It is common belief that some of the greatest animals on Earth have died out because of Chicxulub the dinosaur exterminator. Revolutions in the paleontological field have allowed to re-evaluate a series of beliefs, allowing us to affirm that dinosaurs have not extinct, but hide themselves \”in the birds \”.
In order to understand the intimate relationship between birds and dinosaurs and more properly the avian ancestors, João Francisco Botelho, chief researcher of the University of Chile, together with his research team, led a fascination
Specifically, researchers have modified the genome of today’s species in order to induce the expression of ancestral somited genes, which would allow the manifestation of dinosaur characteristics.
The morphological traits taken into consideration by the researchers concerned the fibular bone which, in the theropod dinosaurs, was subject to increased growth and, therefore, longer, while in the birds today such conformation leads the bone structure to be of size
In the ancient bird ancestors, including Archaeopteryx, the fibula had a tubular shape, with a length extending to the ankle. This growth led to a similar development of tibia. In the evolutionary dynamics, this bone structure was adapted to the subsequent families of Avian dinosaurs, decreasing in length.
This bone difference is found in adult specimens but, by embryo analysis, it has been established that this similarity has remained. Birds’ embryos, in fact, have the same bone development that stops during growth, producing shorter and thinner bones.
To obtain dinosaur legs in a chicken, scientists inhibited the expression of a gene called Indian Hedgehog (IHH), causing bone growth similar to that of dinosaurs in today’s specimen. By blocking this gene, researchers have also established biological mechanisms that block the achievement of the bone lengths of dinosaur relatives.
In addition, the research team has found that the development of a bone of the lower limbs, the perone, is caused by the heel. As scholars point out, in fact: “Unlike other animals, the heel in birds’ embryos presses against the lower end of the perone,” and continuing “They are so close that they have even been exchanged for a single element by some researchers.”
Once the IHH gene has been deactivated, it has emerged that the heel tends to express high levels of another gene associated with bone end growth. The procedure thus conducted has allowed the chickens to develop long fibula, similar to those of the Archaeopteryx.
The resulting chickenosaur hybrids did not reach hatching, but this did not affect the experiment in any way, as the goal was precisely to understand the evolutionary mechanisms at the basis of the bone transition between dinosaurs and birds.
Alexander Vargas, co-author of the study, said on the conclusions of the experiment, “Not only do we know much about the development of birds, but also about the dinosaur-bird transition, which is well documented by fossil finds. This leads to the possibility of ascertaining the hypotheses on evolution with laboratory experiments.”
This experiment, as far as the limit of science fiction is concerned, was not the first of its kind. In 2015, the same research team managed to show the growth of dinosaur zombies in chickens and an American research team was able to reproduce a chicken with the face of dinosaur with the goal of ”
This is certainly not the only fascinating phenomenon about the last dinosaurs that survived. According to a recent study, in fact, birds have escaped extinction through their brains.
Below you can admire an image, produced by Botelho and the research team, depicting the morphological differences between a theropod and a chicken and infographics related to biological mechanisms.