Individuals grew up to  in length, had an elongate codavypter or supplementary tail lobe, and had small lobed fins, suggesting that Coelacanthus were open-water predators. The fin rays of the caudal fin are hollow, which gave Coelacanthus its name.
Individuals grew up to in length, had an elongated caudal lobe or supplementary tail fin, and possessed small lobed fins, suggesting that Coelacanthus were open-water predators. The fin rays of the caudal fin were hollow, which is why Coelacanthus was named.