title: Inner ear of the coelacanth fish Latimeria has tetrapod affinities.
abstract: Auditory reception in elasmobranchs, teleosts and amphibians may be mediated by various inner-ear sensory epithelia 1–3, including the basilar papilla, which seems to be the precursor of the cochlea in mammals. The origin of the basilar papilla remains a major unsolved problem for understanding the evolution of hearing in terrestrial vertebrates4–6. Study of living species indicates that the basilar papilla is a unique feature of tetrapods 6,7, but palaeonto-logical data indicate that this epithelium as well as a middle ear, is already present in crossopterygian fish 8–10. However, no basilar papilla has been found in the only living crossopterygian species, the coelacanth Latimeria chalumnae 11. I have re-examined the inner ear of adult and embryonic Latimeria and find a membranous specialization which resembles in structure, position and innerva-tion pattern the basilar papilla of tetrapods, in particular amniotes. No epithelium comparable to the basilar papilla was found in lungfish. I suggest that the basilar papillae of Latimeria and tetrapods are homologous and evolved only once in their common ancestor.
authors.forename: B
authors.initials: B
authors.lastname: Fritzsch
mesh_terms: D000818:Animals; D005075:Biological Evolution; D007758:Ear, Inner / Q000033:anatomy & histology* / Q000294:innervation; D005399:Fishes / Q000033:anatomy & histology* / Q000145:classification; D008297:Male; D009925:Organ of Corti / Q000033:anatomy & histology