Triad

The Triad were the "custodians" of the Silurian race. (TV: Warriors of the Deep)

According to one account, Icthar told Sauvix of Elite Group One that he was the "sole survivor of the Silurian Triad", with Scibus and Tarpok being Icthar's "companions". (TV: Warriors of the Deep) According to another account, Icthar told the Third Doctor that he was the leader of the Triad, with Scibus as Icthar's Second, and Tarpok his Science Adviser. (PROSE: The Scales of Injustice)