Slag was aboard the Ark when it crashed into Mount St. Hilary 4 million years ago. When the Ark's computer detected Shockwave in Antarctica's Savage Land, it awakened Slag and his four teammates, and fashioned them into the Dinobots, adapting them to the dominant lifeforms in the Savage Land.

The Dinobots took an Autobot shuttle to the Savage Land and prepared to confront and neutralize Shockwave.

The Dinobots engaged Shockwave in battle, and though it seemed that they had the upper-hand, Shockwave was merely testing their abilities.

Shockwave soon drove the Dinobots into some nearby tar pits, and used ranged electromagnetic attacks to drive them back into the tar. Snarl collapsed the cliff Shockwave stood upon. neutralizing him, as well.

After 4 million years, Ratchet discovered the Dinobots location in the tar pits and sought to reactivate them. Slag awakened while Ratchet observed his memories, and attacked Ratchet, thinking him to be an enemy. Ratchet showed him his Autobot symbol, which brought Slag's assault to a halt.

Ratchet led Slag and the other Dinobots back to Oregon, to face off with Megatron. Though Megatron defeated the Dinobots, Ratchet caused Megatron to fall from the cliff, where he disappeared into the snow far below. Ratchet then led the Dinobots back toward the Ark.

As Ratchet and the Dinobots approached the Ark, they encountered a human, who was deathly afraid of them. Ratchet then explained to the dinobots how humans are the dominant species on Earth, and they are very mistrustful of Cybertronians.

When they arrived back at the Ark, they were attacked by Guardian, an Autobot security droid who had been reprogrammed by Shockwave and Soundwave to attack any Autobots it encountered. Ratchet caused the droid to disengage and flee into the depths of the Ark. The Dinobots pursued.

Twice more the Dinobots battled Guardian within the Ark. After it was discovered that Guardian was armed with a thermonuclear device that would destroy the Ark and all within it, Swoop grabbed Guardian and flew him to a safe distance from the Ark, where the droid detonated.

After Swoop's apparent death, the Dinobots, left the Ark to go their own way out in the Oregon wilderness.