The truth is out there.

After years of analysis, scientists remain puzzled about the origin of a remarkable 6-inch skeleton found in Chile’s Atacama Desert nearly a decade ago, and DNA tests have only heightened the mystery.

The tiny skeleton has an elongated skull that seems plucked from a Hollywood costume department for a film on alien invaders. That remarkable feature caused many people to conclude that the mummified specimen was an extraterrestrial, but DNA testing conducted by researchers at Stanford University suggests the skeleton belonged to a human girl who was approximately 6 to 8 years old.

As to the misshapen skull, researchers say that DNA analysis turned up birth defects that could, in part, help explain the deformity.

“While the jury is out regarding the mutations that cause the deformity, and there is a real discrepancy in how we account for the apparent age of the bones … every nucleotide I’ve been able to look at is human,” Garry Nolan, professor of microbiology and immunology at the Stanford University School of Medicine, told LiveScience. “I’ve only scratched the surface in the analysis. But there is nothing that jumps out so far as to scream ‘nonhuman.'”

The minuscule growth rate is just one of the oddities surrounding the skeleton. The specimen, for example, has just 10 ribs, whereas a healthy human has 12, LiveScience reported, and 9% of the skeleton’s genes did not match up with a reference human genome.

The genetic anomaly could be explained by various factors, including degraded testing samples, and the skeleton’s DNA suggested that it belonged to a female human who came from the coast of South America.

There is, however, skepticism in the scientific community as to whether known genetic defects can really explain the proportions of the skeleton’s head and body. None of the mutations associated with primordial dwarfism, for instance, were discovered through DNA analysis.

“There is no known form of dwarfism that accounts for all of the anomalies seen in this specimen,” Ralph Lachman, a professor emeritus at the UCLA School of Medicine, wrote in a report on the skeleton.