Ancient Coelacanths Used Lungs to Hear Underwater, Study Reveals

A team of scientists has uncovered a bizarre sensory ability in ancient coelacanths. Led by Lionel Cavin of the University of Geneva, the researchers found that two species from the Triassic period used their lungs to detect sound. This discovery sheds new light on how these prehistoric fish navigated their underwater world.

The study focused on fossils dating back roughly 240 million years. By examining the remains, the team identified a unique anatomical feature: a passage linking the lung to the inner ear. Sound waves absorbed by the lung travelled through this channel, allowing the fish to hear underwater.

Modern coelacanths, such as *Latimeria chalumnae*, still exist today but live in deep ocean caves between 150 and 700 metres in the Indian Ocean and Indonesian waters. Unlike their ancestors, they rely entirely on gills for breathing and show no trace of this lung-hearing function. The findings, published in *Communications Biology*, confirm that this sensory system was exclusive to the Triassic species.

The research highlights a lost evolutionary trait in coelacanths. While today's deep-sea descendants breathe only through gills, their Triassic relatives used lungs for both respiration and sound detection. This discovery adds to the understanding of how ancient marine life adapted to its environment.