The image of a fanged deity engraved on a 4,000-year-old Peruvian gourd suggests an early Andean civilization practised religion earlier than thought.

The softball-sized gourd fragment was found along the coast of Peru and carbon dated to around 2250 BC.

"Like the cross, the Staff God is a clearly recognizable religious icon," said Jonathan Haas, a curator of North American anthropology at the Field Museum in Chicago and one of the study's authors.

"This appears to be the oldest identifiable religious icon found in the Americas. It indicates that organized religion began in the Andes more than 1,000 years earlier than previously thought."

In several Andean cultures, the Staff God commonly holds a staff in one or both hands, according to co-author Alvaro Ruiz, a director of the Proyecto Arqueolgico Norte Chico. The deity is commonly shown in a frontal view with a fanged mouth and clawed feet. Snakes are often part of the figure's headdress or garments.

The seven-centimetre figure on the gourd fits the motif. The simple design of a fierce feline face has fangs, clawed feet, a snake in its left arm and a staff in the right hand.

It appears the gourd was inscribed with a hot implement and then painted. A similar drawing was found on a second gourd fragment from a nearby cemetery.

The burial ground is in the Pativilca River Valley of a region called Norte Chico, about 193 kilometres north of Lima. The region was densely populated between 2600 BC and 2000 BC and appears to have been the ancestral home of Andean civilization that culminated 3,500 years later in the Inca.

Later versions of the Staff God were depicted in gold, clay, textiles and stone throughout Latin America. Pottery was introduced on the Peruvian coast about 1900 BC.

The discovery is described in the May-June issue of Archaeology.