Diatoms will appears as a brown/gold dusting on your rocks and sand. How old is your tank? They are normal in new systems and will normally go away after a few weeks if you keep up with you water parameters.
Dinos are much more problematic. They have a longer stringy appearance and normally have a bubble at the end. You can blow them off with a baster or they will disappear overnight only to return during the day when you're lights are on.
If your arent sure what you have, try posting a picture of your tank.