Thu, 29 Mar 2012 13:08 UTC
published in the journal Antiquity, describes the mounds, measuring from 5 to 400 m long in each of the six valleys Dr. Benfer surveyed in coastal Peru, a region already renowned for the Nazca lines. The mounds pre-date ceramics and were probably built using woven baskets to carry and pile up rock and soil.
"The mounds will draw tourists, one day," Dr. Benfer said. "Some of them are more than 4,000 years old. Compare that to the effigy mounds of North America, which date to between 400 and 1200 AD. The oldest Peruvian mounds were being built at the same time as the pyramids in Egypt."
Like the Nazca lines, which include a series of giant animal outlines drawn on the ground to the south, the animal mounds were best observed from a higher vantage point. Google Earth images of the mounds revealed the shapes of birds, including a giant condor, a 5000-year-old orca, a duck, and a caiman/puma monster seen in bone and rock carvings from the area.
Dr. Benfer also noted the structures may have been built as terrestrial manifestations of constellations the ancient Peruvians saw in the stars above. The mounds not only represented the stars, they aligned with them. So far, the researcher has found astronomical orientations at every giant mound.
For example, at the Chillón Valley site, an earthen condor's charcoal eye lined up with the Milky Way when viewed from a nearby temple. The monstrous caiman/puma mound aligned with the June summer solstice when viewed from the same temple.
"For example, knowing that December 21 had passed was very important. If there was no sign of an El Niño by then, fishers would know they would have another good year, and farmers would face neither drought nor floods," Dr. Benfer said.
Previously, the only other effigy mounds known from South America were a few sites in the Andes, but Benfer's discoveries may be just the beginning.
"I had always noted that a very large structure just north of Lima resembled a bird. But since there were supposedly no giant animal effigy mounds in South America, I thought it couldn't be one," Dr. Benfer said.
Two years ago, while studying satellite views of archeological sites, Dr. Benfer noticed what looked like teeth on one of the mounds north of Lima. The jagged teeth-like structures had been misidentified as irrigation canals. But after a ground survey of the area, he realized he was standing atop the caiman/puma monster of Chillón Valley. He soon found the nearby condor mound and went on to identify numerous other earthen animal effigies.