Flying giant pterosaurs had longer neck than a giraffe, say experts
Pterosaurs, one of the first and largest vertebrates to learn to fly, have often been seen as the cool cousins of the infamous Tyrannosaurus rex.
Now scientists have discovered the 100m-year-old secret to the success of the flying pterosaur: a neck longer than a giraffe.
Palaeontologists from Portsmouth University have been puzzled at how gigantic flying azhdarchid pterosaurs have managed to support their thin necks as they take off and fly while carrying heavy prey animals.
But thanks to new CT scans of intact remains, discovered in Morocco, the mystery has been solved.
The findings, published in iScience, show a complex image of spoke-like structures, arranged in a helix around a central tube inside the neck vertebra, similar to that of a bicycle wheel.
This intricate design is said to demonstrate how these flying reptiles had evolved to support their massive heads that often measure longer than 1.5 metres.
Scientists suspect this “lightweight” construction offered strength, without compromising the pterosaurs’ ability to fly.
Dave Martill, a professor of palaeobiology at Portsmouth, said: “It is unlike anything seen previously in a vertebra of any animal. The neural tube is placed centrally within the vertebra, and is connected to the external wall via a number of thin rod-like trabeculae, radially arranged like the spokes of a bicycle wheel, and helically arranged along the length of the vertebra.
“They even cross over like the spokes of a bicycle wheel. Evolution shaped these creatures into awesome, breathtakingly efficient flyers.”
Researchers had originally set out to study the shape and movements of the pterosaur’s neck, but took advantage of the offer of a CT scan to look inside.
Analysis shows as few as 50 of the “spokes” in the pterosaur’s neck could lead to a 90% increase in resistance to buckling.
Scientists believe the intricate construction could help engineers develop longer, thinner, and stronger lightweight structures.
Cariad Williams, the first author of the report, said: “These animals have ridiculously long necks, and in some species the fifth vertebra from the head is as long as the animal’s body.
“It makes a giraffe look perfectly normal. We wanted to know a bit about how this incredibly long neck functioned, as it seems to have very little mobility between each vertebra.”
Pterosaurs appeared in fossil records from the Triassic period, about 225m years ago, but disappeared at the end of the Cretaceous period, approximately 66m years ago along with their dinosaur cousins.
Researchers say thanks to these north African remains, they now want to answer basic questions, such as the flight abilities of pterosaurs, which can have a wing span of up to 12 metres.
Martill said: “What was utterly remarkable was that the internal structure was perfectly preserved. So too was the bone cell structure when we examined it under the microscope. As soon as we saw the intricate pattern of radial trabeculae we realised there was something special going on.”