I will agree with Green Lantern to the point that previous examples of nonsense don't excuse piling more nonsense on top of that. I just disagree that riding a dinosaur is necessarily nonsense.
The problem, now that I think about that episode a little more, is that there was little point to hopping on a triceratops to escape those bumbling robot pursuers. The beast was hardly any faster than running, difficult to get going, and no one had any believable reason to think it might cooperate in the first place. So the whole bit felt contrived.