You get the idea. Ultimately, isn't a professional historian kind of an oxymoron? There can be a professional economist/military officer/lawyer, who applies their skills to history, but to itself, a historian is not a profession
A paleonthologist, anthropologist, archeologist etc. all have specific skills. They're scientists who can use scientific method (carbon dating etc) to a certain aspect of the past to speak of it with a measure of authority. A historian to me is about as much of a scientist as a priest or a politician. Maybe even less.