2735 are remnants of a pre-human civilization, which is thematically similar to 1000 and appears to be aligned with the cyclical history thing you're hinting at here. But 2735 is weird biology while 1000 is more classic cryptozoology, so it's your call whether 2735 ought to be linked to this narrative.
I don't have any more suggestions and the new links add a lot to the narrative, so I'll leave y'all to it.