New research on two 240-million-year-old coelacanth fossils reveals an intriguing sensory adaptation: ossified lungs that transmit sound to the inner ear, shedding light on how early vertebrates interpreted their environment.
Reconstruction of a Triassic coelacanth. This schematic illustrates the connection between ossified lungs and the inner ear, enabling underwater hearing. Image credit: A. Beneteau & L. Cavin, MHNG.
“Coelacanths are lobe-finned fish with a rich fossil history exceeding 400 million years, offering crucial insights into vertebrate anatomical evolution,” said Professor Lionel Cavin, a paleontologist affiliated with the Natural History Museum of Geneva and the University of Geneva.
“Once believed extinct, the genus Latimeria remains, currently including two recognized species.”
“Fossilized coelacanths possess a series of large, puzzling ossified plates arranged in a tiled pattern within their body cavities, surrounding an internal area that likely contained gas during life.”
In a groundbreaking study, paleontologists investigated the lungs and inner ear anatomy of two Middle Triassic coelacanth species: Glauria Branchiodonta and Loreleia eusingulata from eastern France.
By utilizing a particle accelerator at the European Synchrotron Radiation Facility, researchers uncovered an exceptionally well-preserved ossified lung featuring wing-like bony structures at its tip.
Simultaneously, examinations of modern coelacanth embryos revealed canals linking auditory and balance organs on either side of the skull.
By synthesizing these findings, researchers propose that these structures create a comprehensive sensory system.
Sound waves captured by the ossified lungs are believed to be conveyed through this channel to the inner ear, enhancing the animal’s underwater auditory perception.
“Our hypothesis draws parallels with contemporary freshwater fish like carp and catfish,” explained Luigi Manueli, a PhD student at the Geneva Museum of Natural History and the University of Geneva.
“In these fish, a structure known as the Weber apparatus links the swim bladder to the inner ear, facilitating the detection of underwater sounds.”
“Air pockets in the swim bladder are vital for sensing these waves; otherwise, they would go unnoticed by the fish.”
“This hearing capability likely diminished as modern coelacanth ancestors adapted to deep-sea settings, leading to lung degeneration and the obsolescence of this system,” noted Professor Cavin.
“Remarkably, some structures related to the inner ear remain preserved.”
“These anatomical remnants offer valuable insights into the evolutionary trajectory of these fish and potentially our own aquatic ancestors.”
For more details, refer to the study published in the Journal on February 14, 2026, in Communication Biology.
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L. Manueli et al. 2026. The dual functions of coelacanth lungs: breathing and hearing. Commun. Biol. 9, 400; doi: 10.1038/s42003-026-09708-6
Source: www.sci.news
