Vega Island, next to the Antarctic Peninsula , in Antarctica, has been the scene of an interesting surprise for the study of evolution . There, a team of scientists has found some very special fossils: the oldest remains of a syrinx, the voice apparatus of birds , which provides new data on the evolution of the vocalizations and songs of birds since the end of the Cretaceous. According to the study, published in Nature , the syrinx comes from a specimen of the Vegavis iaai species, a primitive bird that lived between 66 and 68 million years ago in Antarctica. Julia Clarke, from the University of Texas at Austin (USA), who has led the research, thinks that this organ already existed in the time of the dinosaurs but neither these nor the reptiles of that time developed it.
The University of Texas team examined the three-dimensional structure of the syrinx using X-ray computed tomography and compared it with data from more recent fossils and from 12 modern birds to reconstruct the evolution of this complex organ. Taking into account the preserved parts of the syrinx and the position of Vegavis in the phylogenetic tree, experts believe that this bird could produce squawks like geese or even some type of simpler songs.
As a result of the discovery, scientists wonder why other fossils similar to this have not been found in dinosaurs , which may have had a vocal organ in the larynx – like the one found in modern crocodiles – or a more developed one inside the chest, like that of birds. The absence of this organ in the dinosaur fossil record suggests that it may be similar to that of crocodiles and that many taxa did not have a syrinx. Austin’s team believes that the appearance of a more complex syrinx was possibly a late feature that emerged with the evolution of birds , after their ability to fly developed and their breathing technique improved.
