A winged dinosaur widely regarded as the first bird flew like a pheasant, scientists have discovered.
The Jurassic dinobird Archaeopteryx flapped its wings but was not capable of long distance active flight.
Nor could it glide and soar, like modern-day birds of prey.
Instead, Archaeopteryx probably made short bursts of limited low-level flight to escape danger, scientists believe.
Present day pheasants adopt the same strategy when they take to the air to avoid predators, or gun-waving humans.
The new study, which involved using a powerful X-ray beam to probe fossil bones, also confirmed that 150 million years ago Archaeopteryx was an “active” flyer. It flapped its wings and properly flew rather than gliding from tree to tree.
Scientists conducted the research at ESRF, the European Synchrotron facility in Grenoble, France.
Here, electrons accelerated around a circular tunnel generate X-rays 100 billion times more powerful than those in hospitals. The X-rays can be employed to analyse the internal structure of numerous different materials, including fossils.
For the new study, the ESRF X-ray beam was used to peer inside the bones of three Archaeopteryx specimens without damaging the valuable fossils.
Lead researcher Dennis Voeten, from ESRF, said: “We immediately noticed that the bone walls of Archaeopteryx were much thinner than those of earthbound dinosaurs but looked a lot like conventional bird bones.
“Data analysis furthermore demonstrated that the bones of Archaeopteryx plot closest to those of birds like pheasants that occasionally use active flight to cross barriers or dodge predators, but not to those of gliding and soaring forms such as many birds of prey and some seabirds that are optimised for enduring flight.”
Archaeopteryx – which means “ancient wing” – lived in the Late Jurassic period in what is now southern Germany. The first fossil skeleton of one of the creatures, known as the London Specimen, was unearthed in 1861 near Langenaltheim and is housed at London’s Natural History Museum.
Similar in size to a magpie, it shared characteristics of Earth-bound dinosaurs and modern birds, including winged feathers, sharp teeth, three fingers with claws, and a long bony tail.
However despite being thought of as the first bird, experts now view Archeopteryx as a flying dinosaur.
Nor was it a direct ancestor of modern birds. Despite sharing a common dinosaur ancestor with birds, Archaeopteryx represents a “dead end” side branch on the evolutionary tree.
Present day birds are generally believed to have evolved from a group of small meat-eating dinosaurs known as maniraptoran theropods.
The study was published in Nature Communications.