Journey to the Beginning of Time

 Karel Zaman was the Czech answer to Harryhausen, of "Journey to the Beginning of Time" is any indication. Four boys go on an adventure down a river of time, remaining fastidiously scientific all the while - measuring the length of a stegosaurus by paces and hands and discussing the Latin names of ice age creatures. 

I love the kids - they're very no-nonsense and practical, and they fall in the river a lot while never being cutesy, whiny, screamy or any of the other fatal flaws of kids in movies with dinosaurs. The effects are the most entertaining - mostly stop-motion, some puppetry, some guys in elaborate dinosaur costumes (I think). A creative combo of paper puppetry and stock footage brings a leopard attack to life. It's fun to watch the ingenuity of the film effects plus the cleverness and pluck of the boys. It's charmingly didactic as they travel down the river and further back in time.