1. Berg, L. S. (1958) ‘Lower Carboniferous fishes from the Achinsk’s Government’. Vopr. Iktiol. SSSR. (1958) ed. Obruchev, D. V. ( In Russian. )
2. Dean, B. (1907) ‘Notes on acanthodian sharks’ Am. J. Anat., 7, 209–22.
3. Denison, R. H. (1960) ‘Fishes of the Devonian Holland Quarry Shale of Ohio’. Fieldiana, Geol., 11, 555–613.
4. Denison, R. H. (1963) ‘The early history of the vertebrate calcified skeleton’. Clin. Orthop., 34, 141–52.
5. Devillers, C. (1965) ‘The role of morphogenesis in the origin of higher levels of organization’. Syst. Zool., 24, 259–71.