Bats are phylogenetically divided into two major groups, Yangochiroptera and Yinpterochiroptera. Laryngeal echolocation is observed in the Rhinolophoidea clade of Yinpterochiroptera and all species of Yangochiroptera. The former emits echolocation pulse through nose (nasal emitter), while the latter through mouth (oral emitter). Laryngeal echolocation is not found in Pteropodidae (non-laryngeal emitter), a member of Yinpterochiroptera.

To date, it has been highly disputed whether laryngeal echolocation was acquired by the common ancestor of all extant bats and was subsequently lost in Pteropodidae, or it evolved independently in Yangochiroptera and Rhinolophoidea. The cochlea has attracted much interest as the functionality and performance of receiving echolocation sonar among bats, and the relative size of the cochlea in the skull at adulthood has been regarded to reflect ultrasonic sensitivity.

To address the origins of laryngeal echolocation, we reconstructed the three-dimensional model of the prenatal cochlea of various species in bats with micro-CT scanning and identified spatial and temporal variations in the cochlear development among broadly sampled species.

We concluded that the cochlear morphogenesis was differentiated between Rhinolophoidea (nasal emitter) and Yangochiroptera (oral emitter), and that of non-bats was conserved in Pteropodidae (non-laryngeal emitter). We suggest that laryngeal echolocation was convergently evolved in bats.