Even today you'll have detailed descriptions and explanations of some dinosaur, and it turns out we have half of one bone and part of a head, and that's basically it.
Without spending years studying the stuff, it's really hard to figure out what is "this is absolutely known" (as in, we have a full fossil found in one location and in one piece) and what is "this is our current educated best guess".
Without spending years studying the stuff, it's really hard to figure out what is "this is absolutely known" (as in, we have a full fossil found in one location and in one piece) and what is "this is our current educated best guess".