I've heard that the first king of the Mayans remains were DNA tested and that he was not native to the Americas, but that his wife was native. During his reign he built clay lined water reservoirs with large zeolite filters which ended much of the sicknesses that had previously been endemic, banned human sacrifice, monopolized mining of jade and flint, and set up large farms that enabled division of labor, including the use of fertilizer ash from a nearby volcano, and trading with coastal people for fish.

There are lots of examples of Mayan elongated skulls, some from binding, and some seem natural. I've seen the carvings that look like space capsules, but that's it.