A group of researchers from the University of Texas (USA) has analyzed the vocalization of current birds in order to infer the sounds produced by their dinosaur ancestors. “The results show that oral vocalization has evolved up to at least sixteen archeosaurs (the group includes birds, dinosaurs and crocodiles). Nowadays large species, at least the size of the swans, vocalize it like this,” explains researcher Chad Eliason. It has thus been established that sounds similar to ostriches were produced from the covering of ostriches. We already know that most dinosaurs had vivid colored feathers. And now they say the screams were replaced by bliss. The scary dinosaur species in the movies are in the process of extinction.