title: SEM of the enamel layer in oral teeth of fossil and extant crossopterygian and dipnoan fishes.
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003743:Dental Enamel / Q000648:ultrastructure*; D005399:Fishes / Q000033:anatomy & histology*; D005580:Fossils; D008855:Microscopy, Electron, Scanning; D010161:Paleodontology