Hey, nice! That looks like a good standalone topic.
The earliest domes in the Med though are the corbelled domes (such as the so-called “Treasury of Atreus”) built by the Mycenaean Greeks.
Nice corbelled arch at Uxmal. But no dome.
http://worldheritagesites.tumblr.com/post/3204639088/mayan-corbelled-arch-uxmal-mexico