Did you know the 1970s #LandOfTheLost TV show is actually just a spin-off of #DoctorWho ? You'll be surprised how many connections the two shows have!
The basic premise of Land of the Lost is that the Marshall family slips through a crack in time and ends up in this mysterious land of dinosaurs. But beyond just dinosaurs, the place is populated with alien creatures like the Sleestak and the Zarn.
Further, the Land of the Lost is a "closed universe." If you walk to one end of the place, you wind up on the other side like in Pac-Man. Here's Holly looking around the entire Land with a pair of binoculars only to see herself!
The show is much more than just time travel. It's very much in a traditional science fiction wheelhouse of Doctor Who, and had some heavy sci-fi writers at its helm including David Gerrold, Larry Niven, DC Fontana, and Ben Bova among others.

But that's hardly proof it exists in the same timeline as Doctor Who, is it?

The first piece of evidence is that the Land of the Lost is filled with TARDISes. The Marshall family call them "pylons" but they're clearly TARDISes. They have the same basic exterior structure and are impervious to damage.

The "pylons" are bigger on the inside (in this shot, Jackson even literally says the Who classic line, "It's bigger on the inside than it is on the outside!") and change their appearance over the course of the show.
Each pylon has a central control console and while the Marshalls never really figure out how to use them, they do indeed show Holly getting stuck in one and stepping out onto different times/planets.
My working theory is that the Land of the Lost is actually a pocket universe that the Time Lords use to store severely malfunctioning TARDISes until they can be repaired/dismantled. The closed nature of the Land of the Lost might be to prevent unintentional access.
This idea is further underscored by the 'repairman' character, William Blandings. He's virtually omniscient and carries a dimensionally engineered valise that holds WAY more than it seems outwardly capable of, including a universal key for any of the pylons/TARDISes.
But the best is for last: the Land of the Lost features an actual Time Lord! The actress isn't one you'd recognize from Doctor Who, but you know how Time Lords regenerate and change their appearance. This woman tricked Holly into believing she was a future version of herself.
The character's name? The Rani! Even spelled the same as the Kate O'Mara / Anita Dobson / Archie Panjabi version!
She actually appeared several episodes earlier trying to pass herself off as Will & Holly's mother! You can't see her clearly in that episode but it's the same actress: Erica Hagen! So we've got a clearly duplicitous character called The Rani in both series!
(Recall when The Rani tried the same trick on the Doctor? Trying to pass herself off as Mel?)
My theory is that The Rani was unable to get a TARDIS after she was exiled from Gallifrey, and was trying to get to the Land of the Lost to steal one. We don't see her actually do that in the show but a later episode revolves around a missing pylon.
But the problem with stealing a TARDIS from a land full of dinosaurs is that you can pick up unintentional hitchhikers! Like the Tyrannosaurs Rex that we saw in "Mark of the Rani!"
So there you have it! Land of the Lost is actually a Doctor Who spin-off! Dinosaurs aren't exactly uncommon on Doctor Who and now you know why!

@SKleefeld Hat's off!! Good catch!

Land of the Lost appears to be some kind of Gallifreyn zoo! ..prison? ..reality TV show? ..junkyard?

@mousey I don't think they'd leave TARDISes lying around if it were a prison or zoo; I'm leaning towards junkyard.
@SKleefeld recuerdo haber visto algún capítulo de esta serie, nunca recordé el nombre!

@SKleefeld @TerryHancock Terrific theory!

I love this show. It had some really terrible acting and some dodgy effects, but it had such mind blowing concepts for a kids show with dinosaurs.

@michaelgemar @TerryHancock Yeah, the writers really brought a LOT more ideas than could be presented well on the show's timing and budget!
@SKleefeld @TerryHancock Larry Niven! On a kids’ show!
@michaelgemar @TerryHancock Yeah, there was an INSANE pedigree in the writers' room there! One of the episodes was even written by Walter "Chekov" Koenig!
@SKleefeld Dammit, this makes too much sense and now my head hurts.
@SKleefeld This thread is a thing of beauty, and I feel honored just to have stumbled upon it.
@bmac Thanks very much! 😁

@SKleefeld

Thanks for this. I used to love Land of the Lost when I was a kid.