In a rapidly-changing primeval world, a dinosaur is hatched. He is sniffed at by other dinosaurs. He is the last hope for his tribe. He takes charge of a great migration. This movie is

The Land Before Time (1988)

Disney’s Dinosaur (2000)

Walking with Dinosaurs (2013)

https://www.youtube.com/watch?v=D9v9_ws_WTM