Normal Safe, Conquest and Risky Tunnels can’t be made in the prehistoric realms. They can only be made on normal hills, and the prehistoric realms all have prehistoric hills.
So there the gateways you can use in prehistoric realms are:
Time Gates – move you from the present to the past. And connect realms in matching pairs, so there is a similar realm in the now and in the past.
Oryctodromeus Burrows, dug by the Oryctodromeus dinosaur. They connect to another realm in the past that someone has already visited (by going back to there with a Time Machine).
Castles and Keeps and their Whirlpools, I talked about a couple of days ago.
And Stone Circles… which are “magic” so they work in space and time. You will be able to use Stone Circles to help your friends get into the past and to move your dinosaurs into the present eras.
We are all set to go live tomorrow, i’m off to bed now :)
If you want some more details… check out the wiki, it has some of the new units in it already: