A peer-reviewed anatomical study found features consistent with air breathing in a Polypterus faraou fossil roughly 7 million years old from Chad. Tomography revealed open respiratory passages, a broad palate and bones that could expand the mouth cavity. The inference combines several preserved structures; some could also help the fish catch prey, and lungs were not preserved.
A roughly 7 million years old fish fossil from Chad preserves several structures consistent with breathing air. Marcos Vinícius Coelho and colleagues examined Polypterus faraou, an extinct ray-finned fish, using computed tomography. This single peer-reviewed anatomical study found open spiracles, respiratory passages with surrounding valve-like bones, alongside components that could expand the mouth cavity.[1]
The specimen came from Toros-Menalla, a fossil area in Chad, and was compared with six adults from three living species. Researchers scanned the bones and reconstructed them in three dimensions. The fossil’s broad palate and elongated parasphenoid, a bone along the skull’s underside, contributed to the proposed mouth-pumping mechanism.[1]
At 9.2 centimetres, the parasphenoid extended along roughly 85 per cent of the skull’s length. Flattening during preservation displaced some bones, leaving certain boundaries and joints difficult to distinguish. The authors accounted for this deformation when interpreting the apparent arrangement of the mouth-pump components.[1]
Thick, overlapping scales resembled those of living relatives that can draw air as the body covering recoils. The fossil lacked preserved ribs, preventing direct assessment of rib-driven aspiration. Some mouth structures could also assist prey capture. The air-breathing interpretation rests on combined skeletal features, rather than preserved lungs or observed respiratory movement.[1]
