Analyzed and attributed to a male by a British doctor, the bones were later lost.
"The entire incident was forgotten until TIGHAR discovered the original British files in 1998, including the skeletal measurements the doctor made," TIGHAR said in a statement.
A re-evaluation of the measurements by forensic anthropologists Karen Burns and Richard Jantz led to the conclusion that the bones were actually consistent with a female of Earhart's height and ethnic origin.
"While working on a new evaluation of the bones described by the British doctor in 1941, Dr. Jantz noticed that the skeleton's forearms were considerably larger than average," Gillespie said.
Statistically, women born in the late 19th century had an average radius to humerus ratio of 0.73. But the ratio in the skeletal remains was of 0.756.
The question now was if Amelia had similarly longer-than-average forearms.
TIGHAR asked forensic imaging specialist Jeff Glickman to find clues from a historical photo of Amelia where her bare arms were clearly visible.
"Working with Dr. Jantz to identify the correct points on the shoulder, elbow and wrist for comparing bone length, Glickman found that Earhart's humerus to radius ratio was 0.76 - virtually identical to the castaway's," TIGHAR said.
RELATED: Credible Amelia Earhart Signals Were Ignored
"The match does not, of course, prove that the castaway was Amelia Earhart, but it is a significant new data point that tips the scales further in that direction," Gillespie said.
According to TIGHAR, Earhart made more than 100 radio transmissions in the days after her plane vanished from the radar, but her distress calls were ignored.
"Earhart and Noonan eventually died as castaways on the waterless, uninhabited atoll, their aircraft washed into the ocean," Gillespie said.
After 11 expeditions to Nikumaroro, Gillespie is trying to raise money for a 12th in summer 2017, on the 80th anniversary of the disappearance of the legendary pilot.
The search for whatever remains of Earhart's twin-engine Electra will rely on two three-person manned submersibles operated by the University of Hawaiii's Undersea Research Laboratory (HURL). They will inspect the underwater area down to a depth of up to 6,500 feet.
Gillespie estimates the expedition will cost around $1,750,000.
WATCH VIDEO: How Flying Fuels the Human Imagination