Archaeologists found the remains of at least 180 people – European, Indian and African – in a cemetery near the ruins of a colonial church in Campeche, Mexico.

The particular mix of strontium in the teeth of the four, the researchers concluded, showed that they were born and spent their early years in West Africa. Some of their teeth were filed and chipped to sharp edges in a decorative practice characteristic of Africa.

Because other evidence indicated that the cemetery was in use starting around 1550, the archaeologists believe they have found the earliest remains of African slaves brought to the New World.

In a report to be published in The American Journal of Physical Anthropology, the archaeology team led by T. Douglas Price of the University of Wisconsin concluded, "Thus these individuals are likely to be among the earliest representatives of the African diaspora in the Americas, substantially earlier than the subsequent, intensive slave trade in the 18th century."