Artículos de revistas
Incremental Markings Of Enamel In Ectothermal Vertebrates.
Registro en:
Archives Of Oral Biology. v. 45, n. 5, p. 363-8, 2000-May.
0003-9969
10739857
Autor
Line, S R
Institución
Resumen
The deposition of enamel is marked by the formation of growth lines, which reflect incremental growth. Although periodic markings have been observed in enamel of non-mammalian vertebrates, the cross-striation interval and the pattern of enamel deposition have not been formally investigated. Here a structural study was made of the enamel in four non-mammalian vertebrates, with emphasis on periodic markings. Teeth from Rana catesbeiana, Tropidurus torquatus, Caiman crocodilus and a Canadian carnosaur were analysed. Enamel of T. torquatus and R. castebeiana was aprismatic; that of C. crocodilus and the carnosaur was formed by large, prism-like structures. Conspicuous incremental lines were observed in the enamel of the three living species, which presented a cross-striation repeat smaller than the prism cross-striations of mammalian enamel. Incremental lines of carnosaur enamel had a mean repeat interval similar to that of mammalian prism cross-striations. As metabolic activity in ectotherms is influenced by environmental conditions, the analysis of incremental markings of enamel is a potentially valuable source of information in the study of living and fossil reptiles and amphibians. 45 363-8