Briggs's freighter

Briggs' freighter was a spacecraft under the command of Captain Briggs. Its cargo, unknown to the crew, was an army of Cybermen. They awoke and took over the ship. They planned to destroy life on Earth by hitting it with the craft that they had reprogrammed. The craft was brought back in time to c. 65.5 million BCE by the Fifth Doctor. Adric's attempt to redirect the ship was interrupted by a Cyberman. The ship crashed into the Yucatán Peninsula, causing the extinction of the Dinosaurs and facilitating the rise of mammals and ultimately humans. (DW: Earthshock)

The ship's crash was foretold to the Silurians in a prophesy. In anticipation, they constructed a massive ark with which to transport and preserve myriad species of dinosaurs on another planet. Their plan was completed in 2367 CE by the Eleventh Doctor and Brian Williams who founded the planet Siluria to replace the Cretaceous Earth which Biggs' freighter had destroyed. (DW: Dinosaurs on a Spaceship)