There is much debate surrounding the age of the Clovis -- a prehistoric culture named for stone tools found near Clovis, New Mexico in the early 1930s -- who once occupied North America during the end of the last Ice Age. New testing of bones and artifacts show that Clovis tools were made only during a brief, 300-year period from 13,050 to 12,750 years ago.
Ancient Maya in the once-bustling city of Tikal built sophisticated water filters using natural materials they imported from miles away, according to the University of Cincinnati. A multidisciplinary team of UC anthropologists, geographers and biologists identified quartz and zeolite, a crystalline compound consisting of silicon and aluminum, that created a natural molecular sieve. Both minerals are used in modern water filtration.