Barely hatched little pterosaurs knew how to fly!

Les ptérosaures tels que cet Anhanguera occupaient le ciel il y a 66 à 228 millions d'années en arrière. © warpaintcobra, Adobe Stock



Silhouettes of pterosaurs inhabited the Mesozoic sky, between 228 and 66 million years ago, during the Triassic, Jurassic and Cretaceous. These flying reptiles were often called celestial lords, but were they really?

A study recently published in Scientific reports calls into question the flight capacity of pterosaurs, among which are classified pteranodons and pterodactyls. Certain species of pterosaurs, such as Quetzalcoatlus, could reach 12 meters of wing span and have a skull 2 meters long. How could such organisms fly? The inside of the wing bones was hollow to lighten the skeleton and Quetzalcoatlus probably had tendons so strong in the wings that they were accustomed to to propel the body during take-off.

In modern birds, the ability to fly is acquired with the growth of chickens, but is it the same in all birds? cash flying? The authors of the pterosaur study therefore wondered aboutthe appearance of this tendency during the life of these reptiles steering wheel. It is difficult to answer this question because eggs and embryos of the pterosaur are very rare in the register fossil. However, the authors were able to study two species of pterosaurs, Pterodaustro guinazui and Sinopterus dongi whose wing span in adulthood was probably much smaller than the giant Quetzalcoatlus.

Different stages, different flying skills

To estimate the flight capacity of the three young individuals, they compared the wing size as well as the robustness of their wings. humerus those of 22 adults of the same species. Although the authors have only a few young specimens, their measurements show that the upper arm bones of the younger ones were more robust than those of the few adults. Therefore, they conclude that the young people could have flown. In addition, they found that although the wings of the young were long, narrow and adapted to long-haul flights, they always remained shorter and wider than the adults.

The young men were therefore probably able to fly shorter distances than their older ones, but they had to be more skilful in flight, which allowed them to suddenly change direction and speed upand fly in areas with dense vegetation, which was certainly impossible for adults. This agility would also be an advantage for predator escape and agile prey hunting. The conclusions of the study open ecological perspectives for the studied species of pterosaurs.

The authors suggest that juveniles occupied denser ecological niches than adults who were likely to be in more open areas. In addition to the fact that individuals occupied different environments because of their abilities physical, this distribution may have allowed them, as is the case with other species, not to compete for food sources.

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