and unprecedented physical growth.
This change was accompanied by a separation of the membranes between the hind limbs. Pterosaurs could then move more efficiently on land and free themselves from constraints related to verticality. As a result, some pterosaurs reached gigantic sizes, with wingspans of up to 32 feet (10 meters). This adaptation allowed them to conquer new ecological niches.
The legs of pterosaurs evolved, favoring walking over climbing.
Credit: Rudolf Hima
The study also highlights that the analysis of pterosaur terrestrial locomotion is essential for understanding their evolution. Their terrestrial abilities helped them avoid competition with other reptiles. Some developed needle-like teeth to filter food, a behavior reminiscent of flamingos but which appeared much earlier.
Pterosaurs: the first masters of the skies
Pterosaurs are flying reptiles that lived during the Mesozoic era, between 252 and 66 million years ago. They were the first vertebrates to conquer the skies, long before birds.
Although often confused with dinosaurs, pterosaurs belong to a distinct group. They are characterized by wings formed of skin membranes stretched between their long fingers and their bodies. Their sizes varied greatly, ranging from small specimens only a few dozen centimeters across to true giants with wingspans exceeding 32 feet (10 meters).
They were aerial and aquatic predators, feeding primarily on fish and other small prey. Their diversity in size and lifestyles makes them an important group for the study of evolutionary history.