Doraemon the Movie- Nobita's Dinosaur 2006 (English subtitle)

Nobita happens upon a fossilized dinosaur egg, and with Doraemon's help, they hatch and raise it into a fully grown dinosaur. Though they love the creature, they know they can't keep it forever and must send it back to prehistoric times. Their act reveals a group of hunters from the future who threaten the dinosaur population. To save them, Doraemon and his friends embark on a prehistoric adventure.