Ah, the good old days when triceratops roamed, plesiosaurus prowled the seas and pteranodons glided through the skies. If you have a hankering for those Cretaceous or Jurassic Period giants, head over to Prehistorica: The Dawn Kingdom, where you can live out your days as if it were tens of millions of years ago. You're also welcome to visit as a human, but be careful that you're not devoured by a tyrannosaurus (as I'm about to be in the image above) or speared by a triceratops (next image).
Don't have a dinosaur avatar? You're in luck, because plenty are available for sale right there, including a free sample. The mesh animals are remarkably detailed, are gigantic, move quite naturally and include easy-to-use HUDs for roaring, eating and so on. And to start your journey you do, of course, have to travel backwards in time, swirling through a time vortex of some sort, and it's a delight (next image) — I repeated by trip several times just for fun.
Of course, you don't need to be in Prehistorica to enjoy the full benefits of your newfound avatar. I don't think I'll ever forget the moment I (as an apatosaurus) strolled down Route 66 through Bay City past the Brewery, much to the general bemusement of its inebriated occupants. And just to show the size of these things relative to objects in a "regular" sim environment, I've posed below with AM Radio's iconic locomotive at The Far Away, one of my favorite spots to wander in prehistoric garb.