YOU SAID:

one time i ate a dinosaur

INTO JAPANESE

一度私は恐竜を食べた

BACK INTO ENGLISH

Once I ate dinosaurs

INTO JAPANESE

恐竜を食べたことがある

BACK INTO ENGLISH

I've eaten dinosaurs.

INTO JAPANESE

恐竜を食べたことがあります。

BACK INTO ENGLISH

I've eaten dinosaurs.