There are also racial similarities between East Asians and Native Americans, such as sparse body hair, shovel-shaped incisor teeth, and the "Mongolian spot," a blue-black birthmark on the buttocks or lower back of babies, particularly boys.
此外，兩邊在人種上也有一些相似之處，例如體毛稀疏，有箕形門齒，男性在幼年時會有「青屁股」的胎記等。