Ray Bradbury Presents Dinosaur Planet by Stephen Leigh (Paperback)

Eckels, a psychotic time-traveler, has shot a dinosaur and meddled with history, destroying the future and trapping himself in the past. Transported to an alternate prehistoric period by a savage timestorm, Aaron Cofield manages to link up with a lost Time Safari guide, Travis. Together, they must hunt down Eckels and restore the shape of history.

As the rifts in time widen, timestorms and a crazed time-criminal are only part of the danger. Two warlike races of intelligent dinosaurs have appeared . . . dinosaurs who would rather fight for survival than help humans fix history.