William Hanna wanted to do a family-style series, but he and Joseph Barbera couldn't agree on the setting or the costuming. Suddenly, Hanna exclaimed, "Let's do it in a caveman setting! They won't wear clothes, they'll just wear animal skins!" After that great idea everything from then on "perfectly fell into its place."
Since, the windows of the Flintstone house are quit big and do not have any glass, why does Fred keep banging the door after being kicked out by the saber-tooth cat? He could easily follow the cat's example and enter through the window.
First season episodes incorporated an ad for Winston Cigarettes into the opening credits (this version of the opening was removed for syndication). Due to the decision to use a standard opening and closing for syndicated versions of the episodes, numerous episodes have incorrect closing credits. Sixth & last season episode debuted with, The Flintstones: No Biz Like Show Biz (1965) dropped the "Meet the Flintstones" closing credit song, in favor of footage of Pebbles and Bamm-Bamm singing "Let the Sunshine In." (a reminder of Fred Flintstone's dream, earlier in the musical program).
The original closing credits to the first two seasons of the show are similar, but not identical, to the more familiar version. After turning off the TV from the opening credits, Fred goes off to his room (and Dino hops back into the chair). Quietly walking into his room so as not to wake the sleeping Wilma, Fred closes the cover on the bird's cage in the bedroom and yawns, cross-fading to a shot of lights going off one-by-one around Bedrock as everyone turns in for the night. Fred sets the milk bottles out for the milkman, then puts the cat out, who, instead of sneaking back into the house and putting *Fred* out as in the more familiar version, simply slips back into the house and locks the door before Fred can get in. Fred starts pounding on the door, screaming "Wilma!" "Wilma, open this door," louder and louder as he does, causing all those lights that went out around town to all come back one again, one by one. This sequence, like the original opening, was scored with "Rise and Shine."