Palaeontologists have discovered the secret to the success of the flying pterosaur with a neck longer than a giraffe.
Experts had always wondered how gigantic flying azhdarchid pterosaurs managed to support their thin necks, and take off and fly while carrying heavy prey animals.
New CT scans of intact remains discovered in Morocco reveal a complex image of spoke-like structures, arranged in a helix around a central tube inside the vertebra, similar to the spokes of a bicycle wheel.
Experts say the intricate design demonstrates how these flying reptiles evolved to support massive heads that were often longer than 1.5 metres.
The construction offered strength without compromising the ability to fly, according to the study published in iScience.
Dave Martill, professor of palaeobiology at the University of 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 neck, but took advantage of the offer of a CT scan to look inside.
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.”
Analysis revealed that as few as 50 spokes in the pterosaur’s neck could lead to a 90% increase in resistance to buckling.
It is thought the intricate construction could help engineers develop longer, thinner and stronger lightweight structures.