Researchers have identified three new species of lizards in Peru, differentiating them from other species they have previously been mistaken for.

Scientists from San Marcos University in Peru and Brigham Young University in the US report their technique for identifying the news species as a middle ground between the two extremes of species identification.

On one end, purely morphological descriptions of a specimen's physical characteristics can become less useful when specimens appear to look the same. Identifying species by purely genetic data is highly effective, but doing so is expensive, the researchers report.

Here, they have bridged the two extremes, identifying three lizards by both genetic and morphological testing.

The researchers stress the importance of accurately differentiating species that look alike from one another and establishing scientific names for new species in published journals.

"Species delimited but not formally described and without scientific names don't exist in the real world, and this is an issue of pivotal importance in the Andean, Patagonian, and Neotropical regions of South America," the researchers said in a statement.

Two of the new species take their names from two old Andean civilizations, the Wari and the Chavin, and the third is named after the Inca ruler Pachacutec.

"Liolaemus pachacutec was found above Písac, an Inca ruin built by Pachacutec," the researchers said.

"Liolaemus chavin was found in an area close to the center of the Chavín culture, where reptiles and other animals were represented in some remarkable artistic expressions. Liolaemus wari was found close to the center of Wari culture, in Ayacucho department, southeastern Peru."