Janus is a little bit too intelligent to be the son of Dalton, hilarious though Dalton is.

I always looked it as: RPG characters almost never have fathers. Who the hell is Chrono's father? The game certainly never turns any attention to that. It's very rare for an RPG character to have both parents survive long enough to get to the beginning of the game, and it's rarer still for both parents to survive the end of the game. It's an interesting question, but I'm not surprised Square didn't divert much attention to it.