Mexicans in Laos???

I know the prevailing theory is that American Indians came into North America from northeast Asia by way of a land bridge, then distributed down through Central and South America. That seems to me a load of hokum, not least of all because there is almost zero resemblance between the indigenous inhabitants of the Americas and people in northern China (or Russians, for that matter).

Indigenous Americans do, however, look almost exactly like the inhabitants of Cambodia, Laos, the Philippines, and various Pacific islands. Imagine my shock, then, to find in Laos the above carvings, which look exactly the same as Mayan carvings in Central America! Obviously the centerpiece gods are different, but otherwise the above art looks to me about as American as it gets!