Davius

Davius was a continent on Skaro and the original home of the Thals. It was separated from the continent of the humanoid Daleks, Dalazar, by the Ocean of Ooze. (TV21: Genesis of Evil) The continent is divided by the wide River of Whirling Waters. It contains whirlpools and cannot be bridged. On the opposite side of the continent from the Ocean of Ooze is the Serpent Sea. (DWAN:The Dalek Book)

The existence of Davius, Dalazar and the Ocean of Ooze seem to be contradicted by The Daleks and Genesis of the Daleks, in which Thals, Kaleds and Daleks inhabit the same continent.