Power Rangers Dino Thunder is an American children's television series, the twelfth season of the Power Rangers franchise. As with all Power Rangers series, it was adapted from a series from the long running Japanese Super Sentai franchise, in this case the 27th entry, Bakuryū Sentai Abaranger. Dino Thunder was also the subtitle of the Korean dub of Abaranger in South Korea and had a similar/identical logo to the American version as well. The series is notable as it features the return of Jason David Frank reprising his role as Tommy Oliver. It was the first Power Rangers series to be aired on Toon Disney as part of Jetix.
A soccer player, a computer expert, a singer, an artist, and a teacher with a long history of such situations join forces to become Power Rangers and help save the Earth from the scheming of Mesogog, a dinosauric villain who wishes to eradicate all human life and return Earth to the age of dinosaurs.
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.
During the course of the series, the team adds the following to its arsenal of Zords: Cephalozord (based on the Pachycephalosaurus), Dimetrozord (based on the Dimetrodon), Stegozord (based on the Stegosaurus), Parasaurzord (based on the Parasaurolophus), and Ankylozord (based on the Ankylosaurus). The Stegozord later combines with Trent's zord, the Dragozord (based on the Tupuxuara), to form the Dino Stegozord. Tommy pilots the Brachiozord (based on the Brachiosaurus), the carrier for all the other Zords. Conner is also given the power to become the Triassic Ranger, and pilots the Mezodon Rover/Megazord (based on the Styracosaurus), which can combine with the Cephalo, Dimetro, Parasaur and Ankylozords to form the Triceramax Megazord.
At the end of the series, the Rangers destroy Mesogog with their raw Dino Gem power, but the gems are burned out in the process. Just before this, they are also forced to sacrifice all the Zords in their last battle with Zeltrax, one of Mesogog's strongest minions. Finally they return to their normal lives.
- Day of the Dino - Former Veteran Power Ranger Tommy Oliver takes a teaching job at the city of Reefside years after escaping from an ordeal with the evil and mysterious reptilian monster Mesogog, and is assigned to look after three detention students: Conner McKnight (soccer star), Ethan James (hi-tech prankster) and Kira Ford (singer). During a trip to the museum, the trio stumbles upon a secret hideaway and find the magical Dino Gems. Kira rejects her Gem soon after, only to be abducted by Mesogog's forces. -- Kira manages to escape from Mesogog's lair, and the mad scientist reveals his powerful Bio Zords and unleashes them on the city. Tommy grants the students the means to become a new generation of Power Rangers and sends them out to tame the wild creatures. They succeed, and combine their newfound Zords into the Thundersaurus Megazord to halt the evil warrior Zeltrax's attack on the city and save the day.
- Wave Goodbye - Conner resigns his position as the Red Ranger when his Ranger duties interfere with his dreams of being a soccer star and cause him to miss an important try-out. However, he reconsiders after saving a little girl from harm and defeating Mesogog's Birdbrain mutation with a little help from his fellow Rangers and the Raptor Riders given to the Rangers by Tommy. Meanwhile, Mesogog kidnaps Tommy to force him to unleash the power from within a stone.
- Legacy of Power - Mesogog kidnaps Tommy to find out how to access a mysterious power source. As Hayley searches for a way to rescue Tommy, the Rangers watch a video diary on the history of the Power Rangers with footage from the past eleven seasons. This is the 500th episode of the Power Rangers.
- Back In Black - The Rangers rescue Tommy, who steals the stone and discovers that the power within to be another Dino Gem. Harnessing the unique powers of this black gem, Tommy reignites his past and becomes the Black Ranger. To defeat Mesogog's latest creation, the Rangers are sent the Cephala Zord as a boxing glove.
- Diva In Distress - Kira is reunited with her old friend and celebrity, Kylee Styles. The snobbish teenage star falls victim to the youth-draining Donkeyvac monster, and Kira comforts Kylee by reminding her of better times while the others confront this new menace. When Kira helps her friends take down Donkeyvac, everyone's youth is restored, and Kylee and Kira reunite and perform a duet at Hayley's Cyberspace.
- Game On - Mesogog's latest plan takes advantage of Ethan's obsession for a video game by transporting Ethan into the game's virtual world where he meets a strange wizard and the even stranger Triptoids. Kira also gets sucked into the game but the pair manage to return to the real world, and discover that the Triptoids and the wizard have followed them. After the Rangers deal with the Demagnetron monster, Hayley sends the wizard back to the virtual world.
- Golden Boy - In his effort to enhance himself, Zeltrax accidentally creates his own "son" who calls himself Golden Rod. While Tommy's former partner Anton Mercer, adoptive father to Trent Fernandez, purchases the Cyberspace Cafe, the Rangers head to City Hall to stop his plans only to run into Zeltrax and Golden Rod. As the Thundersaurus Megazord struggles against the enlarged Golden Rod's might, Tommy steps in and destroys the son of Zeltrax with his Brachio Staff. Afterwards, the city councilwoman prevents Mercer from taking over the cafe.
- Beneath the Surface - Dr. Oliver and Principal Randall take the students on a dig, using that pretence to hide their true motive of finding a nearby Dino Egg. Pulling a bait and switch on the Rangers, Randall, who is actually Mesogog's henchwoman, Elsa, in disguise, manages to steal the real Dino Egg and hatches the Dimetro Zord. After a brief battle, the Rangers manage to tame the Dimetro Zord, who helps to defeat Scorpex, the latest monster with the saw blade ability
- Ocean Alert - When famous actress Nikki Valentina is captured by Mesogog to be used as a part of his evil schemes, the Rangers must save her and face off against Mesogog's newest monster named Megaldor. Meanwhile, Hayley uncovers a new Dino Egg, which hatches into the Stego Zord.
- White Thunder - When the powerful White Dino Gem goes missing from Mesogog's fortress, a monster is sent to lure out whoever stole it. Mesogog's plan works and the renegade White Ranger appears on the scene, easily defeating the monster and forcing the Rangers to retreat in the face of his might. -- Conner and Kira are sent to locate a new Dino Egg, only to find it in the White Ranger's possession. Hayley alerts the team to the presence of the Angor monster, and the Thundersarus Megazord duels with this new foe while Tommy goes to confront the White Ranger and retrieve the Dino Egg. While the Megazord is successful in defeating the monster with help from the newly-hatched Parasaur Zord which gives the megazord the scissor blade, Tommy fails his mission and the Drago Zord is hatched. -- The White Ranger steals the Rangers' Stego Zord and combines it with his Drago Zord to form the Dino Stegozord, which promptly blasts the Thundersarus Megazord apart. While a trio of auxiliary Zords are sent into battle, Conner dukes it out with the White Ranger and unlocks his Super Dino Mode in the process. Later, Tommy discovers the White Ranger's true identity as Trent, but is encased in amber before he can tell the others.
- Truth And Consequences - As the Rangers attempt to free Tommy from his amber prison, Trent starts causing trouble. In battle against the Rangers, Trent manages to stop himself from hurting a demorphed Kira and later tells her that he is the White Ranger. While Kira is initially shocked, she offers to help him but he declines and decides to leave the city, citing that he is too dangerous to stay around. The ankylo zord reveals itself and strongly beats the Dino Stegazord with the ability of another drill.
- Leader of the Whack - As Trent leaves the city, he notices a meteor crashing into the woods. The Rangers show up to investigate, hoping that the meteor will help free Tommy, and are greeted by Tyrannodrones and the Rojobot monster. During the ensuing battle, the meteor blasts everyone with strange energy that reveals the hidden sides of everyone's personalities. Conner becomes a brainac, Ethan, a jock, Kira turns into a typical valley girl that loves shopping, Cassidy becomes a nerd and Devin becomes the coolest kid in school. The Rangers face off against the now-aggressive monster and defeat him with help from Trent, who has been turned good by the meteor's rays. The Rangers destroy the meteor, revert to normal and use a fragment to set Tommy free. While Tommy is glad to be free, he now finds himself permanently morphed.
- Burning at Both Ends - Trent, now completely overwhelmed by the evil influence of his Dino Gem, joins forces with Mesogog. After tricking the Rangers into believing he has reformed, he presents them with brand new Dino ATV's as a gift of goodwill, but Tommy discovers his ruse. Meanwhile, Mesogog is revealed to be Anton Mercer's unwilling alter-ego.
- The Missing Bone - A failed, fossilized experiment of Tommy and Anton's is revived and brainwashes Kira into retrieving its missing piece. Once it is complete, the Fossilador monster wreaks havoc on Reefside and battles the incomplete Thundersarus Megazord. Once free from Fossilador's control, Kira saves the day with the help of the Pterazord.
- Bully for Ethan - Ethan is bullied by one of his classmates while Trent and Zeltrax forge an uneasy alliance to destroy their enemies. Tommy tries to reason with the vengeful Zeltrax after discovering Zeltrax's true identity as Terence Smith aka Smitty who was his old friend that was lost in an accident in the company he worked for but was saved and reconstructed by Mesogog. and Trent is singled out by Mesogog, who warns Trent not to betray him again.
- Lost & Found in Translation - When Conner, Ethan, and Kira find a show about Power Rangers in Japan, Conner is appalled at its portrayal of them. Meanwhile, the Japanese Rangers must go up against a money hungry monster named Ka-Ching. (This was actually an English dubbed version of the 10th Episode of its sentai counterpart, Bakuryū Sentai Abaranger. The episode is called Abare Leaguer Bind.)
- It's a Mad Mad Mackerel - Kira gets an internship on the Funky Fisherman Show, only to realize how unhappy she is with her new job. Meanwhile, Elsa kidnaps the fisherman's sidekick, Marty the Mackerel, and transforms him into Mad Mackerel to battle the Rangers.
- Copy That - Mesogog attempts to destroy Trent when Zeltrax, through Copyotter, frames the White Ranger for destroying his lab. However, Anton Mercer manages to break through and destroy the White Dino Gem's hold over Trent. Trent returns the favor by promising to use his powers for good. Later, Zeltrax reveals an evil, soulless clone of the White Ranger.
- Triassic Triumph - Zeltrax manifests the White Terrorsaurus from the evil White Ranger clone. While Tommy and Trent search for a powerful new energy source, Conner is left discouraged when his plan to defeat the Terrorsaurus costs the Rangers their Dinozords. Sensing the new power calling out to him, Conner steps up to accept the Shield Of Triumph and with it, the power to become the Triassic Ranger. With a whole new level of power at his command, Conner easily destroys the Terrorsaurus.
- A Star Is Torn - Kira scores a deal with a famous record producer, but isn't pleased with her new image. Meanwhile, as Hayley tries to get a new vehicle up and running, Tommy and Zeltrax duel in a fierce battle aboard the evil cyborg's Aerial Assault Vehicle.
- A Ranger Exclusive - Kira tries to get Cassidy work as a reporter for the local TV station, which falls victim to Mesogog's newest creation. As the monster infiltrates the satellites in an attempt to destroy Jupiter, and thus cause such an incredible impact as to leave the Earth devoid of human life, the Rangers must prevent Mesogog from accomplishing his goal and reverting the Earth to the age of the dinosaurs.
- Tutenhawken's Curse - Ethan is hit with a string of mysterious bad luck after uncovering an ancient curse and awakening Pharaoh Tutenhawken. The Rangers battle Tutenhawken in their search to break the curse, and the Pharaoh takes Cassidy as his queen. With his fellow Rangers at a tactical disadvantage, Ethan comes to the rescue with his new Hovercraft Cycle.
- Disappearing Act - Elsa retrieves some strange slime that matures her new creation, Thornox and Tommy gathers a sample for himself. After Hayley analyzes the substance, she prepares to use it on Tommy in the hopes of demorphing him. The process is a success, but now the good doctor is rendered invisible.
- Fighting Spirit - Tommy informs the Rangers of an experiment that he hopes will restore him to normal. A hesitant Hayley activates a machine that draws power from his Dino Gem and manages to make Tommy visible again, but unfortunately Dr. Oliver is left comatose. Meanwhile, as the Rangers are stripped of their powers by a new White Terrorsaurus, the hospitalized Tommy finds himself in a strange dream-world where he must fight three of his past Ranger alter-ego's in a battle for his life. This episode – rather appropriately – aired on the eleventh anniversary of the first episode of Mighty Morphin' Power Rangers.
- The Passion of Conner - A young environmentalist named Krista is protesting to save an old tree from being torn down. In his efforts to impress Krista and win her heart, Conner finds himself wishing for the same passion she has. When Zeltrax returns and powers up using the serum inside the tree, he transforms the tree into a monster named Deadwood, whom the Rangers kill with the help of the new formation of the Triceramax Megazord. When Zeltrax endangers Krista, Conner's determination to save her grants him access to his Triassic Morpher and Battlizer Armor, which originates from Conner's Triassic power.
- Isn't It Lava-ly - Volcanologist Dr. Morton is captured by Elsa as a part of her latest scheme to activate a long-dormant volcano. Meanwhile, an overconfident Ethan takes part in a video game competition and is shocked to discover his opponent is Devin.
- Strange Relations - As Mesogog and Anton Mercer battle for control, a fluctuation in the Morphing Grid forces the White Ranger and his evil clone to meet in a final battle. Meanwhile, the other Rangers do battle with Mesogog's Jade Gladiator.
- Thunder Storm - Lothor manages to climb his way out of the Abyss Of Evil and, with his own corrupt Power Discs, brainwashes the Ninja Storm trio into servitude. After the Wind Rangers lay waste to their Ninja Academy, Cam alerts Hunter and Blake to the situation at hand while the Rangers face off against the Wind Rangers in the ultimate Ranger showdown! -- As Cam, Hunter and Blake venture into the Abyss of Evil to retrieve their lost powers, the evil Wind Rangers challenge the Rangers to a rematch. Just as both teams are about to morph, Cam and the Thunder Rangers appear and snap the Wind Rangers out of their trance. Meanwhile, Lothor and Mesogog unite to take over the Earth once and for all, only to turn against each other once all eleven Rangers, including Marah and Kapri foil their plan.
- In Your Dreams - Elsa invades the Rangers dreams in order to destroy them for good. With each Ranger facing off against a unique monster, will they be able to overcome their fears?
- Drawn into Danger - Trent attends a comic convention to show his work to famous artist Carson Brady. Elsa is also there and gives Carson a pen that possesses him, making him draw a comic where the Power Rangers face off with Elsa's latest ally, Fridiga. With the Rangers trapped within the comic and forced to live out the storyline, will Trent be able to help them escape?
- House of Cards - Trent arouses the suspicion of his teammates as he tries to keep his promise to his father Anton and keep the scientist's identity as Mesogog secret. When Elsa uses a card she confiscated (during which her secret as Principal Randall is exposed to the Rangers and whole school) from Ethan as the basis for a powerful new monster, which is the Ruby Dragon. Trent's secret is on the verge of being exposed. Although the Rangers defeat their opponent, their real troubles are just beginning as they discover that Anton Mercer is Mesogog.
- A Test of Trust - Conner, Ethan and Kira recall how much they've changed since becoming Rangers, while Trent faces losing his powers unless he finds a way to redeem himself. Will Trent succeed or is this the end for the White Ranger? Meanwhile, Mesogog uses a potion to separate himself from Anton Mercer. To make things worse, he sends the Ugly Monster that easily beats the Triassic Ranger and makes an evil clone of the Megazord, the Replicant Zord!
- Thunder Struck - The first of the two part finale starts with Mesogog torturing Anton Mercer and showing Elsa his latest plan, a giant cannon that can defeat the Rangers and transform Earth back to the age of the Dinosaurs. For that he will be needing the powers within the Dino Gems. But he will also need the power he gave Elsa. So he drains Elsa's power, turning her back into a normal human no longer under his control. She is rescued by the Rangers and taken to the Dino lab. Trent pretends to make a deal with Mesogog, allowing the Rangers to invade and destroy Mesogog's cannon. Trent returns with Anton Mercer intact. Zeltrax comes to the Dino Lab and destroys it and takes the humanoid Elsa away. -- The Rangers return from Mesogog's island to the Dino Lab, where they find it destroyed. Hayley finds a box, in which is a hidden camera. The Rangers and Hayley learn that Zeltrax has captured Elsa. Meanwhile, Zeltrax unleashes the Zelzord. Ethan finds the Zelzord and he reports it to the Rangers. Ethan then morphs and joins the other Rangers. As Zeltrax destroys the city using the Triptoids, Trent fights against the Triptoids, while Tommy summons the zords and the Rangers form the Thundersaurus Megazord. Tommy goes into the Zelzord and Kira rushes in to help Tommy. Tommy and Kira destroy Zeltrax, but the Zelzord survives, and the Rangers sacrifice their zords to destroy the Zelzord. The Rangers meet on the ground, where they find Mesogog, who had survived the final battle. He goes on to tell the rangers that they have foil his plan to transform the earth back to the age of the dinosaurs but he was able absorb enough dino gem energy to complete his transfiguration Mesogog then transforms into the Mesomonster and fights the Rangers until he is knocked down by the Triassic Ranger. However, the Mesomonster clones himself. The Rangers use their Dino Gems to create an unstoppable power which destroys the Mesomonster and his clones, sacrificing their powers in the process. Cassidy and Devin discover the real identities of the Power Rangers but they do not wish to publish it in the news because the Rangers are their friends. The Rangers go to their school prom, but they do not find Kira. Conner says that he will open up a Soccer camp and Ethan will take part in a video competition and he is practicing it right now in the party, since he will not lose it again like last time with Devin. Trent is going to Art School with a fall and Anton Mercer is the happiest person to hear it. The series concludes with Kira singing a song with past memories about their life.