Captain Timelord was sent to the past with his partner Dodgson to find Dennis Nedry in order too save the future. By getting Dennis to destroy the dinosaur embryos, they prevented the memeosaurs from being born. What they didnt anticipate was that it would alter time, causing them to be stuck in our time.
Timelord and Dodgson help Engieclan when they are needed most. When they aren't helping Engieclan, they hide in the shadows.