You can definitely see why the tiny mummified skeleton—found inside a leather pouch behind an abandoned church in Chile's Atacama Desert in 2003—had many claiming an alien had been discovered. The 6-inch skeleton—nearly 2 inches shorter than the shortest baby ever born—had a cone-shaped head, 10 pairs of ribs instead of 12, and the bones of a 6-year-old, the Telegraph reports. According to National Geographic, the mummy—nicknamed 'Ata'—was sold to a Spanish businessman and became the subject of extraterrestrial-related TV shows and a documentary. Dr. Garry Nolan heard about Ata from a friend in 2012. “You can't look at this specimen and not think it's interesting. It's quite dramatic," Nolan tells the Telegraph. "So I told my friend, 'Look, whatever it is, if it's got DNA, I can do the analysis."
Nolan and his team published the results of that analysis Thursday in Genome Research. They concluded Ata is definitely human—a girl who died before or soon after being born. Rather than ancient, the mummy is likely under 40 years old. Ata's bizarre appearance is due to mutations in seven genes that are connected to dwarfism and deformities of the bones and face. Researchers say it's exceedingly rare to see so many mutations in one person and speculate that nitrate mines in the town could be to blame, CNN reports. Moreover, some of the gene mutations in Ata had never been seen before, and that could eventually help modern patients. But not everyone is convinced. “We don’t know what it is, but it most certainly is a not a deformed human,” Steven Greer tells NatGeo. Greer is out to prove the existence of UFOs and was the one who gave Nolan access to Ata. (Read more mummy stories.)