It was described as a new species by Dutch zoologist and museum curator Coenraad Jacob Temminck in 1825 who gave it the scientific name Pteropus medius.
Confusion over the name has prevailed in the literature as in 1782 Danish zoologist Morten Thrane Brünnich, gave the scientific name Vespertilio gigantea as a replacement for Vespertilio vampyrus Linnaeus (1758: 31) 
He was specifically referring to Linnaeus's use of Vespertillo vampyrus.
Carl Linnaeus had previously classified the species as Pteropus vampyrus and as such gigantea could not be used for a species that was already named.

In 1992 Corbett and Hill suggested giganteus was a sub-species of vampyrus.

In 2012, Mlíkovský argued that the correct scientific name of the Indian flying fox should be Pteropus medius rather than P. giganteus.

He asserted that Brünnich coined a new name for a species that had already been described—Vespertilio vampyrus which is now Pteropus vampyrus (the large flying fox).

Mlíkovský made several points in his argument, all with a foundation in the nomenclature rule known as Principle of Priority.

The Principle of Priority posits that the first formal, published scientific name given to a species shall be the name that is used.

Because Brünnich was attempting to rename the large flying fox in his 1782 publication, his name should not apply to either the large or the Indian flying fox—an older name was in existence, and therefore the large flying fox is P. vampyrus, not P. giganteus;
In negating Brünnich's name, Mlíkovský states that the oldest applicable name used to describe the Indian flying fox comes from Coenraad Jacob Temminck's publication in 1825.

Mlíkovský's recommendation has been met with varying degrees of acceptance.

Some authors who have published on the Indian flying fox since 2012 have accepted this taxonomic revision, using the name Pteropus medius.

Other taxonomic authorities, however, such as the Integrated Taxonomic Information System, still recognize Pteropus giganteus as the valid name of the Indian flying fox.

It is most closely related to the grey-headed flying fox, P. poliocephalus.

As the genus Pteropus is divided into closely related species groups, the Indian flying fox is placed in the vampyrus species group, which also includes the Bonin, Ryukyu, little golden-mantled, Rodrigues, large, Lyle's, Aldabra, Madagascan, Seychelles, and Mauritian flying foxes.

There are currently three recognized subspecies of the Indian flying fox: P. m. ariel (G. M. Allen, 1908), P. m. giganteus (Brünnich, 1782), and P. m. leucocephalus (Hodgson, 1835).
It was described as a new species by Dutch zoologist and museum curator Coenraad Jacob Temminck in 1825 who gave it the scientific name Pteropus medius. Confusion over the name has prevailed in the literature as in 1782 Danish zoologist Morten Thrane Brünnich, gave the scientific name Vespertilio gigantea as a replacement for Vespertilio vampyrus Linnaeus (1758: 31) 
He was specifically referring to Linnaeus's use of Vespertillo vampyrus. Carl Linnaeus had previously classified the species as Pteropus vampyrus and as such gigantea could not be used for a species that was already named.
In 1992 Corbett and Hill suggested giganteus was a sub-species of vampyrus.
In 2012, Mlíkovský argued that the correct scientific name of the Indian flying fox should be Pteropus medius rather than P. giganteus.
He asserted that Brünnich coined a new name for a species that had already been described—Vespertilio vampyrus which is now Pteropus vampyrus (the large flying fox).
Mlíkovský made several points in his argument, all with a foundation in the nomenclature rule known as Principle of Priority.
The Principle of Priority posits that the first formal, published scientific name given to a species shall be the name that is used.
Because Brünnich was attempting to rename the large flying fox in his 1782 publication, his name should not apply to either the large or the Indian flying fox—an older name was in existence, and therefore the large flying fox is P. vampyrus, not P. giganteus;
In negating Brünnich's name, Mlíkovský states that the oldest applicable name used to describe the Indian flying fox comes from Coenraad Jacob Temminck's publication in 1825.
Mlíkovský's recommendation has been met with varying degrees of acceptance.
Some authors who have published on the Indian flying fox since 2012 have accepted this taxonomic revision, using the name Pteropus medius.
Other taxonomic authorities, however, such as the Integrated Taxonomic Information System, still recognize Pteropus giganteus as the valid name of the Indian flying fox.
It is most closely related to the grey-headed flying fox, P. poliocephalus.
As the genus Pteropus is divided into closely related species groups, the Indian flying fox is placed in the vampyrus species group, which also includes the Bonin, Ryukyu, little golden-mantled, Rodrigues, large, Lyle's, Aldabra, Madagascan, Seychelles, and Mauritian flying foxes.
There are currently three recognized subspecies of the Indian flying fox: P. m. ariel (G. M. Allen, 1908), P. m. giganteus (Brünnich, 1782), and P. m. leucocephalus (Hodgson, 1835).
Indian flying fox