Creationists are often way too eager to showcase their ignorance on the vast majority of scientific subjects, most prominently the theory of evolution (the vast majority of creationists both don't know even 10% of what the theory actually says, and also attribute to it a large amount of things that it doesn't deal with at all) but also other branches of science such as astronomy, geology and paleontology.
One extremely common (and often overlooked) funny detail that most creationists always get wrong is that they don't even know what a dinosaur is. To a creationist "dinosaur" means, approximately, "any largish reptile that's (allegedly) extinct" (small extinct reptiles are also included if they look like their larger counterparts.)
Most typically this mistake can be seen by them referring to plesiosaurs and pterosaurs as "dinosaurs," even though they aren't classified as that. (Curiously, and rather ironically because of this inclusiveness, they strongly oppose classifying birds as dinosaurs, even though in this case that would be correct according to cladistics. So their ignorance goes both ways: Including wrong clades, and excluding clades that are, in fact, classified as dinosaurs.)
At a superficial level this is just a smallish mistake, and can be categorized as mainly amusing. However, at a more profound level this demonstrates how little research creationists actually do on the very subjects that they are criticizing. This is extremely typical of creationists: Come up with objections and critique, but don't do even the slightest amount of research to get their facts straight.