Ah, an excellent question, and one that our trio should probably be asking themselves (but knowing them, they're likely too busy dodging dinosaurs and making friends with muscle-bound eagles to give it much thought).
The short answer is… yes. Time, after all, is a delicate thing, and even the smallest actions can send ripples through the future. Imagine it like tossing a pebble into a still pond; one little splash, and suddenly the whole surface is moving. Each creature they meet, every strange artifact they uncover, and any adjustments they make to their prehistoric surroundings could, theoretically, set off a chain of events that echoes forward through history.
So yes, every time they interact with something or someone in that ancient world, they're potentially reshaping what the future might hold. And perhaps, just perhaps, some of those strange discoveries they've been uncovering — glowing artifacts, bizarrely modern engravings — could have been left by other "travelers" just like them, who had no idea what their actions would lead to…
But of course, dear reader, I'll leave you to discover just how much they end up changing.