We studied skull, vertebral column, and limb skeleton development in Japanese clawed sala mander Onychodactylus japonicus (Hynobiidae). The study is based on the ontogenetic series of embryos and larvae obtained from wild captured adults by artificial induction of breeding using hormonal stimulation. The first stages of the skeleton formation in O. japonicus are shifted to the late embryonic period and hatching lar vae already possess a well ossified vertebral column, large number of skull ossifications and show signs of ossi fication in the forelimb skeleton. Compared to the primitive pattern of the skeleton development typical for other hynobiid salamanders, O. japonicus shows a number of heterochronies related to embryonization. In particular, this species is characterized by an earlier ossification of the vertebral column compared to that of the skull and by the delayed development and early reduction of the coronoid. Our results, along with the pre viously reported data on the skeleton development in the Fischer's clawed salamander O. fischeri (Smirnov and Vassilieva, 2002), indicate that the genus Onychodactylus is characterized by the loss or reduction of sev eral skeletal features typically found at early larval stages in other Hynobiidae species. In particular, provi sional bones (especially the coronoid) and their dentition are underdeveloped. In addition, it is corroborated that the first tooth generation is absent in Onychodactylus, whereas such monocuspid nonpedicellate tooth generation normally develops at the early larval stages of other caudate amphibians. Since similar patterns of skeleton ontogeny are observed in other caudate groups with different extent of embryonization, it is pro posed that, in different lineages of Urodela, the evolution of ontogeny followed similar pathways and was accompanied by the same changes in skeletogenesis.