Attack of the Super Monsters (1983)

In the near future it's discovered that the dinosaurs did not die off, but instead live on near the center of the Earth. The evil lord Tyrannus uses the mutated dinosaurs descendents to attack Earth in his effort to rule the world. Can Gemini Force, a group of four superpowered teens who've pledged to protect the Earth, stop his plans? Written by Mike Konczewski 70 millions years ago, the creatures known as dinosaurs mysteriously disappeared from planet Earth. Until now, it was assumed they were extinct. In reality, they had burrowed deep into the Earth and evolved into supermonsters. In the year 2000, the people from planet Earth were amazed and terrified by the greatest catastrophe ever known to mankind: the re-appearance of the dinosaurs. Under the direction of their emperor, Tyrannus, the creatures now seek to destroy mankind.

Unfortunately the movie Attack of the Super Monsters is not yet available on HBO Max.