Until the find the bat, or Pharotis imogene, had not been seen in 120 years.
"The species was presumed extinct," University of Queensland researcher Luke Leung said.
Two University of Queensland students caught the female sample of the species in mid-2012 while conducting field work in the Abau coastal district of Papua New Guinea's Central Province.
It did not match any bat known to exist, and was later determined to be the species not seen since the first and only specimens were collected by an Italian scientist in 1890.
Leung said further studies needed to be done to establish whether the animal was one of a small number of mammals endemic to PNG's southeastern peninsula region, or whether it occurred more widely.
"Many of the coastal lowland habitats throughout Papua New Guinea are among the most threatened in the country due to clearing for logging and agriculture," he said.
"And more field surveys of local bat populations could assess the conservation status of the