Dinosaur over the cuckoo's nest

I heard a story about the billboard outside a cinema in 1975.  They pasted up the poster for the Disney movie One of our Dinosaurs is Missing . . .

One of our dinosaurs is missing - Disney

. . . and underneath it there was this amazing and amusing coincidence . . .

One flew over the cuckoo's nest - was it a dinosaur?

Apparently, one of them flew over the cuckoo's nest.