Mayan
The Mayans or Mayas were a Native American Human civilization existed in the southern regions of North America and northern Central America, on Earth, in ancient times. 

Kukulkan, a benevolent alien being, visited the ancient Earth civilizations and influenced their architecture and agricultural development. Kukulkan was worshiped as a god by the Mayans who encountered him. Kukulkan gave the Mayans their remarkably accurate calendar and told them to build a city according to its cycles. On the date the city was finished, Kukulkan was supposed to return. The Mayas built their city but Kukulkan never appeared. As they had only built parts of the city, they had not finished the energy amplification system that was supposed to signal Kukulkan.

Kulkulkan was discovered by the crew of the  in 2270. ()

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Earth groups