Onychonycteris known species, hence "Onychonycteris" meaning "clawed bat". The specific epithet is a tribute to the fossil prospector and preparator who discovered it, Bonnie Finney. "Onychonycteris finneyi" was the strongest evidence so far in the debate on whether bats developed echolocation before or after they evolved the ability to fly. "O. finneyi" had well-developed wings, and could clearly fly, but lacked the enlarged cochlea of all extant echolocating bats, closer resembling the old world fruit bats which do not echolocate. This indicates that early bats could fly before they could echolocate. However, an independent evaluation of the "Onychonycteris" reference fossil in
Aerodramus It has recently been determined that the echolocation vocalizations do not agree with evolutionary relationship between swiftlet species as suggested by DNA sequence comparison. This suggests that as in bats, echolocation sounds, once present, adapt rapidly and independently to the particular species' acoustic environment. A study suggested that the echolocation subunits were mainly located in the central nervous system, while the subunits in the vocal apparatus were already present and capable of use before echolocation even evolved. This study supports the hypothesis of independent evolution of echolocation in "Aerodramus" and "Collocalia", with the subsequent evolution of complex behaviour needed to