Wikipedia
Archaeonycteridae (formerly spelled Archaeonycterididae) is a family of extinct bats. It was originally erected by the Swiss naturalist Pierre Revilliod as Archaeonycterididae to hold the genus Archaeonycteris. It was formerly classified under the superfamily Icaronycteroidea (disused) by Kurten and Anderson in 1980. In 2007, the spelling was corrected to Archaeonycteridae and it was reclassified to the unranked clade Microchiropteramorpha by Smith et al.. The family Palaeochiropterygidae was also merged into Archaeonycteridae by Kurten and Anderson, but modern authorities specializing in bat fossils maintain the distinction between the two.
They existed from the Ypresian to the Lutetian ages of the Middle Eocene epoch (55.8 to 40.4 million years ago).