Eocene bats

thumb|Parti-coloured batVespertilio murinus, Slovakia Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat families, specialised in many forms to occupy a range of habitats and ecological circumstances, and it is frequently observed or the subject of research. The facial features of the species are often simple, as they mainly rely on vocally emitted echolocation. The tails of the species are enclosed by the lo

Icaronycteris is an extinct genus of microchiropteran (echolocating) bat that lived in the early Eocene, approximately , making it the earliest bat genus known from complete skeletons, and the earliest known bat from North America.

Onychonycteris was the more primitive of the three oldest bats known from complete skeletons, having lived in the area that is current day Wyoming during the Eocene period, 52.5 million years ago.

Palaeochiropteryx ( ) is an extinct genus of bat from the Middle Eocene of Europe and North America. It contains three very similar species – Palaeochiropteryx tupaiodon and Palaeochiropteryx spiegeli, both from the famous Messel Pit of Germany, as well as Palaeochiropteryx sambuceus from the Sheep Pass Formation (Nevada, United States). They are usually found complete and exceptionally preserved, even retaining the outlines of their fur, ears, and wing membranes.

Archaeonycteris is an archaic bat genus whose fossilised remains have been found in Germany, France, England and India.

Necromantis is an extinct genus of bat that lived during the Eocene. Its fossils are found in the Quercy Phosphorites Formation of France and the Djebel Chambi in Tunisia. Specimens of Necromantis are notable for their large size and specialization towards a predatory lifestyle.

Onychonycteridae is an extinct family of bats known only from the early Eocene of Europe and North America. The type species, Onychonycteris finneyi, was described in 2008 from two nearly complete skeletons found in the Green River Formation of southwestern Wyoming. Since that time a number of previously described fossil bat species have been assigned to Onychonycteridae, as well as two more recently discovered species.

Aegyptonycteris ("Egyptian bat") is a genus of extinct bat from the Late Eocene of North Africa. It is currently known from a single specimen (holotype CGM 83740) from the Birket Qarun Formation in the Fayum Depression in western Egypt.

Witwatia (from the Egyptian Arabic Wit Wat meaning "large, flapping wings") is an extinct genus of giant bat that contained two species which lived in the Al Fayyum in Egypt during the late Eocene (Priabonian epoch) and one species which lived in Tunisia during the early Eocene. It is known from a lower jaw and teeth. Three species have been named: the type species W. schlosseri, W. eremicus and W. sigei.

Palaeochiropterygidae 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. Palaeochiropterygidae 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.