Doraemon - S1E8

Dinosaur Hunting

Doraemon and Nobita's first time travel. They get into a drawer which leads to them travelling on a time machine and end up ten billion years in the past. After shrinking one dinosaur, Doraemon cannot find his gun but they manage to escape the second one, with Nobita leaving his glasses behind, which are found in the present time, to the amazement of scientists.