Today, this term can always be used in everyday life. It is mostly used after somebody does something that would be considered "dick". Such as fucking your bestfriends girlfriend or eating all of the steak out of the refrigerator.
"dude your a fucking dickosaur, all you had to do was tell me that you used my beard trimmer to trim your pubes, now i have fucking pubes all over my face!"
"i can tell that your dads a dickosaur, he doesn't let you do anything and always gets you in trouble"