1. Aldridge, R.J., Briggs, D.E.G., Smith, M.P., Clarkson, E.N.K. and Clark, N.D.L. (1993) The anatomy of conodonts. Philosophical Transactions of the Royal Society, London Ser B, 340, 405–421.
2. Arsenault, M. and Janvier, P. (1991) The anaspid-like craniates of the Escuminac formation (Upper Devonian) from Miguasha (Quebec, Canada) with remarks on anaspid-petromyzon-tid relationships, in Early Vertebrates and Related Problems of Evolutionary Biology (eds M-m Chang, Y-h Liu and G-r Zhang), Science Press, Beijing, pp. 19–40.
3. Baird, G., Shabica, C.W., Anderson, J.C. and Richardson, E.S. Jr (1985) Biota of a Pennsylvanian muddy coast. Habitats within the mazonian delta complex, journal of Paleontology, 59(2), 253–281.
4. Bardack, D. (1989) Some comments on the Mazon Creek Biota. Acta Musei Reginaehradecensis, ser. Scientiae Naturales, 22, 53–59.
5. Bardack, D. (1991) First fossil hagfish (myxinoidea): a record from the Pennsylvanian of Illinois. Science, 254, 701–703.