Vertebral development patterns have been well characterised in the Paleozoic "lepospondyls" and "labyrinthodonts", as well as in modern amniotes, frogs and caecilians. Each of those groups consistently develop either the neural arches before the centra or the centra before neural arches. Preliminary studies confirmed that members of the Urodela exhibit both developmental patterns. To understand if there is any consistency in patterns of vertebral development within and between families, as well as to investigate the distribution of patterns within the order, 120 salamander larvae from the ten living salamander families were cleared, stained and examined for osteological development. In order to provide a basis of comparison between different developmental stages observed in different families, a staging table was constructed. The complete osteological development of every cleared and stained specimen used in this study was then described. Finally, the general pattern of vertebral development was examined and characteristic patterns for each family were mapped on an accepted phylogeny of salamander relationships.

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