In this season, Tommy Oliver, from Mighty Morphin Power Rangers to Power Rangers Turbo fame, returns as a paleontology professor in Reefside, California. When he is assigned three detention students, Conner McKnight, Ethan James, and Kira Ford, they end up finding the Dino Gems, paving the way for them to become the Dino Rangers. Conner gains the power of the Tyrannozord (based on the Tyrannosaurus), as well as super-speed; Ethan gains the power of the Tricerazord (based on the Triceratops), as well as the ability to make his skin invulnerable; and Kira gains the power of the Pterazord (based on the Pteranodon), as well as a sonic scream. Tommy (known often as Dr. O) himself once again becomes a Power Ranger by joining the team as the Black Dino Ranger with the power of invisibility, and they are also later joined by Trent Mercer as the White Dino Ranger, with the power of camouflage. Trent must deal with the inner struggle of good and evil, as Tommy himself once had to do as the evil Green Ranger, because he gained his powers from a raw Dino Gem in Mesogog's lab, with the powers originally intended to be Mesogog's. Mesogog is in fact, Trent's adopted father Anton Mercer, who, in a faulty lab experiment, began to mutate into Mesogog. Trent later sides with good and saves his father from the mutation.