Janvier, P. (2010). „MicroRNAs revive old views about jawless vertebrate divergence and evolution”. Proceedings of the National Academy of Sciences. 107 (45): 19137—19138. Bibcode:2010PNAS..10719137J. PMC2984170. PMID21041649. doi:10.1073/pnas.1014583107. „Although I was among the early supporters of vertebrate paraphyly, I am impressed by the evidence provided by Heimberg et al. and prepared to admit that cyclostomes are, in fact, monophyletic. The consequence is that they may tell us little, if anything, about the dawn of vertebrate evolution, except that the intuitions of 19th century zoologists were correct in assuming that these odd vertebrates (notably, hagfishes) are strongly degenerate and have lost many characters over time”
Janvier, P. (2010). „MicroRNAs revive old views about jawless vertebrate divergence and evolution”. Proceedings of the National Academy of Sciences. 107 (45): 19137—19138. Bibcode:2010PNAS..10719137J. PMC2984170. PMID21041649. doi:10.1073/pnas.1014583107. „Although I was among the early supporters of vertebrate paraphyly, I am impressed by the evidence provided by Heimberg et al. and prepared to admit that cyclostomes are, in fact, monophyletic. The consequence is that they may tell us little, if anything, about the dawn of vertebrate evolution, except that the intuitions of 19th century zoologists were correct in assuming that these odd vertebrates (notably, hagfishes) are strongly degenerate and have lost many characters over time”
Janvier, P. (2010). „MicroRNAs revive old views about jawless vertebrate divergence and evolution”. Proceedings of the National Academy of Sciences. 107 (45): 19137—19138. Bibcode:2010PNAS..10719137J. PMC2984170. PMID21041649. doi:10.1073/pnas.1014583107. „Although I was among the early supporters of vertebrate paraphyly, I am impressed by the evidence provided by Heimberg et al. and prepared to admit that cyclostomes are, in fact, monophyletic. The consequence is that they may tell us little, if anything, about the dawn of vertebrate evolution, except that the intuitions of 19th century zoologists were correct in assuming that these odd vertebrates (notably, hagfishes) are strongly degenerate and have lost many characters over time”
P. J. P. Whitehead; M.-L. Bauchot; J.-C. Hureau; J. Nielsen; E. Tortonese, ур. (1984). „Hagfish (Myxine glutinosa)”. Fishes of the NE Atlantic and the Mediterranean.