Land of Terror : (#6) (Pellucidar, No 6)

Blurb

If you have ever wondered what a civilized man of the twentieth century would do if catapulted into an Old Stone Age where huge cave bears, saber-toothed tigers, monstrous carnivorous dinosaurs, mammoths, and mastodons roamed the savage terrain, you need look no further than Land of Terror, the sixth installment of Edgar Rice Burroughs's Pellucidar series.