But the X-rays revealed new finds within the arm bones of Archaeopteryx.
During the next 150-plus years, paleontologists discovered 10 more Archaeopteryx skeletons.
"It was surprising to see that the wing bone geometry of Archaeopteryx looks remarkably more like those of modern birds than expected".
The study authors examined cross-sections of the Archaeopteryx bones and compared these structures to bones in flying birds, flightless birds, other dinosaurs and modern crocodilians.
"Many researchers have assumed that Archaeopteryx exhibited a very primitive way of flying that would have been equivalent to that of gliding from tree to tree, like extant flying squirrels do", said palaeontologist Sophie Sanchez of Uppsala University in Sweden. "The variation within modern flying birds is much larger than the differences between Archaeopteryx and the short-flying birds in our data set", Voeten said. One camp said, yes, Archaeopteryx flapped its way off the ground.
Scientists discovered that it would have only used its power of flight for short bursts and distances, most likely to escape risky situations.
About 150 million years ago during the Jurassic period, when Archaeopteryx lived, the southeastern part of Germany where the fossils were found would've been a tropical archipelago.
Voeten and his colleagues also noticed that the bones were well-developed for blood vessels, which could suggest active flight, but they believe that more research is needed regarding this point.
Archaeopteryx boasted teeth, a long tail and had no bony, keeled sternum where flight muscles attach.
Voeten expects that the new study will attract Archaeopteryx flight critics and says, "I warmly welcome them". Future research is needed to refine their hypothesis.
As mentioned above, modern birds are descendants of similar dinosaurs, but Voeten says that the Archaeopteryx was probably not a direct ancestor of birds like the sparrow or ostrich, instead representing an offshoot lineage - a statement backed up by the fact that the Archaeopteryx took flight in quite a weird manner. The Archaeopteryx bone characteristics closely resembled what Voeten called "burst fliers". Its flight capabilities may have enabled Archaeopteryx to escape predators or fly among islands. "From a historical perspective, it is clear that Archaeopteryx represents a true icon of evolution: It played an important role in both the early communication of Darwin's theory of biological evolution and, later, in the recognition that birds are, in fact, dinosaurs. Having been able to contribute to our knowledge on this animal has been a very satisfying experience".