Archeologists excavate bones of mammoth skeletons found at the construction site of the new Felipe Angeles International Airport in Mexico City, Mexico, Sept. 10, 2020. (Photo by Ricardo Flores/Xinhua)

Archeologists excavate bones of mammoth skeletons found at the construction site of the new Felipe Angeles International Airport in Mexico City, Mexico, Sept. 10, 2020. (Photo by Ricardo Flores/Xinhua)

Archeologists excavate bones of mammoth skeletons found at the construction site of the new Felipe Angeles International Airport in Mexico City, Mexico, Sept. 10, 2020. (Photo by Ricardo Flores/Xinhua)

Archeologists excavate bones of mammoth skeletons found at the construction site of the new Felipe Angeles International Airport in Mexico City, Mexico, Sept. 10, 2020. (Photo by Ricardo Flores/Xinhua)