Balavoine, G. and A. Adoutte, 1998 , "One or three Cambrian radiations?", Science, 280, 397 - 398 

Caroll, R.L., 1988 , Vertebrate Paleontology and Evolution, New York: Freeman 

Doolittle, R.F. et al., 1996 , "Determining the divergence times of the major kingdoms of living organisms with a protein clock", Science, 271, 470 - 477 

Gould, S.J., 1989 , Wonderful Life, New York: Norton 

Gu, X., 1998 , "Early metazoan divergence was about 830 million years ago", Journal of Molecular Evolution, 47, 369 - 371 

Hennig, W., 1950 , Grundzuge einer Theorie der phylogentischen Systematik, Berlin: Deutscher Zentralverlag 

Hennig, W., 1966 . Phylogenetic Systematics, Urbana: University of Illinois Press 

Lake, J.A. and J.E.Moore, 1998 , "Phylogenetic analysis and comparative genomics", in Trends in Bioinformatics, pp. 22 - 24, Cambridge: Elsevier 

Margulis, L. and K.V.Schwartz, 1998 , The Five Kingdoms: An Illustrated Guide to the Phyla of Life on the Earth (3 rd edn), San Francisco: W.H.Freeman 

Morris, S.C., 1998a , The Crucible of Creation, Oxford: Oxford University Press 

Morris, S.C., 1998b , "Metazoan phylogenies: falling into place or falling to pieces? A palaeontological perspective", Current Opinion in Genetics and Development, 8, 662 - 667 

Nelson, G. and N. Platnick, 1984 , "Systematics and Evolution", in Beyond Neo-Darwinism, Mae-Wan Ho and Peter Saunders, eds, London: Academic Press 

Wiley, E.O., 1981 , Phylogenetics: The theory and practice of phylogenetic systems, New York: Wiley 

Woese, C.R. and G.E.Fox, 1977 , "The concept of cellular evolution", Journal of Molecular Evolution, 10, 16 

Woese, C.R., 1981 , "Archaebacteria", Scientific American 244(6), 98 - 122 

Young, J.Z., 1962 , Life of Vertebrates (2nd edn), Oxford: Clarendon Press

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