In memory of Sid Krofft, I'm going to present again my #LandOfTheLost / #DoctorWho crossover theory that posits that LOTL is just a DW spin-off. 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.

@SKleefeld Alternate theory: The LotL is a middle-step between SIDRATs and TARDISes.

Either way, though, I wonder if/how Sleestaks, Silurians, and Sea Devils are connected...

@Unlikelylass Oh, now that could be interesting! The old school Silurians in particular are pretty close to Sleestaks design-wise! 🤔