Richard Collins: Baby giant pterosaurs had caring parents
Image Emerging To To Needed Egg Unlike Large Smaller Support The Able Partially Developed Which Their From Only Themselves When Until Wings Able For Yang By Wing Zixiao The Were To Pterosaur Hatching, Babies Were Danger, Helpless From Of After Soon Parental Relatives, Fend Take Flee Prolonged Being They
‘Dear Diplodocus, dear Pterosaur … like you, we must now witness the end of our species, and pass from Earthly view’ — Margaret Atwood in .
In 2017, the well-preserved fossil of a flying reptile was found on the Isle of Skye. It was named ‘dearc sciathánach’ — a translation of ‘pterosaur’, Greek for ‘wing-lizard’.
Now there’s another Celtic connection; Dr Zixiao Yang of University College Cork is lead author of a paper on the family life of pterosaurs. He, with Dr Maria McNamara, and colleagues in Britain and China, has shown that the larger members of the pterosaur tribe were devoted parents.
Check out our new paper freshly out today! It turns out that giant pterosaurs were caring parents! Amazing artwork by James Robins. https://t.co/Tjp5KeM6BI @UCC @uccBEES @RSocPublishing pic.twitter.com/aAema4TnH3
— Zixiao Yang (@ZixiaoYang_Dino) July 19, 2023
Nowadays, birds and bats are the only back-boned animals able to lift themselves into the air by flapping wings. Pterosaurs, however, were doing so 70 million years before birds arrived on the scene and 160 million years before bats evolved.
The 4th finger of the pterosaur’s ‘hand’ was elongated. A web of skin stretched from it to the thigh, enabling all four limbs to be deployed when flying. As in birds, the bones were hollow, as a weight reduction measure. Theirs was a winning formula; pterosaurs would have been a Jurassic twitcher’s dream as so many species evolved. Some were as small as terns. Others, with wingspans of up to 15metres, were the largest creatures ever to fly under their own steam.
It used to be thought that these giraffe-like reptiles, with head crests and stork-like bills, had fluffy downy coats but no true feathers. Then, in 2018, researchers showed that pterosaurs had, in fact, several types of feather. Maria McNamara and colleagues discovered traces of colour pigment in the plumage.
Dr Yang and colleagues have addressed a long-standing conundrum. Previous research had shown that the babies of the smaller pterosaurs had almost fully-formed wings when hatching from the egg. That would have enabled them to take to the air within a few days, requiring limited parental support. It led to a 'love-them-and-leave-them' approach to family life. But was this also the case with the larger species? Did their young arrive with well-developed wings?
To answer that question, the palaeontologists needed to examine fossils of pterosaur babies at the hatching stage or soon after it. However, these creatures’ hollow bones have not helped the scientists: pterosaur remains don’t fossilise well and good examples are rarely found.
"Luckily we were able to use some classic specimens from the Jurassic of Europe and the Cretaceous of North America, together with new finds from China," Dr Yang says on the UCC website. His team measured the growth-rates of skulls, backbones, wings, and limbs of the specimens.
Unlike their smaller relatives, which were able to fend for themselves soon after hatching, the wings of large pterosaur babies were only partially developed when emerging from the egg. Helpless to flee from danger, they needed prolonged parental support until being able to take wing.
The wing-lizards lived throughout the ‘age of dinosaurs’, perishing when an asteroid struck the Earth 66 million years ago. Unlike the dinosaurs, which were ancestors of the birds, the pterosaurs left no descendants. Will we?