Ok, now i understand where you guys are coming from..... I agree that preternia should be a much longer time in the past than 500 yrs. if it's supposed to be the prehistoric age, then why not make it millions of years in the past? why stop at 5000 yrs? (hell, jesus & the romans were 2000+ yrs ago....) pre-history means before history was recorded, imo... so anything from that era would be long forgotten. and since they know what KG, Tytus, He-ro, etc. did, then they can't be pre-historic imo.
but then again, i never thought of King grayskull as being a 'preternia' (or prehistoric) character.... since they established adam as a his direct decendant. Who knows their ancestors from 5000 yrs ago? nobody can trace their family history that far back. hell the mayans lived 500 yrs ago, and much is known about their history, which makes sense to me. not much is known about history or culture from 5000 yrs ago. that's lost with time. so the notion of Eternians knowing the history from that far back is totally far fetched & unrealistic imo.
and the fact that the current Eternian residents dress exactly the same as their 'preternian' counterparts, makes me believe that it couldn't have been all that long ago.

so which characters exactly would qualify as prehistoic, since any one of them could easily live in the current (present) timeline? I mean He-man looks just as much like a cave man as king grayskull...
vikor looks much more ancient than kg or tytus, so he could be prehistoric imo.
sure, preternia can & should be more than 500 yrs ago.... but I don't see Tytus, KG , He-ro, etc. as existing much further back than 500 yrs ago. any longer than that & nobody would remember them or what they did. and don't give me the ' tytus had dinosaurs, so he must be prehistoric' thing, since there are still dragons & dinosaur like creatures in the present Eternian timeline.
and maybe Eternia isn't that old of a planet.... it's a magical world, so any & all Earth based physics & timelines shouldn't even apply.