The archeopteryxes that lived 150 million years ago, long considered to be an intermediate link between lizards and birds, could still fly; This conclusion was completed by a century and a half dispute between scientists who studied the structure of archeopteryx bones using a synchrotron.
Archeopteryxes were the first feathered dinosaurs that fell into the hands of scientists. The first prints of these animals in stone were found in the sixties of the century before last, and paleontologists immediately began to argue about whether archeopteryxes could fly or not. The most convincing, according to experts, argument in favor of what still could, in this century and a half dispute the authors of an article published yesterday in Nature Communications.
Until now, the representatives of the Archaeopteryx taxon were considered the oldest of the known potentially flying representatives of the treasure Avialae – flying dinosaurs, which include modern birds. However, the poor preservation of their remains has so far prevented scientists from unambiguously concluding that the archeopteryxes flew freely or only planned from the highlands.
An international team of scientists who examined the existing remains of archeopteryxes on the synchrotron and described the internal structure of their pelvic bones, argues that this archeopteryxes structure was endowed with a number of features unique to modern flying birds, and does not at all resemble the structure of the bones of representatives of other related taxa – crocodiles and pterosaurs, winged fossil reptiles that lived simultaneously with dinosaurs. Moreover, the rate of metabolism and growth of archeopteryx bones, restored by the capacity of blood vessels, also turned out to be similar to the corresponding parameters of modern flying birds.
Reconstruction: Archeopteryx in flight. Vision of the artist on the basis of a new study.
The ability of an animal to fly like a bird’s bird is determined by the balance between the strength and ease of the skeleton and muscles. The archeopteryx bones, apparently, contained enough cavities and were light enough for the dinosaur to rise into the air, and were strong enough to withstand the load that occurs when the wing hits the air, the article says. The more such a load can sustain a wing, the longer the flight.
Scientists were able to draw some conclusions about how the Archeopteryx flew. The geometry of the transverse section of their bones indicates the nature of the flight, typical for modern pheasants – with alternating series of energetic swings with wings with periods of hovering.
However, they were found in the skeleton of archeopteryxes and differences from bird skeletons. Apparently, the mechanics of the wing wing did not look like a bird at all: they moved the wing faster back and forth than up and down. For this movement, strong pectoral muscles, characteristic of our feathered contemporaries, are not needed. The absence of preserved bones of the upper body of archeopteryxes was previously considered by some scientists as an indirect proof of the inability to fly: for the attachment of strong pectoral muscles, the developed bones of the sternum are needed, and in archeopteryxes they were undeveloped and consisted mainly of cartilaginous tissue, therefore they were not preserved, flightless archeopteryxes.
The special nature of the wing wing, coupled with the ability to climb the air from the Archeopteryx, may mean that they were not the first flying dinosaurs; perhaps their ancestors, previously considered “pedestrians” because of the apparent inability to wave their wings up and down, before Archeopteryx, mastered this other, not preserved to this day mode of flight.