Silurian Ark

The Silurian Ark was a large starship, roughly as wide as Canada, created by the Earth-based Silurian civilisation during the final days of their rule.

Background
These large roughly spherically shaped craft were able to hold thousands of crew in hibernation pods and an entire self-contained ecosystem for animals to thrive. Some parts resembled outside planetary environments that were a near perfect replica of an environment though a keen observer was able to sample the air and detect metallic content therein. Another example of the ship's true nature was present in these environments as underneath the soil and sand were metallic plates. Its engines were powered through hydroelectric means with a large ocean that used waves as a form of energy. (DW: Dinosaurs on a Spaceship)

A computer system allowed easy access to information and included a teleport system to any area of the ship. The control deck served as the command centre for the entire ship and included an automated piloting system that locked the target for the vessel. Piloting of the ship involved parallel bio-compartments chairs that required the users to be of the same gene-chain. (DW: Dinosaurs on a Spaceship)

History
The Silurians constructed the craft near the end of the Maastrichtian age of the Cretaceous period, circa 65.5 Ma BCE, having forecast that an object was to collide with Earth and cause the extinction of most animal species then existing. (DW: Dinosaurs on a Spaceship) The majority of their race entered into hibernation underground, while thousands boarded the Ark to hibernate among a large number of dinosaurs. (DW: Dinosaurs on a Spaceship) After the Ark departed, a interstellar freighter loaded with Cybermen crashed into the Yucatán Peninsula, resulting in the predicted global extinction event, and leading to the rise of mammals and ultimately humans. (DW Earthshock)

The Ark travelled in space where the preserved dinosaurs managed to thrive except for one species. Whilst in hibernation, the ark was boarded by Solomon, a pirate who determined its cargo to be of high value that he could sell. After boarding the ship, he had his two robots wake up a few of the Silurians at a time and disposed of them when they refused to give him the dinosaurs. This led to the entire crew of thousands of Silurians being killed but their unique piloting method meant that Solomon was not able to alter the craft of the ship which automatically headed back towards Earth when no-one was able to pilot it. (DW: Dinosaurs on a Spaceship)

In 2367 CE, the Ark's path toward Earth prompted the Indian Space Agency - if not other humans - to identify it as a threat. Accordingly, the ISA planned to destroy it with a barrage of missiles. In this time, the Eleventh Doctor learnt of the ships existence and was determined to save it. He took Queen Nefertiti, John Riddell, Amy Pond, Rory Williams and, accidentally, Brian Williams to the ship where he encountered Solomon. (DW: Dinosaurs on a Spaceship)

Being a father and son, Brian and Rory were able to operate the parallel bio-compartments chairs and steer the Ark away from Earth. At the same time, the Doctor placed the Ark's signature onto Solomon's ship causing the missiles to target it vice the Ark. (DW: Dinosaurs on a Spaceship)

The Ark and Earth safe, the Doctor and Brian fulfilled the Silurians' plans, establishing a planetary refuge for the dinosaurs, which they dubbed Siluria. (DW: Dinosaurs on a Spaceship)