If you want it ranked hop on over to the Arena chat or the Ranking area and let Rilla know, he will put you on the leaderboard. Then when you want a ranked fight ask around there for a judge who will resolve any disputes and when you post the fight set it to ranked. Then you'll have yourself a ranked match that will count towards your score if you win.

Your opponent will also need to be a member of the rankings. 

Have fun with giant dinosaur combat, I imagine it will be pretty cool.