Icaronycteris

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.

Multiple exceptionally preserved specimens, among the best preserved bat fossils, are known from the Green River Formation of North America. The best known species is I. index. Fragmentary material from France has also been tentatively placed within Icaronycteris as the second species I. menui. I. sigei is based on well-preserved fragments of dentaries and lower teeth found in Western India. In 2023, the species I. gunnelli also from the Green River Formation was distinguished from I. index, and I. menui and I. sigei were proposed to be removed from the genus due to them not being closely related.