Doraemon Movie 40: Nobita no Shin Kyouryuu

At a dinosaur exhibition, Nobita discovers what looks like an ordinary fossil and proudly decides he can hatch a dinosaur himself. With Doraemon's Time Cloth, the fossil reveals not one but two baby dinosaurs, Kyu and Myu, whose unusual features suggest they may belong to a species no one has seen before.

Nobita grows deeply attached to the twins, but raising prehistoric animals in the modern world cannot last. He and his friends travel 66 million years into the past to return Kyu and Myu to their own time, only to discover that finding where the two truly belong is more difficult than expected, especially as the age of the dinosaurs moves toward its catastrophic end.