Dr. Tommy Oliver is a new teacher at Reefside High School. His past was a mystery to his students, until one day, when he was babysitting three students on detention, found his secret lab and grabbed the Dino Gems. That same day, he found a familiar name to him: "Dr. Anton Mercer", which was familiar to him. In the past, Dr. Oliver worked with Dr. Mercer on various dinosaur and fossil projects. One day, he disappeared, and the lab that he and Dr. Mercer worked in was attacked and much of their work was stolen. Dr. Oliver would later realize that Dr. Mercer was Mesogog, and that he was after the Dino Gems.

Dr. Oliver was kidnapped by Mesogog's Tyranodrones one day outside of Hayley's Cyberspace. His three students would later find his video diary and discovered his past as a Power Ranger. When he was rescued from Mesgog's island, he took with him a gem stone. He blocked a sword attack by Zeltrax with the gem stone, and it revealed another Dino Gem. He inserted the gem into his new morpher to become the Black Dino Ranger.

Dr. Oliver's special ability is invicibility. As the Black Dino Ranger, his weapon is the Brachio Staff and he commands the carrier zord, the Brachio Zord.