Wikipedia
Palaeochiropterygidae
Palaeochirpterygidae is a family of extinct bats. It was originally erected by the Swiss naturalist Pierre Revilliod in 1917 after discoveries of Palaeochiropteryx fossils from the Messel Pit of Germany. Palaeochirpterygidae was merged into Archaeonycteridae by Kurten and Anderson in 1980, but modern authorities specializing in bat fossils maintain the distinction between the two. It was classified to the unranked clade Microchiropteramorpha by Smith et al. in 2007.
They existed from the Ypresian to the Lutetian ages of the Middle Eocene epoch (55.8 to 40.4 million years ago).