Tyrus was a Genii and the father of Sora Tyrus. He had traded with Teyla Emmagan many times in the past, but like the rest of his people, he deceived her about their true nature. He accompanied Chief Cowen and Major John Sheppard's team on a recon mission to a Wraith Hive ship. There, they discovered dozens of people cocooned for future feedings.
Though Tyrus and Cowen were reluctant to help them, Teyla and Sheppard insisted. While Teyla was trying to save a conscious victim, Tyrus stopped her, saying that the Hive ship was too close to the Genii homeworld, and shot the cocooned individual. However, this brought the attention of a Wraith warrior, who stunned Tyrus, forcing Teyla to leave him behind. Both Cowen and Sora held Teyla personally responsible for Tyrus's death. (SGA: "Underground")