New evidence that bird ancestors were not dinosaurs

The debate over whether birds originated from dinosaurs has been going on for more than a century. At present, the vast majority of paleontologists believe that birds did descend from dinosaurs, and that they originated from theropod dinosaurs. But recently, scientists Ann Bourque and Alan Fedakzia of the University of North Carolina in the United States have proved through embryological research that birds did not originate from theropod dinosaurs.

During the course of evolution, both toes of theropod dinosaurs and birds degenerated and disappeared. Theropod fossils show that their fourth and fifth toes gradually shrank and eventually disappeared during evolution. However, Ann Bourque and Alain Fedakzia discovered through the observation of embryos that among three birds, chickens, ostriches and cormorants, which are very different in classification, the first toe degenerated and disappeared. and fifth toe, while the three middle toes are preserved. They therefore speculated that birds could not have evolved from theropod dinosaurs, because theropod dinosaurs could not have regrown the fourth toe after degeneration and at the same time degenerated and disappeared the first toe.

Peter Dodson, a dinosaur expert at the University of Pennsylvania School of Veterinary Medicine, has been an active supporter of the hypothesis that birds originated from theropod dinosaurs in the past, but when he learned about Ann Bourque and Alan Fedakzia's After the research work, they praised their results and expressed the need to reconsider the questions about the origin of birds. It can be seen that the new evidence presented by Ann Bourque and Alan Fedakzia does challenge the hypothesis that birds originated from theropod dinosaurs.

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