Siluria

Siluria was a planet chosen by the Eleventh Doctor for the dinosaurs on the Silurian Ark to live on, after saving them from crashing to Earth in 2367. Brian Williams visited Siluria and sent back a postcard to Rory and Amy. (TV: Dinosaurs on a Spaceship)

Trivia

The Ankylosaurus depicted in the postcard uses the same model used in Walking With Dinosaurs