Everyone’s favorite prehistoric flying creature just got a little cooler and a little scarier – paleontologists studying pterosaur fossils have determined the creatures could definitely fly a mere hours after hatching. Forget waiting for the ‘terrible twos’ – looks like other creatures living 228 to 66 million years ago had to fear the ‘terrible pterosaur two hours’!
“Competing views exist on the behavior and lifestyle of pterosaurs during the earliest phases of life. A ‘flap-early’ model proposes that hatchlings were capable of independent life and flapping flight, a ‘fly-late’ model posits that juveniles were not flight capable until 50% of adult size, and a ‘glide-early’ model requires that young juveniles were flight-capable but only able to glide. We test these models by quantifying the flight abilities of very young juvenile pterosaurs via analysis of wing bone strength, wing loading, wingspan and wing aspect ratios, primarily using data from embryonic and hatchling specimens of Pterodaustro guinazui and Sinopterus dongi.”
Who knew the subject of when baby pterosaurs could fly was so controversial? According to a new study published in the journal Scientific Reports, researchers from England’s University of Southampton did and they decided to settle it once and for all. One reason for the confusion is that pterosaurs came in a wide variety of shapes and sizes, thus making it difficult to distinguish between adults and youngsters. Compounding this is their structure – like modern birds, these lightweight aeronauts had hollow bones and thin skins that rarely survived to become fossils. Throw in the fact that very few embryos in eggs survived either and you have an idea of the challenge paleontologists specializing in pterosaurs have faced since the first fossils were discovered in the 18th century.
According to Science News, paleontologist Darren Naish led a team comparing fossilized embryo and hatchling wing measurements with those of adults from two species -- Pterodaustro guinazui, which were the only pterosaurs that had bristle-toothed beaks, and Sinopterus dongi, which had long, crested skulls. The most informational bone for them was humerus, a wing bone used to launch the creatures into flight and a key indicator of when a pterosaur was capable of flight. It turns out hatchling humerus bones were stronger than those of adult pterosaurs, allowing babies to fly almost immediately after hatching, and they had shorter and broader wings that helped them change direction and speed quickly – traits that allowed them to evade predators until they grew into adult bodies.
“Our findings present pterosaurs in contradictory lights. On the one hand, they highlight how conservative these animals were throughout their lifespans: juveniles not only resembled adults, but shared fundamental elements of skeletal structure and function with them. On the other hand, we have also demonstrated how distinct pterosaurs might have been at the beginnings and ends of their lives due to the profound effect of size changes on their ecology and flight behaviour. Our understanding of pterosaur aerodynamics and lifestyle through the perspective of ontogeny is currently limited but promises to be a rich field for future research.”
The biggest surprise in the study was not that baby pterosaurs could fly after hatching, but that the creatures changed habitats based on their size and agility as they aged. Hatchlings were fast and maneuverable, so they could hunt for insects and small animals in dense, grassy areas. Adults were large, slow and not as agile (can we relate?) so they switched to open areas for hunting. In the end, as always, the study created more questions, giving reasons for more studies.
Does this new knowledge help or hurt the hunt for modern-day pterosaurs?