- Blieck, A. 1992. "At the origin of chordates." Géobios 25: 101-113.
- Forey, P. L. (1984). Yet more reflections on agnathan-gnathostome relationships. Journal of Vertebrate Paleontology, 4, 330-343.
- Forey, P. L., et P. Janvier. (1993). Agnathans and the origin of jawed vertebrates. Nature, 361, 129-134.
- Forey, P. L., et P. Janvier. (1994). Evolution of the early vertebrates. American Scientist, 82, 554-565.
- Gagnier, P. Y. (1993a). Sacabambaspis janvieri, Vertébré ordovicien de Bolivie. 1, Analyse morphologique. Annales de Paléontologie, 79, 19-69.
- Gans, C. (1989). Stages in the origin of vertebrates: analysis by means of scenarios. Biological Reviews, 64, 221-268.
- Gans, C. (1993). Evolutionary origin of the vertebrate skull. In The skull (ed. J. Hanken and B. K. Hall), Vol. 2, pp. 1-35. The University of Chicago Press.
- Gans, C., et R. G. Northcutt. (1983). Neural crest and the origin of vertebrates: A new head. Science, 220, 268-274.
- Gee, H. (1996). Before the backbone. Chapman & Hall, London.
- Hardisty, M. W. (1982). Lampreys and hagfishes: Analysis of cyclostome relationships. In The Biology of Lampreys, (ed. M. W. Hardisty and I. C. Potter), Vol.4B, pp. 165-259. Academic Press, London.
- Janvier, P. (1981). The phylogeny of the Craniata, with particular reference to the significance of fossil 'agnathans'. Journal of Vertebrate Paleontology, 1, 121-159.
- Janvier, P. (1993). Patterns of diversity in the skull of jawless fishes. In The skull (ed. J. Hanken and B. K. Hall), Vol. 2, pp. 131-188. The University of Chicago Press.
- Janvier, P. (1996a). The dawn of the vertebrates: characters versus common ascent in current vertebrate phylogenies. Palaeontology, 39, 259-287.
- Janvier, P. (1996b). Early vertebrates. Oxford Monographs in Geology and Geophysics, 33, Oxford University Press, Oxford.
- Jefferies, R. P. S.(1986). The ancestry of the vertebrates. British Museum (Natural History), London.
- Løvtrup, S. (1977). The Phylogeny of Vertebrata. Wiley, New York.
- Maisey, J. G. (1986). Heads and tails: a chordate phylogeny. Cladistics, 2, 201-256.
- Maisey, J. G. (1988). Phylogeny of Early vertebrate skeletal induction and ossification pattern. Evolutionary Biology, 22, 1-36.
- Moy-Thomas, J. A., et Miles, R. S. (1971). Palaeozoic Fishes, 2nd edn, extensively revised by R. S. Miles. Chapman and Hall, London.
- Nelson, G. J. 1969. "Gill arches and the phylogeny of fishes, with notes on the classification of vertebrates." Bulletin of the American Museum of Natural History 141: 475-552.
- Nelson, G. J. 1989. "Phylogeny of major fish groups." In The hierarchy of life, ed. B. Fernholm, K. Bremer, et H. Jörnvall, 325-336, Excerpta Medica, Amsterdam.
- Northcutt, R. G., et C. Gans. 1983. "The genesis of neural crest and epidermal placodes: a reinterpretation of vertebrate origins." The Quarterly Review of Biology 58: 1-28.
- Schaeffer, B., et K. S. Thomson. 1980. "Reflections on agnathan-gnathostome relationships." In Aspects of vertebrate life, ed. L. L. Jacobs, 19-33. Museum of Northern Arizona Press, Flagstaff.
- Yalden, D. W. (1985). "Feeding mechanisms as evidence for cyclostome monophyly." Zoological Journal of the Linnean Society 84: 291-300.
- ↑
Donoghue, Phillip C. J.; Forey, Peter L.; Aldridge, Richard J. (2000). "Conodont affinity and chordate phylogeny". Biological Reviews 75 (2): 191–251