* ActingForTwo: Many of the puppeteers portray 2 or more characters, with some of them[[labelnote:*]]mainly Bruce Lanoil and Allan Trautman[[/labelnote]] also doing voice work for those secondary characters on occasion.
** The show also made use of Creator/JasonAlexander, Creator/TimCurry and Creator/RobertPicardo as reoccurring voices. Resulting in a lot of vocal YouLookFamiliar moments.
* CrossDressingVoices: In the Mexican Spanish dub, Creator/MariaFernandaMorales voices the male Baby Sinclair.
** Same for the Brazilian Portuguese dub, where Baby voice actress is Marisa Leal.
* EditedForSyndication and ClumsyCopyrightCensorship: Because of music clearance issues, the Netflix version of "A New Leaf" replaces the scene of Mr. Richfield singing "Purple Haze" while high with an alternate scene of Mr. Richfield singing an original song about how happy the happy plant is making him. It's not as clumsy as other examples, but it is a screw to people who wanted to see the episode as originally aired.
** On a lesser note, the original run of the series on ABC had a laugh track, which was removed for syndication and home video releases. Many agree the series is better without a laugh track.
* InMemoriam: A dedication to Creator/JimHenson appears in "The Mighty Megalosaurus". Henson died before the series premiered on ABC.
* MissingEpisode: The Disney Channel did not rerun "Baby Talk" or "Dirty Dancing".
* TheOtherDarrin: Played with. Fran's animatronic was redesigned for the second season so it absolutely does not resemble her first incarnation, but her voice actress (Jessica Walter) stayed on and played her for the entire series.
* OutOfOrder: Even though Charlene grew a bigger tail in "Charlene's Tale", certain episodes filmed prior showing her shorter tail such as "Employee of the Month" and "Unmarried... with Children" aired after it. There's also the seven episodes filmed prior to the series finale that were shown afterwards when the show moved to syndication.
* ScrewedByTheNetwork: During production of the fourth season, Creator/{{ABC}} cancelled the series altogether and aired "Changing Nature" as the series finale.
* TorchTheFranchiseAndRun: This is why the series ended with the ecological disaster that killed off the dinosaurs.
* WhatCouldHaveBeen:
** This was originally intended to be a dramatic feature film called ''The Natural History Project'' with Warner Bros. set to distribute and Creator/JimHenson directing. However ''WesternAnimation/TheLandBeforeTime'' was released and Henson decided to turn the idea into a sitcom, which CBS greenlighted. It wasn't until Henson's death and CBS putting the show into turnaround that the show got made.
** A ''Dinosaurs'' [[TheMovie movie]] was planned at one point, but the project fell through.
** In the early development phase, Ethyl was originally conceived as a pterodactyl who hung upside-down in the closet, but after coming up with a few story ideas for her, they quickly realized that keeping her in the closet would limit what they could do.
* The only puppet that still exists is Baby Sinclair, aside from a somewhat degraded unisaur head. The latex used to make the puppets degrades quickly in light, so most of them disintegrated rather fast.