Philip Paley

As part of a deal with an intelligence agency to look for his missing brother, a renegade pilot goes on missions with an advanced battle helicopter.

Rick Marshall and his children Will and Holly are on a weekend expedition rafting down a river when an enormous earthquake diverts them to an eclectic alien world inhabited by dinosaurs, chimpanzee-like cavemen called Pakuni, and aggressive, humanoid lizard creatures called Sleestak.