The Quantasaurus Rex is Time Force's most powerful Zord. When it was launched through the time gate, it was accidentally lost in time, separated form its controller box. The box was found in 2001 by Eric, who used it to become the Quantum Ranger. He then travelled to prehistoric times, and lost the Q-Rex to a mutant, but later took control of it. Eric uses the Q-Rex as part of the Silver Guardians, and helps the Rangers when they need it. The Q-Rex can fire lasers from shoulder mounted cannons. It can also transform into Megazord mode, in which it can fire missiles, and deliver the max blizzard attack. Q-Rex is powered by a Trixyrium Crystal, which led to vortexes nearly swallowing the city when it fought Frax's own Trixyrium powered robot. Q-Rex continues in service under the command of Eric.

Max Blizzard
Q-Rex's shoulder blasters release the Max Blizzard attack, which cryogenically freezes defeated mutants.

Flying Fist
Q-Rex's left fist can be launched to deliver an explosive attack on any foe.

Missiles
Q-Rex's right hand is a missile launcher, which can fire a barrage of missiles at its enemies.