Early civilization uncovered in southeast.

• Position: Anthropology - Forida's Aucilla River

The discovery of stone tools alongside mastodon bones in Florida's Aucilla River shows that humans settled the southeastern U.S. as much as 1,500 years earlier than scientists previously believed. The site dates back 14,550 years, according to radiocarbon testing. There is a cluster of sites all over North America that date to around 13,200 years old, but there are only about five in all of North and South America that are older.

Jessi Halligan, professor of anthropology at Florida State University, Tallahassee, and her colleagues, including Michael Waters (director of the Center for the Study of the First Americans at Texas A&M University, College Station) and Daniel Fisher (a vertebrate paleontologist from the University of Michigan, Ann Arbor) excavated what is called the Page-Ladson site, which is located about 30 feet underwater In a sinkhole. The site was named after Buddy Page, a diver who first brought the site to the attention of archaeologists in the 1980s, and the Ladson family, which owns the property.

In the 1980s and 1990s, researchers James Dunbar and David Webb investigated the site and retrieved several stone tools and a mastodon tusk with cut marks in a layer more than 14,000 years old. However, the findings received little attention because they were considered too old to be real and questionable because they were found...