Edgar Rice Burroughs 
Tarzan the Terrible 

Lieutenant Obergatz had fled in terror from the seeking vengeance of Tarzan of the Apes. And with him, by force, he had taken Tarzan’s beloved mate, Jane. Now the ape-man was following the faint spoor of their flight, into a region no man had ever penetrated. The trail led across seemingly impassable marshes into Pal-ul-don — a savage land where primitive Waz-don and Ho-don fought fiercely, wielding knives with their long, prehensile tails — and where mighty triceratops still survived from the dim dawn of time…