Originally placed in the Vespertilionidae family but now thought to have diverged from them about 38–49 million years ago.

 

Long-fingered bats are so called because of their uniquely elongated second phalanx of the third digit, which allows the wing to ‘bend’ back onto itself, hence the alternative name ‘bent-wing bats’.

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The second phalanx is more than three times the length of the first phalanx; in Vespertilionid bats, by contrast, it is usually not more than twice the length of the preceding phalanx.

 

The lengthening of this digit gives the wing its long and narrow shape, allowing it to fly swiftly and efficiently in open areas.

This family is represented by the single genus Miniopterus.