| Onychonycteridae Temporal range: | |
|---|---|
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| Onychonycteris finneyi fossil | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Chiroptera |
| Family: | † Onychonycteridae Simmons, et al, 2008 |
| Genera | |
See text | |
| Synonyms | |
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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. [1] Since that time a number of previously described fossil bat species have been assigned to Onychonycteridae, [2] as well as two more recently discovered species. [3] [4]
Most species belonging to Onychonycteridae are known only from isolated teeth and jaw fragments, however, they can be recognized by their relatively square-shaped upper molars, simple lower fourth premolar, and primitive, necromantodont lower molars. [5] [2] Onychonycteris finneyi exhibits additional primitive features of its skeleton, including claws on all five fingers and a simple cochlea that suggests it was incapable of echolocation. [6] [1] The dimensions of its wings suggest it employed a more primitive method of flight than living bats. [7]
The monophyly of Onychonycteridae has been largely supported in several recent phylogenetic analyses. Hand et al. recovered a clade of onychonycterids with Onychonycteris diverging basally, followed by Eppsinycteris, Aegina, and finally the sister species Honrovits tsuwape and Honrovits (Hassianycteris) joeli. [8] Jones et al. found Onychonycteridae to be split into two subclades, one consisting of Honrovits, Aegina, and Onychonycteris, and the other consisting of Eppsinycteris, Marnenycteris, and the enigmatic Archaeonycteris? praecursor. [9] Volactrix was included in the latter analysis, but was not recovered among Onychonycteridae. [9]