The skull of modern birds arose after a series of decreases in the growth of theropods, a group of carnivorous dinosaurs. Moreover, this phenomenon was instrumental in the evolutionary process by which the ability to fly was developed, according to a study published in Nature.I
Paedomorphosis is a phenomenon by which an adult individual of a species retains some juvenile characteristics of their ancestors. This process led to the development of the skull of modern birds, which are characterized by a small body size, large eyes and globular or encephalized brains. These features would be the result of at least four successive episodes of shortening the normal growth of their ancestors theropods. The study also suggests that this reduction in the size of the bird and the increase in head development were instrumental in the evolutionary process that shaped the mechanical and neural control needed to develop the flight.
The research team, in which scientists from the Autonomous University of Madrid participated, used geometric morphometric techniques, thanks to which it was possible to compare the most complete collection to date shows youth and adults embryos fossil dinosaurs and modern birds. The authors have pointed out that this type of studies comparing extinct species with their living descendants are key to unravel the nature of the evolutionary mechanisms.