Published by Rand McNally in 1972 (though it may have originally been a British book),this is the only book I know of to combine cavemen and dinosaurs just like in the movies (comics did it, but not books). They do this through the device of having the hero of the piece, a cave teen named Tule, stumble upon a lost island where dinosaurs still live. Though the author cared enough about scientific accuracy to give such a rationale, that didn't stop him from identifying triceratops as "the ancestor of the modern rhinoceros." Ah well. The big selling point of the book were the origami dinosaurs you could cut out and fold up. Just trying finding a copy of the book with those still in tact (or try finding a copy of it at all!). My mom folded 'em up for me. I still prefered my plastic dinos, but I loved this book and read it bazillions of times. Notice that the dinosaurs are patterend after Zallinger's beasts from the Giant Golden Book of Dinosaurs, right down to their skin coloring.
Found guilty of heresy, Tule is made a sacrifice to the sea gods.
He survives, but finds getting his meals difficult on dinosaur island.
Finally, as he's about the make his escape, Tule is set upon by the ancestor of the modern day rhinoceros and the ancestor of the modern day VW bus.