Dr. Tommy Oliver and Dr. Anton Mercer were working in a secret island laboratory to harness the power of the dinosaurs.  The island is attacked by Mesagog and destroyed.

     Several years pass.  Dr. Oliver becomes a high school science teacher and continues his work on the ancient Dino Gems in secret.  Conner, Ethan, and Kira stumble across his secret shortly after finding the Dino Gems.  With Dr. Oliver as their mentor, they become the Dino Thunder Rangers.  It isn't long before Dr. Oliver gets the black Dino Gem and goes from mentor to Ranger. 

    Mesagog eventually finds the White Dino Gem and plans to use it's power.  Before he can unlock it Anton's son Trent accidentally finds Mesagog's lair and the White Dino Gem fuses it's power with him.   Because the gem was so full of evil power, it turns Trent into the Evil White Ranger.  While under the gem's power Trent discovers that his father is Mesagog, thanks to a science experiment gone terribly wrong.  After being freed from the gem's power Trent promises his father that he'll join the Rangers, but will not reveal his secret.

    Eventually the Rangers do discover Anton's secret, and they almost make Trent quit the team.  In the end though, they decided to forgive him and let him stay. 

    Around that same time, Mesagog finds a way to separate himself from Anton Mercer, who weakens him.  With Anton free, the Rangers are able to go all out against Mesagog and eventually destroy him.