I'm a spinosaurus with a System to raise a dinosaur army

After dying following a car accident, Fen Chiang finds himself in a limbo between the afterlife and the mortal world where he meets God himself, who makes him a strange request: to immediately reincarnate in a world called Eden, where all species that existed on Earth (dinosaurs, prehistoric mammals, synapsids, pterosaurs, etc.) coexist together, to save it from the human beings who are destroying it due to excessive pollution. Armed with his knowledge and a System, our hero, now reincarnated as a spinosaurus named Sobek, must embark on a difficult journey to reunite the dinosaurs and curb humanity's greed. However, defeating the most powerful species that ever existed will not be an easy task even for a dinosaur army, and surely humanity will not abandon the title of dominant species very easily...