Triassic Coelacanths Used Ossified Lungs as Underwater Auditory Sensors According to New Research

A 240-million-year-old auditory system in coelacanths utilized ossified lungs to sense sound, a discovery that reveals new paths in vertebrate evolution.

By: AXL Media

Published: Mar 26, 2026, 7:45 AM EDT

Source: Information for this report was sourced from Université de Genève

The Evolutionary Shift from Respiratory to Auditory Function

While modern coelacanths are known as deep-sea dwellers that breathe exclusively through gills, their Triassic ancestors possessed a much more versatile anatomical toolkit. Research conducted on fossils from Lorraine, France, indicates that 240-million-year-old coelacanths featured a well-developed lung encased in bony, tile-like plates. While this organ was traditionally viewed solely as an adaptation for air breathing, new evidence suggests it played a vital role in environmental perception. According to Lionel Cavin, a curator at the Natural History Museum of Geneva, these ancient fish utilized their lungs to navigate and sense their surroundings in ways their modern descendants, the Latimeria genus, no longer can.

Synchrotron Imaging Unveils Hidden Bony Wings

To peer inside the densest parts of the fossilized remains, the international research team employed the European Synchrotron Radiation Facility in Grenoble. This high-powered particle accelerator allowed for micrometric precision in mapping the internal skeletal structures of the prehistoric fish. The resulting 3D renderings revealed a specialized ossified lung equipped with wing-like bony appendages at its extremity. These "wings" are believed to have acted as resonators, capturing underwater sound waves that would otherwise pass through the soft tissue of a fish’s body undetected, providing a structural foundation for an advanced sensory network.

The Mechanical Connection Between Lung and Ear

The discovery of the lung’s bony structures was only one piece of the anatomical puzzle, as researchers also identified a connecting canal in modern coelacanth embryos. This canal links the hearing and balance organs on either side of the skull, suggesting a pathway for sound transmission. Scientists propose that vibrations captured by the ossified lung were funneled through this canal directly to the inner ear. First author Luigi Manuelli noted that this system bears a striking functional resemblance to the Weberian apparatus found in modern carp and catfish, where a swim bladder acts as a primary sensor for underwater acoustic waves.