A nearly complete early Eocene bat preserves limb and cochlear proxies bearing on flight and echolocation.
Represented range52.5–50.3 Ma
RegionsFossil Butte Member, Green River Formation, Wyoming, USA
CladesOnychonycteris finneyi · Chiroptera
Claim ledger
morphology · medium
Onychonycteris finneyi holotype ROM 55351A preserves a nearly complete skeleton with wing proportions compatible with powered flight and a relatively small cochlea interpreted as lacking specialized laryngeal echolocation; neither behaviour was observed and the specimen is not a direct ancestor of living bats.