Nomen dubium

A nomen dubium is like calling someone by the name "maybe." It means that scientists are unsure if the name they have given to a plant, animal or fossil is the right name. They may not be sure because they don't have all the information they need or the information they do have is conflicting. So, instead of guessing the name, they use the words "nomen dubium." It's like saying "I'm not sure, so I won't give it a name until I am sure."