A Joke: from dinosaurs to Heidegger, but not seriously

I always wonder where Jokes come from (surely we all do). I assume they arise out of the evolution of a conversation. When I hear a joke or tricky saying, I often spend a lot of my subsequent thought time wondering how this came to be, what conversation was necessary, what subject matter and what development of ideas, etc. Anyway, this morning I was mucking around with my kids and we ended up with the joke (not that they got it):

What do you call an existentialist? A Daseinosaur! HAHAHAHA!

. . . get it, because it's a kind of old and outdated way of thinking . . . daseinosaurs! . . . hilarious!

Oh dear . . . whew! Anyway, it started out when my kids and I were imagining a story about a family of "designosaurs" who were architects and very upstanding and proper members of a middle class, suburban neighborhood. Even though they're actually dinosaurs, none of the neighbors noticed that little fact because the designosaurs wore spectacles and normal clothes to mask their reptilian identity. Oh the crazy things those designosaurs would get up to in the effort to mask their true identities and behaviors (eating goats chained to trees, being very very big, having rows of six inch long teeth, the usual stuff dinosaurs have to hide when they live amongst us).

So it evolved from that to other words that sound like dino, and thus "Dasein" which interestingly, for those who don't know, is itself a morphed word from Da Sein (which means "being there" or "there being" but in its morphed form became one of Heidegger's buzz words).