S3·E4 Land of the Dinosaurs

Ariel suggests that her family takes a trip up to the frozen north, but something else lies beneth the ice. Dinosaurs, and Ariel thinks that they're adorable so she free's them with her father's triton, but they seem more harmful than adorable. Later on King Triton stops them and after that he uses his triton to destroy all the ice and discover the dinosaurs' home. Now the dinosaur's can roam the land freely thanks to Ariel's curiosity.