Dinosaur Samurai — Stephen Leigh

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 Travis, a lost Time Safari guide. Together, they must hunt down Eckels and restore the shape of history. Attacked by sentient dinosaurs, Aaron and Travis escape to an alternate medieval Japan. Caught between dinosaurs, ferocious samurai warriors, and the cold-blooded Eckels, the two must fight for their own survival-and to restore the timestream of our future!