According to the researcher, who recently discovered an impact crater in the Bayuda Desert in Sudan using Google Maps, several images seem to depict birds, with ponds representing their eyes.
Others appear to depict snakes, tortoises, fish, armadillos but also "abstract drawings," with patterns of stripes and other objects less easy to identify.
"The patterns are complex and some of this structure certainly reflects Andean concepts of cosmology, deep structure, social organization, measurement systems and art," said Erickson.
But he questioned Sparavigna's interpretation of the earthworks.
"The identifications of particular symbols such as birds, snakes, etc. are not convincing. For example, what appears to be 'a bird wing' in one image, is a modern plowed field with stacks of drying barley or wheat," he said.
According to Sparavigna, Ericskon's observation indicates that superimposed modern cultivations pose a threat to the geoglyphs.
"Modern agriculture can easily destroy them," said Sparavigna.