Member of the Genii, officer in the Genii military and ambassador for his people in trade negotiations with the Athosians. Tyrus had known Teyla Emmagan for some years. Teyla had shared in a friendship with his daughter Sora, who had become betrothed since their last meeting.
When the truth of the Genii, that they were a growing military force, was revealed, Tyrus and Chief Cowen accompanied Major John Sheppard's unit in a joint mission to recover a Wraith data storage device in a hive ship.
While aboard, Teyla and Tyrus were paired. When a cocooned man pleaded to be set free before a Wraith could feed on him, Tyrus killed him with his weapon. This set off the internal alarms and alerted the awake Wraith soldiers to their position. Tyrus took a Wraith stunner rifle discharge to the chest and face. Teyla (who thought she knew Tyrus) fled from the scene, unable to save him, but disturbed and dismayed with his behavior.
The loss of her father to the Wraith had a grave impact on Sora, and she eventually disobeyed Commander Acastus Kolya's direct orders to not engage Teyla when she had the chance to kill her. Sora did not get to avenge Tyrus's death in the blood of Emmagan, but likely realized by Teyla sparing her life that there was truly nothing the Athosian could have done for him.