"These construction characteristics have not been seen before in northern Peru," he said.
"Though the construction materials were very primitive, the mural and structures themselves are surprisingly sophisticated and artistically elaborate."
The site was built by a culture that predated other pre-Columbian cultures such as the Cupisnique, Chavinoide, Chavín, and Moche, Alva said. (See pictures of a Moche temple.)
Daniel H. Sandweiss, an anthropology professor at the University of Maine, said the discovery is significant—and also sheds light on a long-standing mystery.
"The Lamabayeque valley complex is the largest extent of irrigable land on the Peruvian coast and offered many attractive resources for hunter-gatherer-fishers before irrigation agriculture," he said.
"Yet preceramic occupations were virtually unknown there, even though most of the Peruvian coast has an abundant preceramic record."
Alva said some of the artifacts found in Ventarrón suggest that the region of Lambayeque was a cultural exchange point between Peru's Pacific coast and other regions.
His team, for example, found ceremonial offerings including the skeletons of a parrot and a monkey that would have come from Peru's jungle regions.
They also found shells that would have come from coastal Ecuador, he said.
Michael E. Moseley, an anthropologist at the University of Florida, was not involved in the research.
"Dr. Alva has a track record for unique discoveries," Moseley said, "and his latest unearthing of ancient temple murals greatly enlightens understanding of the vibrance of ceremonialism in native America millennia ago."
Luis Jaime Castillo, an archaeologist at Peru's Catholic University in Lima, agreed the finding is important.
"It suggests that societies in their formative period, the period before complex societies came into being, extended into the northern reaches of Peru earlier than we thought."
The finding was also fortuitous given the site's recent history.
Over the years, Ventarrón has been almost totally destroyed by locals digging for materials to make adobe buildings and livestock corrals.
What's more, Alva said the tomb was ransacked in 1990 and 1992, but the raiders failed to find the staircase leading to the temple.
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