Name of the Dinosaur

Dinosaurs residing in the paleontological museum decided that their names are too complicated. Visitors get confused, and the dinosaurs themselves often make mistakes. Where can they get new names? Of course, from the feedback book!
Children who came to the museum for a tour will be in for a big surprise — the dinosaurs have become their namesakes! Maybe they should also change their names? After all, everything will get mixed up in the museum: children, dinosaurs… And only Petya will figure out what to do. But if he is neither a boy nor a dinosaur, then who is he?