World Out of Step — John Russell Fearn

The Cosmic Crusaders find themselves on a truly strange world--a misfit planet that seems mysteriously cursed. Instead of evolving naturally from birth to death, it's a world out of step with the universe, leaping ahead into the future at unexpected moments. With each 50-year "step," much of the population dies, and the young replace them as middle-aged individuals. The Crusaders are suspicious that the adviser to the planet ruler is actually an alien from another world, and is causing the constant time dislocations for nefarious purposes. But when he traps the Golden Amazon and her three companions, sending their spaceship crashing onto a neighboring world dominated by huge, dinosaur-like creatures, the Crusaders appear to have met their match.

Another stirring sci-fi adventure by a master storyteller!