Getter Robo Arc is the fifth Getter Robo series chronologically.

Taking place several years after Getter Robo Go, Earth is now a post-apocalyptic world. Hayato, now an aging scientist, has completed Professor Saotome's masterpiece, Getter Robo Arc. Piloting it are Ryoma's son Takuma, the human-dinosaur Kamui, and the younger brother of Tayel, Baku. Alongside the reformed Dinosaur Empire, they fight the insectoid Andromeda Flow Country attacking from across time and space.

(Source: MAL News)